阅读说明：本技术 基板检查方法和基板检查装置 (Substrate inspection method and substrate inspection apparatus ) 是由 久野和哉 清富晶子 于 2019-07-19 设计创作，主要内容包括：本发明提供基板检查方法和基板检查装置,能够在检查基板时准确地探测基板周缘部的宏观的异常。检查基板的方法包括以下工序：特征量获取工序,获取作为检查对象的所述基板的周缘部的图像、即检查对象周缘图像中的多个分割区域的各个分割区域的特征量,所述分割区域是将所述基板的周缘部的图像中的规定的区域进行分割所得到的区域；以及判定工序,基于所述特征量获取工序中的获取结果来进行与所述基板的周缘部的检查有关的规定的判定。(The invention provides a substrate inspection method and a substrate inspection apparatus, which can accurately detect macroscopic abnormality of a peripheral portion of a substrate when the substrate is inspected. The method for inspecting a substrate includes the steps of: a feature value acquisition step of acquiring a feature value of each of a plurality of divided regions in an image of a peripheral portion of the substrate to be inspected, the divided regions being obtained by dividing a predetermined region in the image of the peripheral portion of the substrate; and a determination step of performing a predetermined determination regarding inspection of the peripheral edge portion of the substrate based on the acquisition result in the feature amount acquisition step.)

1, A substrate inspection method for inspecting a substrate, the substrate inspection method comprising the steps of:

a feature value acquisition step of acquiring a feature value of each of a plurality of divided regions in an image of a peripheral portion of the substrate to be inspected, the divided regions being obtained by dividing a predetermined region in the image of the peripheral portion of the substrate; and

and a determination step of performing a predetermined determination regarding inspection of the peripheral portion of the substrate based on the acquisition result in the feature amount acquisition step.

2. The substrate inspection method according to claim 1,

in the determination step, the predetermined determination is performed based on the acquisition result in the feature amount acquisition step and the feature amount of the divided region in a reference peripheral image that is an image of the peripheral portion of the substrate that is a reference of the predetermined determination.

3. The substrate inspection method according to claim 1 or 2,

the feature amount is an average value of pixel values in the divided region.

4. The substrate inspection method according to claim 1 or 2,

the feature amount is a standard deviation of pixel values in the divided region.

5. The substrate inspection method according to claim 1 or 2,

the feature amount is a histogram of pixel values in the divided region.

6. The substrate inspection method according to claim 3,

the feature quantity is a quantity related to a pixel value of a specific color.

7. The substrate inspection method according to claim 1 or 2,

the divided region is a region obtained by dividing the predetermined region in a radial direction of the substrate.

8. The substrate inspection method according to claim 1 or 2,

the divided region is a region obtained by dividing the predetermined region in the circumferential direction of the substrate.

9. The substrate inspection method according to claim 1 or 2,

further comprises an imaging step of imaging the peripheral edge of the substrate,

the inspection target peripheral image is an image of the peripheral portion of the substrate obtained based on the imaging result in the imaging step.

10, kinds of substrate inspection apparatus for inspecting a substrate, the apparatus comprising:

a feature value acquisition unit that acquires a feature value of each of a plurality of divided regions in an image of a peripheral portion of the substrate to be inspected, the divided regions being obtained by dividing a predetermined region in the image of the peripheral portion of the substrate; and

and a determination unit that performs a predetermined determination regarding inspection of the peripheral edge portion of the substrate based on the acquisition result obtained by the feature amount acquisition unit.

Technical Field

The present disclosure relates to substrate inspection methods and substrate inspection apparatuses.

Background

Patent document 1 discloses types of inspection units for inspecting respective surfaces (front surface, back surface, and end surface) at the periphery of a substrate, the inspection units including a holding table configured to hold and rotate the substrate, a mirror member inclined with respect to a rotation axis of the holding table and having a reflection surface facing the peripheral edge region of the end surface and the back surface of the substrate held by the holding table, and a camera, the camera further including an image pickup element to which light obtained by reflecting light from the peripheral edge region of the front surface of the substrate held by the holding table and light from the end surface of the substrate held by the holding table by the reflection surface of the mirror member is input via a lens.

Disclosure of Invention

Problems to be solved by the invention

The technology of the present disclosure can accurately detect macroscopic abnormalities in the peripheral portion of a substrate when the substrate is inspected.

Means for solving the problems

The aspects of the present disclosure are a method for inspecting a substrate, including a feature value acquisition step of acquiring a feature value of each of a plurality of divided regions in an image of a peripheral portion of the substrate as an inspection target, the divided regions being obtained by dividing a predetermined region in the image of the peripheral portion of the substrate, and a determination step of performing a predetermined determination regarding inspection of the peripheral portion of the substrate based on an acquisition result in the feature value acquisition step.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, it is possible to accurately detect macroscopic abnormalities at the peripheral portion of a substrate when inspecting the substrate.

Drawings

Fig. 1 is a plan view schematically showing the configuration of a substrate processing system according to the present embodiment.

Fig. 2 is a side view schematically showing the internal configuration of the substrate processing system according to the present embodiment.

Fig. 3 is a side view schematically showing the internal configuration of the substrate processing system according to the present embodiment.

Fig. 4 is a cross-sectional view schematically showing the structure of the inspection apparatus.

Fig. 5 is a vertical cross-sectional view schematically showing the structure of the inspection apparatus.

Fig. 6 is a side view schematically showing the configuration of the peripheral imaging subunit.

Fig. 7 is a view showing a state of reflection of light from the peripheral edge portion of the substrate.

Fig. 8 is a block diagram schematically showing the configuration of the control unit.

