JP2016218018A - Inspection device and substrate processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection device that can implement appearance inspection of substrates with high accuracy, and to provide a substrate processing device that includes the inspection device.SOLUTION: Front surface image data on a non-defect sample substrate and a substrate to be inspected is acquired. For pixels deemed to mutually correspond to the front surface image data on the substrates, a difference in a gradation value is calculated. A determination is made whether a value based on the calculated difference falls within a tolerable range. To set up the tolerable range, a difference in the gradation value between an i-th object pixel of the sample substrate and a plurality of pixels in a fixed area including the object pixel is calculated (step S101). An average value of the differences in the gradation value is determined as a representative value corresponding to the object pixel (step S101). The representative values for all of the object pixels are determined (steps S103 and S104), and a minimum value and maximum value of all of the representative value are set up as a lower limit value and upper limit value of the tolerable range, respectively (steps S105 and S106).SELECTED DRAWING: Figure 15

Description

  The present invention relates to an inspection apparatus and a substrate processing apparatus including the inspection apparatus.

  Substrate visual inspection is performed in various processing steps for semiconductor substrates, liquid crystal display substrates, plasma display substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomask substrates. Is called.

  In the substrate processing apparatus described in Patent Document 1, an appearance inspection of a substrate is performed after a resist film is formed on the substrate and before the exposure processing is performed on the substrate. In the appearance inspection of a substrate, surface image data of the substrate is generated by imaging the substrate with an imaging device. When all of the surface image data has brightness within a predetermined allowable range, it is determined that the substrate is normal. On the other hand, if at least part of the surface image data does not have brightness within an allowable range, it is determined that the substrate is abnormal. In this way, defects on the appearance of the substrate are detected.

JP 2011-66049 A

  However, according to the defect detection method described in Patent Document 1, even when the substrate surface has a defect, the substrate is normal when the brightness of reflected light from the defect is within an allowable range. It is determined that Therefore, there are cases where a defect cannot be detected.

  The objective of this invention is providing the inspection apparatus which can perform the external appearance inspection of a board | substrate with high precision, and a substrate processing apparatus provided with the same.

  (1) An inspection apparatus according to a first invention is an inspection apparatus for inspecting the appearance of a substrate, acquires image data of a substrate having no appearance defect as first image data, and a substrate to be inspected. An image data acquisition unit that acquires image data of a substrate to be inspected as a second image data by imaging the image, and a range setting for setting an allowable range for determining whether or not the substrate has an appearance defect A value related to the difference between the gradation values for the pixels regarded as corresponding to each other in the first and second image data acquired by the image data acquisition unit and the image data acquisition unit, and each calculated difference information is set as a range. A determination unit that determines whether or not the substrate to be inspected has a defect in appearance based on whether or not it is within an allowable range set by the unit, and the range setting unit includes the first image data Predetermined For each of the plurality of target pixels, a difference in gradation value between the target pixel and a plurality of pixels in a certain region including the target pixel is calculated and determined in advance based on the calculated plurality of differences. The representative value in the range from the minimum value to the maximum value of the plurality of differences is determined by the determined method, and the values regarding the minimum value and the maximum value of the plurality of representative values respectively determined for the plurality of target pixels are allowed. Set as the lower and upper limit values.

  In the inspection apparatus, image data of a substrate having no defect in appearance is acquired as first image data, and image data of a substrate to be inspected is acquired as second image data. For a normal part of the substrate to be inspected, the difference between the gradation values of the corresponding pixels of the first and second image data is small. On the other hand, for the defective portion of the substrate to be inspected, the difference between the gradation values of the corresponding pixels of the first and second image data is large. Therefore, even when the gradation value of the pixel corresponding to the defective portion is close to the gradation value of the pixel corresponding to the normal portion, the above difference corresponding to the defective portion is the above difference corresponding to the normal portion. Compared to larger.

  Therefore, a value related to a difference in gradation value is calculated as difference information for pixels considered to correspond to each other in the first and second image data. Thereby, the difference information about the pixel corresponding to the defective portion can be distinguished from the difference information corresponding to the normal portion. Therefore, it is possible to determine whether or not there is a defect by predetermining the tolerance range so that the tolerance range includes difference information corresponding to a normal part and does not include difference information corresponding to a defective part. Become.

  However, the pixel of the second image data that is considered to correspond to a certain pixel of the first image data may deviate from the true corresponding pixel. In this case, if the allowable range is set on the assumption that the correspondence relationship between the first and second image data is accurate, the difference information corresponding to the normal part may be out of the allowable range. For this reason, it is necessary to set a large allowable range in order to prevent erroneous determination due to deviation. On the other hand, if the allowable range is set excessively large, the defect detection accuracy decreases.

  In the present invention, for each of a plurality of target pixels of the first image data, a difference in gradation value between the target pixel and a plurality of pixels in a certain region including the target pixel is calculated. In this case, the plurality of differences calculated for each target pixel are levels calculated by the determination unit due to a shift in the correspondence between the first and second image data when the substrate to be inspected has no defect. It is considered that it is almost equivalent to the difference between the key values.

  Therefore, a representative value within the range from the minimum value to the maximum value of the plurality of differences is determined by a predetermined method based on the plurality of differences calculated for each target pixel. In this case, the representative value for each target pixel is calculated when the portion corresponding to each target pixel is normal when there is a difference in the correspondence between the first and second image data. It represents the difference between key values.

  Therefore, values relating to the minimum value and the maximum value of the plurality of representative values determined for the plurality of target pixels of the first image data are set as the lower limit value and the upper limit value of the allowable range, respectively. Thereby, the possibility that the difference information calculated due to the deviation in the correspondence relationship is out of the allowable range for the normal part is reduced. Therefore, the possibility that a normal part is erroneously determined as a defect is reduced.

  Further, the lower limit value and the upper limit value of the allowable range are limited to values relating to the minimum value and the maximum value of the representative value. Thereby, the possibility that the difference information calculated due to the shift in the correspondence relationship is included in the allowable range for the defective portion is reduced. Therefore, the possibility of erroneous determination that the defective portion is normal is reduced. As a result, it is possible to detect a defect in the appearance of the substrate with high accuracy even when the corresponding pixels of the first and second image data are misaligned.

  (2) For a predetermined method, for each of a plurality of predetermined target pixels of the first image data, a gradation between the target pixel and a plurality of pixels in a fixed region including the target pixel A method may be used in which an average value difference is determined as a representative value.

  Thereby, a desired allowable range can be appropriately set according to a defect determination condition or the like.

  (3) For a predetermined method, for each of a plurality of predetermined target pixels of the first image data, a gradation between the target pixel and a plurality of pixels in a fixed region including the target pixel A method of determining the maximum value difference as a representative value may be used.

  Thereby, a desired allowable range can be appropriately set according to a defect determination condition or the like.

  (4) The difference information includes a value obtained by adding a constant value to a difference between gradation values of pixels that are considered to correspond to each other in the first and second image data, and includes a minimum value of a plurality of representative values. The value related to the maximum value may include a value obtained by adding a certain value to the minimum value and the maximum value of the plurality of representative values.

  In this case, the gradation value of the image based on the difference information corresponding to all the pixels can be increased as a whole. Thereby, the user can visually recognize the image based on the difference information without a sense of incongruity. Moreover, the allowable range is appropriately set by adding the constant value added to the difference between the gradation values to the minimum value and the maximum value of the plurality of representative values.

  (5) The range setting unit sets, as a lower limit value of the allowable range, a first value that is smaller than a minimum value of the plurality of representative values by a predetermined value instead of a value related to the minimum value of the plurality of representative values, Instead of the value relating to the maximum value of the plurality of representative values, a second value larger than the maximum value of the plurality of representative values by a predetermined value may be set as the upper limit value of the allowable range.

  There is a possibility that part of the difference information that does not correspond to the defect due to the influence of noise or disturbance becomes smaller than the value related to the minimum value of the plurality of representative values. In addition, some difference information that does not correspond to a defect may be larger than a value related to the maximum value of a plurality of representative values. According to said structure, even if difference information is smaller than the value regarding the minimum value of a some representative value, if difference information is more than 1st value, it will not determine with a defect. Even if the difference information is larger than a value related to the maximum value of the plurality of representative values, it is not determined that there is a defect if the difference information is equal to or smaller than the second value. Therefore, erroneous determination due to the influence of noise or disturbance can be prevented.

  (6) The determination unit may detect a defect on the appearance of the substrate based on a pixel whose difference information is outside the allowable range.

  In this case, when the substrate to be inspected has an appearance defect, the position and shape of the defect can be identified.

  (7) The determination unit may determine that the substrate to be inspected has an appearance defect when the number of pieces of difference information outside the allowable range is equal to or greater than a predetermined number.

  There is a possibility that some difference information that does not correspond to the defect is outside the allowable range due to the influence of noise or disturbance. According to the above configuration, if the number of difference information outside the allowable range is not equal to or greater than a predetermined number, it is not determined that there is a defect. Therefore, erroneous determination due to the influence of noise or disturbance can be prevented.

  (8) The determination unit performs smoothing of the first image data acquired by the image data acquisition unit, and performs first smoothing from the gradation value of each pixel of the first image data before smoothing. The first corrected image data is generated by subtracting the gradation value of each pixel of the image data, and the second image data acquired by the image data acquisition unit is smoothed to obtain the second before smoothing. The second corrected image data is generated by subtracting the gradation value of each pixel of the second image data after smoothing from the gradation value of each pixel of the image data, and the generated first and second The difference between the gradation values for the pixels considered to correspond to the corrected image data is calculated as difference information for the pixels corresponding to each other in the first and second image data, and the range setting unit adds the first image data to the first image data. Instead, the first modification generated by the determination unit For each of a plurality of target pixels of image data, a difference in gradation value between the target pixel and a plurality of pixels in a certain region including the target pixel is calculated, and based on the calculated plurality of differences A representative value within a range from a minimum value to a maximum value of a plurality of differences may be determined by a predetermined method.

