JP2005284046A - Method for detecting pattern displacement and exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for detecting pattern displacement by which the displacement between a transfer pattern and a substrate pattern at an arbitrary position corresponding to irregular elongation and contraction caused in the substrate can be detected without being affected by limitation of an exposure device in an alignment mechanism, and to provide the exposure device. <P>SOLUTION: A pattern for checking a photographing position displayed on a spatial light modulation element 1 is photographed by an photographing means, and an observable range 2 on the image of the spatial light modulation element is detected from the acquired image data. The moving distance of the substrate to be exposed is determined from the detection result of the observable range 2 and from design feature point data on a designed transfer image, the substrate 4 is moved by the determined moving distance and photographed by the photographing means. Detection of the displacement is carried out by comparing the substrate feature point data acquired by photographing the substrate 4 with the design feature point data obtained by moving the image into the observable range 2 on the spatial light modulating element 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pattern shift amount detection method and an exposure apparatus. For example, a lower layer pattern and an upper layer pattern when exposing transfer data with a spatial light modulator such as liquid crystal in a semiconductor integrated circuit manufacturing process or other substrate manufacturing process. The present invention relates to a pattern deviation amount detection method and an exposure apparatus characterized by a configuration for detecting the deviation amount of an arbitrary point.

  In recent years, the need for computer-related devices such as personal computers, consumer devices such as AV devices, mobile phones, and PDA communication devices has been diversified, and the importance has been increasing.

  Also, in the semiconductor manufacturing field and printed wiring board manufacturing field, the trend toward short lifecycles has become stronger along with diversification, and in order to succeed in business, not only miniaturization of electronic circuit patterns but also flexible response to product needs There is a growing need to respond to the diversification and shortening of the life cycle.

  In particular, in the field of printed wiring board manufacturing, not only miniaturization of patterns, but also the short development time and function changes for system on chip (SOC) to meet a wide variety of product needs. As a result, a system using a system in package (SIP) technology is being developed.

  Recently, the use of flexible printed circuit boards (FPCs) has been increasing in small IT-related devices such as mobile phones and small HDDs, and these devices have become smaller and lighter. This contributes to higher performance and functionality.

  Furthermore, it is predicted that the need to form electronic circuit patterns on various substrates such as glass, metal pieces, ceramics, organic materials, cloth, etc. will increase in the future in addition to printed circuit boards and flexible printed circuit boards. Is done.

  However, when electronic circuit patterns are formed on such various substrates and miniaturization and high-density mounting are performed, it is difficult to directly apply a semiconductor exposure technique using a mask intended for a silicon wafer. It is believed that there is.

  For example, pattern expansion and contraction occurs in the printed wiring board material depending on the process, and the expansion / contraction amount is about 250 to 500 ppm. This expansion / contraction amount varies not only from lot to lot, but may also reach about 200 ppm even within the same lot.

  In addition, depending on the design of the substrate as well as the process, the amount of expansion and contraction varies depending on the location within the same substrate, so the substrate pattern already formed on the substrate and the pattern to be transferred next are accurately overlaid. It becomes difficult.

  As a countermeasure against such substrate roughness, temperature, humidity, process history, etc., two methods are currently applied. The first method is called a mask correction method, and the amount of substrate expansion / contraction is reduced. This is a method of making a correction mask including the amount of expansion / contraction of the substrate by feeding back to the mask data, and the second method is a method of correcting the transfer pattern in real time by changing the projection magnification of the lens (for example, non-patent). References 1 and 2).

However, the first method has a problem that the actual expansion / contraction amount of the substrate varies from one substrate to another, and it is impossible to superimpose with high accuracy.
Further, the second method cannot be overlaid when the correctable magnification is exceeded and cannot cope with irregular expansion and contraction in any direction within a shot. .

  Also in the reticleless exposure method using liquid crystal, it is also proposed to measure an alignment mark by an alignment mechanism, calculate a distortion amount based on the measurement result, and correct design data based on the distortion amount (for example, Patent Document 1). However, it cannot cope with irregular strain deformation in the substrate.