Fig. 9 is a diagram illustrating an example of an inspection target image.

Fig. 10A is a diagram showing an example of the reference peripheral image.

Fig. 10B is a diagram illustrating examples of the inspection target peripheral image.

Fig. 11A is a diagram illustrating another example of the imaging peripheral image.

Fig. 11B is a diagram illustrating another example of the imaging periphery image.

Fig. 11C is a diagram showing another example of the imaging peripheral image.

Fig. 12A is a diagram for explaining a specific example of judgment in the judgment section and inspection in the inspection section.

Fig. 12B is a diagram for explaining a specific example of the judgment in the judgment section and the inspection in the inspection section.

Fig. 13A is a diagram for explaining another specific example of judgment in the judgment section and inspection in the inspection section.

Fig. 13B is a diagram for explaining another specific example of the judgment in the judgment section and the inspection in the inspection section.

Fig. 13C is a diagram for explaining another specific example of the judgment in the judgment section and the inspection in the inspection section.

Fig. 13D is a diagram for explaining another specific example of the judgment in the judgment section and the inspection in the inspection section.

Detailed Description

First, a conventional substrate inspection apparatus described in patent document 1 will be described.

In a manufacturing process of a semiconductor device, a semiconductor wafer (hereinafter, referred to as a "wafer") as a substrate is subjected to various processes such as an ion implantation process, a film formation process, a photolithography process, and an etching process. In the photolithography process for forming a predetermined resist pattern on a wafer, a process for forming a resist film by applying a resist solution on the wafer, a development process for developing the resist film exposed to light in a predetermined pattern, and the like are performed in this order.

In the case of a wafer subjected to various processes related to the manufacturing process of the semiconductor device, the peripheral edge portion is made thinner than the center of the wafer by polishing the peripheral edge portion of the wafer. Thus, the peripheral region of the wafer surface is inclined with respect to the central region of the wafer surface. Further, the tilt and variations in processing conditions in various processes involved in the manufacturing process make it difficult to control the state of the peripheral edge of the wafer. Monitoring the state of the peripheral portion of the wafer to detect an abnormality contributes not only to an increase in the number of effective chips but also to an improvement in the yield of chips in the vicinity of the peripheral portion.

Therefore, the inspection unit of patent document 1 includes a camera for inspecting the peripheral edge of the wafer, the camera having an imaging element to which light from the peripheral edge region of the front surface of the wafer and reflected light obtained by reflecting light from the side end surface of the wafer by the reflection surface of the mirror member are input. In other words, the inspection unit of patent document 1 images the peripheral edge portion of the wafer and inspects the peripheral edge portion of the wafer based on the imaging result.

As described above, as a method for inspecting the state of the peripheral edge portion of the wafer using the captured peripheral edge image obtained based on the imaging result of the peripheral edge portion of the wafer, for example, the following method is available. The periphery comparison method is a method of detecting an abnormality based on a difference between an image of a region to be inspected in a captured image and an image of a peripheral region thereof. In addition, there is also a method (edge tracking method) of acquiring a position of an edge of a film formed on a wafer from a light and a shade in an image. In this method, for example, when an annular film is formed along the peripheral edge portion of the wafer, the position of the inner edge of the annular film is obtained. Then, the distance from the edge of the wafer to the inner edge of the annular film can be calculated, and whether or not the film formation is acceptable can be determined based on the calculation result.

However, in any of the methods, a macroscopic abnormality cannot be detected, for example, in a case where a resist film is formed annularly along the peripheral edge portion of the wafer, such as a state shown in fig. 11C described later, in fig. 11C, the edge of the resist film R on the side opposite to the peripheral end surface side of the wafer W is clear, but in a case where no resist film R is formed on the peripheral end surface side of the wafer W, in the case where an abnormality such as that shown in fig. 11C exists, it is determined that a circular film is formed in the center portion in the above-described periphery comparison method, and it is determined that no abnormality exists because the edge of the resist film can be obtained in the above-described edge tracing method.

In the inspection of the peripheral edge portion of the wafer, a substrate image (golden image) as a reference is registered in advance, and abnormality determination is not performed by pattern matching based on the golden image. This is because: in the peripheral portion of the wafer, the matching between the patterns is poor, and it is difficult to accurately determine the abnormality even when the images are compared.

Next, a substrate processing method and a substrate inspection apparatus according to the present embodiment for detecting macroscopic abnormalities in the peripheral portion of a substrate when inspecting the substrate will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description thereof is omitted.

Fig. 1 is a plan view schematically showing the configuration of a substrate processing system 1 including a substrate inspection apparatus according to the present embodiment. Fig. 2 and 3 are a front view and a rear view schematically showing an outline of the internal configuration of the substrate processing system 1, respectively. In the present embodiment, a case where the substrate processing system 1 is a coating and developing system that performs a coating and developing process on the wafer W will be described as an example.

As shown in fig. 1, the substrate processing system 1 includes a cassette transfer station 10 for carrying in and out a cassette C containing a plurality of wafers W, and a processing station 11 including a plurality of types of processing devices for performing predetermined processing on the wafers W, and the substrate processing system 1 is configured by connecting the cassette transfer station 10, the processing station 11, and an interface station 13 adjacent to the processing station 11 for transferring the wafers W to and from the exposure device 12.

The cassette transfer station 10 is provided with a cassette mounting table 20. The cassette mounting table 20 is provided with a plurality of cassette mounting plates 21, and the cassette mounting plates 21 are used for mounting the cassettes C when the cassettes C are carried in and out from the outside of the substrate processing system 1.