  Normally, gradation changes due to defects and normal surface structures on the substrate occur more locally or more dispersively than gradation changes due to moire. Therefore, the first and second image data after smoothing includes a gradation change due to moire, and does not include a gradation change due to an appearance defect and a gradation change due to a surface structure. Therefore, the first moire is removed by subtracting the tone value of each pixel of the first image data after smoothing from the tone value of each pixel of the first image data before smoothing. Modified image data is generated. Further, the second moire is removed by subtracting the tone value of each pixel of the second image data after smoothing from the tone value of each pixel of the second image data before smoothing. Modified image data is generated.

  Difference information is calculated based on the first and second corrected image data. Based on the calculated difference information, it is determined whether or not the substrate to be inspected has an appearance defect. Therefore, it is possible to prevent the defect detection accuracy from being lowered due to moire, and to perform a visual inspection of the substrate with high accuracy.

  Further, for each of the plurality of target pixels of the first corrected image data, a difference in gradation value between the target pixel and a plurality of pixels in a certain area including the target pixel is calculated and calculated. The representative value is determined based on the plurality of differences. Therefore, the allowable range corresponding to the second corrected image data is appropriately set.

  (9) The determination unit may smooth the first and second image data by moving average filter processing.

  In this case, the first and second image data can be smoothed easily in a short time.

  (10) The determination unit is configured so that the first and second image data after smoothing includes a gradation change due to moire and does not include a gradation change due to an appearance defect and a normal surface structure. The first and second image data may be smoothed.

  In this case, it is possible to appropriately generate the first and second corrected image data that does not include the gradation change due to moire and includes the gradation change caused by the appearance defect and the normal surface structure.

  (11) The inspection apparatus further includes a substrate holding and rotating device that rotates while holding the substrate, and the image data acquisition unit irradiates light to a radial region along the radial direction of the substrate rotated by the substrate holding and rotating device. You may include an illumination part and the line sensor which receives the light reflected in the radial area | region of a board | substrate.

  In this case, the first and second image data can be acquired with a simple configuration.

  (12) A substrate processing apparatus according to a second aspect of the present invention is a substrate processing apparatus disposed adjacent to an exposure apparatus that performs exposure processing on a substrate, and is photosensitive on the substrate before the exposure processing by the exposure apparatus. A film forming unit that forms a film, a development processing unit that performs development processing on a photosensitive film on a substrate after exposure processing by an exposure apparatus, and an inspection of the appearance of the substrate after the formation of the photosensitive film by the film forming unit And an inspection device.

  In the substrate processing apparatus, a photosensitive film is formed on a substrate before exposure processing, and development processing is performed on the substrate after exposure processing. The appearance inspection of the substrate after the formation of the photosensitive film is performed by the above-described inspection apparatus. Thereby, even when the pixels corresponding to each other in the first and second image data are misaligned, a defect on the appearance of the substrate can be detected with high accuracy. Therefore, the appearance inspection of the photosensitive film on the substrate can be performed with high accuracy.

  (13) The inspection apparatus may inspect the appearance of the substrate after the formation of the photosensitive film by the film forming unit and after the development processing by the development processing unit.

  In this case, the appearance inspection of the photosensitive film patterned by the development process can be performed with high accuracy.

  According to the present invention, the appearance inspection of a substrate can be performed with high accuracy.

1 is a schematic plan view showing a configuration of a substrate processing apparatus according to a first embodiment. FIG. 2 is a schematic side view of a substrate processing apparatus mainly showing a coating processing section, a coating development processing section, and a cleaning / drying processing section of FIG. 1. FIG. 2 is a schematic side view of a substrate processing apparatus mainly showing a heat treatment section and a cleaning / drying processing section in FIG. 1. It is a typical side view mainly showing the conveyance part of FIG. It is a typical side view for demonstrating the structure of a test | inspection unit. It is a typical perspective view for demonstrating the structure of a test | inspection unit. It is a figure for demonstrating the production | generation of surface image data. It is a figure which shows the surface image of the sample board | substrate without a defect. It is a figure which shows the appearance frequency of the gradation value in the surface image data of the sample board | substrate without a defect. It is a flowchart of the defect determination process which concerns on 1st Embodiment. It is a flowchart of the defect determination process which concerns on 1st Embodiment. It is a figure which shows the some surface image produced | generated in a defect determination process. It is a figure for demonstrating the difference image data produced | generated in the state in which the shift | offset | difference had arisen in the correspondence of a pixel between the surface image data of a test | inspection board | substrate and a sample board | substrate. It is a figure which shows the dispersion | variation in the determination image data obtained for every test | inspection board | substrate. It is a flowchart of an allowable range setting process. It is a figure which shows typically the moire which arises in a surface image. It is a flowchart of a moiré removal process. It is a figure for demonstrating the change of the surface image at the time of performing a moire removal process about an inspection board | substrate. It is a figure for demonstrating the change of the surface image at the time of performing a moire removal process about an inspection board | substrate. It is a flowchart which shows a part of defect determination process which concerns on 2nd Embodiment. It is a flowchart which shows a part of defect determination process which concerns on other embodiment.

  Hereinafter, an inspection apparatus and a substrate processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the substrate means a semiconductor substrate, a liquid crystal display substrate, a plasma display substrate, a photomask glass substrate, an optical disk substrate, a magnetic disk substrate, a magneto-optical disk substrate, or a photomask substrate. Etc.

[1] First Embodiment (1) Overall Configuration of Substrate Processing Apparatus FIG. 1 is a schematic plan view showing the configuration of a substrate processing apparatus 100 according to a first embodiment. 1 and 2 and subsequent drawings are provided with arrows indicating X, Y, and Z directions orthogonal to each other in order to clarify the positional relationship. The X direction and the Y direction are orthogonal to each other in the horizontal plane, and the Z direction corresponds to the vertical direction.

  As shown in FIG. 1, the substrate processing apparatus 100 includes an indexer block 11, a first processing block 12, a second processing block 13, a cleaning / drying processing block 14A, and a loading / unloading block 14B. The cleaning / drying processing block 14A and the carry-in / carry-out block 14B constitute an interface block 14. The exposure device 15 is disposed adjacent to the carry-in / carry-out block 14B. In the exposure device 15, the substrate W is subjected to exposure processing by a liquid immersion method.

  The indexer block 11 includes a plurality of carrier placement units 111 and a conveyance unit 112. On each carrier placement section 111, a carrier 113 that houses a plurality of substrates W in multiple stages is placed.

  The transport unit 112 is provided with a control unit 114 and a transport mechanism 115. The control unit 114 includes, for example, a CPU (Central Processing Unit) and a memory, or a microcomputer, and controls various components of the substrate processing apparatus 100. The transport mechanism 115 has a hand 116 for holding the substrate W. The transport mechanism 115 transports the substrate W while holding the substrate W by the hand 116.

  A main panel PN is provided on the side surface of the transport unit 112. The main panel PN is connected to the control unit 114. The user can check the processing status of the substrate W in the substrate processing apparatus 100 on the main panel PN.

  The first processing block 12 includes a coating processing unit 121, a transport unit 122, and a heat treatment unit 123. The coating processing unit 121 and the heat treatment unit 123 are provided so as to face each other with the conveyance unit 122 interposed therebetween. Between the transport unit 122 and the transport unit 112, a substrate platform PASS1 on which the substrate W is placed and substrate platforms PASS2 to PASS4 (see FIG. 4) described later are provided. The transport unit 122 is provided with a transport mechanism 127 for transporting the substrate W and a transport mechanism 128 (see FIG. 4) described later.

  The second processing block 13 includes a coating and developing processing unit 131, a conveying unit 132, and a heat treatment unit 133. The coating / development processing unit 131 and the heat treatment unit 133 are provided so as to face each other with the conveyance unit 132 interposed therebetween. Between the transport unit 132 and the transport unit 122, a substrate platform PASS5 on which the substrate W is placed and substrate platforms PASS6 to PASS8 (see FIG. 4) described later are provided. The transport unit 132 is provided with a transport mechanism 137 for transporting the substrate W and a transport mechanism 138 (see FIG. 4) described later.

  The cleaning / drying processing block 14 </ b> A includes cleaning / drying processing units 161, 162 and a transport unit 163. The cleaning / drying processing units 161 and 162 are provided to face each other with the conveyance unit 163 interposed therebetween. The transport unit 163 is provided with transport mechanisms 141 and 142. Between the transport unit 163 and the transport unit 132, a placement / buffer unit P-BF1 and a later-described placement / buffer unit P-BF2 (see FIG. 4) are provided.

  A substrate platform PASS9 and a later-described placement / cooling unit P-CP (see FIG. 4) are provided between the transport mechanisms 141 and 142 so as to be adjacent to the carry-in / carry-out block 14B. In the placement / cooling section P-CP, the substrate W is cooled to a temperature suitable for the exposure process.

  A transport mechanism 146 is provided in the carry-in / carry-out block 14B. The transport mechanism 146 carries the substrate W into and out of the exposure apparatus 15. The exposure apparatus 15 is provided with a substrate carry-in portion 15a for carrying in the substrate W and a substrate carry-out portion 15b for carrying out the substrate W.

  FIG. 2 is a schematic side view of the substrate processing apparatus 100 mainly showing the coating processing unit 121, the coating and developing processing unit 131, and the cleaning / drying processing unit 161 of FIG.

  As shown in FIG. 2, the coating processing section 121 is provided with coating processing chambers 21, 22, 23, and 24 in a hierarchical manner. The coating development processing unit 131 is provided with development processing chambers 31 and 33 and coating processing chambers 32 and 34 in a hierarchical manner. Each of the coating processing chambers 21 to 24, 32, and 34 is provided with a coating processing unit 129. A development processing unit 139 is provided in each of the development processing chambers 31 and 33.

  Each coating processing unit 129 includes a spin chuck 25 that holds the substrate W and a cup 27 that is provided so as to cover the periphery of the spin chuck 25. In the present embodiment, each coating processing unit 129 is provided with two spin chucks 25 and two cups 27. The spin chuck 25 is rotationally driven by a driving device (not shown) (for example, an electric motor). As shown in FIG. 1, each coating processing unit 129 includes a plurality of coating nozzles 28 that discharge a processing liquid and a nozzle transport mechanism 29 that transports the coating nozzles 28.