  In order to solve such problems, it is necessary to detect the amount of deviation between the transfer pattern and the substrate pattern at an arbitrary position in order to perform high-precision alignment on the substrate that is irregularly expanded and contracted within the same substrate. is there.

Therefore, a mask manufacturing method has also been proposed in which the substrate is divided into a grid-like mesh, the amount of displacement due to distortion at each lattice point is measured, and the transfer pattern is corrected based on the measured amount of displacement (for example, , See Patent Document 2).
Japanese Patent Laid-Open No. 11-045851 Japanese Patent Laid-Open No. 09-015834 USHIO ELECTRIC homepage, http: // www. usio. co. jp / Ad dating quenching homepage, http: // www. adtec. com. indexj. htm

  However, in the method of dividing into a grid-like mesh, if the non-uniformity of expansion and contraction within the same substrate is large like an FPC substrate, a pattern alignment defect will occur unless a sufficiently fine mesh is set. However, there is a problem that the time for measurement and calculation is greatly increased and the throughput is greatly reduced.

  Accordingly, the present inventors divided the pattern into triangular meshes by the feature points such as contact holes in the pattern of the transfer pattern and the substrate pattern in the reticleless exposure method using a spatial light modulation element such as liquid crystal, and It has been proposed to deform the transfer pattern for each triangle according to non-uniform stretching deformation (see Japanese Patent Application No. 2002-351000).

  However, in an exposure apparatus using an ordinary photomask other than an electron beam and a laser direct drawing exposure apparatus or a reticleless exposure apparatus, the alignment mark is limited as a requirement from the exposure apparatus side to be arranged in a predetermined area. Therefore, in a normal exposure apparatus, there is a problem that it is difficult to detect the shift amount between the transfer pattern and the substrate pattern at an arbitrary position. Is the same.

  Accordingly, an object of the present invention is to detect a shift amount between a substrate pattern and a transfer pattern at an arbitrary position corresponding to irregular expansion / contraction generated on a substrate without being restricted by an exposure apparatus in an alignment mechanism.

FIG. 1 is a diagram illustrating the basic configuration of the present invention. Means for solving the problems in the present invention will be described with reference to FIG.
Refer to FIG. 1. (1) In order to achieve the above object, in the pattern displacement amount detection method, the present invention photographs a photographing position confirmation pattern displayed on the spatial light modulation element 1 serving as a photomask by photographing means, The observable range 2 on the spatial light modulation element image is detected from the acquired image data, the movement amount of the exposed substrate is determined from the detection result of the observable range 2 and the design feature point data on the design transfer image, and the exposure is performed. After the determined amount of movement of the substrate 4 is moved, the image is taken by the photographing means, and the corresponding substrate feature point data on the exposed substrate 4 acquired by photographing the exposed substrate 4 and the observable range 2 are displayed on the spatial light modulator. The shift amount detection processing is performed based on the comparison with the design feature point data to which the image is moved.

  In this way, by displaying the position of the design feature point 3 of the transfer pattern displayed on the spatial light modulation element 1 in the observable range 2, a contact hole or the like that cannot be photographed with a conventional exposure apparatus, etc. The design feature point 3 of the transfer pattern can be photographed, whereby the substrate feature point 5 arranged at an arbitrary position on the substrate 4 to be exposed and the design of the transfer pattern can be designed simply by moving the substrate 4 to be exposed. The amount of deviation of the feature point 3 can be detected.

  In addition, when only the locations where contact between the upper and lower sides such as contact holes is absolutely necessary is used as a feature point, the number of measurement points can be reduced compared to the measurement of the amount of displacement of the fine grid mesh, and It is possible to reliably connect the patterns.

