JP2020034355A - Substrate inspection device, substrate processing device, substrate inspection method, and substrate processing method - Google Patents

Abstract

To provide a substrate inspection device, a substrate processing device, a substrate inspection method and a substrate processing method with which it is possible to inspect a substrate with high accuracy on the basis of image data.SOLUTION: Real image data indicating the image of a substrate to be inspected that includes a peripheral part at least a portion of which is circular as a real image is acquired by a data acquisition unit 1. The outer shape of the substrate in the real image is specified on the basis of the acquired real image data by an outer shape specification unit 2. The specified outer shape of the substrate in the real image is considered to be elliptical, and a correction parameter for correcting the real image data on the basis of the major and minor axes of the elliptical shape is calculated by a parameter calculation unit 3. The real image data acquired so that the major and minor axes of the outer shape of the substrate in the real image become equal, is corrected on the basis of the calculated correction parameter as corrected image data by a data correction unit 4. The substrate is inspected by an inspection unit 5 on the basis of the corrected image data having been corrected.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a substrate inspection apparatus for inspecting a substrate, a substrate processing apparatus, a substrate inspection method, and a substrate processing method.

  In various processing steps for the substrate, the substrate is inspected. For example, in the substrate inspection device described in Patent Literature 1, a band-like light larger than the diameter of the substrate in one direction is emitted downward from the light projecting unit. In this state, the substrate to be inspected is moved in another direction orthogonal to one direction so as to pass below the light projecting unit. As a result, each part of the substrate is sequentially irradiated with the belt-like light. Thereafter, the belt-like light is sequentially reflected by each part of the substrate and received by the light receiving unit. Image data representing an image of the entire surface of the substrate is generated based on the amount of light received by the light receiving unit. The substrate is inspected based on the generated image data.

JP 2018-36235 A

  In Patent Literature 1, when the pixel size of the light receiving unit corresponding to the moving direction of the substrate matches the moving pitch of the substrate, image data indicating an image of the substrate with an accurate aspect ratio is generated. . However, in practice, it is difficult to match the pixel size with the substrate movement pitch due to the mounting accuracy of the substrate movement mechanism and the like. Therefore, image data indicating an image of the board with an accurate aspect ratio is not generated, and even when the board has a perfect circular shape, the image of the board indicated by the image data has an elliptical shape. In such a case, the accuracy of the board inspection based on the image data is reduced.

  An object of the present invention is to provide a substrate inspection apparatus, a substrate processing apparatus, a substrate inspection method, and a substrate processing method capable of inspecting a substrate with high accuracy based on image data.

  (1) A substrate inspection apparatus according to a first aspect of the present invention includes a substrate holding unit that holds a substrate to be inspected having at least a portion having a circular outer periphery, and an image of the substrate held by the substrate holding unit. A data acquisition unit for acquiring actual image data indicated by the following, an outline identification unit for identifying the outline of the board in the actual image based on the actual image data acquired by the data acquisition unit, and an actual image identified by the outline identification unit A parameter calculation unit that calculates a correction parameter for correcting actual image data based on the major axis and the minor axis of the elliptical shape, assuming that the outer shape of the substrate is an elliptical shape, and a correction parameter calculated by the parameter calculating unit. The real image data acquired by the data acquisition unit is corrected as corrected image data such that the major axis and the minor axis of the outer shape of the substrate in the actual image are equal based on the actual image. It comprises a chromatography data correcting section, an inspection unit for inspecting a substrate based on the corrected image data corrected by the data correction unit.

  In this substrate inspection apparatus, a substrate to be inspected having at least a part of a circular outer peripheral portion is held by a substrate holding portion. Real image data indicating an image of the board held by the board holding unit as a real image is obtained. The outer shape of the board in the real image is specified based on the obtained real image data. The outer shape of the substrate in the specified real image is regarded as an elliptical shape, and a correction parameter for correcting the real image data is calculated based on the major axis and the minor axis of the elliptical shape. Based on the calculated correction parameters, the real image data acquired so that the major axis and the minor axis of the outer shape of the substrate in the actual image become equal are corrected as corrected image data. The substrate is inspected based on the corrected image data.

  According to this configuration, even when the substrate in the real image is distorted into an elliptical shape, the corrected image data is generated by correcting the real image data using the correction parameters based on the major axis and the minor axis of the elliptical shape. Is done. In the corrected image based on the corrected image data, a substantially circular substrate is shown. Thereby, the board can be inspected with high accuracy based on the corrected image data. Further, there is no need to separately prepare a special substrate or jig for calculating the correction parameters, and it is not necessary to set the correction parameters in advance. Therefore, the time and cost required to generate the corrected image data can be reduced.

  (2) The board to be inspected has a non-circular portion for indicating the orientation of the board, and the outer shape specifying unit excludes the real image data of the portion corresponding to the non-circular portion of the board from the real image. May be specified. According to this configuration, even when the substrate to be inspected has a non-circular portion, the outer shape of the substrate in the actual image can be easily regarded as an elliptical shape. Thereby, the correction parameter can be easily calculated.

  (3) The substrate holding unit holds the substrate such that the non-circular portion of the substrate faces in a predetermined direction, and the data acquisition unit controls the substrate in a state where the non-circular portion faces in a predetermined direction. May be obtained. In this case, it is easy to specify the outer shape of the substrate in the actual image by excluding the actual image data of the portion corresponding to the non-circular portion of the substrate.

