JP6423064B2 - Substrate processing system - Google Patents

Description

  The present invention relates to a substrate processing system for liquid processing a substrate.

  For example, in a photolithography process in a semiconductor device manufacturing process, a resist coating process is performed by applying a resist solution on a semiconductor wafer (hereinafter referred to as “wafer”) as a substrate, and the resist film is exposed to a predetermined pattern. A series of processes such as an exposure process for developing and a development process for developing the exposed resist film are sequentially performed to form a predetermined resist pattern on the wafer. These series of processes are performed by a coating and developing system that is a substrate processing system equipped with various processing apparatuses for processing wafers, a transport mechanism for transporting wafers, and the like.

  Such a coating and developing processing system is provided with an inspection apparatus that performs so-called macro defect inspection on a wafer (Patent Document 1). In the macro defect inspection, a wafer that has been subjected to a predetermined process by the coating and developing processing system is imaged by an imaging device such as a CCD line sensor under a predetermined illumination, and a captured image of the wafer is acquired. And the presence or absence of a defect is determined by comparing the acquired captured image with the image of the wafer used as a reference.

JP 2012-104593 A

  By the way, in the above-described macro defect inspection, inspection recipes such as a reference wafer image, illumination illuminance, and imaging speed are set. However, since various films are formed on the wafer surface in the photolithography process, the surface state such as reflectivity of the wafer surface varies from process to process. Therefore, there is a problem that the accuracy of the macro defect inspection varies depending on the surface state of the wafer.

  The present invention has been made in view of this point, and an object of the present invention is to properly inspect a substrate in a substrate processing system.

  In order to achieve the above object, the present invention provides a substrate processing system including a plurality of processing apparatuses that perform predetermined processing on a substrate, and images a surface of the substrate before being processed by the processing apparatus. A first imaging device that obtains one substrate image, a second imaging device that obtains a second substrate image by imaging the surface of the substrate processed by the processing device, and the first substrate An image storage unit for storing an image, extracting pixel values of the first substrate image stored in the image storage unit, and calculating an average value of pixel values of the entire surface of the first substrate image as a feature amount of the substrate; And classifying the first board image into a plurality of groups based on the feature amount, a first board image classified into each group, and a second board image corresponding to the first board image To generate a reference image, and based on the generated reference image, It is characterized by having a control unit for generating a.

  According to the present invention, the pixel value of the first substrate image before the substrate processing stored in the control unit is extracted, and the first substrate image is based on the average value of the pixel values of the entire surface of the first substrate image. Are classified into a plurality of groups, a first substrate image classified into each group and a second substrate image corresponding to the first substrate image are combined to generate a reference image, and the generated reference Since the inspection recipe is generated based on the image, it is possible to appropriately determine the presence or absence of a defect in the substrate image of the processed substrate based on the inspection recipe. Therefore, it is possible to always perform an optimal inspection regardless of the surface state of the substrate, and to suppress variations in accuracy of the macro defect inspection.

  The control unit may further include a storage unit that stores the inspection recipe.

  The control unit includes a difference image generation unit that generates a difference image between the first board image and the second board image corresponding to the first board image, and a plurality of groups classified into the groups. A reference image generation unit configured to combine a plurality of the difference images corresponding to the first substrate image to generate a reference image serving as a reference for defect inspection, and the reference image generated by the reference image generation unit An inspection recipe may be generated based on the above.

  According to the present invention, it is possible to properly inspect a substrate in a substrate processing system.

It is a top view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a front view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a rear view which shows the outline of a structure of the substrate processing system concerning this Embodiment. It is a cross-sectional view which shows the outline of a structure of a test | inspection apparatus. It is a longitudinal cross-sectional view which shows the outline of a structure of an inspection apparatus. It is a block diagram which shows the outline of a structure of a control apparatus typically. It is explanatory drawing which shows the relationship between a pixel value and an inspection recipe. It is a flowchart which shows the outline of the process of a defect inspection of a wafer. It is explanatory drawing which shows the relationship between a pixel value and an inspection recipe.