  (2) In the present invention, in the above (1), when the exposed substrate 4 is moved by the movement amount determined from the detection result of the observable range 2 and the design feature point data on the design transfer image, When the substrate feature point 5 on the substrate 4 is outside the observable range 2, the exposed substrate 4 is further moved to the observable range 2, and the movement amount of the exposed substrate 4 is added to the shift amount. .

  As described above, even when the non-uniform expansion and contraction is large, by further moving the substrate to be exposed 4 and adding this movement amount to the shift amount, the shift amount can be detected by the alignment scope having a narrow visual field provided in the exposure apparatus. It becomes possible.

  (3) Further, in the above (1) or (2), the present invention provides the spatial light modulation element 1 at least for each distance that does not exceed the observable range 2 of the photographing means when detecting the observable range 2. One or more specific patterns are displayed.

  In this way, by displaying a plurality of specific patterns in the observable range 2, the observation coordinates of the imaging means can be easily specified.

  (4) Further, in the above (3), the present invention is characterized in that a character is included as the specific pattern.

  In this way, by using characters as the specific pattern, it is possible to easily specify the observation coordinates even when a human observes visually.

  (5) Further, the present invention is characterized in that, in the above (3) or (4), a scale in units of pixels of the spatial light modulator 1 is displayed together with a specific pattern.

  In this way, by displaying a scale in units of pixels on the spatial light modulator 1 together with the specific pattern, the observation coordinates can be specified more accurately.

  (6) In addition, the present invention provides a spatial light modulation element 1 serving as a photomask, a stage for holding the substrate 4 to be exposed, an actual pattern on the substrate 4 to be exposed placed on the stage, and the spatial light modulation element 1. In the exposure apparatus provided with at least a photographing device for photographing only a part of both of the transfer patterns displayed on the light source and a light source for supplying exposure light for exposing the substrate to be exposed 4, spatial light is obtained by the photographing device. A part of the image on the modulation element 1 is acquired as image data and stored in an observation position detecting means for detecting an observation position coordinate from the image data, an observation position coordinate, a design feature point coordinate on the design transfer image, and a design pattern storage device. An image generation means for outputting deviation amount detection data to the spatial light modulator 1 using the designed transfer image, and the substrate feature point 5 on the exposed substrate 4 is observed based on the design feature point coordinates Stage control means for transmitting a stage control signal for moving the stage to the active range 2 and deviation amount measurement processing means for detecting the deviation amount using the transfer image data and substrate image data acquired by the photographing apparatus are provided. It has an arithmetic and control unit.

  By using an exposure apparatus having such a configuration, it is possible to detect the amount of deviation between a pattern on an arbitrary substrate generated by non-uniform expansion and contraction and a design transfer pattern without requiring a specially configured photographing means. Is possible.

  (7) Further, the present invention is characterized in that, in the above (6), the shift amount measurement processing means uses stage position information in addition to the transfer image data and the substrate image data.

  As described above, by using the stage coordinate information in the deviation amount measurement processing apparatus, it is possible to detect the deviation amount even when the substrate feature point 5 is located outside the observable range 2.

  According to the present invention, the alignment mark arrangement range limitation limited by the effective image capturing area of the imaging apparatus is relaxed, and the feature point at an arbitrary position on the substrate can be used as an alignment mark, and it is predicted that it will be widely used in the future. It is possible to detect any non-uniform amount of distortion that occurs at individual positions over the entire surface of a flexible substrate that is susceptible to the effects of weakness and distortion, and enables accurate alignment corresponding to the non-uniform amount of distortion. It becomes.

  The present invention captures a position confirmation pattern displayed on a spatial light modulation element such as a liquid crystal with an alignment scope, detects an observable range on the spatial light modulation element image from the acquired image data, and displays an observable range detection result. Then, the board movement amount is determined from the feature point data on the design transfer image, and then the board is moved by the determined movement amount, then imaged by the alignment scope, and the feature point data on the board and the spatial light obtained by board imaging. The deviation amount is obtained by comparing with the feature point data on the design image moved to the observable range on the modulation element.

