JP4389871B2 - Reference pattern extraction method and apparatus, pattern matching method and apparatus, position detection method and apparatus, exposure method and apparatus - Google Patents

Description

  The present invention relates to an exposure method in a lithography process when manufacturing an electronic device such as a semiconductor element, a liquid crystal display element, a plasma display element, a thin film magnetic head, and the like, and particularly used for positioning a wafer, a reticle, etc. in an exposure apparatus. Preferred reference pattern extraction method and apparatus, pattern matching method and apparatus for detecting an image such as a mark using the extracted reference pattern, position detection method and apparatus for detecting an exposure position based on the detected mark and the like Further, the present invention relates to an exposure method and an apparatus for performing exposure based on a detected position.

  When manufacturing an electronic device such as a semiconductor element, a liquid crystal display element, a plasma display element, a thin film magnetic head, etc., a fine pattern formed on a mask or a reticle (hereinafter referred to as a reticle) using an exposure apparatus. The image is repeatedly projected and exposed onto a substrate such as a semiconductor wafer or glass plate coated with a photosensitive agent. At this time, the exposure apparatus needs to match the position of the substrate and the position of the projected pattern image with high accuracy. Particularly in the manufacture of semiconductor elements, the pattern to be formed has become very fine as the degree of integration has increased in recent years. Therefore, in order to manufacture a semiconductor device having a desired performance, alignment with very high accuracy is required.

This alignment in the exposure apparatus is performed by detecting an alignment mark (hereinafter also referred to simply as a mark or a pattern) formed on a substrate or a reticle with an alignment sensor, detecting the position of the substrate, and controlling the position. To do. Various methods are used as a method for detecting the position of the mark, but in recent years, an FIA (Field Image Alignment) type alignment sensor that detects the position of the mark by image processing has been used. This is a method for detecting position information of a mark by performing image processing on a signal (pattern signal, n-dimensional signal) obtained by imaging a substrate surface in the vicinity of the mark. As a method of image processing, a template matching method for detecting a mark by matching (matching) a reference pattern (template) corresponding to a mark signal prepared in advance with a captured image is known (for example, Patent Document 1).
JP 2001-210577 A

By the way, in such template matching, generation of a template is important.
Normally, a template specifies a pattern extracted from actual data as a template, or information on a known pattern to be used as a template such as an alignment mark (mark design data, arrangement information on a wafer, etc.) It is common to create based on. Therefore, a template cannot be set when actual data is not obtained or cannot be obtained for creating a template, or when a pattern to be a template is not specified. In such a case, a method of selecting a template by an operator can be considered. However, in such a method, there is no robustness, the accuracy is low, it is difficult to search, and the performance depends on individual differences among workers. It is not appropriate due to the above problems.

Also, the range (observation field of view) of the image of the substrate surface imaged during alignment is not always a fixed position due to errors related to the wafer loading operation and errors related to pattern manufacturing. It varies. Under such conditions, the pattern used as a template must be a pattern that is always included in the observation field. This is because if the pattern does not exist in the observation field, it cannot be detected. On the other hand, the pattern used as a template needs to be a unique pattern that exists only in the maximum range that can be an observation visual field (hereinafter referred to as an observation visual field maximum range or an input data maximum range). This is because even if a plurality of patterns are detected, their positions cannot be specified.
However, when the variation (error) of the observation visual field becomes large, the maximum range that can be the observation visual field becomes wide, and conversely, the region that is always included in the observation visual field becomes small. In some cases, a region that is always included in the observation visual field may not exist. In such a situation, it becomes difficult or difficult to select a pattern as a template, and template matching cannot be substantially performed.
In order to increase information on patterns that can be templates, it is necessary to enlarge the area that is always included in the observation field. However, for that purpose, it is necessary to reduce the variation (error) of the area acquired as the observation field of view, and new difficulty arises.

  An object of the present invention is to provide a reference pattern extraction method and apparatus capable of appropriately and efficiently extracting a reference pattern (template) effective for template matching. Specifically, an object of the present invention is to provide a reference pattern extraction method and apparatus capable of extracting an effective reference pattern from the observation visual field maximum range without depending on a region always included in the observation visual field. It is another object of the present invention to provide a reference pattern extraction method and apparatus capable of generating a template capable of effectively performing template matching without requiring actual data for template creation.

  Another object of the present invention is to provide a pattern matching method capable of appropriately performing template matching and detecting a desired mark or the like using an effective reference pattern (template) extracted as described above. It is in. Specifically, a pattern matching method is provided that can detect a desired pattern appropriately using a template extracted from the entire observation visual field maximum range by the method according to the present invention even when the observation visual field varies to some extent. There is to do. It is another object of the present invention to provide a pattern matching method capable of appropriately detecting a desired pattern using a template according to the present invention created without requiring actual data.

Another object of the present invention is to detect a desired pattern used for positioning using such a template matching method according to the present invention, and a position detection method and apparatus capable of appropriately detecting the position. Is to provide.
Another object of the present invention is to provide an exposure method capable of detecting an exposure position of a substrate or the like using such a position detection method according to the present invention and appropriately exposing a desired position of the substrate or the like. And providing such a device.

  In order to achieve the object, the reference pattern extraction method of the present invention provides a measurement target region (VIEW_Area) having an area smaller than the predetermined region (OR_Area) arbitrarily disposed in the predetermined region (OR_Area) on the object. A reference pattern extraction method for extracting a reference pattern having a unique signal feature in the first step of obtaining pattern signal information in the predetermined area (OR_Area) (step S410), obtained in the first step From the obtained pattern signal information, it is recognized that the measurement area (VIEW_Area) is unique in each measurement area (VIEW_Area) at every position that can be taken by the measurement area (VIEW_Area) in the predetermined area (OR_Area). Possible to extract multiple unique patterns with different uniqueness The second step (steps S430 to S470) and the position where the measured region (VIEW_Area) can take all the unique patterns extracted in the second step within the predetermined region (OR_Area) Regardless, it has a third step (step S480) for extracting as the reference pattern (see FIGS. 11A to 11C and FIG. 12).

According to such a reference pattern extraction method, based on the pattern signal information obtained in the first step, in the second region, for example, in a predetermined region (OR_Area) that is the maximum range that can be an observation field of view (VIEW_Area). A plurality of unique patterns which are different from each other in uniqueness and which are recognized to be unique in the measurement target region (VIEW_Area) arbitrarily arranged in the predetermined region (OR_Area) are extracted. In the third step, all of the extracted unique patterns are set as reference patterns (templates) regardless of the range that the measurement target area (VIEW_Area) can take. That is, a plurality of reference patterns are extracted from the observation visual field maximum range without depending on the region always included in the observation visual field.
Therefore, when an image is captured by setting an observation field of view (VIEW_Area) at the time of template matching or the like, the observation field of view (VIEW_Area) includes any of a plurality of set unique patterns, and even within the observation field of view. A unique pattern can be detected even within a predetermined area, and position measurement can be appropriately performed based on the position of the unique pattern.

Preferably, in the second step, the individual unique patterns are extracted in units of specific areas (elements) having an area smaller than the measurement target area (VIEW_Area).
Preferably, in the second step, the unique pattern is extracted while using information on pattern shape characteristics as the index of uniqueness.
Preferably, in the second step, in addition to the information on the pattern shape characteristics, at least one of the number of patterns having different pattern shape characteristics and their arrangement relation is also used as the uniqueness index. The unique pattern is extracted while being used.

Preferably, in the second step, the unique pattern is extracted while using at least one of the number of patterns having the same pattern shape feature and the arrangement relationship thereof as an index of uniqueness. .
Preferably, when the arrangement relationship between the patterns is used as the index of uniqueness, design value information relating to the arrangement relationship is used.
Preferably, the information on the pattern shape feature is subjected to correlation calculation processing for each pattern signal information in the specific area or calculation processing using the SSDA method with respect to the pattern signal information in the predetermined area (OR_Area). Seek by doing.
Preferably, the information regarding the shape feature of the pattern is information amount of at least one of SN ratio, edge amount, entropy amount, variance value, and moment amount in the pattern signal information in each of the specific regions. Find using.

Preferably, in the first step, pattern signal information in the predetermined area (OR_Area) is obtained using an imaging unit capable of imaging the predetermined area (OR_Area) at a time.
Further preferably, in the first step, the measurement area (VIEW_Area) at a plurality of positions is used while changing the position of the object with respect to the imaging means using an imaging means capable of imaging the measurement area (VIEW_Area). The pattern signal information in each of the predetermined areas (OR_Area) is obtained by obtaining the pattern signal information in each of them and combining the obtained plurality of pattern signal information.
Preferably, in the first step, the object is positioned with respect to the imaging unit using design value information relating to a pattern formed on the object.

In addition, the pattern matching method according to the present invention uses the reference pattern obtained by the reference pattern extraction method described above to perform correlation calculation processing on pattern signal information in the measurement target area (VIEW_Area) on the object. I do.
Preferably, the correlation calculation process is performed on the pattern signal information in the measurement target area (VIEW_Area) by sequentially using all of the plurality of unique patterns.

Further, the reference pattern extraction apparatus according to the present invention is unique in a measurement target area (VIEW_Area) having an area smaller than the predetermined area (OR_Area) arbitrarily arranged in the predetermined area (OR_Area) on the object. A reference pattern extraction apparatus for extracting a reference pattern having a signal feature, comprising: pattern signal information acquisition means for obtaining pattern signal information in the predetermined area (OR_Area); and the pattern signal information obtained from the pattern signal information. At every position that can be taken by the measurement target area (VIEW_Area) within a predetermined area (OR_Area), each position can be recognized as unique within the measurement target area (VIEW_Area), and the uniqueness is different from each other. Unique pattern extraction means for extracting multiple unique patterns ,
Reference pattern extraction means for extracting all of the extracted plurality of unique patterns as the reference pattern regardless of the position where the measurement target area (VIEW_Area) can take in the predetermined area (OR_Area). .

  Further, the pattern matching apparatus according to the present invention uses the reference pattern obtained by the reference pattern extraction apparatus described above to perform the plurality of pattern signal information on the measurement target area (VIEW_Area) on the object. A correlation calculation processing means for performing correlation calculation processing using all of the unique patterns sequentially.

  Another reference pattern extraction method according to the present invention is a reference pattern extraction method for extracting a reference pattern used for identifying a predetermined pattern formed on an object, the reference pattern extraction method being formed on the object. A unique signal among the first step of obtaining design value information relating to at least one of the shape of the pattern and its arrangement information, the second step of converting the design value information into pattern signal information, and the pattern signal information A third step of extracting a unique pattern having characteristics; and a fourth step of determining the reference pattern based on the unique pattern extracted in the third step.

  According to such a reference pattern extraction method, design value information relating to the pattern formed on the object in the first step is obtained, and pattern signal data of the pattern formed on the object from the design value information in the second step. Is generated. Then, a unique pattern is extracted in the third step from the pattern signal data, and this is set as a template (reference pattern) in the fourth step. As described above, in this reference pattern extraction method, the reference pattern is generated without using any pattern signal data captured from an actual object. Further, a unique pattern, that is, a pattern that exists singly in the pattern detection region and whose position can be specified by detecting the pattern is automatically detected and used as a template. Therefore, an effective template can be appropriately generated even when pattern signal data cannot be obtained or when a pattern to be a template is not clearly specified.

Preferably, in the third step, the unique pattern is extracted by performing correlation calculation processing for each partial pattern signal information in the pattern signal information or calculation processing using the SSDA method with respect to the pattern signal information. To do.
Preferably, in the third step, the unique pattern is extracted while changing a size of an area obtained from the partial pattern signal information.
Preferably, in the fourth step, when a plurality of the unique patterns are extracted in the third step, a unique pattern having the largest feature difference with respect to other patterns in the pattern signal information is selected. Determine as a pattern.

  A reference pattern extraction apparatus according to the present invention is a reference pattern extraction apparatus that extracts a reference pattern used when identifying a predetermined pattern formed on an object, and the reference pattern extraction apparatus is configured to extract a pattern formed on the object. A design value information acquisition means for obtaining design value information related to at least one of the shape and its arrangement information, an information conversion means for converting the design value information into pattern signal information, and a unique signal among the pattern signal information Unique pattern extraction means for extracting a unique pattern having characteristics, and reference pattern determination means for determining the reference pattern based on the extracted unique pattern.

  In addition, a reference pattern extraction method according to the present invention is a reference pattern extraction method for extracting a reference pattern used when identifying a predetermined pattern formed on an object. A second step of obtaining design value information related to at least one of the shape and arrangement state of the pattern formed on the object, the pattern signal information obtained in the first step, and A third step of extracting a part of the pattern signal information as information on the reference pattern based on the design value information obtained in the second step.

  According to such a reference pattern extraction method, first, pattern signal data is obtained by imaging a pattern formed on an object in the first step. And the design value information regarding the pattern formed on the object in the second step is acquired, and the reference pattern is generated based on the design value information and the imaging pattern signal data in the third step. That is, the detection of the pattern signal to be used as a template and the detection of the pattern area are performed based on the design value information, and actual imaging data is used only for obtaining the pattern signal to be actually used as a template. Therefore, a pattern having a high correlation with an actual pattern can be set as a template. In addition, since the process using the design value information can be performed in parallel as appropriate, it is effective to set a template efficiently and while checking and confirming the performance mutually.

  Preferably, the third step includes a step of converting the design value information into pattern signal information, and unique pattern position information relating to a position of a portion having a unique signal feature from the converted pattern signal information. A step of determining, a step of specifying a part of the pattern signal information obtained in the first step based on the unique pattern position information, and a step of extracting the specified portion as information relating to the reference pattern And have.

  A reference pattern extraction apparatus according to the present invention is a reference pattern extraction apparatus that extracts a reference pattern used when identifying a predetermined pattern formed on an object, and images the object to obtain pattern signal information. Obtained by the pattern signal information obtaining means, the design value information obtaining means for obtaining the design value information related to at least one of the shape and arrangement state of the pattern formed on the object, and the pattern signal information obtaining means. Reference pattern extraction means for extracting a part of the pattern signal information as information on the reference pattern based on the pattern signal information and the design value information obtained by the design value information acquisition means.

  The pattern matching method according to the present invention is a pattern matching method for identifying a predetermined pattern formed in a predetermined region (OR_Area) on an object, and a plurality of reference patterns having different uniqueness as the reference pattern. A pattern obtained in the second step by sequentially using all of the plurality of reference patterns, a second step of obtaining pattern signal information by imaging the inside of the predetermined area (OR_Area) And a third step of performing a correlation calculation process on the signal information.

Preferably, the plurality of reference patterns have different pattern shape characteristics.
Preferably, the plurality of reference patterns are different from each other in at least one of the number of patterns having a specific shape and the arrangement relationship.

  The pattern matching device according to the present invention is a pattern matching device for identifying a predetermined pattern formed in a predetermined region (OR_Area) on an object, and a plurality of reference patterns having different uniqueness as the reference pattern. A reference pattern preparation means for preparing a pattern signal information acquisition means for obtaining pattern signal information by imaging the inside of the predetermined area (OR_Area), and sequentially using all of the plurality of reference patterns. And correlation calculation processing means for performing correlation calculation processing on information.

  The reference pattern extraction method according to the present invention is a reference pattern extraction method for extracting a reference pattern used for identifying a pattern formed on an object, wherein a first detection magnification is set on the object. A first step of obtaining first pattern signal information by performing photoelectric detection via an optical system having a unique pattern signal feature based on the first pattern signal information obtained in the first step; A second step of specifying a predetermined region on the object that is presumed to have a unique pattern, and a second detection magnification that is higher than the first detection magnification in the predetermined region specified in the second step Based on the second pattern signal information obtained in the third step, the third step of obtaining the second pattern signal information in the predetermined region by photoelectric detection through an optical system having Standard putter And a fourth step of extracting the unique pattern should be.

  The reference pattern extraction apparatus according to the present invention is a reference pattern extraction apparatus that extracts a reference pattern used when identifying a pattern formed on an object, and the first detection magnification is set on the object. A first information acquisition means for photoelectrically detecting the first pattern signal information through an optical system, and a unique pattern having a unique pattern signal feature based on the first pattern signal information And a predetermined area specifying means for specifying a predetermined area on the object, and the specified predetermined area is photoelectrically detected via an optical system having a second detection magnification higher than the first magnification. Second information acquisition means for obtaining second pattern signal information in the predetermined area, and extracting the unique pattern to be used as the reference pattern based on the second pattern signal information. And a reference pattern determining means for determining.