  In each coating processing unit 129, one of the plurality of coating nozzles 28 is moved above the substrate W by the nozzle transport mechanism 29. In a state where the spin chuck 25 is rotated by a driving device (not shown), the processing liquid is discharged from the coating nozzle 28. Thereby, the processing liquid is applied onto the substrate W. A rinse liquid is discharged from the edge rinse nozzle (not shown) to the peripheral edge of the substrate W. Thereby, the processing liquid adhering to the peripheral edge of the substrate W is removed.

  In the present embodiment, the treatment liquid for the antireflection film is supplied from the coating nozzle 28 to the substrate W in the coating processing unit 129 of the coating processing chambers 22 and 24. In the coating processing units 129 of the coating processing chambers 21 and 23, a resist film processing liquid is supplied from the coating nozzle 28 to the substrate W. In the coating processing unit 129 of the coating processing chambers 32 and 34, a processing liquid for resist cover film is supplied from the coating nozzle 28 to the substrate W.

  As shown in FIG. 2, each development processing unit 139 includes a spin chuck 35 and a cup 37, similar to the coating processing unit 129. In the present embodiment, each development processing unit 139 is provided with three sets of spin chucks 35 and cups 37. The spin chuck 35 is rotationally driven by a driving device (not shown) (for example, an electric motor). Further, as shown in FIG. 1, the development processing unit 139 includes two development nozzles 38 that discharge the developer and a moving mechanism 39 that moves the development nozzles 38 in the X direction. In the development processing unit 139, one developing nozzle 38 moves in the X direction and supplies the developing solution to each substrate W. Subsequently, the other developing nozzle 38 moves and supplies the developing solution to each substrate W. . In this case, by supplying the developer to the substrate W, the resist cover film on the substrate W is removed, and the substrate W is developed.

  The cleaning / drying processing unit 161 is provided with a plurality (four in this example) of cleaning / drying processing units CD1. In the cleaning / drying processing unit CD1, the substrate W before the exposure processing is cleaned and dried.

  FIG. 3 is a schematic side view of the substrate processing apparatus 100 mainly showing the heat treatment units 123 and 133 and the cleaning / drying processing unit 162 of FIG.

  As shown in FIG. 3, the heat treatment part 123 has an upper heat treatment part 301 provided above and a lower heat treatment part 302 provided below. Each of the upper heat treatment part 301 and the lower heat treatment part 302 is provided with a plurality of heat treatment units PHP, a plurality of adhesion strengthening treatment units PAHP, and a plurality of cooling units CP.

  In the heat treatment unit PHP, the substrate W is heated and cooled. Hereinafter, the heat treatment and the cooling treatment in the heat treatment unit PHP are simply referred to as heat treatment. In the adhesion reinforcement processing unit PAHP, adhesion reinforcement processing for improving the adhesion between the substrate W and the antireflection film is performed. Specifically, in the adhesion reinforcement processing unit PAHP, an adhesion enhancing agent such as HMDS (hexamethyldisilazane) is applied to the substrate W, and the substrate W is subjected to heat treatment. In the cooling unit CP, the substrate W is cooled.

  The heat treatment part 133 includes an upper heat treatment part 303 provided above and a lower heat treatment part 304 provided below. Each of the upper thermal processing section 303 and the lower thermal processing section 304 is provided with a cooling unit CP, an edge exposure unit EEW, an inspection unit IP, and a plurality of thermal processing units PHP. In the edge exposure unit EEW, exposure processing (edge exposure processing) of the peripheral edge of the substrate W is performed. In the inspection unit IP, an appearance inspection of the substrate W after the development processing is performed. The inspection unit is configured by the inspection unit IP and the control unit 114 of FIG. Details of the inspection unit IP will be described later. In the upper thermal processing section 303 and the lower thermal processing section 304, the thermal processing unit PHP provided adjacent to the cleaning / drying processing block 14A is configured to be able to carry the substrate W from the cleaning / drying processing block 14A.

  The cleaning / drying processing unit 162 is provided with a plurality (four in this example) of cleaning / drying processing units CD2. In the cleaning / drying processing unit CD2, the substrate W after the exposure processing is cleaned and dried.

  FIG. 4 is a schematic side view mainly showing the conveyance units 122, 132, and 163 of FIG. As shown in FIG. 4, the transfer unit 122 includes an upper transfer chamber 125 and a lower transfer chamber 126. The transfer unit 132 includes an upper transfer chamber 135 and a lower transfer chamber 136. The upper transfer chamber 125 is provided with a transfer mechanism 127, and the lower transfer chamber 126 is provided with a transfer mechanism 128. The upper transfer chamber 135 is provided with a transfer mechanism 137, and the lower transfer chamber 136 is provided with a transfer mechanism 138.

  Each of the transport mechanisms 127, 128, 137, and 138 has hands H1 and H2. Each of the transport mechanisms 127, 128, 137, and 138 can hold the substrate W using the hands H 1 and H 2, and can freely move in the X direction and the Z direction to transport the substrate W.

  Substrate platforms PASS1 and PASS2 are provided between the transport unit 112 and the upper transport chamber 125, and substrate platforms PASS3 and PASS4 are provided between the transport unit 112 and the lower transport chamber 126. Substrate platforms PASS5 and PASS6 are provided between the upper transport chamber 125 and the upper transport chamber 135, and substrate platforms PASS7 and PASS8 are provided between the lower transport chamber 126 and the lower transport chamber 136. It is done.

  A placement / buffer unit P-BF1 is provided between the upper transfer chamber 135 and the transfer unit 163, and a placement / buffer unit P-BF2 is provided between the lower transfer chamber 136 and the transfer unit 163. . A substrate platform PASS9 and a plurality of placement / cooling units P-CP are provided so as to be adjacent to the interface block 15 in the transport unit 163.

  The transport mechanism 127 is configured to be able to transport the substrate W between the substrate platforms PASS1, PASS2, PASS5, PASS6, the coating processing chambers 21, 22 (FIG. 2), and the upper thermal processing section 301 (FIG. 3). The transport mechanism 128 is configured to be able to transport the substrate W between the substrate platforms PASS3, PASS4, PASS7, PASS8, the coating processing chambers 23, 24 (FIG. 2), and the lower thermal processing section 302 (FIG. 3).

  The transport mechanism 137 moves the substrate W between the substrate platforms PASS5 and PASS6, the placement / buffer unit P-BF1, the development processing chamber 31 (FIG. 2), the coating processing chamber 32, and the upper thermal processing unit 303 (FIG. 3). It is configured to be transportable. The transport mechanism 138 transfers the substrate W between the substrate platforms PASS7 and PASS8, the placement / buffer unit P-BF2, the development processing chamber 33 (FIG. 2), the coating processing chamber 34, and the lower thermal processing unit 304 (FIG. 3). It is configured to be transportable.

(2) Configuration of Inspection Unit FIGS. 5 and 6 are a schematic side view and a schematic perspective view for explaining the configuration of the inspection unit IP. As shown in FIG. 5, the inspection unit IP includes a holding rotation unit 51, an illumination unit 52, a reflection mirror 53, and a CCD line sensor 54.

  The holding rotation unit 51 includes a spin chuck 511, a rotation shaft 512, and a motor 513. The spin chuck 511 holds the substrate W in a horizontal posture by vacuum-sucking the substantially central portion of the lower surface of the substrate W. The rotating shaft 512 and the spin chuck 511 are integrally rotated by the motor 513. Thereby, the substrate W held by the spin chuck 511 rotates around the axis along the vertical direction (Z direction). In this example, the surface of the substrate W is directed upward. The surface of the substrate W is the surface of the substrate W on which a circuit pattern is formed.

  As shown in FIG. 6, the illumination unit 52 emits strip-shaped inspection light. The inspection light is applied to a linear region (hereinafter referred to as a radial region) RR along the radial direction of the surface of the substrate W held by the spin chuck 511. The inspection light reflected by the radius region RR is further reflected by the reflection mirror 53 and guided to the CCD line sensor 54. The received light amount distribution of the CCD line sensor 54 corresponds to the brightness distribution of the reflected light in the radius region RR. Based on the received light amount distribution of the CCD line sensor 54, surface image data of the substrate W is generated. The surface image data represents an image of the surface of the substrate W (hereinafter referred to as a surface image). In this example, the received light amount distribution of the CCD line sensor 54 is given to the control unit 114 of FIG. 1, and the control unit 114 generates surface image data.

  FIG. 7 is a diagram for explaining generation of surface image data. FIGS. 7A, 7B, and 7C sequentially show the irradiation state of the inspection light on the substrate W. FIGS. 7D, 7E, and 7F show FIGS. ), (B), and (c), surface images corresponding to the surface image data generated are shown. 7A to 7C, a dot pattern is attached to a region on the substrate W irradiated with the inspection light.

  As shown in FIGS. 7A to 7C, the substrate W is rotated while the inspection region is continuously irradiated with the inspection light on the radial region RR on the substrate W. Accordingly, the inspection light is continuously irradiated in the circumferential direction of the substrate W. When the substrate W rotates once, the entire surface of the substrate W is irradiated with inspection light.

  Based on the received light amount distribution of the CCD line sensor 54 obtained during one rotation of the substrate W, surface image data representing a rectangular surface image SD1 is generated as shown in FIGS. . 7D to 7F, the horizontal axis of the surface image SD1 corresponds to the position of each pixel of the CCD line sensor 54, and the vertical axis of the surface image SD1 corresponds to the rotation angle of the substrate W. In this case, the brightness distribution of the reflected light on the surface of the substrate W in the radial direction of the substrate W is expressed in the direction of the horizontal axis of the surface image SD1. Further, the brightness distribution of the reflected light on the surface of the substrate W in the circumferential direction of the substrate W is represented in the direction of the vertical axis of the surface image SD1. When the substrate W rotates once, the brightness distribution of the reflected light over the entire surface of the substrate W is obtained as surface image data representing one rectangular surface image SD1.

  The surface image data of the obtained surface image SD1 is corrected so as to represent the surface image of the shape (circular shape) of the substrate W. Based on the corrected surface image data, an appearance inspection of the substrate W is performed. In this embodiment, an appearance inspection of a resist film (hereinafter referred to as a resist pattern) patterned by a development process is performed.