  (4) The parameter calculation unit may calculate the correction parameter by performing a multiple regression analysis using the outline of the board specified by the outline specifying unit and an equation indicating an ellipse. According to this configuration, even when distortion occurs in the substrate in the actual image, the correction parameter can be calculated with high accuracy.

  (5) The outer shape specifying unit may specify the outer shape of the board in the real image by performing a filtering process on the real image data acquired by the data acquiring unit. In this case, the outer shape of the board in the actual image can be easily specified.

  (6) The board inspection apparatus captures an image of the board held by the board holding unit using a line sensor extending in the first direction to generate actual image data, and picks up an image of the board held by the board holding unit. A moving unit configured to move at least one of the substrate holding unit and the imaging unit so as to move in a second direction that intersects the first direction with respect to the unit. The generated real image data may be acquired.

  In this case, real image data can be easily generated by moving at least one of the substrate holding unit and the imaging unit in the second direction at a predetermined pitch by the moving unit. Here, if the pixel size of the line sensor in the direction corresponding to the second direction does not match the above-described movement pitch, the substrate in the actual image is distorted into an elliptical shape. Even in such a case, a substantially circular substrate is shown in the corrected image based on the corrected image data. Thereby, the board can be inspected with high accuracy based on the corrected image data.

  (7) The substrate processing apparatus according to the second invention is a substrate inspection apparatus according to the first invention, which inspects the substrate after the processing film is formed by the film formation unit and the processing unit. Device.

  In this substrate processing apparatus, the substrate after the processing film is formed by the film forming unit is inspected by the above-described substrate inspection apparatus. Thereby, the board can be inspected with high accuracy based on the corrected image data. Further, there is no need to separately prepare a special substrate or jig for calculating the correction parameters, and it is not necessary to set the correction parameters in advance. Therefore, the time and cost required to generate the corrected image data can be reduced.

  (8) In the substrate inspection method according to the third invention, the step of holding the substrate to be inspected having at least a part of a circular outer peripheral portion by the substrate holding portion includes the steps of: A step of obtaining real image data shown as a real image, and a step of specifying the outer shape of the board in the real image based on the obtained real image data, and regarding the outer shape of the board in the specified real image as an elliptical shape, Calculating a correction parameter for correcting the real image data based on the major axis and the minor axis of the elliptical shape, and the major axis and the minor axis of the outer shape of the substrate in the actual image are equal based on the calculated correction parameter. Correcting the actual image data acquired as the corrected image data, and inspecting the substrate based on the corrected corrected image data. .

  According to this board inspection method, even when the board in the actual image is distorted in an elliptical shape, the board can be inspected with high accuracy based on the corrected image data. Further, there is no need to separately prepare a special substrate or jig for calculating the correction parameters, and it is not necessary to set the correction parameters in advance. Therefore, the time and cost required to generate the corrected image data can be reduced.

  (9) The board to be inspected has a non-circular portion for indicating the orientation of the board, and the step of specifying the outer shape of the board in the real image includes the step of real image of a portion corresponding to the non-circular portion of the board. It may include specifying the outer shape of the board in the actual image excluding the data. According to this configuration, even when the substrate to be inspected has a non-circular portion, the outer shape of the substrate in the actual image can be easily regarded as an elliptical shape. Thereby, the correction parameter can be easily calculated.

  (10) The step of holding the substrate to be inspected by the substrate holding unit includes holding the substrate by the substrate holding unit such that the non-circular portion of the substrate faces a predetermined direction. To specify the outer shape is to acquire real image data indicating a real image of the substrate in a state where the non-circular portion is oriented in a predetermined direction, thereby obtaining actual image data of a portion corresponding to the non-circular portion of the substrate. May be specified to specify the outer shape of the board in the actual image. In this case, it is easy to specify the outer shape of the substrate in the actual image by excluding the actual image data of the portion corresponding to the non-circular portion of the substrate.

  (11) The step of calculating the correction parameter may include calculating a correction parameter by performing a multiple regression analysis using the specified outer shape of the substrate and an equation indicating an ellipse. According to this configuration, even when distortion occurs in the substrate in the actual image, the correction parameter can be calculated with high accuracy.

  (12) The step of specifying the outer shape of the board in the real image may include specifying the outer shape of the board in the real image by performing a filtering process on the obtained real image data. In this case, the outer shape of the board in the actual image can be easily specified.

  (13) The board inspection method includes the board holding unit and the imaging unit such that the board relatively moves in a second direction intersecting the first direction with respect to the imaging unit including the line sensor extending in the first direction. Moving at least one of the two by the moving unit, and generating the real image data by imaging the substrate held by the substrate holding unit by the imaging unit. It may include obtaining actual image data generated by the unit.

  In this case, real image data can be easily generated by moving at least one of the substrate holding unit and the imaging unit in the second direction at a predetermined pitch by the moving unit. Here, if the pixel size of the line sensor in the direction corresponding to the second direction does not match the above-described movement pitch, the substrate in the actual image is distorted into an elliptical shape. Even in such a case, a substantially circular substrate is shown in the corrected image based on the corrected image data. Thereby, the board can be inspected with high accuracy based on the corrected image data.