  Embodiments of the present invention will be described below. FIG. 1 is a plan view showing an outline of a configuration of a substrate processing system 1 according to the present embodiment. 2 and 3 are a front view and a rear view, respectively, schematically showing the outline of the internal configuration of the substrate processing system 1. In the present embodiment, the case where the substrate processing system 1 is a coating and developing processing system that performs coating and developing processing on the wafer W will be described as an example. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 1, the substrate processing system 1 includes a cassette station 10 in which a cassette C containing a plurality of wafers W is loaded and unloaded, and a processing station 11 having a plurality of various processing apparatuses for performing predetermined processing on the wafers W. And an interface station 13 that transfers the wafer W to and from the exposure apparatus 12 adjacent to the processing station 11 is integrally connected.

  The cassette station 10 is provided with a cassette mounting table 20. The cassette mounting table 20 is provided with a plurality of cassette mounting plates 21 on which the cassette C is mounted when the cassette C is carried into and out of the substrate processing system 1.

  As shown in FIG. 1, the cassette station 10 is provided with a wafer transfer device 23 that is movable on a transfer path 22 that extends in the X direction. The wafer transfer device 23 is also movable in the vertical direction and the vertical axis direction (θ direction), and includes a cassette C on each cassette mounting plate 21 and a delivery device for a third block G3 of the processing station 11 described later. The wafer W can be transferred between the two.

  The processing station 11 is provided with a plurality of, for example, four blocks G1, G2, G3, and G4 having various devices. For example, the first block G1 is provided on the front side of the processing station 11 (X direction negative direction side in FIG. 1), and the second block is provided on the back side of the processing station 11 (X direction positive direction side in FIG. 1). Block G2 is provided. A third block G3 is provided on the cassette station 10 side (Y direction negative direction side in FIG. 1) of the processing station 11, and the interface station 13 side (Y direction positive direction side in FIG. 1) of the processing station 11 is provided. Is provided with a fourth block G4.

  For example, in the first block G1, as shown in FIG. 2, a plurality of liquid processing apparatuses, for example, a development processing apparatus 30 that develops the wafer W, an antireflection film (hereinafter referred to as “lower antireflection") A lower antireflection film forming device 31 for forming a film), a resist coating device 32 for applying a resist solution to the wafer W to form a resist film, and an antireflection film (hereinafter referred to as “upper reflection” on the resist film of the wafer W). An upper antireflection film forming device 33 for forming an “antireflection film” is arranged in this order from the bottom.

  For example, three development processing devices 30, a lower antireflection film forming device 31, a resist coating device 32, and an upper antireflection film forming device 33 are arranged in a horizontal direction. The number and arrangement of the development processing device 30, the lower antireflection film forming device 31, the resist coating device 32, and the upper antireflection film forming device 33 can be arbitrarily selected.

  In the development processing device 30, the lower antireflection film forming device 31, the resist coating device 32, and the upper antireflection film forming device 33, for example, spin coating for applying a predetermined coating solution onto the wafer W is performed. In spin coating, for example, a coating liquid is discharged onto the wafer W from a coating nozzle, and the wafer W is rotated to diffuse the coating liquid to the surface of the wafer W.

  For example, in the second block G2, as shown in FIG. 3, a heat treatment apparatus 40 for performing heat treatment such as heating and cooling of the wafer W, an adhesion apparatus 41 for improving the fixability between the resist solution and the wafer W, and the wafer W A peripheral exposure device 42 for exposing the outer peripheral portion is provided side by side in the vertical direction and the horizontal direction. The number and arrangement of the heat treatment apparatus 40, the adhesion apparatus 41, and the peripheral exposure apparatus 42 can be arbitrarily selected.

  For example, the third block G3 is processed by the inspection apparatus 50 for inspecting the wafer W before being processed by the processing station 11, the plurality of transfer apparatuses 51, 52, 53, 54, 55, and the processing station 11. An inspection device 56 for inspecting the subsequent wafer W is provided in order from the bottom. The fourth block G4 is provided with a plurality of delivery devices 60, 61, 62 in order from the bottom. The configuration of the inspection devices 50 and 56 will be described later.