(3) Appearance Inspection Method The brightness of a normal portion of the surface image of the substrate W can be known based on, for example, surface image data of a sample substrate having no defect. FIG. 8 is a view showing a surface image of a sample substrate having no defect. In the surface image SD2 of FIG. 8, the surface structure of the substrate W including the mesh-like resist pattern RP is represented. Here, the surface structure of the substrate W means not a defect but a normally formed structure such as a circuit pattern and a resist pattern. In this example, the brightness of the surface image SD2 is represented by the gradation value of each pixel. The larger the gradation value, the brighter the pixel.

  FIG. 9 is a diagram illustrating the appearance frequency of the gradation value in the surface image data of the sample substrate having no defect. In FIG. 9, the horizontal axis indicates the gradation value, and the vertical axis indicates the appearance frequency of each gradation value. As shown in FIG. 9, in this example, the lower limit value of the gradation value in the surface image data is TH1, and the upper limit value is TH2. Two peaks are shown between the lower limit value TH1 and the upper limit value TH2. Of the two peaks, the peak with the small gradation value is mainly based on the gradation value of the resist pattern RP in FIG. 8, and the peak with the large gradation value is mainly the gradation of the surface structure of the substrate W excluding the resist pattern RP. Based on value.

  Usually, the gradation value of the defect is different from the gradation value of the normal part. Accordingly, as indicated by the white arrow a1 and the dotted line in FIG. 9, it is determined that the substrate W from which the gradation value that deviates from between the lower limit value TH1 and the upper limit value TH2 is detected has an appearance defect. be able to. In addition, it is possible to determine that the substrate W from which no gradation value deviating between the lower limit value TH1 and the upper limit value TH2 is detected has no appearance defect.

  However, depending on the defect formed on the substrate W, as indicated by the white arrow a2 and the one-dotted line in FIG. 9, the gradation value of the pixel corresponding to the defect is the lower limit value TH1 and the upper limit value TH2. There is a possibility of being located between. In this case, in the above determination method, it is determined that there is no appearance defect.

  Therefore, in the present embodiment, the following defect determination process is performed by the control unit 114 of FIG. 10 and 11 are flowcharts of the defect determination process according to the first embodiment. FIG. 12 is a diagram illustrating a plurality of surface images generated in the defect determination process. In the following description, the substrate W to be inspected is called an inspection substrate W.

  Before the start of the defect determination process, an inspection is performed with high accuracy in advance, and a substrate that is determined to be free of defects by the inspection is prepared as a sample substrate. As shown in FIG. 10, the control unit 114 first acquires surface image data of a sample substrate having no defect (step S11), and corrects the acquired surface image data to generate a surface image of the shape of the substrate W. (Step S12). In the present embodiment, the surface image data is acquired by the inspection unit IP. The surface image data may be acquired by another apparatus instead of the inspection unit IP. FIG. 12A shows a surface image SD2 of the sample substrate generated by the process of step S12. In the surface image SD2 of FIG. 12A, the surface structure of the sample substrate including the resist pattern RP is represented.

  Subsequently, the control unit 114 performs an allowable range setting process based on the corrected surface image data of the sample substrate (step S13). In the allowable range setting process, the allowable range used in the process of step S17 described later is set. Details of the allowable range setting process will be described later.

  Next, the control unit 114 acquires the surface image data of the inspection substrate W (step S14), corrects the acquired surface image data, and performs the surface image of the shape of the substrate W in the same manner as the processes of steps S11 and S12. Is generated (step S15). FIG. 12B shows a surface image SD3 of the inspection substrate W generated by the process of step S14. In the surface image SD3 of FIG. 12B, in addition to the surface structure of the inspection substrate W, a defect DP in appearance is represented. In FIG. 12B and FIGS. 12C, 12D, and 12E described later, the outer edge of the defect DP is indicated by a dotted line so that the shape of the defect DP can be easily understood.

  Subsequently, as shown in FIG. 11, the control unit 114 calculates a difference between gradation values of pixels regarded as corresponding to each other in the surface image data of the inspection substrate W and the sample substrate (step S <b> 16). More specifically, the control unit 114 subtracts the gradation value of each pixel of the surface image SD2 regarded as corresponding to the pixel from the gradation value of each pixel of the surface image SD3.

  In this case, the pixels considered to correspond to each other between the surface image SD2 and the surface image SD3 are, for example, patterns of the surface structure of the sample substrate included in the surface image SD2 and the surface structure of the inspection substrate W included in the surface image SD3. Required by matching. Alternatively, the pixels considered to correspond to each other between the surface image SD2 and the surface image SD3 are, for example, in a positional relationship between the notch for positioning the sample substrate and the inspection substrate W and each pixel of the CCD line sensor 54 in FIG. Based on. The notch is, for example, an orientation flat or a notch.

  The surface image SD3 of the inspection substrate W includes an image similar to the surface structure of the sample substrate included in the surface image SD2 together with the image of the defect DP. Therefore, for the pixel corresponding to the normal part of the inspection substrate W, the difference obtained by the process of step S16 is small. On the other hand, when a defect in appearance exists on the inspection substrate W, the above difference is large for the pixel corresponding to the defective portion. Thereby, it is possible to distinguish the difference in gradation value for the pixel corresponding to the defective portion from the difference in gradation value for the pixel corresponding to the normal portion.

  In the following description, the surface image data including the difference obtained by the process of step S16 is referred to as difference image data. FIG. 12C shows a surface image SD4 represented by the difference image data. In the surface image SD4 in FIG. 12C, the brightness of the defective DP portion is sufficiently darker than the normal portion of the inspection substrate W.

  Next, the control unit 114 adds a certain value to the gradation value of each pixel of the difference image data (step S17). Hereinafter, the surface image data after the processing in step S17 is referred to as determination image data. For example, the center value of the gradation value range is added to the gradation value of each pixel. Specifically, when the gradation value is represented by a numerical value of 0 or more and 255 or less, 128 is added to the gradation value of each pixel. FIG. 12D shows a surface image SD5 represented by the determination image data. The surface image SD5 in FIG. 12D has appropriate brightness.

  For example, the control unit 114 displays the generated surface image SD5 on the main panel PN of FIG. In this case, the user can visually recognize the surface image SD5 of FIG. Note that if the user does not visually recognize the surface image SD5, the processing in step S17 may not be performed.

  Thereafter, the control unit 114 determines whether or not the gradation value of each pixel of the determination image data is within the allowable range set in the allowable range setting process of Step S13 (Step S18). The allowable range is basically set so as to include the gradation value of the pixel of the determination image data corresponding to the normal portion and not include the gradation value of the pixel of the determination image data corresponding to the defective portion.

  When the gradation value of each pixel of the determination image data is within the allowable range, the control unit 114 determines that there is no appearance defect on the inspection substrate W (step S19), and ends the defect determination process. On the other hand, when the gradation value of any pixel is outside the allowable range, the control unit 114 determines that the inspection substrate W has a defect in appearance (step S20). Further, the control unit 114 detects the defect by extracting one or a plurality of pixels whose gradation values are outside the allowable range (step S21), and ends the defect determination process.

  In step S21 described above, the control unit 114 may generate a surface image SD6 indicating the extracted defect DP as shown in FIG. Further, the control unit 114 may display the generated surface image SD6 on the main panel PN of FIG. As described above, when a defect on the appearance of the inspection substrate W is detected, the position and shape of the defect can be identified.

  The inspection substrate W determined to have a defect in the defect determination process is subjected to a process different from that of the substrate W determined to have no defect after being unloaded from the substrate processing apparatus 100. For example, the inspection substrate W determined to have a defect is subjected to a precision inspection or a reproduction process.

(4) Allowable Range Setting Process As described above, in the process of step S16 of the defect determination process, the difference between the gradation values of pixels that are regarded as corresponding to each other in the surface image data of the inspection substrate W and the sample substrate is calculated. At this time, the pixel of the surface image data of the inspection substrate W that is considered to correspond to the pixel of the surface image data of the sample substrate may deviate from the true corresponding pixel. Such a shift in the correspondence between pixels occurs due to, for example, the arrangement state of the inspection substrate W or the surface structure of the inspection substrate W at the time of generating the surface image data.

  FIG. 13 is a diagram for explaining the difference image data generated in a state where the correspondence between the pixels is shifted between the surface image data of the inspection substrate W and the sample substrate. FIG. 13A shows a partially enlarged view of the surface image SD2 of the sample substrate. FIG. 13B shows a partially enlarged view of the surface image SD3 of the inspection substrate W that is considered to correspond to the surface image SD2 of FIG. FIG. 13C shows a surface image SD4 representing the difference between the surface images SD2 and SD3 of FIGS. 13A and 13B. 13A to 13C, pixels on the surface image are represented by dotted lines. In the surface image SD4 in FIG. 13C, pixels having a difference (gradation value) of 0 are shown in white, and pixels having a difference (gradation value) other than 0 are shown in a dot pattern.

  Assuming that the correspondence between the pixels of the surface image data of the inspection substrate W and the sample substrate is accurate, the difference between the gradation values of the pixels corresponding to the surface image data of the inspection substrate W and the sample substrate is normal for a normal portion. It is considered to be zero. However, in the examples of FIGS. 13A and 13B, each pixel of the surface image SD3 considered to correspond to each pixel of the surface image SD2 is shifted one by one in the vertical and horizontal directions from the actually corresponding pixel. ing. In this case, as shown in FIG. 13C, the difference (gradation value) does not become zero for some pixels in the surface image SD4.

  Therefore, when the same defect determination process is performed for a plurality of inspection substrates W, there is a possibility that a difference may occur in determination image data obtained for each inspection substrate W for a normal portion. FIG. 14 is a diagram illustrating variation in determination image data obtained for each inspection substrate W. FIG. 14A shows an example of the surface image SD5 of the determination image data generated in a state where there is no deviation in the pixel correspondence. FIG. 14B shows an example of the surface image SD5 of the determination image data generated in a state where the correspondence between the pixels is shifted.