  The reference pattern extraction method according to the present invention is a reference pattern extraction method for extracting a reference pattern to be used when identifying a pattern formed on an object, wherein pattern signal information of a predetermined area on the object is obtained. Based on the first step to be obtained and the pattern signal information obtained in the first step, it is necessarily included in the measurement region having an area smaller than the predetermined region and disposed at an arbitrary position in the predetermined region. A second step of extracting a unique pattern having a unique pattern signal feature in the predetermined area and determining the reference pattern based on the extracted unique pattern; Based on the pattern signal information obtained in the first step when the unique pattern cannot be extracted from the specific area in two steps. A third step of extracting a unique pattern which is arranged at an arbitrary position in the predetermined region and whose area is equal to or smaller than the area of the specific region and has a unique signal characteristic in the predetermined region; A fourth step of resetting the predetermined region so that the specific region is defined so as to include the unique pattern when the unique pattern is extracted in a third step; In addition, the first step and the second step are performed on the predetermined region, and the unique pattern is extracted.

  The reference pattern extraction apparatus according to the present invention is a reference pattern extraction apparatus that extracts a reference pattern used when identifying a pattern formed on an object, and is configured to obtain pattern signal information of a predetermined area on the object. A specific area that is necessarily included in a measurement area that has an area smaller than the predetermined area and is arranged at an arbitrary position in the predetermined area based on the obtained pattern signal information acquisition means and the obtained pattern signal information A reference pattern determining means for extracting a unique pattern having a unique pattern signal characteristic in the predetermined area and determining the reference pattern based on the extracted unique pattern, and the reference pattern When the determining unit cannot extract the unique pattern from the specific area, the pattern signal Based on the pattern signal information obtained by the information acquisition means, the pattern is arranged at an arbitrary position in the predetermined area and has an area equal to or smaller than the area of the specific area, and has a unique signal characteristic in the predetermined area. A unique pattern extracting means for extracting the unique pattern, and when the unique pattern is extracted by the unique pattern extracting means, the predetermined area is reconfigured so that the specific area is defined to include the unique pattern. Predetermined pattern resetting means for setting, the pattern signal information acquiring means acquires the pattern signal information for the reset predetermined area, and the reference pattern determining means determines the reference pattern To do.

  The reference pattern extraction method according to the present invention is a reference pattern extraction method for extracting a reference pattern to be used when identifying a pattern formed on an object, wherein pattern signal information of a predetermined area on the object is obtained. A first step of acquiring, extracting a unique pattern having a unique pattern signal feature in the predetermined area based on the acquired pattern signal information, and determining the reference pattern based on the extracted unique pattern; If the unique pattern cannot be extracted from the predetermined area in the first step, the area near the predetermined area, and the area where the unique pattern having a unique pattern signal feature is highly likely to exist A second step of resetting the predetermined area, and the second step with respect to the reset predetermined area. Subjected to a step to determine the reference pattern.

  The reference pattern extraction apparatus according to the present invention is a reference pattern extraction apparatus that extracts a reference pattern used to identify a pattern formed on an object, and that is used to obtain pattern signal information of a predetermined area on the object. A reference pattern determining means for acquiring, extracting a unique pattern having a unique pattern signal feature in the predetermined area based on the acquired pattern signal information, and determining the reference pattern based on the extracted unique pattern; When the unique pattern cannot be extracted from the predetermined area in the reference pattern determining means, the area near the predetermined area, where there is a high possibility that a unique pattern having a unique pattern signal feature exists. And a predetermined area resetting means for resetting the predetermined area. To the predetermined region is performed again determination of the reference pattern in the reference pattern determining means.

Further, the pattern matching method according to the present invention performs correlation calculation processing on the pattern signal information in the measurement target area (VIEW_Area) on the object using the reference pattern extracted by the above-described reference pattern extraction method. Do.
In addition, the pattern matching device according to the present invention performs correlation calculation processing on the pattern signal information in the measurement target area (VIEW_Area) on the object, using the reference pattern extracted by the reference pattern extraction device. Do.

The position detection method according to the present invention obtains the position information of the unique pattern in the measurement target area (VIEW_Area) using the pattern matching method described above.
The position detection apparatus according to the present invention further includes position information detection means for obtaining position information of the unique pattern in the measurement target area (VIEW_Area) using the pattern matching apparatus.

The exposure apparatus according to the present invention obtains position information on a moving coordinate system of the object of a unique pattern formed on the substrate as the object using the position detection method described above, and uses the position information as the position information. Based on this, the substrate is aligned, and a predetermined pattern is transferred and exposed onto the aligned substrate.
Further, an exposure apparatus according to the present invention is based on the position detection apparatus described above for obtaining position information of a unique pattern formed on a substrate as the object on a moving coordinate system of the object, and the position information. Positioning means for aligning the substrate, and exposure means for transferring and exposing a predetermined pattern on the aligned substrate.

  Another reference pattern extraction method according to the present invention is a reference pattern extraction method for extracting a reference pattern having a unique signal feature from an object on which a pattern is formed, wherein a measurement area having a predetermined area is arranged. In a reference pattern extraction method for extracting a reference pattern having a unique signal feature in a predetermined area wider than the measured area, the reference area is included in the measured area located at a first position in the predetermined area. A first reference pattern having a unique signal characteristic is extracted from the pattern to be measured, and the measurement target area is located at a second position different from the first position in the predetermined area, and is located at the first position. A unique pattern from the pattern included in the measurement area located at the second position including at least a part of the pattern different from the measurement area. Extracting the second reference pattern having a No. features.

  According to another pattern matching method of the present invention, a measurement area having a predetermined area is arranged on an object on which a pattern is formed, and a specific pattern that matches a predetermined reference pattern from patterns included in the measurement area. In the pattern matching method for detecting the specific pattern from a predetermined region in a wider range than the measurement target region, the pattern matching method for detecting the specific pattern is located at a first position in the predetermined region as the reference pattern. A first reference pattern having a unique signal characteristic is extracted from a pattern included in the measured region, and the measured region is located at a second position different from the first position in the predetermined region. And located at the second position including at least a part of the pattern different from the measurement target area located at the first position. A second reference pattern having a unique signal feature is extracted from a pattern included in the measured area, the measured area is set on the object, and the first image is obtained from the image of the object in the measured area. A pattern that matches the reference pattern or the second reference pattern is detected.

  Another position detection method according to the present invention is a position detection method for detecting position information of an object on which a pattern is formed, wherein a measurement area having a predetermined area is arranged on the object, and the measurement area In the position detection method for detecting relative position information between the specific pattern and the measurement target region by detecting a specific pattern that matches a predetermined reference pattern from the patterns included in the pattern, the measurement target region is used as the reference pattern. A first reference pattern having a unique signal characteristic is extracted from a pattern included in the measurement target region located at the first position in a predetermined region in a wider range, and the first position in the predetermined region Includes at least a part of the measured region located at a different second position and different from the measured region located at the first position. A second reference pattern having a unique signal characteristic is extracted from a pattern included in the measurement area located at the second position, the measurement area is set on the object, and the measurement area in the measurement area is A specific pattern that matches the first reference pattern or the second reference pattern is detected from the image of the object, and relative position information between the specific pattern and the measured region is detected.

  Another reference pattern extraction apparatus according to the present invention is a reference pattern extraction apparatus that extracts a reference pattern having a unique signal feature from an object on which a pattern is formed, and a measurement target area having a predetermined area is arranged. A first reference pattern having a unique signal characteristic from a pattern included in the measurement area when the measurement area is located at a first position in a predetermined area on the object that is wider than the measurement area to be obtained. And at least a part of the pattern to be measured that is located at a second position different from the first position in the predetermined area and that is different from the area to be measured located at the first position. A unique pattern extraction that extracts a second quasi-pattern having a unique signal feature from a pattern included in the measurement target region located at the second position including It comprises a device.

  Further, another pattern matching apparatus according to the present invention arranges a measurement area having a predetermined area on an object on which a pattern is formed, and a specific pattern that matches a predetermined reference pattern from the patterns included in the measurement area In the pattern matching apparatus for detecting the specific pattern from the predetermined area wider than the measurement target area, the pattern matching apparatus is located at a first position in the predetermined area as the reference pattern. A first reference pattern having a unique signal characteristic is extracted from a pattern included in the measured region, and the measured region is located at a second position different from the first position in the predetermined region. And located at the second position including at least a part of the pattern different from the measurement target area located at the first position. A unique pattern extracting device for extracting a second reference pattern having a unique signal feature from a pattern included in the measured area; a setting means for setting the measured area on the object; Detecting means for detecting a pattern matching the first reference pattern or the second reference pattern from the image of the object.

  In addition, another position detection device according to the present invention arranges a measurement area having a predetermined area on an object on which a pattern is formed, and a specific pattern that matches a predetermined reference pattern from patterns included in the measurement area The position detection apparatus detects relative position information between the object and the measurement area, and the measurement area is a first area within a predetermined area wider than the measurement area as the reference pattern. A first reference pattern having a unique signal characteristic is extracted from a pattern included in the measurement target region positioned at the first position when positioned at the position, and the first position within the predetermined region is Before being located at the second position including at least a part of the pattern to be measured which is located at a different second position and different from the area to be measured located at the first position. A unique pattern extraction device for extracting a second reference pattern having a unique signal feature from a pattern included in the measurement target area; setting means for setting the measurement target area on the object; and And a detection device that detects a pattern matching the first reference pattern or the second reference pattern from an image of the object and detects relative position information between the object and the measurement target area.

  In this column, the reference numerals of the corresponding components shown in the attached drawings are shown for each component, but this is only for easy understanding and does not relate to the present invention. It is not intended to indicate that the means is limited to the embodiments described below with reference to the accompanying drawings.

  According to the present invention, it is possible to provide a reference pattern extraction method and apparatus capable of appropriately and efficiently extracting a reference pattern (template) effective for template matching. Specifically, it is possible to provide a reference pattern extraction method and apparatus capable of extracting an effective reference pattern from the observation visual field maximum range without depending on a region always included in the observation visual field. In addition, it is possible to provide a reference pattern extraction method and apparatus capable of generating a template capable of effectively performing template matching without requiring actual data for template creation.

  In addition, it is possible to provide a pattern matching method that can appropriately perform template matching using a valid reference pattern (template) extracted as described above to detect a desired mark or the like. Specifically, it is possible to provide a pattern matching method capable of appropriately detecting a desired pattern using a template extracted from the entire observation visual field maximum range even if the observation visual field varies to some extent. In addition, it is possible to provide a pattern matching method capable of appropriately detecting a desired pattern using a template according to the present invention created without requiring actual data.

In addition, it is possible to provide a position detection method and apparatus capable of detecting a desired pattern used for positioning by using such a template matching method and appropriately detecting the position.
Further, it is possible to provide an exposure method and apparatus capable of detecting an exposure position of a substrate or the like using such a position detection method and appropriately exposing a desired position of the substrate or the like.

FIG. 1 is a view showing the arrangement of an exposure apparatus according to an embodiment of the present invention. FIG. 2 is a view showing a distribution of optical information from the mark on the wafer on the pupil image plane of the TTL type alignment system of the exposure apparatus shown in FIG. FIG. 3 is a view showing a light receiving surface of a light receiving element of the TTL alignment system of the exposure apparatus shown in FIG. 4 is a cross-sectional view of the index plate of the off-axis alignment optical system of the exposure apparatus shown in FIG. FIG. 5 is a view showing the configuration of the FIA operation unit of the off-axis alignment optical system of the exposure apparatus shown in FIG. FIG. 6 is a flowchart showing a template creation method according to the first embodiment of the present invention. FIG. 7A is a first diagram for explaining a template creation method according to the first embodiment of the present invention. FIG. 7B is a second diagram for explaining the template creation method according to the first embodiment of the present invention. FIG. 8A is a third diagram for explaining the template creation method according to the first embodiment of the present invention. FIG. 8B is a fourth diagram for explaining the template creation method according to the first embodiment of the present invention. FIG. 9 is a flowchart showing the overall flow of the exposure processing according to the first embodiment of the present invention. FIG. 10 is a flowchart showing a template creation method according to the second embodiment of the present invention. FIG. 11A is a first diagram for explaining a template creation method according to the third embodiment of the present invention. FIG. 11B is a second diagram for explaining the template creation method according to the third embodiment of the present invention. FIG. 11C is a third diagram for explaining the template creation method according to the third embodiment of the present invention. FIG. 12 is a flowchart showing a template creation method according to the third embodiment of the present invention. FIG. 13A is a first diagram for explaining a process of selecting one element from a plurality of elements detected for the same pattern. FIG. 13B is a second diagram for explaining a process of selecting one element from a plurality of elements detected for the same pattern. FIG. 14 is a first diagram for explaining a process of configuring a template with a plurality of elements. FIG. 15 is a second diagram for explaining a process of configuring a template with a plurality of elements. FIG. 16A is a third diagram for explaining a process of configuring a template with a plurality of elements. FIG. 16B is a fourth diagram for describing the process of configuring a template with a plurality of elements. FIG. 16C is a fifth diagram for explaining the process of configuring a template with a plurality of elements. FIG. 17 is a flowchart showing a flow of search alignment processing according to the third embodiment of the present invention. FIG. 18 is a flowchart showing a template creation method according to the fourth embodiment of the present invention. FIG. 19A is a first diagram for explaining a template creation method according to the fourth embodiment of the present invention. FIG. 19B is a second diagram for explaining the template creation method according to the fourth embodiment of the present invention. FIG. 20A is a third diagram for explaining the template creation method according to the fourth embodiment of the present invention. FIG. 20B is a fourth diagram for explaining the template creation method according to the fourth embodiment of the present invention. FIG. 21 is a fifth diagram for explaining the template creation method according to the fourth embodiment of the present invention. FIG. 22 is a sixth diagram for explaining the template creation method according to the fourth embodiment of the present invention. FIG. 23 is a flowchart showing a template creation method according to the fifth embodiment of the present invention. FIG. 24A is a first diagram for describing a template creation method according to the fifth embodiment of the present invention. FIG. 24B is a second diagram for explaining the template creation method according to the fifth embodiment of the present invention. FIG. 25A is a third diagram for explaining the template creation method according to the fifth embodiment of the present invention. FIG. 25B is a fourth diagram for explaining the template creation method according to the fifth embodiment of the present invention. FIG. 26 is a fifth diagram for explaining the template creation method according to the fifth embodiment of the invention. FIG. 27 is a flowchart showing a template creation method according to the sixth embodiment of the present invention. FIG. 28 is a diagram for explaining a template creation method according to the sixth embodiment of the present invention. FIG. 29 is a flowchart for explaining a device manufacturing method according to the present invention.

First Embodiment A first embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, an exposure apparatus having an off-axis alignment optical system for detecting a predetermined reference pattern of a wafer by image processing, and a template (reference pattern) when alignment is performed by template matching in this exposure apparatus Will be described, and an alignment method using the template in the exposure apparatus will be described.

First, the overall configuration of the exposure apparatus will be described with reference to FIGS.
FIG. 1 is a diagram showing a schematic configuration of an exposure apparatus 100 according to the present embodiment.
In the following description, the XYZ orthogonal coordinate system shown in FIG. 1 is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. The XYZ orthogonal coordinate system is set so that the X axis and the Z axis are parallel to the paper surface, and the Y axis is set to a direction perpendicular to the paper surface. In the XYZ coordinate system in the figure, the XY plane is actually set to a plane parallel to the horizontal plane, and the Z-axis is set vertically upward.

  As shown in FIG. 1, exposure light EL emitted from an illumination optical system (not shown) is irradiated with a uniform illuminance distribution onto a pattern area PA formed on a reticle R via a condenser lens 1. As the exposure light EL, for example, g-line (436 nm), i-line (365 nm), KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F2 laser light (157 nm), or the like is used.

  The reticle R is held on the reticle stage 2, and the reticle stage 2 is supported so that it can move and rotate in a two-dimensional plane on the base 3. A main control system 15 that controls the operation of the entire apparatus controls the operation of the reticle stage 2 via the drive device 4 on the base 3. The reticle R is positioned with respect to the optical axis AX of the projection lens PL by detecting a reticle alignment mark (not shown) formed in the periphery of the reticle R with a reticle alignment system including a mirror 5, an objective lens 6, and a mark detection system 7. The

The exposure light EL that has passed through the pattern area PA of the reticle R is incident on, for example, a telecentric projection lens PL on both sides (or one side) and projected onto each shot area on the wafer (substrate) W. The projection lens PL has the best aberration correction with respect to the wavelength of the exposure light EL, and the reticle R and the wafer W are conjugated with each other under the wavelength. The illumination light EL is Keller illumination and is formed as a light source image at the center in the pupil EP of the projection lens PL.
The projection lens PL has a plurality of optical elements such as lenses. As the glass material of the optical element, an optical material such as quartz or fluorite is used according to the wavelength of the exposure light EL.