  As shown in FIG. 1, a wafer transfer region D is formed in a region surrounded by the first block G1 to the fourth block G4. In the wafer transfer region D, for example, a plurality of wafer transfer devices 70 having transfer arms that are movable in the Y direction, the X direction, the θ direction, and the vertical direction are arranged. The wafer transfer device 70 moves in the wafer transfer area D and transfers the wafer W to a predetermined device in the surrounding first block G1, second block G2, third block G3, and fourth block G4. it can.

  Further, in the wafer transfer region D, a shuttle transfer device 80 that transfers the wafer W linearly between the third block G3 and the fourth block G4 is provided.

  The shuttle conveyance device 80 is linearly movable in the Y direction of FIG. 3, for example. The shuttle transfer device 80 moves in the Y direction while supporting the wafer W, and can transfer the wafer W between the transfer device 52 of the third block G3 and the transfer device 62 of the fourth block G4.

  As shown in FIG. 1, a wafer transfer device 90 is provided next to the third block G3 on the positive side in the X direction. The wafer transfer device 90 has a transfer arm that is movable in the X direction, the θ direction, and the vertical direction, for example. The wafer transfer device 90 moves up and down while supporting the wafer W, and can transfer the wafer W to each delivery device in the third block G3.

  The interface station 13 is provided with a wafer transfer device 100 and a delivery device 101. The wafer transfer apparatus 100 has a transfer arm that is movable in the Y direction, the θ direction, and the vertical direction, for example. The wafer transfer apparatus 100 can transfer the wafer W between each transfer apparatus, the transfer apparatus 101, and the exposure apparatus 12 in the fourth block G4, for example, by supporting the wafer W on a transfer arm.

  Next, the configuration of the above-described inspection apparatus 50 will be described. As shown in FIG. 4, the inspection device 50 includes a casing 150. A wafer chuck 151 for holding the wafer W is provided in the casing 150 as shown in FIG. A guide rail 152 extending from one end side (X direction negative direction side in FIG. 4) to the other end side (X direction positive direction side in FIG. 4) is provided on the bottom surface of the casing 150. . On the guide rail 152, a drive unit 153 that rotates the wafer chuck 151 and is movable along the guide rail 152 is provided.

  An imaging unit 160 as a first imaging device is provided on the side surface on the other end side in the casing 150 (X direction positive direction side in FIG. 4). As the imaging unit 160, for example, a wide-angle CCD camera is used. Near the upper center of the casing 150, a half mirror 161 is provided. The half mirror 161 is provided at a position facing the imaging unit 160 in a state where the mirror surface is inclined 45 degrees upward from the state in which the mirror surface is directed vertically downward toward the imaging unit 160. An illumination device 162 is provided above the half mirror 161. The half mirror 161 and the illumination device 162 are fixed to the upper surface inside the casing 150. Illumination from the illumination device 162 passes through the half mirror 161 and is illuminated downward. Therefore, the light reflected by the object below the illumination device 162 is further reflected by the half mirror 161 and taken into the imaging unit 160. That is, the imaging unit 160 can capture an image of an object in an irradiation area by the illumination device 162. Then, an image of the wafer W (first substrate image) captured by the imaging unit 160 of the inspection apparatus 50 is input to the control apparatus 200 described later.

  Since the inspection device 56 has the same configuration as the inspection device 50, the description of the inspection device 56 is omitted. The imaging unit 160 of the inspection apparatus 56 functions as the second imaging apparatus of the present invention, and the image of the wafer W (second substrate image) captured by the imaging unit 160 of the inspection apparatus 56 is similarly controlled. Input to the device 200.

  The above substrate processing system 1 is provided with a control device 200 as shown in FIG. The control device 200 is configured by a computer including a CPU, a memory, and the like, for example, and has a program storage unit (not shown). The program storage unit stores a program for controlling the inspection of the wafer W performed based on the substrate image captured by the inspection apparatuses 50 and 56. In addition, the program storage unit controls the operation of drive systems such as the above-described various processing apparatuses and transfer apparatuses to perform predetermined operations of the substrate processing system 1, that is, application and development of a resist solution on the wafer W. Also stored are programs for realizing heat treatment, wafer W delivery, control of each unit, and the like. The program is recorded on a computer-readable storage medium H such as a computer-readable hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical desk (MO), or a memory card. May have been installed in the control device 200 from the storage medium H.