The cassette transfer station 10 is provided with a wafer transfer device 23 that is movable on a transfer path 22 extending in the X direction. The wafer transfer device 23 is also movable in the vertical direction and about the vertical axis (θ direction), and is capable of transferring the wafer W between the cassettes C on the cassette mounting plates 21 and a transfer device of the third block G3 of the process station 11, which will be described later.

The processing station 11 is provided with a plurality of blocks including various devices, for example, four blocks G1, G2, G3, G4., for example, a -th block G1 is provided on the front side (the X-direction negative side in fig. 1) of the processing station 11, a second block G2. is provided on the back side (the X-direction positive side in fig. 1) of the processing station 11, a third block G3 is provided on the cartridge transfer station 10 side (the Y-direction negative side in fig. 1) of the processing station 11, and a fourth block G4 is provided on the interface station 13 side (the Y-direction positive side in fig. 1) of the processing station 11.

As shown in fig. 2, a plurality of liquid processing apparatuses, for example, a developing apparatus 30, a lower anti-reflection film forming apparatus 31, a resist coating apparatus 32, and an upper anti-reflection film forming apparatus 33 are disposed in the order from the bottom to the top in the developing apparatus 30 at st block G1. for developing the wafer W, the lower anti-reflection film forming apparatus 31 for forming an anti-reflection film (hereinafter referred to as "lower anti-reflection film") on the lower layer of the resist film of the wafer W, the resist coating apparatus 32 for coating the resist liquid on the wafer W to form the resist film, and the upper anti-reflection film forming apparatus 33 for forming an anti-reflection film (hereinafter referred to as "upper anti-reflection film") on the upper layer of the resist film.

For example, three developing apparatuses 30, three lower antireflection film forming apparatuses 31, three resist coating apparatuses 32, and three upper antireflection film forming apparatuses 33 are arranged in the horizontal direction. The number and arrangement of the developing apparatus 30, the lower anti-reflection film forming apparatus 31, the resist coating apparatus 32, and the upper anti-reflection film forming apparatus 33 can be arbitrarily selected.

In the developing apparatus 30, the lower anti-reflection film forming apparatus 31, the resist coating apparatus 32, and the upper anti-reflection film forming apparatus 33, for example, spin coating is performed to coat a predetermined coating liquid on the wafer W. In the spin coating, for example, a coating liquid is discharged from a coating nozzle onto the wafer W, and the wafer W is rotated to spread the coating liquid on the surface of the wafer W.

As shown in fig. 3, the second block G2 is provided with a heat treatment apparatus 40 for performing heat treatment such as heating and cooling of the wafer W, an adhesion apparatus 41 for improving the adhesion of the resist solution to the wafer W, and a peripheral exposure apparatus 42 for exposing the outer peripheral portion of the wafer W. The heat treatment device 40, the adhering device 41, and the peripheral exposure device 42 are arranged in the vertical direction and the horizontal direction, and the number and arrangement thereof can be arbitrarily selected.

For example, in the third block G3, a plurality of passing apparatuses 50, 51, 52, 53, 54, 55, 56 are provided in this order from the bottom up. In the fourth block G4, a plurality of delivery devices 60, 61, and 62 and an inspection device 63 as a substrate inspection device are provided in this order from the bottom up. The structure of the inspection device 63 will be described later.

As shown in fig. 1, a wafer conveyance area D is formed in an area surrounded by the th block G1 to the fourth block G4, and the wafer conveyance device 70 is disposed in the wafer conveyance area D.

The wafer carrier device 70 includes, for example, a carrier arm 70a that is movable in the Y direction, the X direction, the θ direction, and the up-down direction, the wafer carrier device 70 is movable in the wafer carrier region D, and carries the wafer W to a predetermined unit in the peripheral th block G1, the second block G2, the third block G3, and the fourth block G4, for example, as shown in fig. 3, a plurality of wafer carrier devices 70 are arranged in the up-down direction, and the wafer W can be carried to a predetermined unit located at the same level in the height positions of the respective blocks G1 to G4.

In the wafer transfer area D, a shuttle transfer device 80 is provided for linearly transferring the wafer W between the third block G3 and the fourth block G4.

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

As shown in fig. 1, a wafer carrier 90 is provided beside the third block G3 in the positive X-direction. The wafer transfer device 90 includes a transfer arm 90a that is movable in, for example, the X direction, the θ direction, and the up-down direction. The wafer transfer device 90 moves in the vertical direction while supporting the wafer W, and can transfer the wafer W to each transfer device in the third block G3.

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

Next, the structure of the inspection apparatus 63 will be described, and as shown in fig. 4, the inspection apparatus 63 includes a housing 150, and a carrying-in/out port 150a for carrying in/out the wafer W with respect to the housing 150 is formed in side walls of the housing 150.

As shown in fig. 5, a wafer chuck 151 for holding a wafer W is provided in the housing 150, a guide rail 152 extending from an end side (positive X-direction side in fig. 4) to a end side (negative X-direction side in fig. 4) in the housing 150 is provided on the bottom surface of the housing 150, a driving unit 153 for rotating the wafer chuck 151 and moving the wafer chuck 151 along the guide rail 152 is provided on the guide rail 152, and by this configuration, the wafer W held by the wafer chuck 151 can be moved between a th position near the loading/unloading port 150a and a second position near the edge imaging subunit 170 and the back side imaging subunit 180.

Also, a front side imaging subunit 160, a peripheral side imaging subunit 170, and a back side imaging subunit 180 are provided in the housing 150.

The surface imaging subunit 160 has a camera 161 and an illumination module 162.

The camera 161 is provided above the other end side (negative X direction side in fig. 4) in the housing 150, and the camera 161 includes an imaging element (not shown) such as a lens (not shown) or a CMOS image sensor.