  The wafer W is placed on the wafer stage 9 via the wafer holder 8. On the wafer holder 8, a reference mark 10 used for baseline measurement or the like is provided. The wafer stage 9 is an XY stage for two-dimensionally positioning the wafer W in a plane perpendicular to the optical axis AX of the projection lens PL, and positions the wafer W in a direction (Z direction) parallel to the optical axis AX of the projection lens PL. A stage for rotating the wafer W slightly, a stage for adjusting the inclination of the wafer W with respect to the XY plane by changing an angle with respect to the Z axis, and the like.

An L-shaped moving mirror 11 is attached to one end of the upper surface of the wafer stage 9, and a laser interferometer 12 is disposed at a position facing the mirror surface of the moving mirror 11. Although illustrated in a simplified manner in FIG. 1, the movable mirror 11 includes a plane mirror having a reflecting surface perpendicular to the X axis and a plane mirror having a reflecting surface perpendicular to the Y axis.
The laser interferometer 12 includes two X-axis laser interferometers that irradiate the moving mirror 11 with a laser beam along the X axis and a Y-axis that irradiates the movable mirror 11 with a laser beam along the Y axis. The X coordinate and Y coordinate of the wafer stage 9 are measured by one laser interferometer for the X axis and one laser interferometer for the Y axis. Further, the rotation angle of the wafer stage 9 in the XY plane is measured by the difference between the measurement values of the two X-axis laser interferometers.

A position measurement signal PDS indicating the X coordinate, the Y coordinate, and the rotation angle measured by the laser interferometer 12 is supplied to the stage controller 13. The stage controller 13 controls the position of the wafer stage 9 via the drive system 14 according to the position measurement signal PDS under the control of the main control system 15.
The position measurement information PDS is output to the main control system 15. The main control system 15 outputs a control signal for controlling the position of the wafer stage 9 to the stage controller 13 while monitoring the supplied position measurement signal PDS.
Further, the position measurement signal PDS output from the laser interference system 12 is output to a laser step alignment (LSA) arithmetic unit 25 described later.

The exposure apparatus 100 includes a laser light source 16, a beam shaping optical system 17, a mirror 18, a lens system 19, a mirror 20, a beam splitter 21, an objective lens 22, a mirror 23, a light receiving element 24, an LSA arithmetic unit 25, and a projection lens PL. A TTL type alignment optical system having the above as a constituent member.
The laser light source 16 is a light source such as a He—Ne laser, for example, and emits a non-photosensitive laser beam LB to the photoresist applied on the wafer W with red light (for example, wavelength 632.8 nm). . The laser beam LB passes through the beam shaping optical system 17 including a cylindrical lens and the like, and enters the objective lens 22 via the mirror 18, the lens system 19, the mirror 20, and the beam splitter 21. The laser beam LB transmitted through the objective lens 22 is reflected by a mirror 23 provided below the reticle R and obliquely with respect to the XY plane, and enters the periphery of the field of view of the projection lens PL in parallel with the optical axis AX. Then, the wafer W is irradiated vertically through the center of the pupil EP of the projection lens PL.

The laser beam LB is focused as slit-shaped spot light SP0 in the space in the optical path between the objective lens 22 and the projection lens PL by the action of the beam shaping optical system 17.
The projection lens PL re-images the spot light SP0 on the wafer W as a spot SP.
The mirror 23 is fixed so as to be outside the periphery of the pattern area PA of the reticle R and within the field of view of the projection lens PL. Therefore, the slit-shaped spot light SP formed on the wafer W is located outside the projection image of the pattern area PA.

  In order to detect the mark on the wafer W by the spot light SP, the wafer stage 9 is moved horizontally with respect to the spot light SP in the XY plane. When the spot light SP relatively scans the mark, specularly reflected light, scattered light, diffracted light, and the like are generated from the mark, and the amount of light changes depending on the relative position of the mark and the spot light SP. Such optical information travels backward along the light transmission path of the laser beam LB and reaches the light receiving element 24 via the projection lens PL, the mirror 23, the objective lens 22, and the beam splitter 21. The light receiving surface of the light receiving element 24 is disposed on a pupil image plane EP ′ substantially conjugate with the pupil EP of the projection lens PL, has a non-sensitive area with respect to specularly reflected light from the mark, and receives only scattered light and diffracted light.

  FIG. 2 is a diagram showing a distribution of light information from the mark on the wafer W on the pupil EP (or the pupil image plane EP ′). Above and below (Y-axis direction) the specularly reflected light D0 extending in a slit shape in the X-axis direction at the center of the pupil EP, positive first-order diffracted light + D1, second-order diffracted light + D2, and negative first-order diffracted light -D1, respectively. The second-order diffracted light -D2 is arranged, and scattered light ± Dr from the mark edge is positioned on the left and right sides (X-axis direction) of the regular reflection light D0. This is described in detail in, for example, Japanese Patent Laid-Open No. 61-128106, and detailed description thereof is omitted. However, the diffracted light ± D1, ± D2 is generated only when the mark is a diffraction grating mark.

In order to receive the optical information from the mark having the distribution shown in FIG. 2, the light receiving element 24 has four independent light receiving surfaces 24a, 24b, 24c,. The light receiving surfaces 24a and 24b receive scattered light ± Dr, and the light receiving surfaces 24c and 24d are arranged to receive diffracted light ± D1 and ± D2.
FIG. 3 is a view showing a light receiving surface of the light receiving element 24. When the numerical aperture (NA) on the wafer W side of the projection lens PL is large and the third-order diffracted light generated from the diffraction grating mark also passes through the pupil EP, the light-receiving surfaces 24c and 24d receive the third-order diffracted light. It is good to make it large enough to receive light.

  Each photoelectric signal from the light receiving element 24 is input to the LSA arithmetic unit 25 together with the position measurement signal PDS output from the laser interferometer 12, and the mark position information AP1 is generated. The LSA arithmetic unit 25 samples and stores the photoelectric signal waveform from the light receiving element 24 when the wafer mark is scanned with respect to the spot light SP based on the position measurement signal PDS, and analyzes the waveform to analyze the mark. The mark position information AP1 is output as the coordinate position of the wafer stage 9 when the center coincides with the center of the spot light SP.

In the exposure apparatus shown in FIG. 1, only one set of TTL alignment systems (16, 17, 18, 19, 20, 21, 22, 23, and 24) is shown, but is orthogonal to the paper surface. Another set is provided in the direction (Y-axis direction), and similar spot light is formed in the projection image plane. The extension lines in the longitudinal direction of these two spot lights are directed toward the optical axis AX.
Further, the solid line shown in the optical path of the TTL alignment optical system in FIG. 1 represents the imaging relationship with the wafer W, and the broken line represents the conjugate relationship with the pupil EP.

  The exposure apparatus 100 also includes an off-axis alignment optical system (hereinafter referred to as an alignment sensor) on the side of the projection optical system PL. This alignment sensor is an FIA (Field Image Alignment) type alignment sensor that performs signal processing (including image processing) on a signal (n-dimensional signal) obtained by imaging the vicinity of the alignment mark on the substrate surface and detects position information of the mark. is there.

In the exposure apparatus 100, the alignment sensor performs search alignment measurement and fine alignment measurement.
Search alignment measurement (hereinafter sometimes simply referred to as “search alignment”) detects a plurality of search alignment marks formed on the wafer, and rotates the wafer relative to the wafer holder or in the XY plane. This is a process for detecting a positional shift at. In this embodiment, as a signal processing method for search alignment, a method (template matching method) for detecting a predetermined pattern corresponding to the template using a preset reference pattern (template) is used.

Further, fine alignment measurement (hereinafter sometimes simply referred to as “fine alignment”) detects an alignment mark for fine alignment formed corresponding to a shot area, and finally positions each exposure shot. It is a process for performing. In the present embodiment, as an image processing method for fine alignment, a method (edge measurement method) for extracting the edge of a mark and detecting its position is used.
In both search alignment and fine alignment, the image processing method is not limited to the method of the present embodiment, and each of them is a template matching method, an edge measurement method, or another image processing method. May be.
The observation magnification at the time of search alignment measurement and the observation magnification at the time of fine alignment measurement may be equal to each other, or the magnification at the time of fine alignment may be set higher than the magnification at the time of search alignment. Also good.

The alignment sensor includes a halogen lamp 26 that emits irradiation light for illuminating the wafer W, a condenser lens 27 that condenses the illumination light emitted from the halogen lamp 26 on one end of an optical fiber 28, and a waveguide for the illumination light. Optical fiber 28 to be used.
The reason why the halogen lamp 26 is used as the light source of the illumination light is that the wavelength range of the illumination light emitted from the halogen lamp 26 is 500 to 800 nm, and the wavelength range in which the photoresist coated on the upper surface of the wafer W is not exposed. This is because the wavelength band is wide and the influence of the wavelength characteristics of the reflectance on the surface of the wafer W can be reduced.

  The illumination light emitted from the optical fiber 28 vortexes through a filter 29 that cuts the photosensitive wavelength (short wavelength) region and the infrared wavelength region of the photoresist applied on the wafer W, and passes through the lens system 30. Reach half mirror 31. The illumination light reflected by the half mirror 31 is reflected almost parallel to the X-axis direction by the mirror 32, and then enters the objective lens 33. Further, the field of the projection lens PL is formed around the lower part of the lens barrel of the projection lens PL. It is reflected by a prism (mirror) 34 fixed so as not to be shielded from light, and irradiates the wafer W vertically.

  Although not shown, an appropriate illumination field stop is provided at a position conjugate with the wafer W with respect to the objective lens 33 in the optical path from the emission end of the optical fiber 28 to the objective lens 33. The objective lens 33 is set to a telecentric system, and an image of the exit end of the optical fiber 28 is formed on the surface 33a of the aperture stop (same as the pupil), and Keller illumination is performed. The optical axis of the objective lens 33 is determined to be vertical on the wafer W so that the mark position is not displaced due to the tilt of the optical axis when the mark is detected.

  The reflected light from the wafer W is imaged on the index plate 36 by the lens system 35 via the prism 34, the objective lens 33, the mirror 32, and the half mirror 31. The index plate 36 is arranged conjugate with the wafer W by the objective lens 33 and the lens system 35, and is linearly extended in the X-axis direction and the Y-axis direction in a rectangular transparent window as shown in FIG. Index marks 36a, 36b, 36c, and 36d. FIG. 4 is a cross-sectional view of the indicator plate 36. Accordingly, the mark image of the wafer W is formed in the transparent window 36e of the index plate 36. The mark image of the wafer W and the index marks 36a, 36b, 36c, 36d are connected to the relay systems 37, 39 and the mirror. The image is formed on the image sensor 40 through the control unit 38.

  The image sensor 40 (photoelectric conversion means, photoelectric conversion element) converts an image incident on the imaging surface into a photoelectric signal (image signal, image data, data, signal). For example, a two-dimensional CCD is used. A signal (n-dimensional signal) output from the image sensor 40 is input to the FIA calculation unit 41 together with the position measurement signal PDS from the laser interferometer 12.

In the present embodiment, the image sensor 40 obtains a two-dimensional image signal and inputs it to the FIA arithmetic unit 41 for use. In template matching performed during the search alignment process, signals obtained by the two-dimensional CCD are integrated (projected) in the non-measurement direction and used as a one-dimensional projection signal for measurement in the measurement direction.
However, the format of the signal obtained by the image sensor 40 and the signal to be processed in the subsequent signal processing is not limited to such an example of the present embodiment. At the time of template matching, two-dimensional image processing may be performed and a two-dimensional signal may be used for measurement. Alternatively, a three-dimensional image signal may be obtained and three-dimensional image processing may be performed. More specifically, the CCD signal is expanded in n dimensions (n is an integer of n ≧ 1) to generate, for example, an n-dimensional cosine component signal, an n-dimensional sine signal, or an n-order frequency signal. The present invention can also be applied to a device that performs position measurement using an n-dimensional signal.
In the description of the present specification, the term “image”, “image signal”, “image information”, “pattern signal”, and the like are similarly applied to not only a two-dimensional image but also such an n-dimensional signal (an n-dimensional image signal or the above-described one). As well as signals developed from image signals).

  The FIA arithmetic unit 41 detects an alignment mark from the input image signal, and obtains a deviation of the mark image with respect to the index marks 36a to 36d of the alignment mark. Then, the mark center detection position of the wafer stage 9 when the image of the mark formed on the wafer W is accurately positioned at the center of the index marks 36a to 36d from the stop position of the wafer stage 9 represented by the position measurement signal PDS. Information AP2 concerning is output.

Next, the FIA arithmetic unit 41 according to the present invention detects the position of a predetermined alignment mark image and the deviation thereof at the time of each alignment process of search alignment and fine alignment. In this embodiment, a template matching method is used during search alignment, and an edge detection processing method is used during fine alignment to detect mark position and displacement.
The configuration of the FIA arithmetic unit 41 and these processes will be described in more detail in the next stage, focusing on the search alignment process (template matching process) according to the present invention.
The overall configuration of the exposure apparatus 100 has been described above.

The configuration and operation of the FIA arithmetic unit 41 will be described in detail with reference to FIG.
FIG. 5 is a block diagram showing an internal configuration of the FIA arithmetic unit 41.
As shown in FIG. 5, the FIA calculation unit 41 includes an image signal (pattern signal) storage unit 50, a template data storage unit 52, a data processing unit 53, and a control unit 54.

  The image signal storage unit 50 stores an image signal (pattern signal) input from the image sensor 40. The image signal storage unit 50 stores an image (pattern signal) captured by the image sensor 40.

The template data storage unit 52 stores template data used in a template matching process performed at the time of search alignment, for example. The template data is reference pattern data for performing pattern matching with an image signal (pattern signal) stored in the image signal storage unit 50 in order to detect a mark on the wafer.
In addition, the mark used in this specification is a concept that widely includes a pattern set as a reference pattern that is a part of a circuit or wiring, in addition to a mark pattern that is specifically formed for alignment.
The template data may be generated by a computer system or the like different from the exposure apparatus 100 and stored in the template data storage unit 52, or based on image information (pattern signal) captured by the alignment sensor, the FIA calculation unit 41. And may be stored in the template data storage unit 52.
A method of creating this template (reference pattern) according to the present invention will be described in detail later.

The data processing unit 53 performs desired image processing (signal processing) such as template matching and edge detection processing on the image signal (pattern signal) stored in the image signal (pattern signal) storage unit to detect a mark. Detection of position information, detection of deviation information, and the like are performed.
For example, the data processing unit 53 performs matching between an image signal (pattern signal) stored in the image signal storage unit 50 and a template stored in the template data storage unit 52, and the presence or absence of a mark in the image signal (pattern signal). Is detected. In that case, the data processing unit 53 sequentially scans the visual field region in the search region corresponding to the size of the pattern to be detected, and compares and collates the image signal (pattern signal) of the region and the template data at each position. Then, the degree of similarity between the patterns (between images (pattern signals)), the degree of correlation, and the like are detected as evaluation values. If the degree of similarity is equal to or greater than a predetermined threshold, a mark exists in the area, that is, It is determined that the mark image is included in the image (pattern signal) at the location.
Finally, the data processing unit 53 determines where the mark is in the field of view. Thereby, information AP2 regarding the mark center position of the wafer stage 9 when the image of the mark formed on the wafer W is accurately positioned at the center of the index marks 36a to 36d is obtained.

  The control unit 54 appropriately stores and reads image signals in the image signal storage unit 50, stores and reads template data in the template data storage unit 52, and processes such as matching and edge detection described above in the data processing unit 53, respectively. The overall operation of the FIA arithmetic unit 41 is controlled as shown in FIG.

Next, a method for creating template data stored in advance in the template data storage unit 52 and used in the template matching process in the above-described search alignment will be described.
FIG. 6 is a flowchart showing the template creation process.
The template data creation process described below is performed by executing a program for performing the process described below as shown in the flowchart of FIG. 6 in an external computer apparatus or the like different from the exposure apparatus 100. Is preferred. However, the present invention is not limited to this, and may be performed in the exposure apparatus 100. More specifically, for example, the processing may be performed by the data processing unit 53 in the FIA arithmetic unit 41.