  Further, as illustrated in FIG. 6, the control device 200 includes a feature amount extraction unit 210 that extracts a predetermined feature amount from the first board image captured by the imaging unit 160 of the inspection device 50, and a feature amount within a predetermined range. The inspection recipe corresponding to the feature amount extracted by the feature amount extraction unit 210 is selected from the storage unit 211 in which a plurality of inspection recipes set corresponding to the storage unit 211 are stored and the plurality of inspection recipes stored in the storage unit 211 And a defect determination unit 213 that determines the presence / absence of a defect based on the selected inspection recipe and the second substrate image imaged by the imaging unit 160 of the inspection device 56. . Further, the control device 200 includes the first substrate image captured by the imaging unit 160, the image storage unit 214 that stores the first substrate image, and the first substrate image stored in the image storage unit 214. Based on the feature quantity extracted by the quantity extraction unit 210, an image classification unit 215 for classifying into a plurality of groups, and a second corresponding to the plurality of first substrate images classified into each group by the image classification unit 215. A reference image generation unit 216 that combines the substrate images to generate a reference image, and an inspection recipe generation unit 217 that generates an inspection recipe based on the reference image generated by the reference image generation unit 216 and stores the inspection recipe in the storage unit 211. And are further provided.

  In the present embodiment, the feature amount extracted by the feature amount extraction unit 210 is, for example, a pixel value of a board image. Then, the feature quantity extraction unit 210 calculates an average value, for example, for the pixel values of the entire surface of the board image, and obtains the average value as the feature quantity of the board image. In the present embodiment, the case where the substrate image is an 8-bit image having, for example, 256 gradations (0 to 255) will be described as an example.

  For example, as shown in FIG. 7, for example, three types of inspection recipes 230, 231, and 232 set corresponding to pixel values in different ranges are stored in the storage unit 211. The inspection recipe 230 is used when, for example, the feature amount (average pixel value) of the first board image is in the range of “10 to 70”, and the inspection recipes 231 and 232 are respectively featured. It is used when the amount is “90-140”, “200-240”. Each inspection recipe 230, 231 and 232 includes, for example, imaging conditions when imaging is performed by each imaging unit 160, a reference image serving as a reference for defect inspection, and the like. Note that the number of inspection recipes stored in the storage unit 211 and the range covered by the inspection recipe can be arbitrarily set, and are not limited to the contents of the present embodiment.

  In the recipe selection unit 212, an inspection recipe corresponding to the feature amount extracted by the feature amount extraction unit 210 is selected from the storage unit 211. For example, when the feature amount of the first substrate image acquired by imaging the wafer W of an arbitrary lot with the inspection apparatus 50 is “60”, the recipe selection unit 212 stores the feature amount “10 to 10” from the storage unit 211. The inspection recipe 230 corresponding to the board image “70” is selected.

  The defect determination unit 213 determines the presence / absence of a defect based on the inspection recipe 230 and the second substrate image. Specifically, when the wafer W whose feature value of the first substrate image is “60” finishes the predetermined processing at the processing station 11, the image is picked up by the imaging unit 160 of the inspection device 56 and is then taken into the second substrate image. Is acquired. Then, the defect determination unit 213 determines the presence / absence of a defect in the second substrate image of the same wafer W by the inspection recipe 230 selected based on the feature value “60” of the first substrate image. The functions of the other image storage unit 214, image classification unit 215, reference image generation unit 216, and inspection recipe generation unit 217 will be described later.

  Next, a wafer W processing method and a wafer W inspection method performed using the substrate processing system 1 configured as described above will be described. FIG. 8 is a flowchart showing an example of main steps of the wafer W inspection method. The inspection method will be described with reference to FIG.