The illumination module 162 is disposed centrally above within the housing 150, and the illumination module 162 has a half mirror 163 and a light source 164. The half mirror 163 is provided at a position facing the camera 161 in a state of being inclined upward by 45 degrees in the direction of the camera 161 from a state in which the mirror surface faces vertically downward. The light source 164 is disposed above the half mirror 163. The illumination light from the light source 164 passes through the half mirror 163 and is directed downward. The light having passed through the half mirror 163 is reflected by an object located below the half mirror 163, is reflected by the half mirror 163, and is taken into the camera 161. That is, the camera 161 can photograph an object in the irradiation area of the light source 164. Therefore, when the wafer chuck 151 holding the wafer W moves along the guide rail 152, the camera 161 can photograph the surface of the wafer W passing through the irradiation area of the light source 164. Data of an image captured by the camera 161 is input to a control unit 200 described later.

As shown in fig. 4 to 6, the peripheral image pickup subunit 170 includes a camera 171, an illumination module 172, and a mirror member 173. The camera 171 includes a lens (not shown), an image pickup device (not shown) such as a CMOS image sensor, and the like.

The illumination module 172 is disposed above the wafer W held by the wafer chuck 151, and the illumination module 172 has a light source 174, a half mirror 175, and a focus adjustment lens 176. The light source 174 is disposed above the half mirror 175. The half mirror 175 is provided at a position facing the camera 171 in a state of being inclined upward by 45 degrees in the direction of the camera 171 from a state in which the mirror surface faces vertically downward. The focus adjustment lens 176 is disposed between the camera 171 and the half mirror 175. The focus adjustment lens 176 is not particularly limited as long as it has a function of changing a focal length combined with the lens of the camera 171.

The mirror member 173 is disposed below the illumination module 172, and the mirror member 173 has a reflective surface 173 a.

When the wafer W held by the wafer chuck 151 is in the second position, the reflecting surface 173a faces the side end surface Ws of the wafer W held by the wafer chuck 151 and the peripheral edge area Wp of the back surface Wb.

In the illumination module 172, the entire light emitted from the light source 174 passes through the half mirror 175 and is then irradiated downward. When the wafer W held by the wafer chuck 151 is at the second position, the diffused light having passed through the half mirror 175 is reflected by the peripheral edge area Wp of the front surface Wf of the wafer W located below the half mirror 175 or the reflection surface 173a of the mirror member 173. The reflected light reflected by the reflecting surface 173a is mainly applied to the side end surface Ws of the wafer W (particularly, the upper end side of the chamfered portion when the edge of the wafer W is chamfered) and the peripheral edge portion Wp of the front surface Wf.

As shown in fig. 7, the reflected light reflected from the peripheral area Wp of the front surface Wf of the wafer W goes to the half mirror 175 without going to the reflection surface 173a of the mirror member 173, and the light going to the half mirror 175 is again reflected by the half mirror 175 and then enters the camera 171 without passing through the focus adjustment lens 176, and , the reflected light reflected from the side end Ws of the wafer W is sequentially reflected by the reflection surface 173a of the mirror member 173 and the half mirror 175 and then enters the camera 171 through the focus adjustment lens 176, and thus both the peripheral area Wp of the front surface Wf of the wafer W and the light from the side end Ws of the wafer W are input to the camera 171, that is, when the wafer W held by the wafer chuck 151 is at the second position, both the peripheral area Wp of the front surface Wf of the wafer W and the side end Ws of the wafer W can be imaged by the camera 171, and data of an image obtained by the camera 171 are input to the control section 200, which will be described later.

Further, by providing the focus adjustment lens 427, the peripheral edge area Wp of the front surface Wf of the wafer W and the side end surface Ws of the wafer W are both clear in the image captured by the camera 171.

As shown in fig. 5, the back side imaging subunit 180 has a camera 181 and an illumination module 182.

The camera 181 is disposed below the other end side (the negative X direction side in fig. 5) in the housing 150, and the camera 181 includes an image pickup device (not shown) such as a lens (not shown) or a CMOS image sensor.

The illumination module 182 is disposed below the illumination module 172 and below the wafer W held by the wafer chuck 151. The illumination module 182 includes a half mirror (not shown) and a light source (not shown). The half mirror is provided at a position facing the camera 181 in a state of being inclined downward by 45 degrees in a direction toward the camera 181 in a state of being directed vertically upward from the mirror surface. The light source is arranged below the half-transmitting and half-reflecting mirror. The illumination from the light source passes through the half mirror and then illuminates upward. The light having passed through the half mirror is reflected by an object located above the half mirror, reflected by the half mirror, and taken into the camera 181. That is, the camera 181 can photograph an object in an irradiation area of the light source of the illumination module 182. Therefore, when the wafer W held by the wafer chuck 151 is at the second position, the camera 181 can image the back surface of the wafer W. Data of an image captured by the camera 181 is input to a control unit 200 described later.

In the inspection apparatus 63 configured as described above, when the wafer W is at the second position, the edge imaging subunit 170 and the back imaging subunit 180, which are imaging units, perform imaging in synchronization with the rotation of the wafer chuck 151 holding the wafer W. Thus, the entire peripheral edge of the wafer W, specifically, the entire peripheral edge Wp on the front surface Wf of the wafer W, the entire side end Ws of the wafer W, and the entire peripheral edge Wp on the back surface of the wafer W can be scanned substantially in the circumferential direction to obtain an image.