The template creation method of the present embodiment generates template data from design data without using image data (pattern signal) obtained by imaging a wafer.
First, design value data (design value information) is converted into a two-dimensional image (pattern signal), the data is binarized, and binary image data (pattern signal) is generated (step S110). Since most of the design value data is expressed by a combination of two colors such as white and black, binarization can be easily performed.
Next, a range of input data is set for the binarized design value data (step S120). In the search alignment, the imaged range varies within a predetermined range due to an error caused by a wafer loading operation, an error caused by a pattern manufacturing process, or the like. Even if there is such a variation, it is preferable to always set an area included in the imaging range as the input data range. This is because the reference pattern is always included in the captured image (pattern signal). However, if processing is performed when a reference pattern is not included in the captured image during search alignment, the input data range can be expanded. The input data range may be arbitrarily set according to such a situation.
In the present embodiment, an area AreaI as shown in FIG. 7A is set on the binarized image (pattern signal) data, for example.

When the input data range is set, an area having the same size as a predetermined template size is set within the range, and a temporary template (first partial image information) is set (step S130).
In the example shown in FIG. 7A, an area AreaT (xi, yi) having the same size SizeT as the template is set in the input data range AreaI. Note that (xi, yi) is the coordinate value of the reference point of the area AreaT (in the example of FIG. 7A, the coordinate value of the upper left corner point of the area AreaT).

Next, a correlation search calculation with a temporary template is performed for the entire input data range, and a position where the correlation value exceeds a predetermined threshold and reaches a peak is detected (step S140).
That is, as shown in FIG. 7B, the input data range AreaI is scanned with a window of the same size SizeT as the template (temporary template AreaT), and an image (pattern signal) of the area AreaS (xj, yj) in the window at each position. Correlation values between the (second partial image (pattern signal) information) and the image (pattern signal) of the temporary template AreaT (xi, yi) are sequentially obtained. Then, a region having a sufficiently high correlation value and a peak is detected.
At this time, the correlation search calculation is performed based on the following formula (1) or the following formula (2).
It should be noted that which one of formula (1) and formula (2) is used depends on the case.

Such provisional template setting (step S130) and correlation value peak detection (step S140) are performed for all regions (regions having the same size as the template) that can be set within the input data range. A region showing a correlation value peak with respect to is detected (step S150).
The regions showing the correlation value peak with respect to the same temporary template can be viewed as the same image, that is, the region constituted by the same pattern. Therefore, by detecting a region showing a correlation value peak, a region composed of the same pattern is detected for each pattern. For example, as shown in FIG. 8A, in the area AreaI, there may be five areas composed of the pattern A, two areas composed of the pattern B, and one area composed of the pattern C. Detected.

When the configuration of the pattern existing in the input data range is detected in this way, a pattern to be actually used as a template is selected from the pattern configuration (step S160).
Specifically, first, a pattern that does not have a peak other than itself but exists uniquely (uniquely) is detected from among the patterns that exist in the input data range AreaI. A unique area AreaT (xi, yi) (= AreaS (xj, yj)) that does not have, is detected and used as a template.
For example, in the example shown in FIG. 8A, a pattern C that exists only in one place (image data of the area AreaT (xi, yi) represented by the pattern C) is selected as a template.

  By the way, when a plurality of temporary templates AreaT (xi, yi) having no peak other than itself are detected, the highest correlation value (self detected as a correlation value peak) and the second highest The temporary template AreaT (xi, yi) with the largest correlation value difference (difference in feature values) with the one (the one with the highest correlation value among the areas not detected as correlation value peaks) is selected as the template. To do. This is because the difference between the correlation values corresponds to the SN ratio, and the larger the difference, the more stable the template can be said. This will be specifically described with reference to FIG. 8B.

  For example, as shown in FIG. 8B, it is assumed that a pattern O having a shape similar to the pattern C exists in the area AreaI in addition to the patterns A, B, and C. (In this case, the pattern O may or may not be detected as a correlation peak with respect to the pattern O itself.) In such a case, two unique patterns B and C are included in the input data range AreaI. Patterns exist. However, since there is a pattern O having a similar shape to the pattern C, the difference in correlation value between the pattern C and the pattern O when the pattern C is a temporary template is small. Therefore, in the case of FIG. 8B, the pattern B is selected as a template.

In the present embodiment, template data used in template matching at the time of search alignment is created in this way. The created template data is stored in the template data storage unit 52 of the FIA arithmetic unit 41 together with the position information of the area.
In the above-described method, the image data obtained by converting the design data is binarized and used. However, when it is known in advance that there are a plurality (N) of pattern height directions at the design stage. May be converted into an N value.
Moreover, in the method mentioned above, although the correlation value was calculated | required based on Formula (1) or Formula (2), SSDA method etc. may be applied.

In the above-described method, the template size SizeT is set as a predetermined size in advance, and a temporary template is set with this size, or a correlation value search is performed. However, this size (the size of the partial image information) may be a variable parameter. That is, a size range or a size type is determined in advance, and the template size is sequentially changed within the range. Then, the input data range is scanned for each size, and temporary templates are sequentially detected by the method described above, and finally the most unique temporary template is used as the template.
According to such a method, the template size can be automatically determined, and an appropriate template can be detected in consideration of the template size.

Next, the operation of the exposure apparatus 100 according to the present invention will be described with reference to FIG.
In exposure apparatus 100, first, reticle R and wafer W are transferred onto reticle stage 2 and wafer stage 9, respectively, and placed and supported on each stage. At this time, the wafer W is aligned (pre-aligned) with the wafer stage 9 using an orientation flat or notch formed on the wafer, and then placed on the wafer stage 9 via the wafer holder 8. It is held (step S210).

  Next, search alignment for obtaining the rotation amount and XY deviation of the wafer W mounted on the wafer holder 8 with respect to the wafer holder 8 is performed by the alignment sensor (step S220). In the search alignment, generally, a reference pattern is detected at a plurality of distant locations on the wafer W, and a rotation amount of the wafer, an XY deviation, and the like are obtained based on the positional relationship of each reference pattern.

In the search alignment, first, based on the design position information of the reference pattern, an image (view field image, pattern signal) of a predetermined region including the reference pattern on the wafer W is captured (step S221).
Specifically, the main control system 15 drives the wafer stage 9 via the stage controller 13 and the drive system 14 so that the reference pattern falls within the visual field region of the alignment sensor.

When the movement process is completed, the illumination light from the alignment sensor is illuminated onto the wafer W. That is, the illumination light emitted from the halogen lamp 26 is condensed on one end of the optical fiber 28 by the condenser lens 27 and enters the optical fiber 28. The incident illumination light propagates through the optical fiber 28, is emitted from the other end, passes through the filter 29, and reaches the half mirror 31 through the lens system 30.
The illumination light reflected by the half mirror 31 is reflected almost horizontally with respect to the X-axis direction by the mirror 32, and then enters the objective lens 33. Further, the illumination light of the projection lens PL is formed around the lower portion of the projection lens PL. The light is reflected by the prism 34 fixed so as not to block the field of view, and is irradiated onto the wafer W vertically.

The reflected light from the wafer W is imaged on the index plate 36 by the lens system 35 via the prism 34, the objective lens 33, the mirror 32, and the half mirror 31. The mark image of the wafer W and the index marks 36a, 36b, 36c, and 36d are formed on the image sensor 40 via the relay systems 37 and 39 and the mirror 38.
The image data formed on the image sensor 40 is stored in the image signal storage unit 50 of the FIA arithmetic unit 41 as an image in the visual field area.
If the image (pattern signal) is taken in at the time of search alignment and the magnification of the alignment sensor is set to be lower than that at the time of fine alignment described later, it is on the wafer W more than at the time of fine alignment. A wider area image is captured. Normally, a reference pattern to be detected is set larger than an alignment mark for fine alignment described later.

Next, the data processing unit 53 of the FIA arithmetic unit 41 scans the field-of-view image (pattern signal) stored in the image signal storage unit 50 through a window having the same size as the template stored in the template data storage unit 52. Then, matching (matching) with the template data is performed (step S222). Specifically, the evaluation value of the correlation between the image in the window scanned and set at a predetermined position and the template data is obtained by the above-described equation (1) or equation (2). When the evaluation value is larger than a predetermined threshold value, it is determined that the reference pattern of the template exists at the position, and the position information of the reference pattern is acquired.
These image capture (step S221) and matching (step S222) processing are repeatedly performed on predetermined several regions on the wafer W set in advance for search alignment (step S221 to step S223). .
When the detection of the positions of the reference patterns in several areas is completed (step S223), a predetermined calculation is performed based on the positional relationship between the reference patterns to obtain the rotation amount of the wafer W, the XY deviation, and the like ( Step S224).

When the search alignment is completed, the alignment sensor then performs fine alignment for detecting the positional deviation of each exposure shot on the wafer W (step S230). In the fine alignment, an alignment mark for fine alignment formed corresponding to the exposure shot on the wafer W is detected, the position of the alignment mark is obtained, and the rotation amount and displacement of each shot area are detected.
In this embodiment, the alignment mark is detected and its position information is detected by subjecting the waveform signal of the detected image (pattern signal) to signal processing using an edge measurement technique. Note that the edge measurement method is disclosed in, for example, Japanese Patent Laid-Open No. 4-65603, and the detailed description thereof is omitted.

This fine alignment may be performed by detecting all of the alignment marks provided corresponding to each shot area on the wafer W, or selecting several shot areas and corresponding to the selected shot areas. The alignment mark to be detected may be detected. However, when selecting an alignment mark corresponding to a part of the shot area, a statistical calculation process (EGA process) is performed to calculate the position of the shot area, which will be described later, and the position of each shot area is detected. It becomes.
Note that this image capture at the time of fine alignment may be performed by setting the magnification of the alignment sensor to be higher than that at the time of the search alignment described above. In addition, the alignment mark to be detected is usually a mark that is smaller than the reference pattern used during the search alignment described above, that is, a high-definition mark.

  When the fine alignment is completed, the data processing unit 53 performs processing such as EGA processing based on the search alignment result and the fine alignment result, and calculates the position of each shot area on the wafer W (step S240). .

  After the position of the shot area is calculated, the main control system 15 aligns the reticle R and the shot area of the wafer W based on the baseline amount managed in advance and the calculated shot area. Then, the pattern image of the reticle R is accurately superimposed on the shot area, and exposure is performed (step S250).

As described above, according to this embodiment, design data is converted into two-dimensional image data (pattern signal), a unique pattern is extracted from the obtained image data (pattern signal), and a template creation area is specified. Further, the image data (pattern signal) of the area is extracted to generate a template. Therefore, an effective template can be generated even when actual data cannot be obtained or when a mark to be a template is not formed. Moreover, template matching and search alignment can be appropriately performed using this template.
The template can be automatically generated from the design data. Therefore, the load on the operator can be reduced.
Further, since the template is generated from the design data, the template can be created before manufacturing the wafer, and the exposure process can be performed efficiently.

  In the present embodiment, a method of creating a template to be used in template matching at the time of search alignment is exemplified, but the present invention can also be applied to template creation when template matching is performed at the time of fine alignment.

Second Embodiment In the first embodiment described above, a two-dimensional image (pattern signal) generated by specifying a region for creating a reference pattern (template) from design value data and converting the design value data. A template was generated from image (pattern signal) data in that region of the data. However, this method is applicable and effective even when image (pattern signal) data of an actually manufactured wafer exists. A template generation method based on a similar method in the case where actually manufactured wafer data exists will be described as a second embodiment of the present invention.
In the present embodiment, the configuration of the exposure apparatus and a series of exposure processing methods including template matching at the time of search alignment are the same as those in the first embodiment. Therefore, the description is omitted. Further, when referring to the configuration of the exposure apparatus, the same reference numerals as those used in the first embodiment are used.

FIG. 10 is a flowchart illustrating template creation processing according to the second embodiment of this invention.
In this method using actual image (pattern signal) data, first, the manufactured wafer surface is imaged to obtain image (pattern signal) data (step S310).
Next, a unique pattern is extracted from the design value data, and its position information is detected. The processing until the unique pattern is extracted is almost the same as the processing in the first embodiment described above.
That is, design value data (design value information) is converted into a two-dimensional image (pattern signal) to generate two-dimensional image (pattern signal) data (step S320).

Next, an input data range is set on the design value two-dimensional image (pattern signal) data (step S330).
After the input data range is set, an area having the same size as the template size set in advance is set in the range to obtain a temporary template (step S340).
Next, the entire input data range is subjected to correlation search calculation with the temporary template based on the above-described formula (1) or formula (2), and the position where the correlation value exceeds the predetermined threshold and becomes a peak is detected. (Step S350).

A temporary template is set (step S340) and a correlation value peak is detected (step S350) in sequence for the entire input data range, and a region indicating a correlation value peak for each region is detected (step S360).
When a pattern existing in the input data range is detected by the processing of step S320 to step S360, a pattern that does not have a peak other than itself but has a single (uniquely) is detected, and its position is detected. Information (region information) is obtained (step S370). If there are a plurality of unique patterns, the pattern having the largest correlation value difference from the pattern having the next highest correlation value is detected, and the position information is obtained.

Thus, when the position information of the area where the unique pattern exists is obtained, the pattern of the area corresponding to the actually captured image (pattern signal) data acquired in step S310 is extracted and used as a template (step S380). ).
The extracted template is stored in the template data storage unit 52 of the FIA arithmetic unit 41 together with the position information of the area, and is used for template matching at the time of search alignment.

  In the template creation process described above, the process of capturing the wafer in step S310 and acquiring image (pattern signal) data, the process of detecting the unique pattern area in steps S320 to S370, and the template in step S380 are extracted. The processing to be performed may be performed separately, rather than a series of processing. For example, the process of imaging the wafer and the process of detecting the unique pattern area may be performed separately in advance. Each process may be performed using the exposure apparatus 100, may be performed using an external computer apparatus, an imaging apparatus, or the like, or may be performed using separate apparatuses.

Thus, according to the template creation method of the present embodiment, an effective template can be automatically generated using actual captured image (pattern signal) data of a wafer. Therefore, the load on the operator can be reduced. In addition, an effective template having a high correlation with a pattern formed on an actual wafer can be generated.
In addition, since the detection of the unique pattern area to be used as the template is performed based on the design data, it can be performed in advance, and the template generation process, and hence the exposure process, can be performed efficiently.

Third Embodiment As described above, the range of the observation visual field imaged by the alignment sensor at the time of search alignment varies depending on the position error at the time of wafer insertion, the pattern formation position error at the time of wafer processing, etc. It is not a certain area. The reference pattern (template) used for template matching must be extracted from the range that is always included in the observation field. However, if the observation field varies greatly, the area that is always included in the observation field is very small or exists. It becomes impossible to extract the reference pattern.
Specifically, for example, as shown in FIG. 11A, assuming that the observation field of view is VIEW_Area, the maximum range that can be the observation field of view is OR_Area, and the common area always included in the observation field of view is AND_Area, as shown in FIG. When a unique pattern B exists in the AND_Area, it can be extracted as a template. However, as shown in FIG. 11C, if a unique pattern does not exist in the common area AND_Area, a template cannot be generated.

  In the third embodiment, even when there is no unique pattern in the common area AND_Area as described above, as a method that can appropriately perform template matching, a unique range from the entire maximum visual field range OR_Area, or A method of detecting almost unique patterns and using them as a template by combining or complementing them will be described.

In the description of the present embodiment, the pattern of individual elements constituting the template is referred to as an element.
The configuration of the exposure apparatus and the overall flow of the exposure process are substantially the same as those in the first and second embodiments described above, and a description thereof will be omitted. Further, when referring to the configuration of the exposure apparatus, the same reference numerals as those used in the first embodiment are used.

FIG. 12 is a flowchart illustrating template creation processing according to the third embodiment of this invention.
Hereinafter, the template creation method of the present embodiment will be described with reference to the flowchart shown in FIG.
First, image (pattern signal) data is captured (step S410). Image (pattern signal) data may be generated by converting design value data (design value information) into a two-dimensional image (pattern signal) as in the first and second embodiments, or may be actually manufactured. The obtained wafer may be imaged and acquired.
Next, a range of input data is set for the captured image (pattern signal) data (step S420). As described above, the imaged range during search alignment varies within a predetermined range. Here, in consideration of such variations, the maximum range (maximum visual field range, maximum input data maximum range) OR_Area of the imageable region as shown in FIG. 11A is set as the input data range.

When the maximum field-of-view range OR_Area is set as the input data range, an area of ElementSize having the same size as the template component (element) is set within the range to be a temporary template (step S430).
Next, the correlation search calculation with the temporary template is performed for the entire maximum visual field range OR_Area, and a position where the correlation value exceeds a predetermined threshold and becomes a peak is detected (step S440). The evaluation formula for the correlation search calculation may be an arbitrary formula including the correlation coefficient calculation shown in formula (1) or formula (2), the SSDA method, or the like.