  First, a cassette C storing a plurality of wafers W of the same lot is carried into the cassette station 10 of the substrate processing system 1, and each wafer W in the cassette C is sequentially inspected by the wafer transfer device 23 in the third block G3. 50, the first substrate image is acquired (step S1 in FIG. 8). Next, the feature quantity extraction unit 210 extracts feature quantities from the first board image (step S2 in FIG. 8). If an inspection recipe corresponding to the feature amount of the first board image exists in the storage unit 211, a predetermined inspection recipe is selected by the recipe selection unit 212 (steps S3 and S4 in FIG. 8). Specifically, for example, when the average value of the pixel values as the feature amount is “60”, the recipe selection unit 212 selects the inspection recipe 230 corresponding to the feature amount “60” from the storage unit 211. . For example, when the feature amount is “150” and there is no corresponding inspection recipe in the storage unit 211 (NO in step S3 in FIG. 8), the first board image whose feature amount is “150” is The image is stored in the image storage unit 214 (step S5 in FIG. 8), and a predetermined inspection recipe is selected (step S4 in FIG. 8). Processing after the first substrate image is stored in the image storage unit 214 will be described later. Here, the predetermined inspection recipe may be any inspection recipe among a plurality of inspection recipes stored in the storage unit 211, for example, in this embodiment, the inspection recipe 231 is predetermined. A description will be given assuming that this is an inspection recipe. That is, when the feature amount of the first board image is “150”, there is no corresponding inspection recipe in the storage unit 211, and thus a predetermined inspection recipe 231 is selected.

  Next, the wafer W is transferred to the heat treatment apparatus 40 of the second block G2 and subjected to temperature adjustment processing. Thereafter, the wafer W is transferred to, for example, the lower antireflection film forming device 31 of the first block G1 by the wafer transfer device 70, and a lower antireflection film is formed on the wafer W. Thereafter, the wafer W is transported to the heat treatment apparatus 40 of the second block G2, subjected to heat treatment, and the temperature is adjusted.

  Next, the wafer W is transferred to the adhesion apparatus 41 and subjected to an adhesion process. Thereafter, the wafer W is transferred to the resist coating device 32 of the first block G1, and a resist film is formed on the wafer W.

  When the resist film is formed on the wafer W, the wafer W is then transferred to the upper antireflection film forming apparatus 33 of the first block G1, and an upper antireflection film is formed on the wafer W. Thereafter, the wafer W is transferred to the heat treatment apparatus 40 of the second block G2, and heat treatment is performed. Thereafter, the wafer W is transferred to the peripheral exposure device 42 and subjected to peripheral exposure processing.

  Next, the wafer W is transferred to the transfer device 52 by the wafer transfer device 100, and transferred to the transfer device 62 of the fourth block G4 by the shuttle transfer device 80. Thereafter, the wafer W is transferred to the exposure device 12 by the wafer transfer device 110 of the interface station 13 and subjected to exposure processing in a predetermined pattern.

  Next, the wafer W is transferred to the heat treatment apparatus 40 by the wafer transfer apparatus 70 and subjected to post-exposure baking. Thereby, the deprotection reaction is caused by the acid generated in the exposed portion of the resist film. Thereafter, the wafer W is transferred to the development processing apparatus 30 by the wafer transfer apparatus 70 and subjected to development processing.

  After the development process is completed, the wafer W is transferred to the heat treatment apparatus 40 and subjected to a post-bake process. Next, the temperature of the wafer W is adjusted by the heat treatment apparatus 40. Thereafter, the wafer W is transferred by the wafer transfer device 70 to the inspection device 56 of the third block G3, and a second substrate image is acquired by the imaging unit 160 (step S6 in FIG. 8).

  Next, the defect determination unit 213 of the control device 200 determines the presence / absence of a defect in the second substrate image based on, for example, the inspection recipe 230 selected corresponding to the feature value “60”. The determination of the presence / absence of a defect is performed by, for example, comparing the reference image in the inspection recipe 230 with the second substrate image, and for example, when the pixel value between the reference image and the second substrate image has a difference greater than or equal to a specified value If there is a defect and the difference is smaller than the specified value, it is determined that there is no defect (step S7 in FIG. 8). Similarly, even when the feature amount of the first substrate image is “150”, the presence / absence of a defect is determined based on the selected inspection recipe 231 and the second substrate image.

  When the defect inspection of the wafer W is completed, the wafer W is transferred to the cassette C of the predetermined cassette mounting plate 21 via the wafer transfer device 23, and a series of photolithography steps is completed. Then, this series of photolithography steps is also performed on subsequent wafers W in the same lot.