  (14) A substrate processing method according to a fourth aspect of the present invention includes a step of forming a processing film on the substrate by the film forming unit, and a method of inspecting the substrate after the processing film is formed by the film forming unit according to the third invention. Inspecting according to.

  According to this substrate processing method, the substrate after the processing film is formed by the film forming unit is inspected by the above-described substrate inspection method. Thereby, the board can be inspected with high accuracy based on the corrected image data. Further, there is no need to separately prepare a special substrate or jig for calculating the correction parameters, and it is not necessary to set the correction parameters in advance. Therefore, the time and cost required to generate the corrected image data can be reduced.

  According to the present invention, a board can be inspected with high accuracy based on image data.

1 is an external perspective view of a board inspection device according to one embodiment of the present invention. FIG. 2 is a schematic side view illustrating an internal configuration of the substrate inspection apparatus in FIG. 1. FIG. 2 is a diagram illustrating an example of a real image of a substrate indicated by real image data generated by the imaging unit in FIG. 1. FIG. 3 is a block diagram illustrating a functional configuration of the board inspection device. 5 is a flowchart illustrating an inspection process performed by the control unit in FIG. 4. FIG. 7 is a diagram conceptually illustrating a procedure for generating corrected image data in the inspection processing. FIG. 7 is a diagram conceptually illustrating a procedure for generating corrected image data in the inspection processing. FIG. 7 is a diagram conceptually illustrating a procedure for generating corrected image data in the inspection processing. FIG. 3 is a schematic block diagram illustrating an overall configuration of a substrate processing apparatus including the substrate inspection apparatus of FIGS. 1 and 2.

  Hereinafter, a substrate inspection apparatus, a substrate processing apparatus, a substrate inspection method, and a substrate processing method according to an embodiment of the present invention will be described with reference to the drawings. In the following description, a substrate is a semiconductor substrate, a flat panel display (FPD) substrate such as a liquid crystal display device or an organic EL (Electro Luminescence) display device, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, Photomask substrate, ceramic substrate, solar cell substrate, and the like.

  The substrate used in the present embodiment has an outer peripheral portion that is at least partially circular. Specifically, an orientation flat for positioning is formed on the substrate, and the outer peripheral portion of the substrate excluding the orientation flat has a circular shape. The diameter of the circular portion of the substrate is, for example, 200 mm in diameter. A notch may be formed on the substrate instead of the orientation flat.

(1) Configuration of Board Inspection Apparatus FIG. 1 is an external perspective view of a board inspection apparatus according to one embodiment of the present invention. FIG. 2 is a schematic side view showing the internal configuration of the board inspection apparatus 200 of FIG. As shown in FIG. 1, the board inspection device 200 includes a housing unit 210, a light projecting unit 220, a reflecting unit 230, an imaging unit 240, a board holding device 250, a moving unit 260, a direction detecting unit 270, and a control unit 280. .

  The light projecting unit 220, the reflecting unit 230, the imaging unit 240, the substrate holding device 250, the moving unit 260, and the direction detecting unit 270 are housed in the housing unit 210. The control unit 280 includes, for example, a CPU (Central Processing Unit) and a memory, or a microcomputer, and controls operations of the light projecting unit 220, the imaging unit 240, the substrate holding device 250, the moving unit 260, and the direction detecting unit 270.

  The light projecting unit 220 includes, for example, one or a plurality of light sources, and emits strip-shaped light larger than the diameter of the substrate W obliquely downward. The light from the light projecting unit 220 has a long horizontal cross section extending in the X direction. The reflection unit 230 includes, for example, a mirror. The imaging unit 240 includes an imaging element such as a line sensor 241 in which a plurality of pixels are arranged in a line in the X direction, and one or more condenser lenses. In this example, a CCD (Charge Coupled Device) line sensor is used as an image sensor. Note that a CMOS (complementary metal oxide semiconductor) line sensor may be used as the image sensor.

  As shown in FIG. 2, the substrate holding device 250 is, for example, a spin chuck, and includes a driving device 251 and a rotation holding unit 252. The driving device 251 is, for example, an electric motor, and has a rotating shaft 253. The rotation holding unit 252 is attached to a tip of a rotation shaft 253 of the driving device 251 and is driven to rotate around a vertical axis while holding the substrate W to be inspected.

  The moving section 260 includes a pair of guide members 261 and a moving holding section 262. The pair of guide members 261 are provided so as to extend in the Y direction in parallel with each other. The Y direction is orthogonal to the X direction on a horizontal plane. The movement holding unit 262 is configured to be movable in the Y direction along the pair of guide members 261 while holding the substrate holding device 250. When the moving and holding unit 262 moves in the Y direction while the substrate holding device 250 holds the substrate W, the substrate W passes below the light projecting unit 220 and the reflecting unit 230.

  The direction detection unit 270 is, for example, a reflection-type photoelectric sensor including a light emitting element and a light receiving element, and emits light toward the outer peripheral portion of the substrate W in a state where the substrate W to be inspected is rotated by the substrate holding device 250. And receives the reflected light from the substrate W. The direction detector 270 detects the orientation flat of the substrate W based on the amount of light received from the substrate W. A transmission type photoelectric sensor may be used as the direction detection unit 270.