When the correlation search calculation is performed on one element, a unique element or a unique element to some extent is selected based on the detection result (step S450).
The element is selected by first checking whether or not the number of detected peaks is equal to or less than a predetermined threshold TH_Peak. A peak having a number greater than the threshold TH_Peak is assumed to be less unique and is not used as a template component.

Further, elements are narrowed down using features such as SN ratio, detected edge amount, entropy, dispersion value, moment, and the like. The S / N ratio is represented by the difference in correlation values (difference in feature values) between the highest correlation value and the second highest correlation value. This is because the larger the difference, the more stable the feature pattern. The amount of edges is represented by the number of edges or the number of CCDs that have detected the edge of the 2CCD (pixel area occupied by the 2CCD).
By using such feature amounts, it is possible to select a pattern having the most positioning information than similar elements.

Specifically, for example, as shown in FIG. 13A, a plurality of patterns including a shifted (protruded) pattern may be detected in association with one pattern B as illustrated. In such a case, the correlation coefficient and the evaluation value of the SSDA method all show high values with respect to themselves. However, by using the characteristics such as the SN ratio, edge amount, entropy, variance value, or moment as described above, a pattern with the most positioning information can be selected. In the example shown in FIG. 13A, an element in which a pattern B as shown in FIG. 13B is appropriately cut out is selected.
It should be noted that the narrowing down of elements based on the characteristics such as the SN ratio, detected edge amount, entropy, variance value, moment, etc., is performed in combination with the evaluation value calculation in the correlation search calculation processing in step S440. Also good.

  All the elements that can be set in the maximum visual field range OR_Area for each of the provisional template setting (step S430), correlation value peak detection (step S440), and unique element selection (step S450), That is, the process is performed for the element size ElementSize region (step S460). As a result, a relatively unique element (pattern) included in the maximum visual field range OA_Area is detected.

When relatively unique elements existing within the maximum visual field range OR_Area are detected in this way, they are combined to actually form a template (step S470).
The process of selecting this element and configuring the template will be described by exemplifying specific element detection results and selection results.

First, in step S450, by performing a unique element selection process with the threshold TH_Peak = 1, unique elements (patterns) having no peaks other than themselves, such as elements B and C shown in FIG. 14, are detected. Is done.
In such a case, if either element B or element C exists in the common area AND_Area of the visual field area, the element may be used as a template as it is by a conventional method. However, when these elements B and C are not included in the common area AND_Area as in the example shown in FIG. 14, both the selected patterns B and C are registered as templates.

When performing template matching, matching is performed on both elements. If either element B or element C can be detected, each element is a unique pattern, so the position measurement of the pattern on the wafer can be performed from the position measurement result of this element. In the example shown in FIG. 14, the element B is detected when the observation visual field VIEW_Area is on the left side in the paper surface, and the element C is detected when the observation visual field VIEW_Area is on the right side in the paper surface.
In addition, in the example shown in FIG. 14, although the element A which showed the correlation peak value detected by step S440 is shown, since this exists in the maximum visual field range OR_Area, one of them was detected. However, the position cannot be detected. Such an element is not selected in step S450 as a non-unique element and does not become a template.

In step S450, by performing the unique element selection process with the threshold TH_Peak = 2, a characteristic pattern that is not completely unique but unique to some extent is detected as in element B shown in FIG. 15, for example.
In such a case, normally, since there are a plurality of identical patterns in the maximum visual field range OR_Area, it cannot be used as a template, but by considering these two patterns in combination, the maximum visual field range OR_Area uniquely Patterns that can be identified can be configured. Therefore, this element B is registered as a template in a format including the positional relationship information of these two patterns B.

  When performing template matching, matching is performed using this element B as a reference pattern, and the number of detected elements B is detected. In the example shown in FIG. 15, if two elements B are detected, it can be seen that the observation visual field VIEW_Area is on the left side in the drawing, and position measurement is possible based on the position information of each element B. . Further, when only one element B is detected, it can be seen that the observation visual field VIEW_Area is on the right side in the drawing, and the element B being observed is the element B located on the right side in the drawing. Therefore, position measurement can be performed based on the position information of the element B.

In step S450, by performing the unique element selection process with the threshold TH_Peak = 3, three identical patterns that are not completely unique, such as elements A, B, and C shown in FIG. 16A, are included in the maximum visual field range OR_Area. Characteristic patterns that exist only up to are detected.
Even in such a case, it is possible to detect the position based on the template matching result of the element by creating the template in a format including the positional relationship information of each element. That is, these elements A, B, and C are registered as templates in a format that also includes such positional relationship information of each pattern.

When performing template matching, first, matching is performed using all the patterns of these elements A, B, and C. And position measurement is performed based on the relative positional relationship of each element detected within the visual field region.
For example, with respect to the maximum visual field range OR_Area of FIG. 16A, consider the case where the observation visual field VIEW_Area is arranged at the upper left as shown in FIG. 16B and the case where the observation visual field VIEW_Area is arranged at the lower right as shown in FIG. . In this case, the element B and the element C are arranged in the same positional relationship in any observation visual field. However, in the upper left observation visual field shown in FIG. 16B, there is no other element detected by matching, whereas in the lower right observation visual field shown in FIG. 16C, a further element A is detected. Therefore, the position can be detected by using the presence / absence of this element A and its positional relationship.
That is, by registering together with the position information, the combination of element B and element C, and the combination of element A, element B, and element C are templated so that each substantially functions as one template. Will be.

As described above, in step S470, relatively unique elements detected in the maximum visual field range OR_Area are appropriately combined, and the observation visual field VIEW_Area is arranged at any position in the maximum visual field range OR_Area. Configure the template so that the template is always included.
When actually selecting an element constituting the template, the size of the maximum field of view OR_Area, the size of the observation field of view VIEW_Area, the size of the element ElmetSize, and the arrangement and uniqueness of the elements detected in step S440 Based on such information, the threshold TH_Peak for the number of peaks to be selected is gradually increased from 1, and the elements constituting the template are sequentially selected.

When the template configuration is extracted in this way, the elements constituting the template are registered in a format including their position information, thereby creating a template (step S480). In addition to the information on the pattern of each element (image data, shape data) and the positional relationship between elements, the template stores information on the uniqueness of the element, information on the number of elements, and other information. You may do it.
The data format of the template may be any format.

Next, a method of performing template matching by performing template matching using the template created in this way will be described with reference to the flowchart of FIG.
Note that the processing contents of the pre-process and post-process of search alignment are the same as those in the case of the first embodiment described above with reference to FIG.
In the search alignment, the position of a desired pattern is measured in two or three predetermined areas on the wafer W, and the rotation amount of the wafer W, the XY deviation, and the like are obtained based on the positional relationship of each part.

In the search alignment, first, based on the design value data, an image (field image, pattern signal) of the position measurement position of the wafer W is captured (step S521).
Next, the captured visual field image is scanned through a window having the same size as the element SizeSize of the elements constituting the template, and collation (matching) with the element data is performed (step S522). Specifically, the evaluation value of the correlation between the image (pattern signal) in the window that has been scanned and set at a predetermined position and the element data is obtained by the above-described equation (1) or (2). When the evaluation value is larger than a predetermined threshold value, it is determined that the pattern of the element exists at the position, and information for identifying the element and the position are stored.
As described above, the template of the present embodiment is composed of a plurality of elements. Therefore, this matching process is sequentially performed for all elements (step S523).

  Then, when all the elements present in the field image (pattern signal) can be detected, the relative positional relationship between these elements is detected, and this is compared with the information on the positional relationship between the elements stored in the template. The position of the visual field image (pattern signal) is detected (step S524). At this time, if information on the uniqueness of each element, information on the number of elements, or other information is stored in the template, refer to those information and perform processing preferentially from unique elements, It is preferable to preferentially process an element that can detect the position with less error or error. Specifically, since it has already been described in the description of the template configuration method described above with reference to FIG. 12, the description thereof is omitted here.

Capture of such an image (pattern signal) (step S521), matching for each element (steps S522 and S523), and position detection of a visual field image (pattern signal) based on the relative positional relationship of the detected elements (step S524) This process is repeated for a plurality of predetermined regions on the wafer W preset for search alignment (step S525).
When the position of each region can be detected, a predetermined calculation is performed based on the positional relationship between the regions to obtain the rotation amount of the wafer W, the XY deviation, and the like (step S526).

  As described above, according to the template generation method of the third embodiment, a relatively unique characteristic pattern is extracted from the entire range (maximum visual field image OR_Area) that can be taken by the input data, and the pattern is extracted. A template is substantially generated by combining them. Therefore, a template can be generated even when the input data acquisition position (view image VIEW_Area) changes greatly, or when the input data does not contain much positioning information. As a result, template matching is possible. And

Fourth Embodiment As described above with reference to FIG. 11A, in the search alignment, an imaged range (observation is caused by an error caused by a wafer loading operation, an error caused by a pattern manufacturing process, or the like. The visual field VIEW_Area) varies within a predetermined range (OR_Area). In order to create a template (reference pattern) used for alignment under such conditions, even if the observation field of view varies, it is a pattern within the common area AND_Area that is always included in the observation field of view, and is the maximum that can be the observation field of view. It is necessary to extract a unique pattern as a template within the range OR_Area. However, a pattern that is unique and has sufficient information necessary for position measurement cannot always be detected from the common field of view AND_Area.
In the fourth embodiment, when a unique pattern cannot be detected from the visual field common area AND_Area, the unique pattern is changed by changing the target area for template creation (shifting the common area AND_Area and the visual field maximum range OR_Area). A template creation method that increases the possibility of detection will be described with reference to FIGS.

FIG. 18 is a flowchart showing a flow of template creation processing according to the fourth embodiment of the present invention.
In the template creation method of the present embodiment, first, a target area for unique pattern detection processing is set (step S601). First, as shown in FIG. 19A, a target measurement area AreaV0 on the wafer for pattern detection and position measurement is set by search alignment measurement, based on shot area arrangement on the wafer, search alignment measurement processing conditions, and the like. . When the target measurement area AreaV0 is set, the wafer is loaded into the exposure apparatus 100 on the basis of information such as a wafer loading error and wafer manufacturing error detected in advance, and an image is captured using the alignment sensor as the area AreaV0. The visual field common area AND_Area and the visual field maximum range OR_Area are detected. Then, an arbitrary area in the visual field common area AND_Area is set as an area AreaA for searching for a unique pattern, and an arbitrary area including the detected visual field maximum range OR_Area is set as an area AreaI for verifying the uniqueness of the pattern. . In the present embodiment, the unique pattern search area AreaA is set equal to the visual field common area AND_Area, and the uniqueness verification area AreaI is set equal to the visual field maximum area OR_Area.

  When the setting of the unique pattern search area AreaA and the uniqueness verification area AreaI is completed, the image data (pattern signal information) of the uniqueness verification area AreaI (maximum visual field range OR_Area) is acquired (step S603). Image data may be acquired by converting design value data (design information) into an image signal, or may be acquired by imaging the surface of a manufactured wafer.

Next, a unique pattern is detected using the acquired image data.
First, as shown in FIG. 19B, an area AreaT having the same size as a predetermined template is set in the unique pattern search area AreaA, and this is set as a temporary template (step S605).
Next, the entire area of the uniqueness verification area AreaI is searched in the area AreaS having the same size as the temporary template AreaT (the same size as the template), and the image (pattern signal information) of the area AreaS and the temporary template AreaT at each position are searched. Correlation values with the image (pattern signal information) are sequentially obtained based on the above-described equation (1) or equation (2), and a region having a sufficiently high correlation value and a peak is detected (step S607).

  Temporary templates AreaT are sequentially set for the entire area within the unique pattern search area AreaA, and when a correlation value peak area for each temporary template is detected (step S609), a unique pattern (area) is extracted from them (step S609). Step S611). That is, a single (unique) temporary template that has no peak other than itself in the uniqueness verification area AreaI is extracted from the temporary templates.

When such a unique temporary template is extracted (step S613), image data (image signal information) of the temporary template is extracted as a template (step S615), and the template creation process ends. .
The extracted template is stored in the template data storage unit 52 (see FIGS. 1 and 5) of the FIA arithmetic unit 41 of the exposure apparatus 100 together with the position information of the target measurement area AreaV0 set in step S601 for extracting the template. Stored and used in template matching during search alignment.
If there are a plurality of unique temporary templates, the temporary template having the largest difference between the correlation value for itself and the second highest correlation value is selected as the template, as in the first embodiment. To do.

If a unique temporary template is not extracted from the temporary templates in step S611 (step S613), the unique pattern search area AreaA and the uniqueness verification area AreaI are reset (changed) (step S620). ).
For this purpose, the image data within the field of view maximum range OR_Area already acquired in step S603 and not yet searched for a unique pattern, that is, the current uniqueness verification region AreaI (field of view maximum range OR_Area). A unique pattern is detected from an area outside the unique pattern search area AreaA (field-of-view common area AND_Area) (see FIG. 19A).

In the unique pattern extraction process, first, as shown in FIG. 20A, an area AreaY having the same size as the template is set in the uniqueness verification area AreaI, which is set as a temporary unique pattern area (step S621).
Next, as shown in FIG. 20B, the entire area of the uniqueness verification area AreaI is searched with the area AreaZ having the same size as the temporary unique pattern area AreaY (FIG. 20A) (the same size as the template), and the area AreaZ at each position is searched. The correlation value between the image (pattern signal information) and the temporary unique pattern area AreaY image (pattern signal information) is sequentially obtained based on the above-described equation (1) or equation (2), and the correlation value is sufficiently high. A region having a peak is detected (step S623).

The process of setting the temporary unique pattern area (step S621) and detecting the correlation value peak area in the uniqueness verification area AreaI for the temporary unique pattern (step S623) is performed as the uniqueness verification area AreaI. From the temporary unique pattern area AreaY that can be set within the temporary unique pattern area AreaY (the areas such as Y1 and Y2 in FIG. 20A are shown, where the entire range is included in the unique pattern search area AreaA, as indicated by Y3. This is performed for all the remaining temporary unique pattern areas AreaY (except for this area) (step S625).
Next, a unique pattern having no peak other than itself is extracted from the temporary unique pattern detected by the processing in steps S621 to S625 and the correlation value peak region corresponding thereto (step S627).

In this way, when a unique pattern is detected from the area between the uniqueness verification area AreaI and the unique pattern search area AreaA, the unique pattern is included in a new unique pattern search area AreaA_New (field-of-view common area AND_Area_New). A unique pattern search area (Area A) and a uniqueness verification area (Area I) are newly set so as to be arranged (step S629).
In this embodiment, as shown in FIG. 21, if a unique pattern Q is detected in the uniqueness verification area AreaI, a new target is set so that the center of the unique pattern Q is the center of the observation field of view (VIEW_Area). An imaging range AreaV is set, and based on this, a new visual field common area AND_Area_New and a visual field maximum range OR_Area_New are detected.

When the field-of-view common area AND_Area_New (unique pattern search area AreaA_New) and field-of-view maximum range OR_Area_New (uniqueness verification area AreaI_New) are set in this way, the process returns to step S603, and the above-mentioned areas are again described above. The template creation process is repeated (steps S603 to S609).
When a unique temporary template is extracted in step S611 by such processing (step S613), image data (image signal information) of the temporary template is extracted as a template (step S615), and a template is created. The process ends.

The template creation method of the present embodiment will be described collectively with reference to a specific pattern example shown in FIG.
As shown in FIG. 22, for example, when the initial target measurement area of search alignment measurement is set as AreaV0, the field-of-view common area AND_Area and the field-of-view maximum range are considered in consideration of the wafer insertion error and the like. OR_Area is set as shown. The visual field common area AND_Area is searched with an area AreaT having the same size as the template, and each area is set as a temporary template, and it is verified whether or not each temporary template is unique within the visual field maximum range OR_Area. Thereby, when a unique temporary template is detected, the pattern is registered as a template as it is.

When such a unique pattern is not detected as in the example shown in FIG. 22, the area AreaR in which the uniqueness in the visual field maximum range OR_Area has not yet been detected (the visual field is common within the visual field maximum range OR_Area). The area AND_Area outside the area AND) is searched with the area AreaT having the same size as the template, each area is set as a temporary unique pattern, and it is detected whether each temporary unique pattern is unique within the maximum visual field range OR_Area.
If, for example, a unique pattern Q is detected by this process, the target area AreaV for search alignment measurement is reset so that the pattern Q is included in the visual field common area (AND_Area). Accordingly, the visual field common area AND_Area_New and the visual field maximum range OR_Area_New are re-detected. (Of course, the visual field common area AND_Area_New is detected so as to include the pattern Q.)
Then, a template is created using the newly set area.