  As shown in FIG. 14A, the resist pattern RP does not appear in the surface image SD5 that is generated in a state where there is no deviation in the pixel correspondence. On the other hand, as shown in FIG. 14B, a part of the resist pattern RP appears in the surface image SD5 generated in a state in which the correspondence between the pixels is shifted. In this case, it is necessary to set the allowable range large so that the gradation value of the determination image data corresponding to the normal surface structure is within the allowable range even in a state where the correspondence relationship of the pixels is shifted. . As a result, it is possible to prevent erroneous determination due to a shift in the correspondence between pixels. On the other hand, if the allowable range is set excessively large, the defect detection accuracy decreases.

  Therefore, in the present embodiment, the following allowable range setting process is performed in order to appropriately set the allowable range in consideration of the shift in the correspondence between the surface image data of the inspection substrate W and the sample substrate.

  FIG. 15 is a flowchart of the allowable range setting process. In this example, N pixels of the surface image SD2 (FIG. 12A) of the sample substrate generated in step S12 in FIG. 10 are determined in advance as target pixels. N represents a number that is 2 or more and less than or equal to the total number of pixels of the surface image data of the sample substrate. In the present embodiment, N is the total number of pixels of the surface image data.

  As illustrated in FIG. 15, the control unit 114 determines the difference in gradation value between the i-th (i is a natural number) target pixel in the surface image data of the sample substrate and a plurality of pixels in a certain region including the target pixel. Is calculated (step S101). The initial value of the variable i is 1. The fixed region is set so as to include a fixed number of pixels from the target pixel, for example, with the target pixel as the center.

  The plurality of differences calculated in step S101 are gradation values calculated due to a shift in the correspondence between the sample substrate and the inspection substrate W for the i-th target pixel when the inspection substrate W is not defective. It is considered that the difference is almost equivalent to Therefore, the control unit 114 determines an average value of the calculated gradation value differences as a representative value corresponding to the i-th target pixel (step S102). The determined representative value is a gradation value to be calculated as difference image data when there is a deviation in the correspondence of pixels and the portion of the inspection substrate W that is considered to correspond to the i-th target pixel is normal. Represents the difference.

  Here, when each pixel of the surface image data of the sample substrate is represented by a plane coordinate system composed of the x-axis and the y-axis, the fixed area is, for example, the coordinates (a− 1, b-1), (a-1, b), (a-1, b + 1), (a, b-1), (a, b), (a, b + 1), (a + 1, b-1) , (A + 1, b) and (a + 1, b + 1) are set to include nine pixels.

  In this case, if the gradation value of the target pixel at the coordinates (u, v) is represented by P (u, v), the representative value P ′ (a, b) determined by the processing in steps S101 and S102 is, for example, It can be represented by Formula (1).

P ′ (a, b) = [{P (a−1, b−1) + P (a−1, b) + P (a−1, b + 1) + P (a, b−1) + P (a, b)] + P (a, b + 1) + P (a + 1, b-1) + P (a + 1, b) + P (a + 1, b + 1)} − P (a, b) × 9] / 9 (1)
The representative value P ′ (a, b) is differential image data that may be calculated in a state where a shift of one pixel occurs in the correspondence relationship with respect to the pixel at the coordinates (a, b) on the inspection substrate W. Represents the gradation value.

  After determining the representative value corresponding to the i-th target pixel as described above, the control unit 114 determines whether or not the value of the variable i is N (step S103). When the variable i is not N, the control unit 114 adds 1 to the variable i (step S104), and proceeds to the process of step S101. Thereby, the control unit 114 determines a representative value corresponding to the next target pixel. On the other hand, when the variable i is N, the control unit 114 adds a constant value to all the calculated representative values (step S105).

  Hereinafter, the representative value obtained by adding a constant value in step S105 is referred to as an added representative value. Here, the value added to the representative value in step S105 is equal to the value added to the gradation value of each pixel of the difference image data in step S17 of FIG. In addition, when the process of step S17 is not performed, the process of this step S105 is not performed.

  Thereafter, the control unit 114 sets the calculated minimum value and maximum value of the added representative value as the lower limit value and the upper limit value of the allowable range, respectively (step S106). If the processes in steps S17 and S105 are not performed, the minimum value and the maximum value of the N representative values calculated in the processes in steps S101 to S104 are set as the lower limit value and the upper limit value of the allowable range, respectively. Set. In this way, the allowable range setting process ends. At the end of the allowable range setting process, the variable i is reset to the initial value 1.

  By setting the permissible range in this way, the possibility that the gradation value of the determination image data calculated due to the deviation in the correspondence relationship of the pixels is out of the permissible range with respect to the normal part is reduced. Therefore, the possibility that a normal part is erroneously determined as a defect is reduced.

  Further, the lower limit value and the upper limit value of the allowable range are limited to the minimum value and the maximum value of the addition representative value. As a result, the possibility that the gradation value of the determination image data calculated due to the shift in the correspondence between the pixels is included in the allowable range for the defective portion is reduced. Therefore, the possibility of erroneous determination that the defective portion is normal is reduced. As a result, even when there is a deviation in the correspondence between the surface image data of the inspection substrate W and the sample substrate, it is possible to detect defects on the appearance of the inspection substrate W with high accuracy.

  In the above step S102, instead of the average value of the calculated gradation value differences, the minimum value, the median value, or the maximum value of the calculated gradation value differences corresponds to the i-th target pixel. The representative value may be determined. As described above, the representative value determined in step S102 is any value such as an average value, a minimum value, a median value, or a maximum value as long as it is a value within the range from the minimum value to the maximum value of the plurality of gradation values. It may be set to a value. In this case, a desired allowable range can be appropriately set according to the defect determination conditions and the like.

  Due to the influence of noise, disturbance, or the like, the gradation value of the determination image data may be smaller than the minimum value of the addition representative value for the pixel corresponding to the normal part. Further, there is a possibility that the gradation value of the determination image data is larger than the maximum value of the added representative value for the pixel corresponding to the normal part. Therefore, in step S106, the control unit 114 may perform the following process instead of setting the minimum value and the maximum value of the addition representative value as the lower limit value and the upper limit value of the allowable range, respectively.

  For example, the control unit 114 sets a first value that is smaller than a minimum value of the addition representative value by a predetermined value as a lower limit value of the allowable range, and is a value that is predetermined by a predetermined value than the maximum value of the addition representative value A large second value is set as the upper limit value of the allowable range. Thereby, even when the gradation value of the determination image data is smaller than the minimum value of the addition representative value for the pixel corresponding to the normal portion, no erroneous determination occurs when the gradation value is equal to or greater than the first value. . Further, even when the gradation value of the determination image data is larger than the maximum value of the addition representative value for the pixel corresponding to the normal portion, no erroneous determination occurs when the gradation value is equal to or smaller than the second value. As a result, misjudgment caused by noise or disturbance can be prevented.

(5) Overall Operation of Substrate Processing Apparatus The operation of the substrate processing apparatus 100 will be described with reference to FIGS. A carrier 113 in which an unprocessed substrate W is accommodated is placed on the carrier placement portion 111 (FIG. 1) of the indexer block 11. The transport mechanism 115 transports the unprocessed substrate W from the carrier 113 to the substrate platforms PASS1 and PASS3 (FIG. 4). In addition, the transport mechanism 115 transports the processed substrate W placed on the substrate platforms PASS <b> 2 and PASS <b> 4 (FIG. 4) to the carrier 113.

  In the first processing block 12, the transport mechanism 127 (FIG. 4) causes the substrate W placed on the substrate platform PASS1 (FIG. 4) to adhere to the adhesion reinforcement processing unit PAHP (FIG. 3) and the cooling unit CP (FIG. 3). ), Coating treatment chamber 22 (FIG. 2), heat treatment unit PHP (FIG. 3), cooling unit CP (FIG. 3), coating treatment chamber 21 (FIG. 2), heat treatment unit PHP (FIG. 3), and substrate platform PASS5 ( It conveys in order to FIG.

  In this case, after the adhesion reinforcement processing is performed on the substrate W in the adhesion reinforcement processing unit PAHP, the substrate W is cooled to a temperature suitable for forming the antireflection film in the cooling unit CP. Next, in the coating processing chamber 22, an antireflection film is formed on the substrate W by the coating processing unit 129 (FIG. 2). Subsequently, after the heat treatment of the substrate W is performed in the heat treatment unit PHP, the substrate W is cooled to a temperature suitable for formation of the resist film in the cooling unit CP. Next, in the coating processing chamber 21, a resist film is formed on the substrate W by the coating processing unit 129 (FIG. 2). Thereafter, the substrate W is heat-treated in the heat treatment unit PHP, and the substrate W is placed on the substrate platform PASS5.

  In addition, the transport mechanism 127 transports the substrate W after the development processing placed on the substrate platform PASS6 (FIG. 4) to the substrate platform PASS2 (FIG. 4).

  The transport mechanism 128 (FIG. 4) is configured to adhere the substrate W placed on the substrate platform PASS3 (FIG. 4) to the adhesion reinforcement processing unit PAHP (FIG. 3), the cooling unit CP (FIG. 3), and the coating processing chamber 24 (FIG. 4). 2), sequentially transferred to the heat treatment unit PHP (FIG. 3), the cooling unit CP (FIG. 3), the coating treatment chamber 23 (FIG. 2), the heat treatment unit PHP (FIG. 3), and the substrate platform PASS7 (FIG. 4). Further, the transport mechanism 128 (FIG. 4) transports the substrate W after the development processing placed on the substrate platform PASS8 (FIG. 4) to the substrate platform PASS4 (FIG. 4). The processing contents of the substrate W in the coating processing chambers 23 and 24 (FIG. 2) and the lower thermal processing section 302 (FIG. 3) are the same as those in the coating processing chambers 21 and 22 (FIG. 2) and the upper thermal processing section 301 (FIG. 3). This is the same as the processing content of W.

  In the second processing block 13, the transport mechanism 137 (FIG. 4) is configured to apply the resist film-formed substrate W placed on the substrate platform PASS 5 (FIG. 4) to the coating processing chamber 32 (FIG. 2), and a heat treatment unit. It conveys to PHP (FIG. 3), edge exposure part EEW (FIG. 3), and mounting and buffer part P-BF1 (FIG. 4) in order.