As shown in fig. 1, the substrate processing system 1 described above is provided with a control unit 200. The control unit 200 is configured by a computer including, for example, a CPU, a memory, and the like, and includes a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the wafer W in the substrate processing system 1, including a program for controlling the inspection of the wafer W based on the substrate image captured by the inspection device 63. Further, the program may be recorded in a storage medium H readable by a computer and installed from the storage medium H to the control section 200. Note that the inspection control may be performed not by the apparatus-dedicated control unit 200 but by an application program in a computer apparatus connected to the outside of the substrate processing system 1.

As shown in fig. 8, the control unit 200 includes an image acquisition unit 210, a feature value acquisition unit 211, a determination unit 212, and an inspection unit 213.

Specifically, the image acquisition unit 210 performs necessary image processing on the images captured by the edge imaging sub-unit 170 and the back surface imaging sub-unit 180, thereby obtaining an image obtained by scanning the entire surface of each of the peripheral edge area Wp on the front surface Wf of the wafer W, the side edge surface Ws of the wafer W, and the peripheral edge area Wp on the back surface of the wafer W as the inspection target in the circumferential direction as the inspection target peripheral image.

The feature amount acquiring unit 211 acquires the feature amount of each of a plurality of divided regions obtained by dividing a predetermined region in the image of the peripheral edge portion of the wafer W in the inspection target peripheral image acquired by the image acquiring unit 210.

For example, as shown in fig. 9, the predetermined region a1 is a peripheral edge region Wp on the front surface Wf of the wafer W and is a region excluding the side end surface Ws and the chamfer of the wafer W, and an image Im1 of fig. 9 is an example of an inspection target peripheral edge image, and in this image Im1, the circumferential direction of the wafer W coincides with the left-right direction of the image, and the radial direction of the wafer W coincides with the up-down direction of the image, and in an image Im1 of fig. 9, a symbol N is a notch.

In the example shown in the figure, the divided regions a11 to a15 are regions obtained by dividing the predetermined region a1 in the radial direction of the wafer W. When the predetermined region is divided in the radial direction of the wafer W, the size of each divided region in the radial direction is set to 0.5mm or more.

The predetermined area, the number of divisions of the predetermined area, and the size of each divided area (in this example, the width of the wafer W in the radial direction) are set by a user, for example.

The "feature amount of the divided region" is, for example, an average value of pixel values in the divided region of the captured peripheral image, such as the inspection target peripheral image and a reference peripheral image described later.

The imaging peripheral image is composed of three color components of RGB (Red, Green, Blue: Red, Green, Blue). Therefore, the average value of the pixel values/luminance values of the specific color component in the divided region of the captured peripheral image may be set as "the feature amount of the divided region". In this example, the "feature amount of the divided region" is an average value of pixel values/luminance values of a specific color component in the divided region of the captured peripheral image. The specific color is set by a user, for example.

The determination unit 212 performs a predetermined determination regarding the inspection of the peripheral edge portion of the wafer W based on the acquisition result obtained by the feature amount acquisition unit 211. The type of the determination is different depending on the examination desired by the user. The determination unit 212 performs the predetermined determination, for example, based on the acquisition result obtained by the feature amount acquisition unit 211 and the feature amount of the divided region in the reference peripheral image, which is an image of the peripheral portion of the wafer serving as a reference of the predetermined determination. More specifically, the determination unit 212 compares the average value of the pixel values of the specific color component in each of the divided regions with respect to the inspection target peripheral image and the reference peripheral image, and performs the predetermined determination based on the comparison result. For example, if the comparison result is that the magnitude of the difference between the average value in the divided region in the captured peripheral image and the average value in the divided region in the reference peripheral image is equal to or greater than a threshold value, it is determined that an abnormality exists in the divided region, and if the difference is smaller than the threshold value, it is determined that an abnormality does not exist in the divided region. The feature amount of each divided region in the reference peripheral image and the threshold value are set in advance, and the setting is performed by a user, for example. The feature values and the threshold values in the reference peripheral image are stored in a storage unit (not shown).

Specifically, when the number of divided regions determined to have an abnormality by the determination unit 212 is or more, the inspection unit 213 determines that the inspection is not good, and when not, determines that the inspection is good.

Fig. 10A and 10B are diagrams for explaining specific examples of determination by the determination section 212 and inspection by the inspection section 213, fig. 10A shows an example of of the reference peripheral image, fig. 10B shows an example of of the inspection target peripheral image, and the images shown in the figures subsequent to fig. 10A and 10B are images of the entire peripheral region of the peripheral edge of the front surface or the back surface of the wafer W, the left and right directions of the images are aligned with the circumferential direction of the wafer, and the up and down directions of the images are aligned with the radial direction of the wafer, and the images shown in the figures subsequent to fig. 10A and 10B are not actual images, but simply images represented by gray scales, and further, the dark gray portions in the images in fig. 10A and 10B represent blue in the actual images, the light gray portions represent blue in the actual images, and in the following descriptions, the cut sections F1 to 5 are respectively set with the side end Ws of the wafer W as cut sections 362 mm, 3mm to 3mm, and 3mm to 3mm in the radial direction, respectively, and 3 mm.

Both the image of fig. 10A and the image of fig. 10B are images of the entire peripheral edge region of the front surface Wf of the wafer W, and have dark gray portions P1 and P11 and gray portions P2 and P12, and boundaries between the dark gray portions P1 and P11 and the gray portions P2 and P12 are not smooth, and have fine comb tooth shapes. In the conventional method (the above-described peripheral comparison method and edge tracking method), it is difficult to detect a boundary having a fine comb-tooth shape by separating regions having small differences in pixel values from each other. Therefore, in the conventional method, the widths of the gray portions P2 and P12 in the image having the boundaries between the dark gray portions P1 and P11 and the gray portions P2 and P12 as shown in fig. 10A and 10B cannot be determined.