In this case, although it cannot be said that the pattern Q is immediately detected as a template, it is a unique pattern at least in a region overlapping with the previous maximum field of view OR_Area in the new maximum field of view OR_Area_New. May be detected as a unique pattern (template).
Even if a unique pattern is not detected in the newly set area, the unique pattern search process can be continued by repeating the same process.

  Thus, according to the template creation method of the present embodiment, when a unique pattern suitable for a template is not detected at a preset measurement position of search alignment measurement, a unique pattern search region is slightly set. The detection of the unique pattern is continuously repeated while changing (shifting) each time. Therefore, there is a high possibility that an appropriate template can be automatically created, and the burden on the operator related to template creation can be reduced.

  When changing the unique pattern search area, a pattern that is likely to be a unique pattern (template) is searched within the maximum field of view, and the search area is changed so that the searched pattern is included. . Therefore, there is a high possibility that an appropriate template can be detected after changing the unique pattern search region, and the template can be created more efficiently.

In addition, since the unique pattern search process when changing the unique pattern search area is performed using already acquired image data, there is no need to acquire new image data. Can be processed well.
In addition, according to the method of the present embodiment, a template can be created from design data as well as imaging data from an actual wafer, so convenience is improved.
Further, in such a configuration in which the search range (maximum visual field range OR_Area) can be changed and template creation and search alignment using the template can be performed, the searchable area can be expanded. Therefore, even if the pre-alignment accuracy and the wafer loading accuracy are slightly lowered in the exposure apparatus, this can be dealt with by search alignment, and as a result, a higher-performance exposure apparatus can be provided.

In the above-described method, the unique pattern is extracted in order to change the unique pattern search area in step S627 and the uniqueness criterion for extracting the unique pattern in order to create the actual template in step S611. The uniqueness criterion is the same, but the latter criterion may be different, for example, relaxed compared to the former.
If an appropriate template cannot be detected even if the unique pattern search area is changed, the process is terminated under an arbitrary condition such as limiting the number of area changes.

Fifth Embodiment As a fifth embodiment according to the present invention, as in the fourth embodiment, when an appropriate template cannot be extracted in the template creation area (unique pattern search area) set first. Another method for resetting the template creation area and attempting to create a template again will be described with reference to FIGS.

FIG. 23 is a flowchart illustrating a flow of template creation processing according to the fifth embodiment of this invention.
In the template creation method of the present embodiment, first, a region for creating a template is set (step S651). Specifically, similarly to the fourth embodiment, the field-of-view common area AND_Area and the field-of-view maximum range OR_Area for the target measurement area are set with respect to the target measurement area of the search alignment measurement in consideration of the wafer insertion error and the wafer manufacturing error. In this embodiment, the visual field maximum range OR_Area is set as a template creation region.

  Next, the image data (pattern signal information) of the visual field maximum range OR_Area is acquired (step S652). Also in the present embodiment, this image data may be generated from design information, or may be acquired by imaging an actual pattern on a wafer.

  When the image data is acquired, a template is extracted from the template creation area (step S653). The template extraction method may be any method, and for example, the first to third embodiments described above may be applied. In the present embodiment, the same method as in the first embodiment is used. That is, as described with reference to FIGS. 7A and 7B, the area AreaT having the same size as the template is set as a temporary template in the template creation area AreaI (maximum field of view range OR_Area), and the entire search area (AreaI) is set. Is searched with a window AreaS having the same size as the temporary template AreaT, and the correlation value between the image of the area AreaS (pattern signal information) and the image of the temporary template T (pattern signal information) at each position is expressed by the above-described equation (1). Or it calculates | requires sequentially based on Formula (2), and the area | region where a correlation value is high enough and becomes a peak is detected. When correlation peak values are detected for all temporary templates AreaT set in the template creation area AreaI, a unique temporary template having no peak other than itself is extracted.

  In step S653, when one or more unique temporary templates are extracted (step S655), the most unique temporary template is selected as an actual template, and the image data (image signal information) is extracted as a template (step S655). S657), the template creation process ends.

If no unique temporary template is extracted in step S653 (step S655), the setting of the template creation area AreaI is also changed in this embodiment.
In the present embodiment, for the current template creation area AreaI, it is estimated from the image data (image signal information) at the peripheral portion that there is a high possibility of a unique pattern having a large amount of pattern features. An area is detected (step S661), and the template creation area AreaI is shifted by a desired amount in that direction to form a new template creation area AreaI_New (step S663).

A process for obtaining the feature amount of the pattern feature of the image signal information at the peripheral edge of the template creation area AreaI will be described with reference to FIGS. 24A and 24B.
Assuming that the current template creation area AreaI (maximum visual field range OR_Area) is set as shown in FIG. 24A, a strip shape having a width L1 inside the maximum visual field range OR_Area along the four sides around the maximum visual field range OR_Area. Thus, eight regions E1 to E8 are set as shown in the periphery of the maximum visual field range OR_Area.
Next, a predetermined pattern feature is detected for each of the areas E1 to E8, and the feature amount is obtained. The pattern features include, for example, the amount of pattern in a binarized pattern (pixel amount of a predetermined pixel value), pattern density, frequency component detection result, amount of edge line segment in edge detected pattern, number of edges, edge Density, edge line frequency component detection results, and the like.

And if the feature-value of each peripheral area | region E1-E8 is calculated | required, the area | region with the most feature-value will be detected.
For example, it is assumed that a pattern as shown in FIG. 24B is arranged in the template creation area AreaI shown in FIG. 24A. In this case, patterns are arranged in the areas E1, E2, E3, E5, and E7. In particular, when a complicated pattern is arranged in the area E1, for example, when pattern features are extracted by performing frequency analysis or edge detection. The feature amount of the region E1 is the largest.

  When the peripheral area having the largest feature amount is obtained, the template creation area AreaI is shifted to a predetermined area set in advance in association with the peripheral area, and a new template creation area AreaI_New is set. In the example shown in FIG. 24B, the template creation area AreaI is shifted by a predetermined amount in the direction of the upper side in the paper, which is the direction of the area E1, and a new template creation area AreaI_New is set.

Note that, along with the movement of the template creation area, the target measurement area at the time of search alignment in which the area becomes the maximum visual field range OR_Area will also move.
Further, if the new template creation area AreaI_New is set in the direction of the area having a large amount of pattern feature, the new template creation area AreaI_New may be set in an arbitrary direction and an arbitrary distance with respect to the original area AreaI. For example, the original template creation area AreaI may be set so as to partially overlap as shown in FIG. 25A, or may be set so as not to overlap at all as shown in FIG. 25B.

When a new template creation area is set in this way, the process returns to step S652, the image data of this template creation area AreaI_New is acquired, and the template creation process described above is performed for this new template creation area AreaI_New. The process is repeated (steps S653 to S655).
When a unique temporary template is extracted in step S653 by such processing (step S655), image data (image signal information) of the temporary template is extracted as a template (step S657), and a template is created. The process ends.

  As described above, according to the template creation method of the present embodiment, a unique pattern suitable for use as a template was not detected in a preset template creation area (the maximum field of view OR_Area in the present embodiment). Sometimes the template search position is shifted and reset, and the template is created again. Therefore, there is a high possibility that a template can be created automatically, and the burden on the operator involved in template creation can be reduced.

  In addition, when changing the processing area for template creation, an area or direction where a unique pattern is highly likely to be detected is estimated based on the pattern characteristics of the periphery of the template creation area. The creation area has been changed. Therefore, it is possible to avoid a state where the template creation area is reset to an area where there is no pattern at all, and it is possible to reset the template creation area to an area where a template can be appropriately extracted. it can.

In addition, since the detection of the pattern feature for moving the template creation area is performed using the image data of the area where the image data has already been acquired, there is no need to newly acquire the image data. Processing can be performed efficiently.
In addition, according to the method of the present embodiment, a template can be created from design data as well as imaging data from an actual wafer, so convenience is improved.
Also in the present embodiment, since the template can be created by changing the search range (maximum field of view range OR_Area), the searchable area can be expanded, and the pre-alignment accuracy and wafer insertion accuracy in the exposure apparatus can be expanded. Can also be dealt with by search alignment. As a result, a higher performance exposure apparatus can be provided.

  In the method described above, after setting the visual field maximum range OR_Area as a template creation area in step S651, image data of the same area as the visual field maximum range OR_Area is acquired in step S652. However, image data in a region wider than the maximum visual field range OR_Area may be acquired and used for subsequent pattern feature detection. That is, for example, as shown in FIG. 26, when acquiring image data in step S652, an image of an area AreaE that is expanded by a distance L2 in each of four directions from each side of the maximum field of view range OR_Area is acquired. Then, when the template cannot be extracted from the maximum field of view OR_Area and the pattern feature around the maximum field of view OR_Area is detected to shift the template creation area AreaI, the image data (image signal information) of the expanded portion is used.

  In the example shown in FIG. 26, for example, in a band-shaped region that is sandwiched between lines defined by the distance L2 from the four sides of the maximum field of view OR_Area and lines defined by the distance L3 from the four sides. Similarly to FIGS. 24A and 24B, the areas E1 to E8 are set, the feature amounts of the pattern features in each area are detected, and the movement direction of the template creation area is determined based on this. According to such a method, since it is possible to refer to the pattern features of the region outside the region used as the maximum field of view OR_Area, it is possible to more appropriately estimate the possibility that there is a unique pattern that can be used as a template. And the template creation area can be reset more efficiently.

  In the method of the present embodiment, the direction and distance for shifting the template creation area may be arbitrarily set. As in the present embodiment, a plurality of reset positions may be prepared in advance. For example, the direction in which the template creation area is shifted and the distance to be shifted are determined according to the pattern characteristics of the peripheral edge. Good. For example, the center of gravity of a series of pattern features may be detected, and the template creation area may be shifted in the direction of the center of gravity.

Sixth Embodiment In the fourth and fifth embodiments, when an appropriate template cannot be created from the template creation area, the template creation area is moved and reset. . However, from the initial stage of template creation, an area having a large amount of information suitable for template creation may be selected and set as the template creation area. As a sixth embodiment according to the present invention, a process for selecting a region suitable for template creation from a wide range of regions around the target measurement region and creating a template using image data of the region is shown in FIG. And with reference to FIG.

FIG. 27 is a flowchart illustrating a flow of template creation processing according to the sixth embodiment of this invention.
In the template creation method of the present embodiment, first, wide area image data (image signal information) is acquired by an imaging camera with a low magnification (first detection magnification) (step S701). The range for acquiring image data includes a target measurement area (search measurement visual field area) at the time of search alignment measurement, and further includes a plurality of template creation areas. A magnification that is higher than the imaging magnification (first detection magnification) in this step of acquiring data and lower than the detection magnification set at the time of fine alignment measurement, hereinafter referred to as medium magnification (second detection magnification) for convenience. In consideration of the observation visual field VIEW_Area, and the wafer insertion error and wafer manufacturing error, it is fixedly determined in advance. In the present embodiment, as shown in FIG. 28, the maximum field of view OR_Area when the observation field of view VIEW_Area is imaged at medium magnification at the time of search alignment measurement. The image data of the area AreaX (image data of the low magnification (first detection magnification)) that is the doubled area and is substantially centered on the target measurement area (search measurement visual field area) AreaV0 at the time of search alignment measurement is acquired. .

In the case where such image data is acquired by an apparatus different from the exposure apparatus 100, the wafer surface is imaged and acquired by an imaging system having a low-magnification optical system that is specially provided.
When such data is acquired by the exposure apparatus, for example, an FIA type alignment sensor having a plurality of light receiving systems (low magnification, medium magnification, and high magnification) is used. An alignment sensor based on such a concept is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-257512. Although the alignment sensor is not shown, the alignment lens (objective optical system) is provided in common, but the light receiving system (high magnification system) with a relatively high magnification and a narrow field of view and the field of view with a relatively medium magnification. Two light receiving systems, that is, a wide light receiving system (medium magnification system) are provided, and a light beam reflected on the wafer surface is branched by a beam splitter or the like and is incident on each light receiving system. By adding such a low-magnification light receiving system (including a sensor) as described above to such an alignment sensor, the low-magnification image data in step S701 is imaged by, for example, such an alignment sensor provided in the exposure apparatus. To do.

Once the low-magnification image data is acquired, a unique pattern is then detected from this image data.
First, as shown in FIG. 28, an area AreaY corresponding to the size of the unique pattern to be detected is set in the low-magnification image data area AreaX, and this is set as a temporary unique pattern (step S703). In this embodiment, the size of the unique pattern detected here is the same as the size of the template to be finally generated, but is not limited to this, and is set to an arbitrary size. It's okay.

Next, low-magnification image data (low-magnification image data area AreaX) is searched in the window AreaZ having the same size as the area AreaY, and the image (pattern signal information) in the area AreaZ and the temporary unique pattern AreaY at each position are searched. Correlation values with the image (pattern signal information) are sequentially obtained based on the above-described equation (1) or equation (2), and a region having a sufficiently high correlation value and a peak is detected (step S705).
When correlation peak values are detected for all temporary unique patterns AreaY set in the low-magnification image data area AreaX (step S707), a truly unique temporary unique pattern having no peak other than itself is detected. Is extracted (step S709). In the example shown in FIG. 28, for example, a truly unique pattern is detected in the area AreaU.

  In this unique pattern detection process, the area to be processed (area AreaX) is wide, but the image data is low-magnification image data, so the amount of data is small, and the processing in steps S703 to S709 is practical. You don't spend a lot of time that matters.

When the area AreaU including the unique pattern is detected in the low-magnification image data area AreaX, an area AreaI for acquiring medium-magnification image data (image signal information) for actually creating a template is set (step S711). . As shown in FIG. 28, the area AreaI for acquiring the medium-magnified image is an area having the same size as the field-of-view maximum range OR_Area in search alignment measurement (medium magnification measurement), and the center of the area AreaU has a unique pattern. Set the area so that it is the same as the center of. At this time, the target visual field area AreaV at the time of search alignment measurement is also changed so that the visual field maximum range OR_Area becomes such a region.
Then, the template creation area AreaI on the wafer is imaged through the medium magnification optical system to obtain image data (image signal information) (step S713).

When the image data of the template creation area AreaI is acquired, a unique pattern as a template is detected from this image data.
First, an area AreaT corresponding to the template size is set in the unique pattern search area AreaA (field-of-view common area AND_Area) in the template creation area AreaI, and this is set as a temporary template (step S715). Next, the template creation area AreaI is searched with the window AreaS having the same size as the area AreaT, and the correlation value between the image of the area AreaS (pattern signal information) and the image of the temporary template AreaT (pattern signal information) at each position. Are sequentially obtained based on the above-described equation (1) or equation (2), and a region having a sufficiently high correlation value and a peak is detected (step S717). When correlation peak values are detected for all temporary templates AreaT set in the unique pattern search area AreaA (step S719), a unique pattern having no peak other than itself is extracted (step S719). S721). Then, the image data (image signal information) of the unique pattern is extracted as a template (step S723).

As described above, according to the template creation method of the present embodiment, an area that is likely to have a unique pattern is estimated using a sufficiently wide range of image data for the area to be a template creation area. Template creation processing is performed using the area as a template creation area. Therefore, there is a very high possibility that a unique pattern capable of template creation is detected from the first set area, and an efficient template creation process can be performed.
As a result, since the unique pattern is not detected, the frequency of processing such as resetting the template creation area and re-acquiring image data can be reduced, and the operation of various apparatuses related to the template creation and exposure apparatus can be reduced. And the exposure process can be performed efficiently.

In this embodiment, since a template is created by detecting a unique pattern over a wide area, a highly unique pattern can be used as a template. That is, it is possible to create a high-quality template with strong uniqueness and strong discrimination.
Also in the present embodiment, since the template can be created by changing the search range (maximum field of view range OR_Area), the searchable area can be expanded, and the pre-alignment accuracy and wafer insertion accuracy in the exposure apparatus can be expanded. Can also be dealt with by search alignment. As a result, a higher performance exposure apparatus can be provided.

  In steps S703 to S711, by detecting a unique pattern, an area where there is a high possibility that a unique pattern suitable for template creation exists from the low-magnification image data area AreaX is detected, and the template is actually created. Set as an area for. However, the method for estimating an area where a unique pattern is likely to exist is not limited to this. For example, the feature amount of the pattern feature detected for moving the maximum visual field range OR_Area in the fifth embodiment, that is, the pattern amount (pixel amount of a predetermined pixel value) in the binarized pattern, the pattern density, and the frequency Using the component detection results, the amount of edge line segments in the detected edge pattern, the number of edges, the edge density, the frequency component detection results of the edge line segments, etc., the area where there is a high possibility that a unique pattern exists is estimated. You may do it.