  An imaging operation of the substrate W in the substrate inspection device 200 of FIG. 1 will be described. A slit-shaped opening 211 for transporting the substrate W is formed on the side of the housing 210. The substrate W to be inspected is carried into the housing 210 through the opening 211 by the transfer device 120 of FIG. 9 described later, and is held by the substrate holding device 250.

  Subsequently, while the substrate W is being rotated by the substrate holding device 250, light is emitted to the periphery of the substrate W by the direction detection unit 270, and the reflected light is received by the direction detection unit 270. Thereby, the orientation flat of the substrate W is detected, and the orientation of the substrate W is determined. Based on the result of the determination, the rotational position of the substrate W is adjusted by the substrate holding device 250 such that the orientation flat of the substrate W is oriented in a fixed direction (in this example, one direction in the Y direction).

  Next, the substrate W is moved in one direction by the moving unit 260 so that the substrate W passes below the light projecting unit 220 while the belt-like light is emitted obliquely downward from the light projecting unit 220. Thus, the light from the light projecting unit 220 is applied to the entire surface of the substrate W. The light reflected on one surface of the substrate W is further reflected by the reflection unit 230 and guided to the imaging unit 240.

  The imaging element of the imaging unit 240 sequentially captures one surface of the substrate W by receiving light reflected from one surface of the substrate W at a predetermined sampling cycle. Each pixel constituting the image sensor outputs pixel data indicating a value corresponding to the amount of received light. Based on the plurality of pixel data output from the imaging unit 240, real image data indicating an entire image on one surface of the substrate W is generated. Thereafter, the substrate W is returned to a predetermined position by the moving unit 260, and the substrate W is carried out of the housing unit 210 through the opening 211 by the transfer device 120 of FIG.

(2) Function of Board Inspection Apparatus FIG. 3 is a diagram illustrating an example of a real image of the board W indicated by the real image data generated by the imaging unit 240 in FIG. The position of each pixel of the actual image data is represented by a two-dimensional coordinate system unique to the device (hereinafter, referred to as a device coordinate system). In the present embodiment, the device coordinate system is an xy coordinate system having an x axis and ay axis orthogonal to each other. The positive direction in the x direction is right, and the positive direction in the y direction is up. The origin of the device coordinate system is set to, for example, a pixel at the center of the real image RI.

  The x direction and the y direction correspond to the X direction and the Y direction in FIG. 1, respectively. As described above, in the present example, the substrate W is imaged by the imaging unit 240 in a state where the orientation flat OF faces in one direction in the Y direction. Thereby, as shown in FIG. 3, real image data indicating a real image of the substrate W whose orientation flat OF faces downward in the y direction is generated.

  When the pixel size of the image sensor of the imaging unit 240 in the y direction matches the moving pitch of the substrate W by the moving unit 260 in FIG. 1 in the Y direction, the actual image of the substrate W is accurately proportioned. The actual image data shown is generated. In addition, the aspect ratio means the ratio between the dimension in the x direction and the dimension in the y direction. However, in practice, it is difficult to match the pixel size with the moving pitch of the substrate W due to the mounting accuracy of the components of the moving unit 260 and the like. Therefore, even if the outer peripheral portion of the substrate W except for the orientation flat OF has a circular shape, as shown in FIG. 3, the actual image of the substrate W indicated by the generated actual image data has a substantially elliptical shape. Become. In such a case, the accuracy of the inspection of the substrate W based on the actual image data decreases.

  Further, in the present embodiment, an orientation flat OF is formed on the substrate W, and the aspect ratio of the substrate W is not 1: 1. Therefore, even if the actual image is simply stretched in the vertical or horizontal direction so that the aspect ratio of the substrate W in the actual image is 1: 1, image data indicating an accurate image of the substrate W cannot be generated. In this example, the diameter of the substrate is 200 mm, which is relatively small. In this case, the substrate W indicated by the stretched image becomes less accurate. Therefore, the board inspection apparatus 200 performs the following correction processing on the actual image data to generate corrected image data indicating an accurate image of the board W as a corrected image.

  FIG. 4 is a block diagram showing a functional configuration of the board inspection device 200. As shown in FIG. 4, the board inspection apparatus 200 includes a data acquisition unit 1, an outer shape identification unit 2, a parameter calculation unit 3, a data correction unit 4, and an inspection unit 5 as functional units. The functional units of the board inspection apparatus 200 are realized, for example, by the CPU of the control unit 280 executing a computer program stored in a memory. Note that some or all of the functional units of the board inspection apparatus 200 may be realized by hardware such as an electronic circuit.

  The data acquisition unit 1 acquires, from the imaging unit 240, actual image data indicating an actual image of the substrate W in a state where the orientation flat OF faces in a specific direction. The outer shape specifying unit 2 specifies the outer shape of the substrate W in the real image based on the real image data acquired by the data acquiring unit 1. The outer shape of the substrate W in the actual image is specified by excluding the actual image data of a portion corresponding to the orientation flat OF of the substrate W. In this example, since the orientation flat OF is oriented in a specific direction in the actual image, it is easy to specify the outer shape of the substrate W in the actual image by excluding the actual image data corresponding to the orientation flat OF. become.