  In this case, if the feature point on the substrate is out of the observable range simply by moving the substrate by the amount of movement determined from the observation range detection result and the feature point data on the design transfer image, the substrate can be further observed. The amount of displacement is measured by moving to.

Here, with reference to FIG. 2 to FIG. 11, a pattern deviation amount detection method according to the first embodiment of the present invention will be described.
FIG. 2 is a system configuration diagram in the pattern shift amount detection method according to the first embodiment of the present invention, and supplies exposure light for sensitizing a photosensitive agent applied on an exposed substrate 14 such as a printed wiring board. A light source 11, a spatial light modulation element 12 comprising a transmissive liquid crystal display device for displaying a design transfer pattern, a substrate pattern on the substrate 14 to be exposed, and a projection image by the spatial light modulation element 12. An exposure apparatus 10 having a stage 15 for holding a mirror 16 for reflecting a pattern displayed on the spatial light modulation element 12, an arithmetic control apparatus 20; It comprises an input device 21 such as a keyboard and a mouse, a display device 22 such as a liquid crystal monitor or CRT, and a design pattern storage device 30.

  Here, the arithmetic and control unit 20 is a terminal that outputs an image signal to the spatial light modulation element 12, a terminal that takes in image data obtained from the photographing device 13, a terminal that outputs a stage control signal to be applied to the stage 15, and a design pattern storage device. This is an arithmetic and control unit controlled by a central control unit (CPU) having at least terminals for receiving design pattern data and feature point coordinates from 30. Specifically, for example, these are necessary for general-purpose personal computers or workstations. It can be configured by providing a simple terminal. The arithmetic control unit 20 is programmed in advance with the procedure of the pattern deviation amount detection method of the present invention described below, and executes necessary procedures.

  The design pattern storage device 30 may be an external storage device such as a hard disk drive installed exclusively for the exposure apparatus, but a plurality of data servers connected online on the network are shared and used. Also good.

  The TTL on-axis non-exposure wavelength alignment method (for example, see Non-Patent Document 1 described above) is used for photographing the substrate pattern and the transfer pattern displayed on the transmissive liquid crystal display by the photographing device 13.

In this case, as the photographing apparatus 13, an alignment scope with a narrow field of view used for alignment of alignment marks provided in a normal exposure apparatus is used. Usually, a pair of alignment scopes provided at the left and right centers are used. Use one of them.
Incidentally, the alignment scope is composed of a half mirror tilted with respect to the stage and a CCD image sensor that captures an image reflected from the half mirror.

See FIG. 3 FIG. 3 is a flowchart of the pattern deviation amount detection method according to the first embodiment of the present invention. Observable range detection step, then
B. Deviation detection image generation step, then
C. Spatial light modulator image capturing step, then
D. Exposure substrate image shooting process, finally,
E. The shift amount detection process based on C and D is sequentially performed, and each process will be described in detail below.

4 is an explanatory diagram showing an example of the positional relationship between the spatial light modulation element 12 and the observable range 41 of the photographing apparatus 13 in the observable range detecting process A.
At this time, it can be seen that the observable range 41 of the photographing apparatus 13 is only a part of the effective display area 40 of the spatial light modulator 12.

Moreover, the imaging device 13 has a pair of observable ranges 41 at the center of the left and right of the effective display area 40 of the spatial light modulator 12 as described above.
Needless to say, the substrate pattern already formed on the exposed substrate 14 can be observed at an arbitrary position by moving the stage 15.

  As described above, a transmissive liquid crystal display device is used as the spatial light modulator 12. Here, for example, one pixel is 23 μm, the aperture ratio is 25%, the number of pixels is 1600 × 1200 pixels, and the effective area is 36.889 mm. × 27.685 mm.

  Further, a CCD area sensor of 640 × 480 pixels is used for the image pickup device of the photographing device 13, and the pixel size on the photographed image is 1 μm / 1 pixel at a high magnification of 10 times, and 3 at a low magnification of 3 times. .3 μm / 1 pixel.