  In this case, a resist cover film is formed on the substrate W by the coating processing unit 129 in the coating processing chamber 32. Subsequently, after the substrate W is heat-treated in the heat treatment unit PHP, the edge exposure processing of the substrate W is performed in the edge exposure unit EEW, and the substrate W is placed on the placement / buffer unit P-BF1. The

  Further, the transport mechanism 137 (FIG. 4) takes out the substrate W after the exposure processing and after the heat treatment from the heat treatment unit PHP (FIG. 3) adjacent to the cleaning / drying processing block 14A, and removes the substrate W from the cooling unit CP (FIG. 3). ), The developing chamber 31 (FIG. 2), the heat treatment unit PHP (FIG. 3), the inspection unit IP (FIG. 3), and the substrate platform PASS6 (FIG. 4) in this order.

  In this case, after the substrate W is cooled to a temperature suitable for the development processing in the cooling unit CP, the development processing of the substrate W is performed by the development processing unit 139 in the development processing chamber 31. Subsequently, after heat treatment of the substrate W is performed in the heat treatment unit PHP, an appearance inspection of the substrate W is performed in the inspection unit IP. The substrate W after the appearance inspection is placed on the substrate platform PASS6.

  The transport mechanism 138 (FIG. 4) is configured to apply the resist film-formed substrate W placed on the substrate platform PASS7 (FIG. 4) to the coating processing chamber 34 (FIG. 2), the heat treatment unit PHP (FIG. 3), and edge exposure. It is sequentially conveyed to the section EEW (FIG. 3) and the placement / buffer section P-BF2 (FIG. 4). Further, the transport mechanism 138 (FIG. 4) takes out the substrate W after the exposure process and after the heat treatment from the heat treatment unit PHP (FIG. 3) adjacent to the cleaning / drying processing block 14A, and removes the substrate W from the cooling unit CP (FIG. 3). ), The developing chamber 33 (FIG. 2), the heat treatment unit PHP (FIG. 3), the inspection unit IP (FIG. 3), and the substrate platform PASS8 (FIG. 4) in this order. The processing content of the substrate W in the coating processing chamber 34, the development processing chamber 33, and the lower thermal processing section 304 is the same as the processing content of the substrate W in the coating processing chamber 32, the developing processing chamber 31, and the upper thermal processing section 303.

  In the cleaning / drying processing block 14 </ b> A, the transport mechanism 141 (FIG. 1) performs the cleaning / drying processing unit of the cleaning / drying processing unit 161 on the substrate W placed on the placement / buffer units P-BF 1, P-BF 2 (FIG. 4). It conveys to CD1 (FIG. 2) and mounting and cooling part P-CP (FIG. 4) in order. In this case, after the cleaning and drying processing of the substrate W is performed in the cleaning / drying processing unit CD1, the temperature suitable for the exposure processing in the exposure apparatus 15 (FIGS. 1 to 3) in the placement / cooling unit P-CP. Then, the substrate W is cooled.

  The transport mechanism 142 (FIG. 1) transports the substrate W after the exposure processing placed on the substrate platform PASS9 (FIG. 4) to the cleaning / drying processing unit CD2 (FIG. 3) of the cleaning / drying processing unit 162 for cleaning. The substrate W after the drying treatment is transferred from the cleaning / drying treatment unit CD2 to the heat treatment unit PHP (FIG. 3) of the upper heat treatment section 303 or the heat treatment unit PHP (FIG. 3) of the lower heat treatment section 304. In this heat treatment unit PHP, a post-exposure bake (PEB) process is performed.

  In the interface block 15, the transport mechanism 146 (FIG. 1) transfers the substrate W before exposure processing placed on the placement / cooling unit P-CP (FIG. 4) to the substrate carry-in unit 15 a (FIG. 1) of the exposure apparatus 15. Transport to. The transport mechanism 146 (FIG. 1) takes out the substrate W after the exposure processing from the substrate carry-out portion 15b (FIG. 1) of the exposure apparatus 15, and transports the substrate W to the substrate platform PASS9 (FIG. 4).

  If the exposure apparatus 15 cannot accept the substrate W, the substrate W before the exposure process is temporarily accommodated in the placement / buffer units P-BF1, P-BF2. When the development processing unit 139 (FIG. 2) of the second processing block 13 cannot accept the substrate W after the exposure processing, the substrate W after the exposure processing is placed on the placement / buffer units P-BF1 and P-BF2. Temporarily accommodated.

(6) Effect In the defect determination process described above, the surface image data of the sample substrate having no appearance defect is acquired, and the surface image data of the inspection substrate W is acquired. For the normal portion of the inspection substrate W, the difference between the gradation values of the corresponding pixels of the surface image data of the inspection substrate W and the sample substrate is small. On the other hand, for the pixel corresponding to the defective portion, the above difference is large. Therefore, even when the gradation value of the pixel corresponding to the defective portion is close to the gradation value of the pixel corresponding to the normal portion, the above difference corresponding to the defective portion is the above difference corresponding to the normal portion. Compared to larger.

  Therefore, the difference between the gradation values of the pixels considered to correspond to each other between the surface image data of the inspection substrate W and the sample substrate is calculated, and difference image data is generated. As a result, it is possible to distinguish between a difference for a pixel considered to correspond to a defective portion and a difference for a pixel corresponding to a normal portion. Therefore, it is possible to determine whether or not there is a defect by predetermining the allowable range so that the allowable range includes a difference corresponding to a normal portion and does not include a difference corresponding to a defective portion.

  A pixel on the inspection substrate W that is considered to correspond to a certain pixel on the sample substrate may deviate from a true corresponding pixel. In this case, if the allowable range is set on the premise that the correspondence between the surface image data of the sample substrate and the inspection substrate W is accurate, the determination image data corresponding to the normal part may be out of the allowable range. For this reason, it is necessary to set a large allowable range in order to prevent erroneous determination due to deviation. On the other hand, if the allowable range is set excessively large, the defect detection accuracy decreases.

  In the present embodiment, for each of a plurality of target pixels on the sample substrate, a difference in gradation value between the target pixel and a plurality of pixels in a certain region including the target pixel is calculated. In this case, the plurality of differences calculated for each target pixel are gradation values calculated due to a shift in the correspondence between the surface image data of the sample substrate and the inspection substrate W when the inspection substrate W has no defect. It is considered that the difference is almost equivalent to

  Therefore, an average value of the plurality of differences is determined as a representative value based on the plurality of differences calculated for each target pixel. In this case, the representative value for each target pixel represents the difference in gradation value that is calculated when the portion corresponding to each target pixel is normal when there is a deviation in the correspondence relationship of the pixels. ing.

  Therefore, the minimum value and the maximum value of the plurality of addition representative values determined for the plurality of target pixels of the surface image data of the sample substrate are set as the lower limit value and the upper limit value of the allowable range, respectively. As a result, the possibility that the determination image data calculated due to the difference in the correspondence between the pixels is out of the allowable range with respect to the normal portion is reduced. Therefore, the possibility that a normal part is erroneously determined as a defect is reduced.

  Further, the lower limit value and the upper limit value of the allowable range are limited to the minimum value and the maximum value of the addition representative value. As a result, the possibility that the determination image data calculated due to the shift in the correspondence between the pixels is included in the allowable range for the defective portion is reduced. Therefore, the possibility of erroneous determination that the defective portion is normal is reduced. As a result, even when there is a shift in the corresponding pixels of the surface image data of the sample substrate and the inspection substrate W, it is possible to detect defects on the appearance of the inspection substrate W with high accuracy.

[2] Second Embodiment A substrate processing apparatus according to a second embodiment has the same configuration and operation as the substrate processing apparatus 100 according to the first embodiment except for the following points. In the substrate processing apparatus according to the present embodiment, control unit 114 (FIG. 1) executes moire removal processing in the above-described defect determination processing. Hereinafter, the moire removal process will be described.

(1) Moire In the defect determination process, moire (interference fringes) may occur in the surface images SD2 and SD3 generated in steps S12 and S15. FIG. 16 is a diagram schematically showing moire generated in the surface image SD2. FIG. 16 shows an example in which a plurality (two in this example) of moire occurs on the surface image SD2 of the sample substrate. Each moire in FIG. 16 has a fan shape, and the brightness continuously changes in the circumferential direction.

  Moire tends to occur when the surface image has a periodic pattern. A plurality of circuit patterns respectively corresponding to a plurality of elements are formed on the substrate W to be processed in the substrate processing apparatus 100. These circuit patterns have the same configuration. Therefore, a plurality of circuit patterns become a periodic pattern on the substrate W.

  For example, the resist pattern RP corresponds to a plurality of circuit patterns and has a periodic pattern on the substrate W. Therefore, moire as shown in FIG. 16 is likely to occur in the surface images SD2 and SD3 in FIGS. 12A and 12B including the resist pattern RP.

  In the manufacturing process of the substrate W, the photolithography process including the resist film forming process, the exposure process, and the developing process is performed on the single substrate W a plurality of times. Therefore, at least a part of the circuit pattern is formed on the substrate W except for the initial process. Even if other films such as a resist film are formed on the circuit pattern, the inspection light passes through these films in the inspection unit IP. As a result, moire may occur in the surface image due to the already formed circuit pattern.

  The circuit pattern on the substrate W also has periodicity in the circumferential direction of the substrate W. As described above, the surface image is irradiated with the inspection light to the constant radius region RR (FIGS. 7A to 7C) while the substrate W is rotated, and the reflected light is received by the CCD line sensor 54. Is generated. Therefore, a method for generating a surface image that involves such rotation of the substrate W may also cause moiré in the surface image.

  If moire occurs in the surface image SD3 in FIG. 12B, there is a possibility that the appearance defect of the substrate W and the moire cannot be distinguished in the surface image SD3. Further, the moire generated in the surface image SD2 in FIG. 12A may be different from the moire generated in the surface image SD3 in FIG. In this case, it is necessary to set a wide allowable range in advance so that the gradation value caused by moire rather than a defect is within the allowable range in step S18 (FIG. 11) of the defect determination process.