In the image of fig. 10A, the width of the gray portion P2 is substantially fixed to 13mm in the circumferential direction of the wafer W, whereas in the image of fig. 10B, the width of the gray portion P12 is substantially fixed in the circumferential direction, but the width is smaller than that in the image of fig. 10A. Such a difference occurs due to a difference in processing conditions of wafer processing (including a difference in dissolution state and film thickness characteristics of a coating film after processing).

Table 1 shows an example of the average value of the pixel values of the color components in the slices F1 to F5 of the image in fig. 10A, and table 2 shows an example of the average value of the pixel values of the color components in the slices F1 to F5 of the image in fig. 10B.

[ Table 1]

Slicing	R	G	B
				F1	120	179	211
F2	101	144	203
				F3	100	106	193
F4	101	101	190
				F5	101	101	190

[ Table 2]

Slicing	R	G	B
				F1	124	182	208
F2	104	136	190
				F3	101	107	190
F4	102	104	193
				F5	102	103	192

Table 3 shows the difference between the above average value in each of the slices F1 to F5 in the image of fig. 10A and the above average value in each of the slices F1 to F5 in the image of fig. 10B.

[ Table 3]

Slicing	R	G	B
				F1	4	3	-3
F2	3	-8	-4
				F3	1	1	3
F4	1	3	3
				F5	1	2	2

In the determination by the determination unit 212, the image in fig. 10A is set as a reference peripheral image, the average value of the pixel values of the green (G) component of the image is set as a parameter for determination, and the threshold value relating to the determination is set to, for example, 5. Then, since the average value of the pixel values of the green component in the slice F2 exceeds the threshold value, the determination unit 212 determines that there is an abnormality in the slice F2 of the inspection target peripheral image in fig. 10B. Then, the inspection unit 213 determines that the wafer W indicated by the inspection target peripheral image is not acceptable for inspection. That is, the inspection device 63 can determine that the inspection is not satisfactory when acquiring the inspection target peripheral image in which the macroscopic abnormality such as the narrow width of the gray portion P12 is generated as shown in fig. 10B.

Fig. 11A to 11C are views showing other examples of the picked-up edge image, and fig. 11A to 11C are images of the entire edge area of the front surface Wf of the wafer W, fig. 11A shows the picked-up edge image of the wafer W on which the ring-shaped resist film R is formed along the edge area, fig. 11B shows the picked-up edge image of the wafer W on which the resist film is not formed on the edge area, and fig. 11C is a picked-up edge image of the wafer W on which the edge of the resist film R on the side opposite to the wafer peripheral end surface is clear but the resist film R is not formed on the wafer peripheral end surface side.

In the determination by the determination unit 212, the image of fig. 11A (or an image similar thereto) is set as a reference peripheral image, and the predetermined region is set as a region including an annular resist film formed therein. In the determination by the determination unit 212, the average value of the luminance values of the specific color components in the divided regions is used as a parameter for the determination. Then, when the inspection device 63 acquires the inspection target peripheral image as shown in fig. 11A, the determination unit 212 determines that there is no abnormality for any of the divided regions, and the inspection unit 213 determines that the inspection is acceptable. When the inspection target peripheral image as shown in fig. 11B is acquired, the determination unit 212 determines that there is an abnormality in the divided region on the side edge surface side, and the inspection unit 213 determines that the inspection is not good. In addition, when an inspection target peripheral image including an abnormality that cannot be detected by the conventional method as shown in fig. 11C is acquired, the determination unit 212 determines that an abnormality exists in a certain divided region, and the inspection unit 213 determines that the inspection is not satisfactory. That is, according to the inspection apparatus 63, it is possible to more accurately detect the presence or absence of a macroscopic abnormality such as a macroscopic coating failure, and to perform more accurate inspection based on the detection result.

Next, a process for the wafer W performed by using the substrate processing system 1 configured as described above will be described.

In the processing of the wafers W, first, the cassettes C containing a plurality of wafers W are placed on a predetermined placement plate 21 of the cassette delivery station 10. Thereafter, the wafers W in the cassette C are sequentially taken out by the wafer transfer device 23 and transferred to, for example, the delivery device 53 of the third block G3 of the processing station 3.

Then, the wafer W is carried by the wafer carrier device 70 to the heat treatment apparatus 40 of the second block G2 to be subjected to temperature adjustment processing, and thereafter, the wafer W is carried by the wafer carrier device 70 to, for example, the bottom anti-reflection film forming apparatus 31 of the th block G1 to form a bottom anti-reflection film on the wafer W, and thereafter, the wafer W is carried to the heat treatment apparatus 40 of the second block G2 to be subjected to heat treatment to be subjected to temperature adjustment processing.

Subsequently, the wafer W is carried to the adhering device 41 to be subjected to the adhering process, and thereafter, the wafer W is carried to the resist coating device 32 of block G1 to form a resist film on the wafer W.

Next, the wafer W is transported to the upper anti-reflection film forming apparatus 33 of block G1 to form an upper anti-reflection film on the wafer W, and then, the wafer W is transported to the heat treatment apparatus 40 of the second block G2 to be subjected to heat treatment, and then, the wafer W is transported to the peripheral exposure apparatus 42 to be subjected to peripheral exposure treatment.

Next, the wafer W is carried to the delivery device 52 by the wafer carrier device 70, and is carried to the delivery device 62 of the fourth block G4 by the shuttle carrier device 80. Thereafter, the wafer W is transported to the inspection apparatus 63 by the wafer transport apparatus 100 of the interface station 13.