  Next, processing after the first substrate image is stored in the image storage unit 214 in step S5 will be described. For example, if a feature value “150” that does not correspond to any of the inspection recipes 230, 231, and 232 is extracted from the first substrate image of the first wafer W of the lot, the feature value of the subsequent wafer W is also substantially increased. Is a value around “150”. In such a case, for example, as indicated by broken lines in FIG. 9, the number of first substrate images not corresponding to the inspection recipes 230, 231 and 232 corresponds to the image storage unit 214, that is, the number of wafers W included in the lot. Remembered. 9 represents the number of board images stored in the storage unit 211.

  As a result of accumulating the first substrate image that does not correspond to any of the inspection recipes 230, 231, and 232 in the image storage unit 214, for example, as shown in FIG. When a considerable number exists in the range of 145 to 160, for example, in the image classification unit 215, the board image having the pixel value in the range of 75 to 85 is set as the first group, and the board image having the pixel value in the range of 145 to 160 is set. Are classified into the second group (step S8 in FIG. 8).

  Then, the reference image generation unit 216 combines the second substrate images of the wafer W corresponding to the first substrate image belonging to the first group, and generates a reference image corresponding to the first group ( Step S9 in FIG. Similarly, a reference image corresponding to the second group is also generated. Next, the inspection recipe generation unit 217 generates a recipe corresponding to each group based on the generated reference image, and stores it as a new inspection recipe in the storage unit 211 (step S10 in FIG. 8).

  If the feature quantity of the first substrate image in the subsequent lot corresponds to a new inspection recipe, this new inspection recipe is selected and defect inspection of the wafer W is performed in step S4.

  According to the above embodiment, the wafer W before being processed at the processing station 11 is first imaged by the imaging unit 160 of the inspection apparatus 50 to obtain the first substrate image, and the characteristics of the first substrate image are obtained. Since the inspection recipe is selected based on the amount, it is possible to appropriately determine the presence or absence of a defect in the second substrate image based on the optimal inspection recipe. Therefore, even when the surface state of the wafer W is different from lot to lot, for example, it is possible to always perform the optimum inspection and suppress the variation in the accuracy of the macro defect inspection.

  Even if the inspection recipe corresponding to the feature quantity of the first board image does not exist in the storage unit 211, the first board image is temporarily stored in the image storage unit 214, and a predetermined number of groups are stored. Since new inspection recipes are generated at the time of classification, the inspection recipes stored in the storage unit 211 gradually increase. Therefore, by continuing the wafer W process in the substrate processing system 1, most of the first substrate images correspond to the inspection recipe stored in the storage unit 211, thereby improving the accuracy of the macro defect inspection. Can do.

  In particular, in the process of creating an inspection recipe, it is necessary for an operator to select a plurality of board images and to synthesize the selected board images to create a reference image. And the quality of the reference image varies depending on the skill level of the worker. In this regard, as in the present embodiment, the image classification unit 215 classifies the board images into groups, and generates a new inspection recipe based on the classified board images. In addition, the inspection recipe can be appropriately generated without spending a great deal of labor.

  In the above embodiment, a plurality of inspection recipes 230, 231, and 232 are stored in advance in the storage unit 211, but at least one inspection recipe may be stored in the storage unit 211. That is, in the initial state of operation of the substrate processing system 1, inspection is performed by this one inspection recipe. As described above, new inspection recipes are sequentially generated, and the number of inspection recipes stored in the storage unit 211 is increased. By doing so, it becomes possible to perform the macro defect inspection corresponding to almost all the wafers W carried into the substrate processing system 1.

  In particular, the surface state of the wafer W transferred to the substrate processing system 1 changes depending on the processing recipe in other processing apparatuses installed in a clean room including the substrate processing system 1, for example. In order to input the surface state of W to the substrate processing system 1 one by one, it leads to an increase in the load of a so-called host computer that collectively manages the substrate processing system 1 and other processing apparatuses. In this regard, as in the present invention, a new inspection recipe is sequentially generated based on the substrate image, and the wafer W before being processed in the processing station 11 is imaged by the imaging unit 160 of the inspection apparatus 50 to obtain the surface state. By checking, it is possible to always inspect defects according to the surface state of the wafer W without exchanging with the host computer.