(2) Moire removal processing In the present embodiment, moire removal processing for removing moire from the surface image SD2 of the sample substrate is performed and defect is removed from the surface image SD3 of the inspection substrate W in the defect determination processing. Moire removal processing is performed. In this example, the control unit 114 in FIG. 1 performs a moire removal process.

  FIG. 17 is a flowchart of moire removal processing. 18 and 19 are diagrams for explaining changes in the surface image SD3 when the moire removal process is performed on the inspection substrate W. FIG. In the example of FIGS. 17 to 19, moire is removed from the surface image SD3 of the inspection substrate W having the appearance defect DP.

  FIG. 18A shows a surface image SD3 before moire removal processing. In the surface image SD3 in FIG. 18A, moire and the defect DP of the inspection substrate W are represented. In FIG. 18A and FIGS. 19A and 19B described later, the outer edge of the defect DP is indicated by a dotted line so that the shape of the defect DP can be easily understood. Further, as shown in FIG. 18A, the surface image SD3 shows the surface structure of the inspection substrate W including the mesh-like resist pattern RP.

  As shown in FIG. 17, the control unit 114 first smoothes the surface image data (step S1). The smoothing of the surface image data is to reduce the density fluctuation of the surface image SD3. For example, the surface image data is smoothed by moving average filter processing. In the moving average filter processing, an average of gradation values is calculated for a prescribed number of peripheral pixels centered on the pixel of interest, and the average value is used as the gradation value of the pixel of interest. In this example, all the pixels of the surface image SD3 are set as the target pixel, and the gradation value of each pixel is changed to the average value of the surrounding pixels. The number of peripheral pixels in the moving average filter process is, for example, 100 (horizontal) × 100 (vertical). The number of peripheral pixels in the moving average filter process may be appropriately set depending on the assumed defect size, moire size, and the like.

  By the moving average filter processing, the surface image data can be easily smoothed in a short time. Note that the surface image data may be smoothed by another smoothing process such as a Gaussian filter process or a median filter process instead of the moving average filter process.

  FIG. 18B shows a surface image SD3 after smoothing in step S1 of FIG. The variation of the gradation value due to the defect and the variation of the gradation value due to the surface structure of the inspection substrate W are locally or dispersedly generated as compared with the variation of the gradation value due to the moire. Therefore, the variation in the gradation value due to the defect and the variation in the gradation value due to the surface structure of the inspection substrate W are not the process of step S1. On the other hand, the gradation value variation due to moire continuously occurs in a wide range, and therefore, it is not the process of step S1. Therefore, in the surface image SD3 of FIG. 18B, only moire is represented, and the surface structure of the defect DP and the inspection substrate W is not represented.

  Next, as shown in FIG. 17, the control unit 114 subtracts the gradation value of each pixel of the surface image data after smoothing from the gradation value of each pixel of the surface image data before smoothing (step S2). ). Thereby, moire is removed from the surface image SD3. Hereinafter, the surface image data after the processing in step S2 is referred to as corrected image data. FIG. 19A shows a surface image SD3 corresponding to the corrected image data. In the surface image SD3 in FIG. 19A, only the surface structure of the defect DP and the inspection substrate W is represented, and no moire is represented. Further, the surface image SD3 is entirely dark.

  Next, as shown in FIG. 17, the control unit 114 adds a constant value to the gradation value of each pixel of the corrected image data (step S3). Hereinafter, the surface image data after the processing in step S3 is referred to as addition image data. For example, as in the process of step S17 in FIG. 11, the center value of the range of gradation values is added to the gradation value of each pixel. FIG. 19B shows a surface image SD3 corresponding to the added image data. The surface image SD3 in FIG. 19B has moderate brightness.

  Thereby, the control part 114 complete | finishes a moire removal process. After the moire removal process is completed, the control unit 114 displays the generated surface image SD4 on the main panel PN in FIG. 1, for example. Thereby, the user can visually recognize the surface image SD3 of FIG. Note that if the user does not visually recognize the surface image SD3, the process of step S3 may not be performed.

  In the example of FIGS. 17 to 19, the moire removal process in the case of removing the moire from the surface image SD3 of the inspection substrate W has been described, but the case of removing the moire from the surface image SD2 of the sample substrate is similar to the above example. Is performed.

(3) Visual Inspection Method FIG. 20 is a flowchart showing a part of the defect determination processing according to the second embodiment. As shown in FIG. 20, the control unit 114 performs the moire removal process on the surface image SD2 of the sample substrate after performing the processes of steps S11 to S15 as in the first embodiment (step S31). Subsequently, the control unit 114 performs moire removal processing on the surface image SD3 of the inspection substrate W (step S32). Thereafter, the control unit 114 performs the processing after step S16 in FIG. 11 based on the surface images SD2 and SD3 on which the moire removal processing has been performed.

(4) Effect In the present embodiment, moire removal processing is performed on the surface image SD2 of the sample substrate and the surface image SD3 of the inspection substrate W. In the moire removal process, the acquired surface image data is smoothed, and the gradation value of each pixel of the surface image data after smoothing is subtracted from the gradation value of each pixel of the surface image data before smoothing. Thereby, corrected image data from which moire has been removed is generated. Based on the corrected image data, surface images SD2 and SD3 from which moire has been removed are obtained.

  In this case, in the inspection substrate W including the defect DP, it becomes easy to distinguish the defect DP from the moire. In addition, in steps S16 and S17 of the defect determination process, it is possible to prevent variation in gradation values caused by moire in the difference image data and the determination image data. Accordingly, it is not necessary to set a wide allowable range so as to include variations in gradation values caused by moire. Therefore, it is possible to detect defects on the appearance of the inspection substrate W with higher accuracy.

[3] Other Embodiments (1) In the above embodiment, in step S18 of the defect determination process, when the gradation value of each pixel of the determination image data is outside the allowable range, the appearance on the inspection substrate W is improved. Although it is determined that there is a defect, the present invention is not limited to this.

  In the determination image data, there is a possibility that the gradation values of some pixels that do not correspond to the defect are outside the allowable range due to the influence of noise or disturbance. Therefore, in the defect determination process, the following process may be performed instead of the process of step S18 of FIG.

  FIG. 21 is a flowchart showing a part of defect determination processing according to another embodiment. In this example, the control unit 114 performs the processes of steps S11 to S17 of FIGS. 10 and 11 in the defect determination process, and then replaces the process of step S18 with the number of pixels indicating gradation values outside the allowable range. Are counted (step S41). Moreover, the control part 114 determines whether the counted number is more than a predetermined number (step S42). Further, in step S42, the control unit 114 determines that there is no appearance defect in the inspection substrate W when the counted number is smaller than the predetermined number (step S19). On the other hand, when the counted number is equal to or greater than the predetermined number, the control unit 114 determines that there is an appearance defect on the inspection substrate W (step S20), and detects the defect (step S21).

  In this case, it is not determined that there is a defect when the number of pixels indicating gradation values outside the allowable range is not equal to or greater than a predetermined number. Therefore, erroneous determination due to the influence of noise or disturbance can be prevented.

  (2) In the above embodiment, each time the defect determination process is performed on one inspection substrate W, the surface image data of the sample substrate is acquired and the surface image SD2 of FIG. 12A is generated. Is not limited to this. When performing defect determination processing for a plurality of inspection substrates W having a common surface structure, surface image data of the sample substrate is acquired before the defect determination processing for the plurality of inspection substrates W, and the surface image SD2 is previously controlled by the control unit You may memorize | store in 114 memory. In this case, when performing the defect determination process of each inspection substrate W, the processes of steps S11 and S12 can be omitted. Therefore, the efficiency of the defect determination process is improved.

  Further, the surface image data of the sample substrate may be acquired before the defect determination processing for the plurality of inspection substrates W and the above-described allowable range setting processing may be performed. Furthermore, the allowable range set by the allowable range setting process may be stored in advance in the memory of the control unit 114 together with the surface image SD2. In this case, when performing the defect determination process of each inspection substrate W, the processes of steps S11, S12, and S13 can be omitted. Therefore, the efficiency of the defect determination process is further improved.

  (3) In the above embodiment, the surface image data of the sample substrate is acquired by imaging the sample substrate, but the present invention is not limited to this. Predetermined design data may be used as the surface image data of the sample substrate. In this case, since it is not necessary to image the sample substrate, the processing in steps S11 and S12 can be omitted.

  (4) In the above embodiment, the surface images SD2 and SD3 of the shape of the substrate W are generated by correcting the surface image data of the sample substrate and the inspection substrate W in steps S12 and S15 of the defect determination process. The invention is not limited to this. The surface image data of the sample substrate and the inspection substrate W may not be corrected to the shape of the substrate W. Even in such a case, the defect determination process similar to the above example can be performed based on the surface image data representing the rectangular surface image SD1 of FIG.

  (5) In the above embodiment, in the inspection unit IP, the inspection light is applied to the radius region RR of the substrate W while the substrate W is rotated, and the reflected light is guided to the CCD line sensor 54, whereby the surface image data is obtained. Although generated, surface image data may be generated by other methods. For example, the surface image data may be generated by imaging the entire surface of the substrate W by the area sensor without rotating the substrate W.

  (6) In the above embodiment, the defect determination processing is performed by the control unit 114, but the present invention is not limited to this. For example, a control unit for appearance inspection may be provided so as to correspond to the inspection unit IP, and various processes in the appearance inspection may be performed by the control unit. Alternatively, a plurality of local controllers are provided to correspond to the indexer block 11, the first and second processing blocks 12, 13 and the interface block 14, respectively, and one of the local controllers (for example, the second processing block 13) is provided. Various processes in the appearance inspection may be performed by a local controller corresponding to the above.

  (7) In the above embodiment, the appearance inspection of the substrate W after the development processing is performed in the inspection unit IP, but the present invention is not limited to this. For example, the appearance inspection of the substrate W after the resist film is formed and before the exposure process may be performed by the inspection unit IP. Further, the appearance inspection of the substrate W before the formation of the resist film may be performed by the inspection unit IP.