See Figure 5. Figure 5 is an explanatory view of a relationship between the feature points 42 ₁ and observation range 41 of the design transfer pattern to be detected is displayed on the spatial light modulator 12 in the displacement detection image generation step of the B Yes, it can be seen that the feature point 42 ₁ to be detected does not exist within the observable range 41 of the imaging device 13.

Therefore, in order to detect at which coordinates on the spatial light modulation element 12 the observation field of view of the current photographing apparatus 13 is first detected in the step A of detecting the observable range of A, for example, an image containing a scale serving as a mark. Are displayed on the spatial light modulation element 12 as a shooting position confirmation pattern, and the displayed shooting position confirmation pattern is reflected by the mirror 16 provided on the stage 15 and then shot by the shooting device 13.
Here, the cross mark 43 is used as an example, and the coordinates of the spatial light modulator 12 in the field of view of the current photographing apparatus 13 are determined.

See FIG. 6. FIG. 6 is an explanatory diagram of an example of an image used for detecting which coordinate of the spatial light modulation element 12 corresponds to the observable range 41 of the photographing apparatus 13.
Here, as an example, an image including a cross mark 43 and a scale 45 is used in the peripheral portion, and the scale 45 uses each pattern of the scale and the character representing the position in units of pixels of the spatial light modulator 12. doing.

FIG. 7 is an explanatory diagram of an observation image 44 in which the pattern shown in FIG. 6 is displayed on the spatial light modulator 12 and actually observed by the photographing apparatus 13.
In this way, if a pattern in which coordinates can be specified in advance is arranged for each distance determined by the size of the observable range 41 and is displayed on the spatial light modulation element 12, the observable range can be easily observed even by human eyes. It is possible to determine 41 coordinates.

The coordinates are determined by, for example, the coordinates of the cross mark 43 on the observation image 44, that is, the position coordinates (X _{IPD− design} , Y _IPD-design ) and the origin coordinates (X _LMD-Origin , Y _LMD-Origin ) on the spatial light modulator 12 are determined by the following equations (1) and (2).
X _LMD-Origin = X _LMD-design -α x (X _IPD-design ) (1)
Y _LMD-Origin = Y _LMD-design -α x (Y _IPD-design ) (2)
Here, (X _LMD-design , Y _LMD-design ) are the coordinates of the cross mark 43 on the spatial light modulator 12, and α is the coordinates on the spatial light modulator 12 from the coordinates on the captured image of the imaging device 13. The conversion magnification of length to.

Coordinates (X _LMD, Y _LMD) on the spatial light modulator 12 of the feature point 42 ₁ in the above design transfer pattern so is known, the coordinates after _{(X LMD-Origin, Y LMD} -Origin) each feature point it is possible to detect the feature point ₄₂₁ which is displayed on the spatial light modulator 12 other than the observation range 41 by using the imaging device 13 by causing moved.

The image movement amount for moving the feature point _{42 1 (ΔX LMD, ΔY LMD} ) is expressed by the following equation (3) and (4).
ΔX = X _LMD-Origin -X _LMD (3)
ΔY = Y _LMD-Origin -Y _LMD (4)
In this case, the image movement amount (ΔX _LMD , ΔY _LMD ) is expressed in units of pixels.
By performing the above operation, the above-described deviation detection image generation step B is completed.

FIG. 8 is an explanatory diagram of the C spatial light modulation element image photographing step, and the spatial light modulation element 12 and the observable range 41 after the image is moved using the equations (3) and (4). and shows the relationship of the captured image, the movement of the image, it is possible to observe the feature point ₄₂₁ is displayed on the spatial light modulator 12 in the region other than the observation range 41.
At this time, the coordinates of the image which had been obtained in the feature point 42 _{and second} imaging unit 13 of the design transferred pattern after the movement and _{(X IPD-mask, Y IPD} -mask).