In the inspection apparatus 63, the wafer W is moved to the second position, and the wafer W is imaged by the edge imaging subunit 170 and the back surface imaging subunit 180 in synchronization with the rotation of the wafer chuck 151 holding the wafer W. The imaging result is input to the control unit 200, and the imaging edge image of the wafer W is acquired by the image acquiring unit 210. Next, the feature amount of each divided region in the imaging peripheral image acquired by the image acquisition unit 210 is acquired by the feature amount acquisition unit 211. Next, the determination unit 212 performs a predetermined determination regarding the inspection of the peripheral edge portion of the wafer W based on the acquisition result obtained by the feature amount acquisition unit 211. Then, the inspection unit 213 determines whether the inspection is acceptable or unacceptable based on the determination result obtained by the determination unit 212.

If it is determined that the defect is not acceptable, the wafer W is transported to the delivery apparatus 50 of the third block G3 by the wafer transport apparatus 70 without performing the subsequent exposure process or the like on the wafer W. Thereafter, the wafer W is transferred to the cassette C of the predetermined mounting plate 21 by the wafer transfer device 23 of the cassette transfer station 10.

When the inspection is determined to be acceptable, , the wafer W is transported to the exposure device 12 by the wafer transport device 100 of the interface station 13, and exposure processing is performed in a predetermined pattern, then the wafer W is transported to the delivery device 60 of the fourth block G4 by the wafer transport device 100, and then the wafer W is transported to the heat treatment device 40 by the wafer transport device 70, and post-exposure baking processing is performed, and then the wafer W is transported to the development processing device 30 by the wafer transport device 70, and development processing is performed.

After the development process is completed, the wafer W is carried to the heat treatment apparatus 40 to be subjected to the post-baking process, then the wafer W is carried to the delivery apparatus 50 of the third block G3 by the wafer carrier apparatus 70, and thereafter, the wafer W is carried to the cassette C of the predetermined cassette mounting plate 21 by the wafer carrier apparatus 23 of the cassette delivery station 10, and the photolithography process of series is completed, and then, the photolithography process of series is also performed on the wafer W following in the cassette C.

According to the present embodiment, a predetermined region in the inspection target peripheral image is divided into relatively large divided regions, and for each divided region, determination regarding inspection of the peripheral edge portion of the wafer W is performed based on the feature amount of the divided region. Therefore, macroscopic abnormalities such as large-scale coating defects can be accurately detected.

In the above-described periphery comparison method used in the conventional abnormality detection method, the allowable coating unevenness may be erroneously detected as a defect, but according to the present embodiment, such coating unevenness is not erroneously detected.

In addition, when an annular resist film is formed along the peripheral edge region of the front surface of the wafer W, if a large linear defect exists in the vicinity of the inner end of the resist film, the large linear defect may be erroneously recognized as the inner end of the annular resist film by the edge tracing method or the like. When the erroneous recognition is performed in this manner, it is impossible to accurately check the quality of the annular resist film. According to the present embodiment, such a large linear defect is not erroneously recognized as the inner end of the annular resist film, and the state of formation of the resist film can be accurately inspected.

In order to represent information on the wafer W, a laser mark including a plurality of dots may be formed in a peripheral edge region of the back surface of the wafer W. In the conventional method, the laser mark may be erroneously recognized as the edge of the resist film. In the conventional method, a wafer boat mark (japanese: ボート mark) which may be formed on the peripheral edge of the wafer W may be erroneously recognized as a defect. In contrast, in the present embodiment, when the predetermined region is set, the laser mark forming region and the wafer boat mark forming region are removed from the predetermined region as the removal region, so that the laser mark and the wafer boat mark are not erroneously recognized. The position of the laser mark forming region is fixed, but the wafer boat mark forming region differs for each wafer W. Therefore, when the wafer boat mark formation region is set as the exclusion region, it is preferable that a characteristic shape (pattern) of the wafer boat mark is registered in advance, and the wafer boat mark formation region is automatically recognized based on the registered pattern.

In the above example, the feature amount acquiring unit 211 acquires the feature amount in the peripheral edge area Wp on the front surface Wf of the wafer W to be inspected. However, the feature amount acquiring unit 211 may acquire the feature amount in the peripheral edge area Wp of the back surface Wb of the wafer W to be inspected.

Fig. 12A and 12B are diagrams for explaining specific examples of the judgment by the judgment section 212 and the inspection by the inspection section 213 in the case of acquiring the feature amount in the peripheral edge area Wp of the back surface Wb of the wafer W, fig. 12A shows examples of the reference peripheral edge image, and fig. 12B shows examples of the inspection target peripheral edge image, and in addition, a light gray portion in the images of fig. 12A and 12B shows red in the actual image, and a gray portion shows orange in the actual image, in the following explanation, a line B1 is a divided area of 0mm to 3mm with respect to the side end surface Ws of the wafer W, and similarly, lines B2, B3, and B4 are divided areas of 3mm to 6mm, 6mm to 9mm, and 9mm to 12mm apart from the side end surface Ws of the wafer W, respectively.

Both the image of fig. 12A and the image of fig. 12B are images of the peripheral edge area Wp on the back surface Wb of the wafer W, which are images based on a light gray (red) component, and the image of fig. 12B has a large dark gray portion P21 due to macroscopic defects that are not present in the image of fig. 12B. In such a system, when the region having a different color is large, it is difficult to perform detection by the conventional method.

Table 4 shows an example of the average value of the pixel values of the red component in each of the lines B1 to B4 of the image in fig. 12A, and table 5 shows an example of the average value of the pixel values of the red component in each of the lines B1 to B4 of the image in fig. 11B.