  The parameter calculation unit 3 regards the outer shape of the substrate W in the real image specified by the outer shape specifying unit 2 as an elliptical shape, and calculates a correction parameter for correcting the real image data based on the major axis and the minor axis of the elliptical shape. calculate. Note that the elliptical shape includes a circular shape. Therefore, when the pixel size of the imaging element of the imaging unit 240 in the y direction matches the moving pitch of the substrate W by the moving unit 260 in FIG. 1 in the Y direction, the outer shape of the substrate W is regarded as a circular shape. It will be.

  The data correction unit 4 corrects the actual image data acquired by the data acquisition unit 1 based on the correction parameters calculated by the parameter calculation unit 3 so that the major axis and the minor axis of the outer shape of the substrate W in the actual image are equal. By doing so, corrected image data is generated.

  The inspection unit 5 inspects the substrate W based on the corrected image data corrected by the data correction unit 4. In this example, the presence / absence of a defect on the substrate W to be inspected is determined using sample image data representing an image of the sample substrate having no appearance defect. For example, a substrate that has been inspected with high accuracy in advance and that has been determined to have no defect in the inspection is used as a sample substrate. The sample image data may be acquired by the board inspection device 200 or may be acquired by another device. Further, design data generated in advance may be used as the sample image data.

(3) Inspection Process FIG. 5 is a flowchart showing an inspection process performed by the control unit 280 of FIG. Hereinafter, the inspection processing will be described with reference to FIG. First, the data acquisition unit 1 acquires actual image data from the imaging unit 240 (Step S1). Next, the outer shape specifying unit 2 specifies the outer shape of the substrate W of the real image acquired in step S1 (step S2).

  Subsequently, the parameter calculation unit 3 regards the outer shape of the substrate W specified in Step S2 as an elliptical shape, and calculates a correction parameter based on the major axis and the minor axis of the elliptical shape (Step S3). Thereafter, the data correction unit 4 corrects the real image data acquired in step S1 based on the correction parameters calculated in step S3 such that the major axis and the minor axis of the outer shape of the substrate W in the actual image are equal. To generate corrected image data (step S4).

  Next, the inspection unit 5 compares the sample image data with the corrected image data generated in step S4 (step S5). Note that the inspection unit 5 may store the sample image data in advance, or may acquire the sample image data from a storage device (not shown) or the like. Subsequently, the inspection unit 5 determines whether or not the difference between the values of all the pixels between the sample image data and the corrected image data is equal to or smaller than a predetermined threshold (Step S6).

  When the divergence of the values of all the pixels is equal to or smaller than the threshold, the inspection unit 5 determines that the substrate W indicated by the corrected image is normal (Step S7), and proceeds to Step S9. On the other hand, when the difference between the values of any of the pixels exceeds the threshold, the inspection unit 5 determines that the substrate W indicated by the corrected image is abnormal (step S8), and proceeds to step S9.

  In step S9, the inspection unit 5 determines whether all the substrates W have been inspected (step S9). If all the substrates W have not been inspected, the inspection unit 5 returns to step S1. Steps S1 to S9 are repeated until all the substrates W are inspected. When all the substrates W have been inspected, the inspection unit 5 ends the inspection processing.

  6 to 8 are diagrams for conceptually explaining a procedure for generating corrected image data in the inspection processing. In step S2 of the inspection process in FIG. 5, the actual image data is subjected to a filtering process such as a Sobel filter. In this case, the absolute value of the pixel of the actual image data indicating the outer peripheral portion (edge portion) of the substrate W becomes large. Further, as shown in FIG. 6, a plurality (eight in this example) of virtual lines L1 to L8 extending outward from the origin O of the apparatus coordinate system are set. For example, the virtual lines L1 to L8 are arranged at equal angular intervals (45-degree intervals) with respect to the origin O.

  For each of the virtual lines L1 to L8, the coordinates of the position of the pixel whose absolute value is equal to or larger than a predetermined threshold value from the outside toward the origin O are detected first. In the example of FIG. 6, the coordinates of the positions A1 to A8 are detected for the virtual lines L1 to L8, respectively. The coordinates of the positions A1 to A8 are (x1, y1), (x2, y2),... And (x8, y8), respectively. The outer shape of the substrate W is specified by detecting the coordinates of the positions A1 to A8 of the plurality of outer peripheral portions of the substrate W respectively corresponding to the plurality of virtual lines L1 to L8.

  In the above example, when specifying the outer shape of the substrate W, eight virtual lines L1 to L8 are arranged at intervals of 45 degrees, but the present invention is not limited to this. Seven or less virtual lines L1 to L8 may be arranged, and nine or more virtual lines may be arranged. When a larger number of virtual lines are arranged at smaller angular intervals, the outer shape of the substrate W can be specified with higher accuracy.

  The outer shape of the substrate W specified in this manner is regarded as an elliptical shape by the parameter calculator 3, and the following step S3 is executed. As described above, in the actual image, the orientation flat OF of the substrate W faces downward. Therefore, the position A5 detected for the virtual line L5 extending downward from the origin O corresponds to the position of the orientation flat OF of the substrate W. Therefore, in the present example, the outer shape of the substrate W is specified by excluding the position A5 and detecting the positions A1 to A4 and A6 to A8. This makes it easy to regard the outer shape of the substrate W in the actual image as an elliptical shape.