  In the above embodiment, only the first substrate image determined as “NO” in step S3 is stored in the image storage unit 214, but the first substrate image determined as “YES” in step S3. May also be stored in the image storage unit 214.

  Further, when all the first substrate images are stored, for example, among the first substrate images stored in the image storage unit 214, the first wafer W of the same lot is adopted as the reference image, and the inspection recipe generating unit 217 is used. Thus, a provisional inspection recipe may be generated based on the reference image. Further, when the first wafer W of the same lot is adopted as a reference image and a temporary inspection recipe is generated by the inspection recipe generation unit 217, the storage unit 211 does not necessarily need to store the inspection recipe in advance. .

  In the above embodiment, the reference image generation unit 216 generates the reference image by synthesizing the second substrate image. However, what kind of substrate image is used as the reference image is the content of the present embodiment. It is not limited to. For example, as shown in FIG. 6, the control device 200 is provided with a difference image generation unit 218 that generates a difference image between the first board image and the second board image, and the image storage unit 214 receives a plurality of the difference images. The reference image may be stored and the reference image generation unit 216 may generate the reference image based on the plurality of difference images. Then, the inspection recipe generation unit 217 generates an inspection recipe using a reference image based on this difference image.

  When an inspection recipe generated using a reference image based on the difference image is used, a difference image of the wafer W to be subjected to defect inspection is generated by the difference image generation unit 218, and the defect determination unit 213 generates the difference. The presence / absence of a defect in the wafer W is determined based on the difference image thus obtained and the inspection recipe generated based on the difference image. In this case, it is preferable that the first substrate image and the second substrate image are also stored in the image storage unit 214.

  Then, by using the difference image as the reference image in this way, when the defect determination unit 213 determines that there is a defect, it can be determined that the defect is caused by the substrate processing system 1. . That is, if a defect exists in the wafer W to be inspected before processing at the processing station 11, the defect exists in both the first substrate image and the second substrate image. By generating a difference image between the first substrate image and the second substrate image, those defects existing before the processing at the processing station 11 can be removed from the difference image. Therefore, it can be determined that the defect on the difference image is caused by the processing at the processing station 11. In addition, when it is necessary to determine the presence or absence of defects for all the wafers W carried out of the substrate processing system 1 regardless of the cause of the defects, for example, the first substrate image stored in the image storage unit 214 or the first substrate image The presence or absence of a defect is confirmed for at least one of the two substrate images, and if there is a defect in the first substrate image or the second substrate image even if there is no defect in the difference image, the wafer W It may be determined that there is a defect. When a defect is detected from the first substrate image or the second substrate image, it can be determined that the defect is not caused by processing at the processing station 11.

  Note that when the reference image generation unit 216 generates the reference image based on the difference image, the first substrate image acquired by the imaging unit 160 of the inspection apparatus 50 is also determined to have a defect, and is determined to have a defect. It is preferable that the first substrate image is not stored in the image storage unit 214 or excluded when the reference image generation unit 216 generates the reference image. When a reference image is generated by synthesizing a substrate image including defects, it may not be possible to detect defects included in the reference image, but by generating an image that includes defects when the reference image is generated, More accurate defect inspection can be performed.

  Further, when determining whether or not the defect is caused by processing at the processing station 11, it is not always necessary to use the difference image. For example, the defect determination is performed for each of the first substrate image and the second substrate image. The determination results may be compared. Specifically, as described above, the presence / absence of a defect in the wafer W is determined based on the second substrate image, and when it is determined that there is a defect, the result is compared with the determination result of the defect in the first substrate image. . If a defect present in the second substrate image is also present in the first substrate image, it can be determined that the defect exists before the processing at the processing station 11. On the other hand, when a defect present in the second substrate image does not exist in the first substrate image, it can be determined that the defect is caused by processing in the processing station 11. In this way, when determining whether or not the defect is caused by processing at the processing station 11, it is not always necessary to store all of the first substrate image and the second substrate image itself. Only the determination result of the defect inspection may be stored, and the determination results may be compared with each other. By doing so, the load on the control device 200 for storing images can be reduced.