In addition, the template creation process (reference data extraction process) after setting the template creation area AreaI (maximum field of view OR_Area) is not limited to the processes in steps S713 to S723 described above. For example, a template may be created by applying each process as in the first to third embodiments described above.
In the present embodiment, the template is created based on the actual image data on the wafer, but may be created based on the design data.

In the present embodiment, the area AreaU having a unique pattern is detected from the low-magnification image data area AreaX, and the template creation area AreaI is set based on this area. However, a plurality of areas having unique patterns are detected. In this manner, templates may be created from each area by sequentially setting the template creation areas.
Alternatively, a plurality of detected areas may be ranked based on uniqueness, and a template may be created for each area in that order.

Device Manufacturing Method Next, a device manufacturing method performed using the exposure apparatus 100 including the alignment sensor as described above will be described with reference to FIG.
FIG. 29 is a flowchart showing a manufacturing process of an electronic device such as a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, or a micromachine.
As shown in FIG. 29, in the manufacturing process of the electronic device, first, the function / performance design of the device such as the circuit design of the electronic device is performed, and the pattern design for realizing the function is performed (step S810). Then, a reticle on which the designed circuit pattern is formed is manufactured (step S820).
On the other hand, a wafer (silicon substrate) is manufactured using a material such as silicon (step S830).

Next, using the reticle manufactured in step S820 and the wafer manufactured in step S830, an actual circuit or the like is formed on the wafer by a lithography technique or the like (step S840).
Specifically, first, a thin film with an insulating film, an electrode wiring film, or a semiconductor film is formed on the wafer surface (step S841), and then the entire surface of the thin film is exposed using a resist coating device (coater). An agent (resist) is applied (step S842).
Next, the resist-coated substrate is loaded on the wafer holder, and the reticle manufactured in step S830 is loaded on the reticle stage, and the pattern formed on the reticle is reduced and transferred onto the wafer (step S843). ). At this time, the exposure apparatus sequentially aligns each shot area of the wafer by the alignment method according to the present invention described above, and sequentially transfers the reticle pattern to each shot area.

When the exposure is completed, the wafer is unloaded from the wafer holder and developed using a developing device (developer) (step S844). Thereby, a resist image of a reticle pattern is formed on the wafer surface.
Then, the wafer subjected to the development process is etched using an etching apparatus (step S845), and the resist remaining on the wafer surface is removed using, for example, a plasma ashing apparatus (step S846).
Thereby, patterns such as an insulating layer and electrode wiring are formed in each shot region of the wafer. Then, an actual circuit or the like is formed on the wafer by sequentially repeating this process while changing the reticle.

If a circuit or the like is formed on the wafer, then assembling as a device is performed (step S850). Specifically, the wafer is diced and divided into individual chips, each chip is mounted on a lead frame or a package, bonding for connecting electrodes is performed, and a packaging process such as resin sealing is performed.
Then, inspections such as an operation check test and a durability test of the manufactured device are performed (step S860), and the device is shipped as a completed device.

  The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment includes all design changes and equivalents belonging to the technical scope of the present invention.

For example, in the above-described embodiment, the present invention has been described by exemplifying template generation for performing the search alignment of the wafer W. However, for example, template generation for aligning the reticle R and fine alignment are performed. The present invention can also be applied to template generation for the purpose.
Further, in the above-described embodiment, the case where the present invention is applied to an off-axis type alignment sensor has been described as an example. However, the mark image (pattern signal) imaged by the image sensor is processed to obtain the mark. The present invention can be applied to all devices that detect positions.

In addition, the present invention can be applied to step-and-repeat or step-and-scan reduced projection exposure apparatuses, mirror projection systems, proximity systems, contact systems, and other exposure apparatuses.
In order to manufacture not only an exposure apparatus used for manufacturing a semiconductor element and a liquid crystal display element, but also an exposure apparatus used for manufacturing a plasma display, a thin film magnetic head, and an image sensor (CCD, etc.), and a reticle. The present invention can also be applied to an exposure apparatus that transfers a circuit pattern to a glass substrate or a silicon wafer. In other words, the present invention can be applied regardless of the exposure method and application of the exposure apparatus.

Further, as the exposure light EL of the exposure apparatus 100 of the present embodiment, light emitted from g-line or i-line, or KrF excimer laser, ArF excimer laser, F2 excimer laser is used. In addition to light emitted from (248 nm), ArF excimer laser (193 nm), and F2 laser (157 nm), charged particle beams such as X-rays and electron beams can be used. For example, when using an electron beam, thermionic emission type lanthanum hexabolite (LaB6) and tantalum (Ta) can be used as the electron gun.
In addition, for example, an infrared or visible single wavelength laser oscillated from a DFB semiconductor laser or fiber laser is amplified by a fiber amplifier doped with erbium (or both erbium and yttrium), and further nonlinear optics You may use the harmonic which wavelength-converted into the ultraviolet light using the crystal | crystallization. An yttrium-doped fiber laser is used as the single wavelength oscillation laser.

  The above-described exposure apparatus (FIG. 1) according to the embodiment of the present invention can accurately control the position of the substrate W at high speed so that exposure can be performed with high exposure accuracy while improving throughput. Each element shown in FIG. 1 such as an illumination optical system, an alignment system (not shown) of a reticle R, a wafer alignment system including a wafer stage 9, a movable mirror 11 and a laser interferometer 12, a projection lens PL, etc. is an electrical, mechanical It is manufactured by performing general adjustment (electrical adjustment, operation check, etc.) after being assembled by being connected to each other optically or optically. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

It should be noted that the present invention is incorporated in the description of this specification by using the disclosures of all the above-mentioned publications as long as the national laws of the designated country designated in the international application or the selected selected country permit.
The present disclosure relates to the subject matter included in Japanese Patent Application No. 2003-185392 filed on June 27, 2003 and Japanese Patent Application No. 2004-150499 filed on May 20, 2004. The entire disclosure of which is expressly incorporated herein by reference.

Claims (84)