In step S3 of the inspection process in FIG. 5, a correction parameter is calculated by performing a multiple regression analysis using the elliptical outer shape of the substrate W specified in step S2 and an equation indicating the ellipse. Specifically, the equation representing the ellipse is represented by the following equation (1). In Expression (1), x and y are coordinates in the x direction and the y direction, respectively, in the device coordinate system. a and b are the major axis and minor axis of the ellipse, respectively. O _x and O _y are the coordinates of the center of the ellipse in the x and y directions, respectively.

In the example of FIG. 6, the major axis a is a major axis along the x direction, and the minor axis b is a minor axis along the y direction. In addition, the major axis a may be a minor radius along the x direction, and the minor axis b may be a major radius along the y direction. Further, in the example of FIG. 6, the coordinates ( _Ox , _Oy ) of the center of the ellipse are located at the origin of the device coordinate system, but need not be located at the origin of the device coordinate system.

Next, assuming that the magnification of the minor axis b with respect to the major axis a is k as shown in the following equation (2), equation (1) is transformed into a polynomial represented by the following equation (3). In equation (3), coefficients K ₁ , K ₂ , K ₃ and K ₄ are represented by the following equations (4), (5), (6) and (7), respectively.

Subsequently, the coordinates (x1, y1), (x2, y2),..., And (x8, y8) of the positions A1 to A4, A6 to A8 detected in step S2 are represented by (x, y) in Expression (3). ). Further, the ^{x 2} and objective variable, x, by multiple regression analysis is performed as explanatory variables ^{y 2} and y, the coefficient _K 1 ~K ₄ in the formula (4) to (7) is obtained. According to this method, even when a distortion is generated in the substrate W in the real image, it is possible to obtain the coefficient K ₁ ~K ₄ with high accuracy. Based on the coefficients _K 1 ~K _4, major axis a of the ellipse is determined by the following equation (8). The minor axis b of the ellipse is determined by equation (2). Further, the magnification k is obtained by the following equation (9).

  Thereafter, using the calculated magnification k as a correction parameter, the actual image data is corrected so that the major axis a and the minor axis b are equal. As a result, corrected image data indicating the corrected image CI is generated as shown in FIG. In the example of FIG. 8, the real image data is corrected so that the minor axis b in the y direction is equal to the major axis a. However, the real image data is corrected such that the major axis a in the x direction is equal to the minor axis b. May be done.

(4) Substrate Processing Apparatus FIG. 9 is a schematic block diagram showing an overall configuration of a substrate processing apparatus including the substrate inspection apparatus 200 shown in FIGS. As shown in FIG. 9, the substrate processing apparatus 100 is provided adjacent to the exposure apparatus 300, includes a substrate inspection apparatus 200, and has a control apparatus 110, a transport apparatus 120, a film forming section 130, a developing section 140, and a heat treatment section. 150.

  The control device 110 includes, for example, a CPU and a memory, or a microcomputer, and controls operations of the transport device 120, the film forming unit 130, the developing unit 140, and the heat treatment unit 150. Further, control device 110 gives a command for inspecting substrate W to control unit 280 of substrate inspection device 200 in FIG.

  The transport device 120 transports the substrate W among the film forming unit 130, the developing unit 140, the heat treatment unit 150, the substrate inspection device 200, and the exposure device 300. The film forming unit 130 forms a resist film on the surface of the substrate W by applying a resist liquid on the surface of the substrate W (film forming process). Exposure processing is performed on the substrate W after the film formation processing in the exposure apparatus 300. The developing unit 140 performs a developing process on the substrate W by supplying a developing solution to the substrate W after the exposure process performed by the exposure apparatus 300. The heat treatment unit 150 performs a heat treatment on the substrate W before and after the film forming process by the film forming unit 130, the developing process by the developing unit 140, and the exposure process by the exposure device 300.

  The substrate inspection apparatus 200 performs an inspection process on the substrate W after the resist film is formed by the film forming unit 130. For example, the substrate inspection apparatus 200 inspects the substrate W after the film forming process by the film forming unit 130 and after the developing process by the developing unit 140. Alternatively, the substrate inspection apparatus 200 may inspect the substrate W after the film formation processing by the film formation unit 130 and before the exposure processing by the exposure apparatus 300. In addition, the substrate inspection apparatus 200 may inspect the substrate W after the film forming process by the film forming unit 130 and after the exposure process by the exposure device 300 and before the developing process by the developing unit 140.

  The film forming unit 130 may be provided with a processing unit for forming an anti-reflection film on the substrate W. In this case, the heat treatment unit 150 may perform an adhesion strengthening process for improving the adhesion between the substrate W and the antireflection film. Further, the film forming section 130 may be provided with a processing unit for forming a resist cover film for protecting the resist film formed on the substrate W.

  When an anti-reflection film and a resist cover film are formed on one surface of the substrate W, the substrate inspection may be performed by the substrate inspection device 200 after the formation of each film. In substrate processing apparatus 100 according to the present embodiment, substrate W on which a film such as a resist film, an antireflection film, or a resist cover film is formed is inspected with high reliability by substrate inspection apparatus 200.