Next, the exposure substrate image photographing process of D will be described. When the feature point 17 formed on the exposure substrate 14 is not displaced at all from the feature point 42 ₁ on the design transfer pattern, spatial light modulation is performed. by looking at the imaging apparatus 13 moves the stage only the image moving amount of the element 12, a feature point 42 ₂ after movement design transfer pattern displayed on the spatial light modulator 12 and the feature point 17 on the exposed substrate 14 Should match.

The amount of movement (ΔX _stage , ΔY _stage ) of the stage 15 at this time is expressed by the following equations (5) and (6).
ΔX _stage = β × (ΔX _LMD ) (5)
ΔY _stage = β × (ΔY _LMD ) (6)
Β is the conversion magnification of the length from the coordinates on the spatial light modulator 12 to the coordinates on the stage 15.

That is, the moving amount of the stage 15 corresponding to the movement of the spatial light modulator 12 to display the feature point _{42 2 (ΔX stage, ΔY stage} ) , the number of pixels moved in the spatial light modulator 12 on the (ΔX _LMD, ΔY _LMD ) Is multiplied by β determined by the minimum grid size of the grid constituting the spatial light modulator 12 and the exposure magnification, to obtain the amount of movement in real space.
At this time, the coordinates in the image acquired by the imaging device 13 of the feature point 17 on the exposed substrate 14 after the stage 15 is moved are defined as (X _IPD-sub , Y _IPD-sub ).

Next, the shift amount detection step based on C and D of E will be described.
FIG. 9 is an explanatory diagram of detection of the shift amount when the feature point 17 on the exposed substrate 14 is within the observable range 41 due to the movement of the stage 15, and the design transfer on the image acquired by the photographing apparatus 13. feature point 42 _second coordinate on the pattern _{(X IPD-mask, Y IPD} -mask) and, similarly imaging device 13 by the acquired coordinates of the feature point 17 on the exposed substrate 15 on the image (X _IPD-sub, Y _IPD-sub ) (ΔX _IPD = X _{IPD -sub} -X _{IPD -mask} , ΔY _IPD = Y _{IPD -sub} -Y _{IPD -mask} ).

Next, by multiplying the obtained difference (ΔX _IPD , ΔY _IPD ) by α and β, a deviation amount in the real space can be obtained, and this deviation amount is expressed by the following equations (7) and (8). .
ΔX = α × β × ΔX _IPD (7)
ΔY = α × β × ΔY _IPD (8)

  In this case, since the value of α depends on the imaging magnification, when the length is expressed in units of pixels of the image sensor, for example, at a high magnification of 10 times, it becomes 1 μm / 1 pixel, and at a low magnification of 3 times. It becomes 3.3 μm / 1 pixel.

Refer to FIG. 10. FIG. 10 is an explanatory diagram of the shift amount detection when the feature point 17 on the exposed substrate 14 does not enter the observable range 41 due to the movement of the stage 15.
The coordinates of the stage 15 at this time are obtained and set as stage coordinates (X _S-before , Y _S-before ).

Figure 11 Referring to FIG. 11, the observation range 41 to fall so designed transfer pattern feature points 42 ₂ relationship of the feature point 17 on the exposed substrate 14 of the case of moving the feature point 17 on the exposed substrate 14 And a photographed image at that time.
Note that such movement is performed by trial and error, and the coordinates of the stage 15 at this time are obtained and set as stage coordinates (X _S-after , Y _S-after ).

In this state, exactly as in the case of FIG. 9, the coordinates (X _IPD-sub , Y _IPD-sub ) on the captured image are acquired for the feature point 17 on the exposed substrate 14, and the two stages already acquired are acquired. above coordinates and design transfer pattern on the on the photographed image of the feature point 42 _second coordinate _{(X IPD-mask, Y IPD} -mask) than by calculating the shift amount of the feature point on the feature points and the board design pattern The step of detecting the deviation amount of E becomes possible.