A reference pattern extraction method for extracting a reference pattern having a unique signal feature in a measurement area having an area smaller than the predetermined area arbitrarily disposed in a predetermined area on an object,
A first step of obtaining pattern signal information in the predetermined region;
From the pattern signal information obtained in the first step, it is possible to recognize that each position in the measurement area is unique in every position that the measurement area can take in the predetermined area. A second step of extracting a plurality of unique patterns whose uniqueness is different from each other;
And a third step of extracting all of the plurality of unique patterns extracted in the second step as the reference pattern irrespective of the positions that the measurement target region can take in the predetermined region. Reference pattern extraction method. 2. The reference pattern extraction method according to claim 1, wherein in the second step, each of the unique patterns is extracted in a specific area unit having an area smaller than the measurement target area. 3. The reference pattern extraction method according to claim 1, wherein, in the second step, the unique pattern is extracted while using information on a pattern shape feature as the uniqueness index. In the second step, in addition to the information on the pattern shape feature, the number of patterns having different pattern shape features and at least one of their arrangement relations are also used as the uniqueness index. The reference pattern extraction method according to claim 3, wherein a pattern is extracted. In the second step, the unique pattern is extracted while using at least one of the number of patterns having the same pattern shape feature and the arrangement relationship thereof as an index of uniqueness. The reference pattern extraction method according to claim 2. The reference pattern extraction method according to claim 4 or 5, wherein when the arrangement relationship between the patterns is used as the index of uniqueness, design value information regarding the arrangement relationship is used. The information on the pattern shape feature is obtained by performing correlation calculation processing for each pattern signal information in the specific area or calculation processing using the SSDA method with respect to the pattern signal information in the predetermined area. The reference pattern extraction method according to claim 3. Information relating to the shape feature of the pattern is obtained using at least one information amount of SN ratio, edge amount, entropy amount, variance value, and moment amount in the pattern signal information in each of the specific areas. The reference pattern extraction method according to claim 7. 9. The reference pattern extraction according to claim 1, wherein in the first step, pattern signal information in the predetermined area is obtained using an imaging unit capable of imaging the predetermined area at a time. Method. In the first step,
Using an imaging means capable of imaging the measurement area, and obtaining pattern signal information in the measurement area at a plurality of positions while changing the position of the object relative to the imaging means,
The reference pattern extraction method according to claim 1, wherein pattern signal information in the predetermined area is obtained by combining the plurality of obtained pattern signal information. 11. The reference pattern extraction method according to claim 9, wherein in the first step, the object is positioned with respect to the imaging unit using design value information regarding a pattern formed on the object. A correlation calculation process is performed on pattern signal information in the measurement target area on the object using the reference pattern obtained by the reference pattern extraction method according to claim 1. Pattern matching method. The pattern matching method according to claim 12, wherein correlation calculation processing is performed on pattern signal information in the measurement target area by sequentially using all of the plurality of unique patterns. A reference pattern extraction device that extracts a reference pattern having a unique signal feature in a measurement region having an area smaller than the predetermined region arbitrarily disposed in a predetermined region on an object,
Pattern signal information obtaining means for obtaining pattern signal information in the predetermined area;
From the obtained pattern signal information, it is possible to recognize that each position in the measurement area is unique in each measurement area in all the positions that can be taken in the predetermined area, and Unique pattern extraction means for extracting a plurality of unique patterns having different uniqueness;
A reference pattern extracting means for extracting all of the extracted unique patterns as the reference pattern irrespective of the position where the measurement target area can be taken in the predetermined area. Pattern extraction device. The reference pattern extraction apparatus according to claim 14, wherein the unique pattern extraction unit extracts each unique pattern in a specific area unit having an area smaller than the measurement target area. The reference pattern extraction apparatus according to claim 14, wherein the unique pattern extraction unit extracts the unique pattern while using information on a pattern shape feature as the index of uniqueness. The unique pattern extraction means uses, in addition to the information on the pattern shape feature, at least one of the number of patterns having different pattern shape features and their arrangement relation as the index of uniqueness. The reference pattern extraction device according to claim 16, wherein a unique pattern is extracted. The unique pattern extraction means extracts the unique pattern while using at least one of the number of patterns having the same pattern shape feature and their arrangement relation as an index of uniqueness. The reference pattern extraction device according to claim 15. All of the plurality of unique patterns with respect to pattern signal information in the measurement target area on the object using the reference pattern obtained by the reference pattern extraction device according to any one of claims 14 to 18. A pattern matching apparatus comprising: correlation calculation processing means for sequentially performing correlation calculation processing using the. A reference pattern extraction method for extracting a reference pattern used to identify a predetermined pattern formed on an object,
A first step of obtaining design value information relating to at least one of the shape of the pattern formed on the object and its arrangement information;
A second step of converting the design value information into pattern signal information;
A third step of extracting a unique pattern having a unique pattern signal feature from the pattern signal information;
And a fourth step of determining the reference pattern based on the unique pattern extracted in the third step. In the third step,
The unique pattern is extracted by performing correlation calculation processing for each partial pattern signal information in the pattern signal information or calculation processing using an SSDA method with respect to the pattern signal information. The reference pattern extraction method described. The reference pattern extraction method according to claim 21, wherein, in the third step, the unique pattern is extracted while changing a size of an area obtained from the partial pattern signal information. In the fourth step, when a plurality of the unique patterns are extracted in the third step, a unique pattern having the largest feature difference with respect to other patterns in the pattern signal information is determined as the reference pattern. The reference pattern extraction method according to any one of claims 20 to 22. A reference pattern extraction device that extracts a reference pattern used to identify a predetermined pattern formed on an object,
Design value information obtaining means for obtaining design value information related to at least one of the shape of the pattern formed on the object and its arrangement information;
Information conversion means for converting the design value information into pattern signal information;
Unique pattern extraction means for extracting a unique pattern having a unique signal characteristic from the pattern signal information;
Reference pattern determining means for determining the reference pattern based on the extracted unique pattern. The reference pattern extraction device according to claim 24, wherein the unique pattern extraction unit extracts the unique pattern while changing a size of an area obtained from the partial pattern signal information. A reference pattern extraction method for extracting a reference pattern used to identify a predetermined pattern formed on an object,
A first step of imaging the object to obtain pattern signal information;
A second step of obtaining design value information relating to at least one of a shape and an arrangement state of a pattern formed on the object;
A third step of extracting a part of the pattern signal information as information on the reference pattern based on the pattern signal information obtained in the first step and the design value information obtained in the second step. And a reference pattern extraction method characterized by comprising: The third step includes
Converting the design value information into pattern signal information;
Obtaining unique pattern position information relating to the position of a portion having a unique pattern signal feature from the converted pattern signal information;
Identifying a part of the pattern signal information obtained in the first step based on the unique pattern position information;
The reference pattern extraction method according to claim 26, further comprising: extracting the specified part as information on the reference pattern. A reference pattern extraction device that extracts a reference pattern used to identify a predetermined pattern formed on an object,
Pattern signal information acquisition means for imaging the object and obtaining pattern signal information;
Design value information obtaining means for obtaining design value information related to at least one of the shape and arrangement state of the pattern formed on the object;
Based on the pattern signal information obtained by the pattern signal information acquisition means and the design value information obtained by the design value information acquisition means, a part of the pattern signal information is extracted as information on the reference pattern. And a reference pattern extracting means. The reference pattern extraction means includes
Pattern signal information converting means for converting the design value information into pattern signal information;
Unique pattern position information acquisition means for obtaining unique pattern position information related to the position of a portion having a unique pattern signal feature from the converted pattern signal information;
Pattern signal specifying means for specifying a part of the pattern signal information obtained in the first step based on the unique pattern position information;
29. The reference pattern extraction device according to claim 28, further comprising: a reference pattern extraction unit that extracts the specified part as information relating to the reference pattern. A pattern matching method for identifying a predetermined pattern formed in a predetermined region on an object,
A first step of preparing a plurality of reference patterns having different uniqueness as the reference pattern;
A second step of obtaining pattern signal information by imaging the predetermined area;
A pattern matching method comprising: a third step of performing correlation calculation processing on the pattern signal information obtained in the second step by sequentially using all of the plurality of reference patterns. The pattern matching method according to claim 30, wherein the plurality of reference patterns have different pattern shape characteristics. 32. The pattern matching method according to claim 30, wherein the plurality of reference patterns are different from each other in at least one of the number and arrangement relationship of patterns having a specific shape. A pattern matching device for identifying a predetermined pattern formed in a predetermined region on an object,
Reference pattern preparation means for preparing a plurality of reference patterns having different uniqueness as the reference pattern,
Pattern signal information obtaining means for obtaining pattern signal information by imaging the predetermined area;
A pattern matching apparatus comprising: correlation calculation processing means for performing correlation calculation processing on the obtained pattern signal information by sequentially using all of the plurality of reference patterns. A reference pattern extraction method for extracting a reference pattern used when identifying a pattern formed on an object,
A first step of performing photoelectric detection on the object via an optical system having a first detection magnification to obtain first pattern signal information;
Based on the first pattern signal information obtained in the first step, a second step of identifying a predetermined region on the object that is presumed to have a unique pattern having a unique pattern signal feature;
The predetermined area specified in the second step is photoelectrically detected via an optical system having a second detection magnification higher than the first detection magnification, and a second pattern signal in the predetermined area is detected. A third step of obtaining information;
And a fourth step of extracting the unique pattern to be used as the reference pattern based on the second pattern signal information obtained in the third step. In the second step,
A plurality of candidate areas are set within a range where pattern signal information is obtained in the first step on the object,
Based on the first pattern signal information of each of the set candidate areas, a unique pattern having a unique signal feature in the candidate area is extracted,
35. The reference pattern extraction method according to claim 34, wherein one or a plurality of candidate areas are specified as the predetermined area in descending order of uniqueness of the unique pattern obtained from each of the plurality of candidate areas. Until the appropriate reference pattern is determined in the fourth step, the candidate area is regarded as the predetermined area in order from the candidate area from which the unique pattern having the large uniqueness is extracted, and the first area in the predetermined area is determined. 36. The reference according to claim 35, wherein the pattern signal information of 2 is obtained, the unique pattern is extracted based on the second pattern signal information, and the reference pattern is determined based on the unique pattern. Pattern extraction method. The process of extracting the reference pattern from the predetermined region in the third step and the fourth step is performed using the reference pattern extraction method according to any one of claims 1 to 11, 26, or 27, and 37. The reference pattern extraction method according to any one of claims 34 to 36, wherein the reference pattern extraction method is performed based on the pattern signal information of No. 2. In the second step, based on the first pattern signal information, in the candidate region that is smaller than the candidate region and is always included in the measurement target region arranged at an arbitrary position in the candidate region A unique pattern having a unique signal feature in the candidate region,
In the fourth step, based on the second pattern signal information, a pattern that exists in an area within the predetermined area that is necessarily included in the measurement target area disposed at an arbitrary position within the predetermined area, 37. The reference pattern extraction method according to claim 35 or 36, wherein a unique pattern having a unique signal characteristic in the predetermined area is extracted. A reference pattern extraction device that extracts a reference pattern used to identify a pattern formed on an object,
A first information acquisition means for obtaining first pattern signal information by performing photoelectric detection on the object via an optical system having a first detection magnification;
Predetermined area specifying means for specifying a predetermined area on the object on which the unique pattern having a unique pattern signal characteristic is presumed to exist based on the first pattern signal information;
The second pattern signal information in the predetermined area is obtained by photoelectrically detecting the specified predetermined area through an optical system having a second detection magnification higher than the first magnification. Information acquisition means;
And a reference pattern determining means for extracting and determining the unique pattern to be used as the reference pattern based on the second pattern signal information. The second information acquisition unit and the reference pattern determination unit that extract the reference pattern from the predetermined region use the reference pattern extraction device according to any one of claims 14 to 18, 28, or 29, and The reference pattern extraction apparatus according to claim 39, wherein the reference pattern extraction apparatus performs the determination based on the second pattern signal information. A reference pattern extraction method for extracting a reference pattern used when identifying a pattern formed on an object,
A first step of obtaining pattern signal information of a predetermined area on the object;
Based on the pattern signal information obtained in the first step, a pattern that has an area smaller than the predetermined area and is present in a specific area that is necessarily included in a measurement area that is arranged at an arbitrary position in the predetermined area A second step of extracting a unique pattern having a unique pattern signal feature in the predetermined region and determining the reference pattern based on the extracted unique pattern;
When the unique pattern cannot be extracted from the specific region in the second step, the pattern is arranged at an arbitrary position in the predetermined region based on the pattern signal information obtained in the first step, and the area is A third step of extracting a unique pattern having a signal characteristic that is unique within the predetermined region, the pattern being an area of a specific region or less;
A fourth step of resetting the predetermined region so that the specific region is defined so as to include the unique pattern when the unique pattern is extracted in the third step. The reference pattern extraction method, wherein the first pattern and the second process are performed on the predetermined region to extract the unique pattern. A reference pattern extraction device that extracts a reference pattern used to identify a pattern formed on an object,
Pattern signal information obtaining means for obtaining pattern signal information of a predetermined area on the object;
Based on the obtained pattern signal information, a pattern having an area smaller than the predetermined region and present in a specific region that is necessarily included in a measurement target region arranged at an arbitrary position in the predetermined region, A reference pattern determining means for extracting a unique pattern having a unique pattern signal characteristic in the predetermined region and determining the reference pattern based on the extracted unique pattern;
When the unique pattern cannot be extracted from the specific area in the reference pattern determining means, based on the pattern signal information obtained by the pattern signal information acquiring means, arranged at an arbitrary position in the predetermined area, Unique pattern extraction means for extracting a unique pattern having an area that is equal to or smaller than the area of the specific region and having a unique signal characteristic in the predetermined region;
A predetermined area resetting means for resetting the predetermined area so that the specific area is defined to include the unique pattern when the unique pattern is extracted by the unique pattern extraction means; The reference pattern extraction apparatus, wherein the pattern signal information acquisition unit acquires the pattern signal information for the reset predetermined area, and the reference pattern determination unit determines the reference pattern. A reference pattern extraction method for extracting a reference pattern used when identifying a pattern formed on an object,
Obtaining pattern signal information of a predetermined area on the object, extracting a unique pattern having a unique pattern signal characteristic in the predetermined area based on the acquired pattern signal information, and based on the extracted unique pattern A first step of determining the reference pattern;
If the unique pattern cannot be extracted from the predetermined area in the first step, the area near the predetermined area, and the area where the unique pattern having a unique pattern signal feature is highly likely to exist A second step of resetting a predetermined region, and performing the first step on the reset predetermined region to determine the reference pattern. In the second step, a region having a large amount of pattern feature is detected based on at least one of the pattern signal information of the predetermined region before the resetting and the pattern signal information near the predetermined region, 44. The reference pattern extraction method according to claim 43, wherein the predetermined area is reset. In the second step, a region having a large amount of pattern feature is detected based on a feature pattern obtained by binarizing or detecting an edge based on the pattern signal information, and the predetermined region is set in the direction of the region. The reference pattern extraction method according to claim 44, wherein resetting is performed. 46. In the second step, the position of the center of gravity of the feature pattern is measured, and the predetermined area is reset so that the position of the center of gravity is an area from which the unique pattern is to be extracted. Standard pattern extraction method. 47. In the first step, the reference pattern is determined by the reference pattern extraction method according to any one of claims 1-11, 20-23, 26, or 27. The reference pattern extraction method described. A reference pattern extraction device that extracts a reference pattern used to identify a pattern formed on an object,
Obtaining pattern signal information of a predetermined area on the object, extracting a unique pattern having a unique pattern signal characteristic in the predetermined area based on the acquired pattern signal information, and based on the extracted unique pattern Reference pattern determining means for determining the reference pattern;
In the case where the unique pattern cannot be extracted from the predetermined area in the reference pattern determining means, the area near the predetermined area, where there is a high possibility that a unique pattern having a unique pattern signal feature exists. A predetermined area resetting means for resetting the predetermined area, and the reference pattern determining means determines the reference pattern again for the reset predetermined area. Extraction device. In the predetermined area resetting means, an area having a large pattern feature amount is detected based on at least one of the pattern signal information of the predetermined area before the resetting and the pattern signal information near the predetermined area. The reference pattern extraction device according to claim 48, wherein the predetermined region is reset in a region direction. In the predetermined area resetting means, an area with a large amount of pattern feature is detected based on a feature pattern obtained by binarizing or detecting an edge based on the pattern signal information, and the area in the direction of the area is detected. The reference pattern extraction apparatus according to claim 49, wherein the predetermined area is reset. The predetermined area resetting means measures the centroid position of the feature pattern, and resets the predetermined area so that the centroid position becomes an extraction target area of the unique pattern. 50. The reference pattern extraction device according to 50. A pattern in a measurement target area on the object using the reference pattern extracted by the reference pattern extraction method according to any one of claims 20 to 23, 26, 27, 34 to 38, 41 or 43 to 47. A pattern matching method characterized by performing correlation calculation processing on signal information. A pattern in a measurement area on the object using the reference pattern extracted by the reference pattern extraction device according to any one of claims 24, 25, 28, 29, 39, 40, 42, and 48 to 51. A pattern matching device characterized by performing correlation calculation processing on signal information. 53. A position detection method, comprising: obtaining position information of the unique pattern in the measurement target area using the pattern matching method according to claim 12, 13, 30-32 or 52. 54. A position detection apparatus comprising position information detection means for obtaining position information of the unique pattern in the measurement target area using the pattern matching apparatus according to claim 19, 33, or 53. The position detection method of the unique pattern formed on the substrate as the object using the position detection method according to claim 53 on the moving coordinate system of the object,
Aligning the substrate based on the position information;
An exposure method, wherein a predetermined pattern is transferred and exposed on the aligned substrate. The position detection device according to claim 55, wherein position information of a unique pattern formed on a substrate as the object is obtained on a moving coordinate system of the object;
Alignment means for aligning the substrate based on the position information;
An exposure apparatus comprising: exposure means for transferring and exposing a predetermined pattern on the aligned substrate. A reference pattern extraction method for extracting a reference pattern having a unique signal feature from an object on which a pattern is formed, wherein a measurement area having a predetermined area can be arranged and a predetermined area in a wider range than the measurement area In a reference pattern extraction method for extracting a reference pattern having a unique signal feature in
Extracting a first reference pattern having a unique signal characteristic from a pattern included in the measurement target region located at a first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A reference pattern extraction method, wherein a second reference pattern having a unique signal feature is extracted from a pattern included in the measurement area located at a position. A range included in the measured region when the measured region is at the first position in the predetermined region, and a range included in the measured region when the measured region is at the second position. When a part overlaps, the first reference pattern is a pattern extracted from a range excluding the overlap range in the measurement area at the first position, and the second reference pattern is the first reference pattern. 59. The reference pattern extraction method according to claim 58, wherein the reference pattern extraction method is a pattern extracted from a range excluding the overlapping range among the measurement target regions at two positions. A range included in the measured region when the measured region is at the first position in the predetermined region and a range included in the measured region when the measured region is at the second position. 59. The reference pattern extraction method according to claim 58, wherein there is no overlapping range. 59. The reference pattern extraction method according to claim 58, wherein the first reference pattern and the second reference pattern are extracted based on design value information for forming a pattern on the object. Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. 59. The reference pattern extraction method according to claim 58, wherein the second reference pattern composed of a plurality of reference patterns having unique signal characteristics is extracted from a pattern included in the measurement target region located in the measurement area. . Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern composed of a specific pattern arranged at a predetermined position with respect to the pattern having the unique signal feature and the pattern having the unique signal feature from the pattern included in the measurement area located at 59. The reference pattern extraction method according to claim 58, wherein: A pattern matching method for disposing a measurement area having a predetermined area on an object on which a pattern is formed, and detecting a specific pattern that matches a predetermined reference pattern from patterns included in the measurement area, In a pattern matching method for detecting the specific pattern from a predetermined area wider than the area,
As the reference pattern, a first reference pattern having a unique signal feature is extracted from a pattern included in the measurement target region located at a first position in the predetermined region, and
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern having a unique signal feature is extracted from the pattern included in the measurement area located at
Setting the measurement area on the object;
A pattern matching method, wherein a pattern that matches the first reference pattern or the second reference pattern is detected from an image of the object in the measurement area. A range included in the measured region when the measured region is at the first position in the predetermined region, and a range included in the measured region when the measured region is at the second position. When a part overlaps, the 1st standard pattern is extracted from the range excluding the overlap range among the measurement area in the 1st position, and the 2nd standard pattern exists in the 2nd position The pattern matching method according to claim 64, wherein the pattern is extracted from a range excluding the overlapping range in the measurement target region. A range included in the measured region when the measured region is at the first position in the predetermined region and a range included in the measured region when the measured region is at the second position. The pattern matching method according to claim 64, wherein there is no overlapping range. .
The pattern matching method according to claim 64, wherein the first reference pattern and the second reference pattern are extracted based on design value information for forming a pattern on the object. As the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. The pattern matching method according to claim 64, wherein the second reference pattern including a plurality of reference patterns having unique signal characteristics is extracted from patterns included in the measurement target region positioned at the position. As the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern composed of a specific pattern arranged at a predetermined position with respect to the pattern having the unique signal feature and the pattern having the unique signal feature from the pattern included in the measurement area located at The pattern matching method according to claim 64, wherein the pattern matching method is extracted. A position detection method for detecting position information of an object on which a pattern is formed, wherein a measurement area having a predetermined area is arranged on the object and matches a predetermined reference pattern from patterns included in the measurement area In a position detection method for detecting relative position information between the specific pattern and the measurement target region by detecting the specific pattern,
As the reference pattern, a first reference pattern having a unique signal feature is extracted from a pattern included in the measurement area located at a first position within a predetermined area wider than the measurement area, and
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern having a unique signal feature is extracted from the pattern included in the measurement area located at
Setting the measurement area on the object;
Detecting a specific pattern that matches the first reference pattern or the second reference pattern from an image of the object in the measurement area, and detecting relative position information between the specific pattern and the measurement area. Position detection method. A range included in the measured region when the measured region is at the first position in the predetermined region, and a range included in the measured region when the measured region is at the second position. When a part overlaps, the 1st standard pattern is extracted from the range excluding the overlap range among the measurement area in the 1st position, and the 2nd standard pattern exists in the 2nd position The position detection method according to claim 70, wherein extraction is performed from a range excluding the overlapping range in the measurement target region. A range included in the measured region when the measured region is at the first position in the predetermined region and a range included in the measured region when the measured region is at the second position. The position detection method according to claim 70, wherein there is no overlapping range. .
The position detection method according to claim 70, wherein the first reference pattern and the second reference pattern are extracted based on design value information for forming a pattern on the object. As the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. The position detection method according to claim 70, wherein the second reference pattern including a plurality of reference patterns having unique signal characteristics is extracted from patterns included in the measurement target region positioned at the position. As the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern composed of a specific pattern arranged at a predetermined position with respect to the pattern having the unique signal feature and the pattern having the unique signal feature from the pattern included in the measurement area located at The position detection method according to claim 70, wherein: is extracted. A reference pattern extraction device for extracting a reference pattern having a unique signal feature from an object on which a pattern is formed,
In a predetermined area on the object in a wider range than the measurement area where a measurement area of a predetermined area can be arranged, the pattern is unique from the pattern included in the measurement area when the measurement area is positioned at the first position. A first reference pattern having a unique signal characteristic is extracted, and the measurement target region is located at the second position different from the first position in the predetermined region and is located at the first position. A unique pattern extracting device for extracting a second quasi-pattern having a unique signal feature from a pattern included in the measurement region located at the second position including at least a part of a pattern different from the region, A reference pattern extraction device. The unique pattern extraction device is configured as the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. 77. The reference pattern extraction device according to claim 76, wherein the second reference pattern composed of a plurality of reference patterns having unique signal characteristics is extracted from a pattern included in the measurement area located at a position. . The unique pattern extraction device is configured as the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern composed of a specific pattern arranged at a predetermined position with respect to the pattern having the unique signal feature and the pattern having the unique signal feature from the pattern included in the measurement area located at 77. The reference pattern extraction apparatus according to claim 76, wherein: A pattern matching device that arranges a measurement area having a predetermined area on an object on which a pattern is formed, and detects a specific pattern that matches a predetermined reference pattern from patterns included in the measurement area, In a pattern matching device that detects the specific pattern from a predetermined area wider than the area,
As the reference pattern, a first reference pattern having a unique signal feature is extracted from a pattern included in the measurement area located at a first position in the predetermined area, and the first position in the predetermined area is extracted. Included in the measured region that is located at the second position that is at a part of the measured region that is located at a second position different from the measured region that is different from the measured region that is located at the first position. A unique pattern extraction device that extracts a second reference pattern having a unique signal feature from
Setting means for setting the measurement area on the object;
A pattern matching apparatus comprising: a detecting unit that detects a pattern that matches the first reference pattern or the second reference pattern from the image of the object in the measurement target area. The unique pattern extraction device is configured as the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. 80. The pattern matching apparatus according to claim 79, wherein the second reference pattern including a plurality of reference patterns having unique signal characteristics is extracted from patterns included in the measurement region located at a position. The unique pattern extraction device is configured as the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern composed of a specific pattern arranged at a predetermined position with respect to the pattern having the unique signal feature and the pattern having the unique signal feature from the pattern included in the measurement area located at The pattern matching device according to claim 79, wherein the pattern matching device is extracted. A measurement area having a predetermined area is arranged on an object on which a pattern is formed, and a specific pattern matching a predetermined reference pattern is detected from the patterns included in the measurement area, and the object and the measurement area are A position detection device for detecting relative position information of
As the reference pattern, when the measurement area is located at the first position in a predetermined area wider than the measurement area, a unique signal is obtained from a pattern included in the measurement area located at the first position. A first reference pattern having a characteristic, and a region to be measured located at a second position different from the first position in the predetermined region, the region to be measured located at the first position; A unique pattern extraction device for extracting a second reference pattern having a unique signal feature from a pattern included in the measurement region located at the second position including at least a part of a different pattern;
Setting means for setting the measurement area on the object;
A detection device that detects a pattern that matches the first reference pattern or the second reference pattern from an image of the object in the measurement target region and detects relative position information of the object and the measurement target region. A position detection device. The unique pattern extraction device is configured as the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. 83. The position detection apparatus according to claim 82, wherein the second reference pattern including a plurality of reference patterns having unique signal characteristics is extracted from patterns included in the measurement target region positioned at the position. The unique pattern extraction device is configured as the reference pattern,
Extracting the first reference pattern having a unique signal characteristic from the pattern included in the measurement target region located at the first position in the predetermined region;
The second position that is at least a part of the measurement area that is located at a second position different from the first position in the predetermined area and that is different from the measurement area that is located at the first position. A second reference pattern composed of a specific pattern arranged at a predetermined position with respect to the pattern having the unique signal feature and the pattern having the unique signal feature from the pattern included in the measurement area located at The position detecting device according to claim 82, wherein the position detecting device is extracted.

Images