  In this example, the substrate processing apparatus 100 that performs the processing of the substrate W before and after the exposure processing is provided with the substrate inspection apparatus 200. However, the substrate inspection apparatus 200 may be provided in another substrate processing apparatus. For example, the substrate processing apparatus that performs the cleaning processing on the substrate W may be provided with the substrate inspection apparatus 200, or the substrate processing apparatus that performs the etching processing on the substrate W may be provided with the substrate inspection apparatus 200. Alternatively, the board inspection device 200 may be used alone.

(5) Effect In the substrate processing apparatus 100 according to the present embodiment, the substrate W is held by the substrate holding device 250, and the moving unit 260 moves the substrate holding device 250 at a predetermined pitch in the Y direction. Real image data is generated by the imaging unit 240. Here, when the pixel size of the line sensor 241 in the y direction corresponding to the Y direction does not match the moving pitch of the substrate holding device 250, the substrate W in the real image RI is distorted into an elliptical shape.

  Even in such a case, in the board inspection apparatus 200, the actual image data is acquired by the data acquisition unit 1. Based on the acquired real image data, the outer shape of the substrate W in the real image RI is specified by the outer shape specifying unit 2. The outer shape of the substrate W in the specified real image RI is regarded as an elliptical shape, and a correction parameter is calculated by the parameter calculating unit 3 based on the major axis and the minor axis of the elliptical shape. Based on the calculated correction parameters, the image data is corrected by the data correction unit 4 as corrected image data so that the major axis and the minor axis of the outer shape of the substrate W in the real image RI are equal. The inspection unit 5 inspects the substrate W based on the corrected image data.

  According to this configuration, even when the substrate W in the real image RI is distorted into an elliptical shape, the real image data is corrected using the correction parameters based on the major axis and the minor axis of the elliptical shape, so that the corrected image data is corrected. Is generated. In the corrected image CI based on the corrected image data, a substantially circular substrate W is shown. Thereby, the substrate W can be inspected with high accuracy based on the corrected image data. Further, there is no need to separately prepare a special substrate or jig for calculating the correction parameters, and it is not necessary to set the correction parameters in advance. Therefore, the time and cost required to generate the corrected image data can be reduced.

(6) Other Embodiments (a) In the above embodiment, the substrate W on which the positioning orientation flat OF is formed is inspected by the substrate inspection device 200, but the present invention is not limited to this. Instead of the orientation flat OF, the substrate W on which the notch for positioning is formed may be inspected by the substrate inspection device 200. Alternatively, a circular substrate W in which the orientation flat OF and the notch are not formed may be inspected by the substrate inspection device 200.

  (B) In the above embodiment, the appearance inspection of the substrate W is performed as the inspection of the substrate W, but the present invention is not limited to this. Another inspection may be performed as the inspection of the substrate W. For example, an inspection may be performed based on the corrected image data to determine whether the distance (edge width) between the outer peripheral portion of the substrate W and the outer peripheral portion of the film formed on the substrate W is appropriate. . In this case, by using the corrected image data, the edge width can be appropriately detected. This makes it possible to improve the accuracy of determining whether or not the edge width is appropriate.

  (C) In the above-described embodiment, the substrate W is imaged by the imaging unit 240 in a state where the rotation position of the substrate W is adjusted by the substrate holding device 250 so that the orientation flat OF faces in a fixed direction. The invention is not limited to this. The substrate W may be imaged by the imaging unit 240 with the orientation flat OF facing in any direction. In this case, the outer shape specifying unit 2 performs image processing or the like on the real image data, thereby excluding the real image data of the portion corresponding to the orientation flat OF of the substrate W, and specifying the outer shape of the substrate W in the real image. .

(7) Correspondence relationship between each component of the claim and each element of the embodiment Hereinafter, an example of correspondence between each component of the claim and each element of the embodiment will be described. It is not limited to the example. Various other elements having the configuration or function described in the claims may be used as the constituent elements in the claims.

  In the above embodiment, the substrate W is an example of a substrate, the substrate holding device 250 is an example of a substrate holding unit, the real image RI is an example of a real image, and the data acquisition unit 1 is an example of a data acquisition unit. It is. The outer shape specifying unit 2 is an example of an outer shape specifying unit, the parameter calculating unit 3 is an example of a parameter calculating unit, the corrected image CI is an example of a corrected image, the data correcting unit 4 is an example of a data correcting unit, The inspection unit 5 is an example of the inspection unit.

  The substrate inspection device 200 is an example of a substrate inspection device, the orientation flat OF is an example of a non-circular portion, and the X direction and the Y direction are examples of first and second directions, respectively. The line sensor 241 is an example of a line sensor, the imaging unit 240 is an example of an imaging unit, the moving unit 260 is an example of a moving unit, the film forming unit 130 is an example of a film forming unit, and the substrate processing apparatus 100 Is an example of a substrate processing apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Data acquisition part, 2 ... Outline specification part, 3 ... Parameter calculation part, 4 ... Data correction part, 5 ... Inspection part, 100 ... Substrate processing device, 110 ... Control device, 120 ... Transportation device, 130 ... Coating processing part , 140: development processing unit, 150: heat treatment unit, 200: substrate inspection apparatus, 210: housing unit, 211: opening, 220: light emitting unit, 230: reflecting unit, 240: imaging unit, 241: line sensor, 250: substrate holding device, 251: driving device, 252: rotation holding unit, 253: rotation shaft, 260: moving unit, 261: guide member, 262: movement holding unit, 270: direction detection unit, 280: control unit, 300 Exposure device, A1-A8 position, CI corrected image, L1-L8 virtual line, OF orientation flat, RI real image, W substrate