  For example, as a result of inspecting the wafer W after processing at the processing station 11 by the inspection device 56, the wafer W determined to have a defect is unloaded from the substrate processing system 1 and then corrected by rework. However, if the defect is not caused by processing at the processing station 11, the defect is not eliminated even if rework is performed. In such a case, the wafer W that does not contribute to the production is repeatedly processed by the substrate processing system 1, and as a result, the productivity is lowered. However, for the wafer W having a defect not caused by the processing in the processing station 11. Such a situation can be avoided by preventing the substrate processing system 1 from being loaded again.

  When it is determined that a defect has occurred due to processing in the processing station 11, for example, in the wafer W subsequent to the wafer W determined to have a defect, the transfer route in the processing station 11 is changed, By determining the defect for the wafer W processed by the changed route, it is possible to detect which route the defect has occurred. In other words, if there is a defect in the route after the change, if there is a portion where the route overlaps in the route before the change and the route after the change, it can be determined that the defect occurs in the overlap portion. . On the other hand, if no defect has occurred in the route after the change, it can be determined that the overlapping portion is not the cause of the defect.

  In the above embodiment, when inspecting the defect of the wafer W, the inspection apparatus 50 that inspects the wafer W before processing in the processing station 11 and the inspection apparatus 56 that inspects the wafer W after processing in the processing station 11 are used. However, it is preferable that the specifications of each device in the inspection apparatus 50 and the inspection apparatus 56 are the same. That is, if the specifications of each device are the same between the inspection apparatus 50 and the inspection apparatus 56, a difference between the first board image and the second board image is caused due to the difference in the specifications. Can be avoided. As a result, more accurate macro defect inspection and differential image generation are possible.

  In the above embodiment, the first substrate image and the second substrate image are acquired by different inspection devices 50 and 56, respectively. However, the first substrate image and the second substrate image are not necessarily different inspection devices. It is not necessary to acquire, and you may make it acquire with the same inspection apparatus. However, from the viewpoint of the interference of the transfer route of the wafer W and the throughput, it is preferable that the wafer W before being processed in the processing station 11 and the wafer W after the processing are imaged by separate inspection apparatuses.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood. The present invention is not limited to this example and can take various forms. The present invention can also be applied to a case where the substrate is another substrate such as an FPD (flat panel display) other than a wafer or a mask reticle for a photomask.

DESCRIPTION OF SYMBOLS 1 Substrate processing system 30 Development processing apparatus 31 Lower antireflection film forming apparatus 32 Resist coating apparatus 33 Upper antireflection film forming apparatus 40 Heat processing apparatus 41 Adhesion apparatus 42 Peripheral exposure inspection apparatus 70 Wafer transfer apparatus 110 Processing container 150 Imaging part 200 Control apparatus 210 Feature Quantity Extraction Unit 211 Storage Unit 212 Recipe Selection Unit 213 Defect Determination Unit 214 Image Storage Unit 215 Image Classification Unit 216 Reference Image Generation Unit 217 Inspection Recipe Generation Unit 218 Difference Image Generation Unit 230.231, 232 Inspection Recipe W Wafer

Claims (3)

A substrate processing system including a plurality of processing apparatuses for performing predetermined processing on a substrate,
A first imaging device for capturing a first substrate image by imaging the surface of the substrate before being processed by the processing device;
A second imaging device for obtaining a second substrate image by imaging the surface of the substrate after being processed by the processing device;
An image storage unit for storing the first substrate image, extracting pixel values of the first substrate image stored in the image storage unit, and calculating an average value of pixel values of the entire surface of the first substrate image; Classifying the first board image into a plurality of groups based on the feature quantity of the board,
A reference image is generated by combining the first substrate image classified into each group and the second substrate image corresponding to the first substrate image, and an inspection recipe is generated based on the generated reference image. A control unit to generate;
A substrate processing system comprising: The substrate processing system according to claim 1, wherein the control unit includes a storage unit that stores the inspection recipe. The control unit generates a difference image between the first substrate image and the second substrate image corresponding to the first substrate image;
A reference image generation unit configured to combine a plurality of the difference images corresponding to the plurality of first substrate images classified into the respective groups to generate a reference image serving as a reference for defect inspection,
The substrate processing system according to claim 1, wherein an inspection recipe is generated based on the reference image generated by the reference image generation unit.

Images