  (8) In the above embodiment, the inspection unit IP is provided in the second processing block 13, but the arrangement and number of the inspection units IP may be changed as appropriate. For example, the first processing block 12 may be provided with an inspection unit IP, or the interface block 14 may be provided with an inspection unit IP.

  (9) In the above embodiment, the inspection unit IP is provided in the substrate processing apparatus 100 adjacent to the exposure apparatus 15 that performs the exposure processing of the substrate W by the immersion method. However, the present invention is not limited to this, and liquid is used. Alternatively, the inspection unit IP may be provided in a substrate processing apparatus adjacent to an exposure apparatus that performs the exposure treatment of the substrate W.

  (10) In the above embodiment, the inspection unit IP is provided in the substrate processing apparatus 100 that processes the substrate W before and after the exposure process, but the inspection unit IP may be provided in another substrate processing apparatus. For example, the inspection unit IP may be provided in a substrate processing apparatus that performs a cleaning process on the substrate W, or the inspection unit IP may be provided in a substrate processing apparatus that performs an etching process on the substrate W. Alternatively, the inspection unit IP may be used alone instead of the inspection unit IP being provided in the substrate processing apparatus.

[4] Correspondence between each constituent element of claim and each element of the embodiment Hereinafter, an example of correspondence between each constituent element of the claim and each element of the embodiment will be described. It is not limited to.

  In the above embodiment, the sample substrate is an example of a substrate having no defect in appearance, the inspection substrate W is an example of a substrate to be inspected, the inspection unit IP and the control unit 114 are examples of an inspection device, The control unit 114 is an example of a range setting unit and a determination unit, and the illumination unit 52, the CCD line sensor 54, and the control unit 114 are examples of an image data acquisition unit.

  Further, the surface image data of the sample substrate is an example of the first image data, the surface image data of the inspection substrate W is an example of the second image data, and the difference image data and the determination image data are examples of the difference information. Yes, the corrected image data of the sample substrate is an example of the first corrected image data, the corrected image data of the inspection substrate W is an example of the second corrected image data, and the holding rotating unit 51 is an example of the substrate holding and rotating device. The illumination unit 52 is an example of an illumination unit, and the CCD line sensor 54 is an example of a line sensor.

  In addition, an example of a value obtained by adding a constant value to the difference between the gradation values of pixels in which the gradation values of the plurality of pixels of the determination image data are considered to correspond to each other in the first and second image data. is there. Further, the minimum value and the maximum value of the addition representative value are examples of values obtained by adding a fixed value to the minimum value and the maximum value of a plurality of representative values, respectively.

  Further, the substrate processing apparatus 100 is an example of a substrate processing apparatus, the exposure apparatus 15 is an example of an exposure apparatus, the coating processing unit 129 is an example of a film forming unit, and the development processing unit 139 is an example of a development processing unit. is there.

  As each constituent element in the claims, various other elements having configurations or functions described in the claims can be used.

  The present invention can be effectively used for visual inspection of various substrates.

DESCRIPTION OF SYMBOLS 11 Indexer block 12 1st process block 13 2nd process block 14 Interface block 14A Cleaning / drying process block 14B Loading / unloading block 15 Exposure apparatus 51 Holding | maintenance rotation part 52 Illumination part 53 Reflection mirror 54 CCD line sensor 100 Substrate processing apparatus 112, 122, 132, 163 Conveying unit 114 Control unit 121 Coating processing unit 123, 133 Heat treatment unit 127, 128, 137, 138 Conveying mechanism 129 Coating processing unit 131 Coating development processing unit 132 Conveying unit 139 Development processing unit 161, 162 Cleaning and drying processing Section 163 Conveying section 511 Spin chuck 512 Rotating shaft 513 Motor IP inspection unit DP Defect RP Resist pattern RR Radial area SD1 to SD6 Surface image W Substrate

A placement / buffer unit P-BF1 is provided between the upper transfer chamber 135 and the transfer unit 163, and a placement / buffer unit P-BF2 is provided between the lower transfer chamber 136 and the transfer unit 163. . A substrate platform PASS9 and a plurality of placement / cooling units P-CP are provided so as to be adjacent to the interface block 14 in the transport unit 163.

Subsequently, the control unit 114 performs an allowable range setting process based on the corrected surface image data of the sample substrate (step S13). In the allowable range setting process, the allowable range used in the process of step S18 described later is set. Details of the allowable range setting process will be described later.

In the interface block 14 , the transport mechanism 146 (FIG. 1) transfers the substrate W before exposure processing placed on the placement / cooling unit P-CP (FIG. 4) to the substrate carry-in unit 15 a (FIG. 1) of the exposure apparatus 15. Transport to. The transport mechanism 146 (FIG. 1) takes out the substrate W after the exposure processing from the substrate carry-out portion 15b (FIG. 1) of the exposure apparatus 15, and transports the substrate W to the substrate platform PASS9 (FIG. 4).

(9) In the above embodiment, the inspection unit IP is provided in the substrate processing apparatus 100 adjacent to the exposure apparatus 15 that performs the exposure processing of the substrate W by the immersion method. However, the present invention is not limited to this, and liquid is used. Alternatively, the inspection unit IP may be provided in a substrate processing apparatus adjacent to an exposure apparatus that performs exposure processing of the substrate W.

Claims (13)

An inspection device for inspecting the appearance of a substrate,
Image data acquisition for acquiring image data of a substrate having no appearance defect as first image data and acquiring image data of the substrate to be inspected as second image data by imaging the substrate to be inspected And
A range setting unit for setting an allowable range for determining whether or not the substrate has an appearance defect;
A value related to a difference in gradation value is calculated as difference information for the pixels considered to correspond to each other in the first and second image data acquired by the image data acquisition unit, and each calculated difference information is the range setting unit. A determination unit that determines whether or not the substrate to be inspected has an appearance defect based on whether or not it is within an allowable range set by
The range setting unit, for each of a plurality of predetermined target pixels of the first image data, a difference in gradation value between the target pixel and a plurality of pixels in a fixed region including the target pixel And a representative value within a range from a minimum value to a maximum value of the plurality of differences is determined by a predetermined method based on the plurality of differences calculated, and each of the plurality of target pixels is determined. An inspection apparatus that sets values relating to a minimum value and a maximum value of a plurality of representative values as a lower limit value and an upper limit value of the allowable range, respectively. In the predetermined method, for each of a plurality of predetermined target pixels of the first image data, a gradation value between the target pixel and a plurality of pixels in a fixed region including the target pixel The inspection apparatus according to claim 1, wherein the average value of the differences is determined as the representative value. In the predetermined method, for each of a plurality of predetermined target pixels of the first image data, a gradation value between the target pixel and a plurality of pixels in a fixed region including the target pixel The inspection apparatus according to claim 1, wherein the maximum value of the difference is determined as the representative value. The difference information includes a value obtained by adding a constant value to a difference between gradation values for pixels considered to correspond to each other in the first and second image data,
The value relating to the minimum value and the maximum value of the plurality of representative values includes a value obtained by adding the constant value to the minimum value and the maximum value of the plurality of representative values, respectively. The inspection apparatus according to one item. The range setting unit sets, as a lower limit value of the allowable range, a first value that is smaller than a minimum value of the plurality of representative values by a predetermined value instead of a value related to the minimum value of the plurality of representative values. The second value that is larger than the maximum value of the plurality of representative values by a predetermined value instead of the value related to the maximum value of the plurality of representative values is set as the upper limit value of the allowable range. 5. The inspection apparatus according to any one of 4. The inspection apparatus according to claim 1, wherein the determination unit detects a defect on the appearance of the substrate based on a pixel whose difference information is outside the allowable range. The determination unit according to any one of claims 1 to 6, wherein the determination unit determines that the substrate to be inspected has a defect in appearance when the number of difference information outside the allowable range is equal to or greater than a predetermined number. The inspection apparatus according to one item. The determination unit smoothes the first image data acquired by the image data acquisition unit, and the first image after smoothing from the gradation value of each pixel of the first image data before smoothing The first corrected image data is generated by subtracting the gradation value of each pixel of the data, and the second image data acquired by the image data acquisition unit is smoothed to obtain the second before smoothing. The second corrected image data is generated by subtracting the gradation value of each pixel of the second image data after smoothing from the gradation value of each pixel of the image data, and the generated first and second A difference of gradation values for pixels considered to correspond to the corrected image data of the first and second image data is calculated as the difference information for the corresponding pixels of the first and second image data;
The range setting unit, for each of a plurality of target pixels of the first corrected image data generated by the determination unit instead of the first image data, in the fixed region including the target pixel and the target pixel A representative that calculates a difference in gradation value between a plurality of pixels and is within a range from a minimum value to a maximum value of the plurality of differences by the predetermined method based on the calculated plurality of differences. The inspection apparatus according to claim 1, wherein a value is determined. The inspection apparatus according to claim 8, wherein the determination unit smoothes the first and second image data by moving average filter processing. The determination unit is configured so that the first and second image data after smoothing includes a gradation change due to moire and does not include a gradation change due to an appearance defect and a normal surface structure. The inspection apparatus according to claim 8 or 9, wherein the first and second image data are smoothed. It further includes a substrate holding and rotating device that rotates while holding the substrate,
The image data acquisition unit
An illumination unit that irradiates light to a radial region along the radial direction of the substrate rotated by the substrate holding and rotating device;
The inspection apparatus according to claim 1, further comprising: a line sensor that receives light reflected by the radial region of the substrate. A substrate processing apparatus disposed adjacent to an exposure apparatus that performs exposure processing on a substrate,
A film forming unit for forming a photosensitive film on a substrate before the exposure processing by the exposure apparatus;
A development processing unit for performing development processing on the photosensitive film on the substrate after the exposure processing by the exposure apparatus;
The substrate processing apparatus provided with the inspection apparatus as described in any one of Claims 1-11 which performs the external appearance inspection of the board | substrate after formation of the photosensitive film | membrane by the said film formation unit. The substrate processing apparatus according to claim 12, wherein the inspection apparatus performs an appearance inspection of the substrate after the photosensitive film is formed by the film forming unit and after the development processing by the development processing unit.

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