Claims (14)

A substrate holding unit that holds a substrate to be inspected having at least a part of a circular outer periphery,
A data acquisition unit that acquires actual image data indicating an image of the substrate held by the substrate holding unit as an actual image,
Based on the real image data acquired by the data acquisition unit, an outer shape specifying unit that specifies the outer shape of the board in the real image,
A parameter calculation unit that calculates a correction parameter for correcting the real image data based on the major axis and the minor axis of the elliptical shape, considering the outer shape of the substrate in the real image specified by the outer shape specifying unit as an elliptical shape,
Data correction for correcting real image data acquired by the data acquisition unit as corrected image data so that the major axis and the minor axis of the outer shape of the substrate in the actual image are equal based on the correction parameter calculated by the parameter calculation unit. Department and
A board inspection apparatus comprising: an inspection unit configured to inspect a substrate based on the corrected image data corrected by the data correction unit. The substrate to be inspected has a non-circular portion to indicate the orientation of the substrate,
The board inspection apparatus according to claim 1, wherein the outer shape specifying unit specifies the outer shape of the board in the real image by excluding the real image data of a portion corresponding to the non-circular portion of the board. The substrate holding unit holds the substrate such that the non-circular portion of the substrate is oriented in a predetermined direction,
The substrate inspection apparatus according to claim 2, wherein the data acquisition unit acquires actual image data indicating an actual image of the substrate in a state where the non-circular portion faces the predetermined direction. The said parameter calculation part calculates a correction parameter by performing multiple regression analysis using the outline of the board | substrate specified by the said outline specification part, and the equation which shows an ellipse. A substrate inspection apparatus according to item 1. The substrate inspection apparatus according to any one of claims 1 to 4, wherein the outer shape specifying unit specifies the outer shape of the board in the real image by performing a filtering process on the real image data acquired by the data acquiring unit. . An imaging unit that generates actual image data by imaging the substrate held by the substrate holding unit with a line sensor extending in a first direction;
At least one of the substrate holding unit and the imaging unit is moved such that the substrate held by the substrate holding unit moves relative to the imaging unit in a second direction that intersects the first direction. Further comprising a moving unit,
The board inspection device according to claim 1, wherein the data acquisition unit acquires actual image data generated by the imaging unit. A film forming unit for forming a processing film on the substrate,
A substrate processing apparatus, comprising: the substrate inspection apparatus according to any one of claims 1 to 6, which inspects the substrate after the processing film is formed by the film forming unit. A step of holding a substrate to be inspected having at least a part of a circular outer peripheral portion by a substrate holding portion,
Acquiring real image data indicating an image of the board held by the board holding unit as a real image,
Based on the acquired real image data, identifying the outer shape of the board in the real image,
Calculating the correction parameter for correcting the real image data based on the major axis and the minor axis of the elliptical shape, considering the outer shape of the substrate in the specified real image as an elliptical shape;
Correcting the real image data acquired so that the major axis and the minor axis of the outer shape of the substrate in the real image are equal based on the calculated correction parameters as corrected image data,
Inspecting the substrate based on the corrected image data corrected. The substrate to be inspected has a non-circular portion to indicate the orientation of the substrate,
9. The method according to claim 8, wherein the step of specifying the outer shape of the board in the real image includes specifying the outer shape of the board in the real image by excluding the real image data of a portion corresponding to the non-circular portion of the board. Board inspection method. The step of holding the substrate to be inspected by a substrate holding unit includes holding the substrate by the substrate holding unit such that the non-circular portion of the substrate faces a predetermined direction,
Identifying the outer shape of the board in the real image is obtained by obtaining real image data indicating a real image of the board in a state where the non-circular portion faces the predetermined direction. The board inspection method according to claim 9, further comprising specifying the outer shape of the board in the real image by excluding the real image data of the part corresponding to the part. 11. The method according to claim 8, wherein the step of calculating the correction parameter includes calculating a correction parameter by performing a multiple regression analysis using the specified outline of the substrate and an equation indicating an ellipse. The substrate inspection method according to the above section. 12. The method according to claim 8, wherein the step of specifying the outer shape of the board in the real image includes specifying the outer shape of the board in the real image by performing a filtering process on the acquired real image data. The board inspection method described. Moving at least one of the substrate holding unit and the imaging unit such that the substrate moves in a second direction that intersects the first direction relative to an imaging unit that includes a line sensor extending in a first direction. Moving by a part,
Generating actual image data by imaging the substrate held by the substrate holding unit by the imaging unit,
The board inspection method according to any one of claims 8 to 12, wherein the step of acquiring the actual image data includes acquiring actual image data generated by the imaging unit. Forming a processing film on the substrate by a film forming unit;
And inspecting the substrate after the formation of the processing film by the film forming unit using the substrate inspection method according to claim 8.

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