The deviation amounts (ΔX, ΔY) in this case are expressed by the following equations (9) and (10).
ΔX = (X _S-before −X _S-after ) + α × β × (X _IPD-sub −X _IPD-mask )
= (X _S-before -X _S-after ) + α × β × ΔX _IPD (9)
ΔY = (Y _S-before −Y _S-after ) + α × β × (Y _IPD-sub −Y _IPD-mask )
= (Y _S-before −Y _S-after ) + α × β × ΔY _IPD (10)

The detection of such deviation amount is performed for each feature point ₄₂₁ on the design transfer pattern, based on the obtained shift amount, correcting the design transferred pattern by the pattern correction method described in Japanese Patent Application No. 2002-351000 mentioned above Then, the corrected result is displayed on the spatial light modulation element 12 and the exposed substrate 14 is exposed.

As described above, in the present invention, the feature point 42 ₁ on the design transfer pattern is moved on the spatial modulation element 12 so as to be in the observable range 41 of the photographing apparatus 13 to be the feature point 42 ₂ , Since the stage 15 is moved on the spatial modulation element 12 by an amount corresponding to the amount of movement of the feature point, it is possible to detect the amount of pattern deviation using an alignment scope with a narrow field of view provided in a normal exposure apparatus. .

  Further, in the present invention, since the deviation amount is detected only for the feature points such as contact holes to which the actual upper and lower patterns need to be connected, the defect defect of the device or the mounting board due to the pattern deviation may not occur. In addition, since the detection points are not increased unnecessarily as in the case of a grid mesh, the throughput is improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations and conditions described in the embodiments, and various modifications can be made.
For example, in the description of the above embodiment, a transmissive liquid crystal panel is used as the spatial light modulation element. However, a reflective mirror display element (DMD: digital micromirror or the like) in which a large number of minute mirrors are arranged in a two-dimensional array. A so-called mirror device) may be used.

  For example, a transmissive liquid crystal panel used in an exposure apparatus has a liquid crystal panel of about 800,000 (1024 × 768) pixels, and each pixel has a size of about 20 μm. By reducing the size to 1/5 on the substrate by the reduction projection optical system, the pattern corresponding to one pixel becomes a rectangle having a side of 4 μm. In DMD, about 1 million (about 500 × about (2000) micromirrors are used, and each micromirror has a size of about 16 μm, and this is reduced and projected to a size of 1/160 on the substrate by a reduction projection optical system. A pattern corresponding to one micromirror is a square having one side of 0.1 μm.

  Furthermore, the spatial light modulation element is not limited to the transmissive liquid crystal panel or DMD, and an LED array, a laser diode array, or a self-luminous element such as a CRT may be used.

  In the description of the above embodiment, the FPC board is assumed. However, the present invention is not limited to the FPC board, but can be applied to a normal printed wiring board. The present invention is also applied to a manufacturing process or a semiconductor substrate manufacturing process.

  For example, when reduced projection exposure is performed using a DMD as a spatial light modulation element as described above, a pattern having a width of 0.1 μm can be drawn, but the distortion of the wafer increases as the diameter of the silicon wafer increases. This is effective when

  Alternatively, the number of multilayer wiring layers increases with higher integration, but as the number of multilayer wiring layers increases, the unevenness of the outermost surface of the substrate increases and the distortion of the surface pattern also increases. By applying this, it is possible to suppress the occurrence of defective defects due to pattern deviation.

  As a practical example of the present invention, a pattern shift amount detection process in an exposure apparatus for a printed wiring board is typical. However, the resolution of the spatial light modulator is further increased, or the reduction ratio is increased by a projection lens. By increasing it, it can be used as an exposure apparatus for manufacturing a liquid crystal panel or an exposure apparatus for manufacturing a semiconductor integrated circuit device.

It is a principle block diagram of this invention. It is a system block diagram in the pattern deviation amount detection method of Example 1 of this invention. It is a flowchart of the pattern deviation | shift amount detection method of Example 1 of this invention. It is explanatory drawing of the positional relationship of a spatial light modulation element and an observable range. It is explanatory drawing of the relationship between the feature point on a design transcription | transfer pattern, and an observable range. It is explanatory drawing of an example of the image used when detecting the observable range. It is explanatory drawing of an example of the image displayed on the spatial light modulation element image | photographed with the imaging device. It is explanatory drawing of the relationship between the spatial light modulation element after an image movement, an observable range, and a picked-up image. It is explanatory drawing of deviation | shift amount detection when the feature point on a to-be-exposed board | substrate enters in the observable range. It is explanatory drawing of the deviation | shift amount detection when the feature point on a to-be-exposed board | substrate does not enter into an observable range. It is explanatory drawing of the relationship between the spatial light modulation element after a board | substrate movement, an observable range, and a picked-up image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spatial light modulation element 2 Observable range 3 Design feature point 4 Substrate to be exposed 5 Substrate feature point 6 Image after movement 7 Substrate after movement 10 Exposure apparatus 11 Light source 12 Spatial light modulation element 13 Imaging apparatus 14 Substrate to be exposed 15 stage 16 mirror 17 feature point 20 arithmetic control device 21 input device 22 display device 30 design pattern storage device 40 effective display area 41 observable range 42 ₁ feature point 42 ₂ feature point 43 cross mark 44 observation image 45 scale

Claims (7)

The photographing position confirmation pattern displayed on the spatial light modulation element to be a photomask is photographed by photographing means, the observable range detection on the spatial light modulation element image is performed from the acquired image data, and the observable range detection result Then, the movement amount of the substrate to be exposed is determined from the design feature point data on the design transfer image, the movement amount of the substrate to be exposed is moved, the image is taken by the photographing means, and the object to be obtained obtained by photographing the substrate to be exposed is obtained. Pattern deviation amount detection characterized in that deviation amount detection processing is performed by comparing corresponding substrate feature point data on an exposure substrate and design feature point data obtained by moving an image on the spatial modulation element to the observable range. Method. The substrate feature point on the exposed substrate is outside the observable range when the exposed substrate is moved by the amount of movement determined from the observation range detection result and the design feature point data on the design transfer image 2. The pattern displacement amount detection method according to claim 1, wherein the substrate to be exposed is further moved to the observable range, and the amount of movement of the substrate to be exposed is added to the displacement amount. The at least one specific pattern is displayed on the spatial light modulation element for each distance that does not exceed the observable range of the photographing unit when the observable range is detected. 3. A method for detecting a pattern deviation amount according to 2. The pattern deviation amount detection method according to claim 3, wherein a character is included as the specific pattern. 5. The pattern deviation amount detection method according to claim 3, wherein a scale in units of pixels of the spatial light modulation element is displayed together with the specific pattern. A part of both a spatial light modulator serving as a photomask, a stage for holding the substrate to be exposed, an actual pattern on the substrate to be exposed placed on the stage, and a transfer pattern displayed on the spatial light modulator A part of an image on the spatial light modulation element by the photographing apparatus in an exposure apparatus comprising at least a photographing device for photographing only a light source and a light source for supplying exposure light for exposing the substrate to be exposed Observation position detecting means for detecting observation position coordinates from the image data, using the observation position coordinates, design feature point coordinates on the design transfer image, and a design transfer image stored in a design pattern storage device Image generating means for outputting deviation amount detection data to the spatial light modulation element, and the feature points of the substrate to be exposed based on the design feature point coordinates. Stage control means for transmitting a stage control signal for moving the stage within a possible range, and deviation amount measurement processing means for detecting a deviation amount using transfer image data and substrate image data acquired by the photographing apparatus. An exposure apparatus having an arithmetic and control unit. 7. The exposure apparatus according to claim 6, wherein the shift amount measurement processing means uses stage position information in addition to the transfer image data and the substrate image data.

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