[ Table 4]

Thread	R
		B1	92
B2	188
		B3	197
B4	199

[ Table 5]

Thread	R
		B1
	90
		B2	172
B3	167
		B4	195

In the determination by the determination unit 212, the image of fig. 12A is set as a reference peripheral image, the average value of the pixel values of the red component of the image is set as a parameter for determination, and the threshold value relating to the determination is set to, for example, 5. Then, since the average value of the pixel values of the red component in the lines B2 and B3 of the inspection target peripheral image in fig. 12B exceeds the threshold value, the determination unit 212 determines that there is an abnormality in the divided region corresponding to the lines B2 and B3. Then, the inspection unit 213 determines that the wafer W indicated by the inspection target peripheral image is not acceptable for inspection. That is, therefore, the inspection device 63 can determine that the inspection is not satisfactory when acquiring the inspection target peripheral image in which the macroscopic defect as shown in fig. 12B is generated.

In the above example, a region obtained by dividing a predetermined region in an image of the peripheral portion of the substrate in the radial direction is defined as a divided region. The divided region may be a region obtained by dividing the predetermined region in the circumferential direction. When the divided regions are divided in the circumferential direction, the width of the divided regions in the circumferential direction is, for example, 30 ° to 60 °.

In the above example, the average value of the pixel values of the specific color component in the divided region is obtained as the feature amount of the divided region. Alternatively, the standard deviation of the pixel values in the divided region may be acquired as the feature amount of the divided region.

Fig. 13A to 13D are diagrams for explaining specific examples of the determination by the determination section 212 and the inspection by the inspection section 213 when the region obtained by dividing the predetermined region in the circumferential direction is set as a divided region and the standard deviation of the pixel values in the divided region is acquired as the feature amount of the divided region, fig. 13A shows example of the reference peripheral image, fig. 13B to 13D show example of the inspection target peripheral image, and it is assumed that the light gray portion in the images of fig. 13A to 13D shows orange in the actual image and the dark gray portion shows blue in the actual image, and in the following explanation, the block K1 is a divided region occupying a range of 0 ° to 60 ° from the notch of the wafer W, and similarly, the blocks K2, K3, K4, K5, and K6 are divided regions of 60 ° to 120 °, 120 ° to 180 ° and 240 ° to 300 ° from the wafer W, respectively.

The image of fig. 13A and the image of fig. 13D are captured peripheral images of the wafer W in which the ring-shaped film is satisfactorily formed on the peripheral edge of the resist film along the peripheral edge. Further, the pixel value of the image of fig. 13D is higher than that of the image of fig. 13A. The image of fig. 13B and the image of fig. 13C are captured peripheral images of the wafer W on which the annular film is not partially formed on the peripheral edge of the resist film.

Table 6 shows examples of differences between the average value and standard deviation of the pixel values of the color components and the values of the image in fig. 13A in each block of the image in fig. 13B, table 7 shows examples of differences between the average value and standard deviation of the pixel values of the color components and the values of the image in fig. 13A in each block of the image in fig. 13C, and table 8 shows examples of differences between the average value and standard deviation of the pixel values of the color components and the values of the image in fig. 13A in each block of the image in fig. 13D.

[ Table 6]

[ Table 7]

[ Table 8]

In the determination by the determination unit 212, the image of fig. 13A is set as a reference peripheral image, the average value of the pixel values of the red (R) component of the image is set as a parameter for determination, and the threshold value relating to the determination is set to, for example, 10, and the inspection unit 213 determines that the inspection is not good when it is determined that any blocks (divided regions) are abnormal, and accordingly, the average value of the pixel values of the red component of at least blocks of each of the image of fig. 13B, the image of fig. 13C, and the image of fig. 13D exceeds the threshold value.

Therefore, the feature amount acquisition unit 211 and the determination unit 212 are configured as follows.

The feature value acquisition unit 211 acquires the standard deviation of the pixel values of the color components in each block (divided region) of the inspection target peripheral image as the feature value of the divided region of the inspection target peripheral image.

Then, the determination unit 212 calculates, for each block, the difference between the standard deviation of the specific color component (red component in this example) in the block of the inspection target peripheral image and the standard deviation in the reference peripheral image. When the difference falls within a predetermined range, the determination unit 212 determines that there is no abnormality in the block of the inspection target peripheral image, and when the difference does not fall within the predetermined range, the determination unit 212 determines that there is an abnormality.

Here, in the determination by the determination unit 212, the image of fig. 13A is used as the reference peripheral image, the standard deviation of the pixel value of the red (R) component is used as the feature amount, and the predetermined range relating to the determination is set to 10 to 19, for example. The image in fig. 13B and the image in fig. 13C have blocks in which the difference between the standard deviation of the red component and the standard deviation of the reference peripheral image (the image in fig. 13A) does not fall within the predetermined range. In contrast, in the image of fig. 13D, the difference between the standard deviation of the red component of any block and the standard deviation of the reference peripheral image (the image of fig. 13A) is within the predetermined range. Therefore, only when the image of fig. 13B or the image of fig. 13C is acquired as the inspection target peripheral image, the determination unit 212 determines that there is an abnormality and the inspection unit 213 determines that the inspection is not acceptable. When the image of fig. 13D is acquired as the inspection target peripheral image, the determination unit 212 determines that there is no abnormality, and the inspection unit 213 determines that the inspection is acceptable. Therefore, according to this example, the presence or absence of macroscopic coating failure can be accurately checked.

In addition, when a region obtained by dividing the image in the radial direction is defined as a divided region, an average value of pixel values in the divided region may be used as the feature amount. In addition, when a region obtained by dividing the region in the circumferential direction is a divided region, the standard deviation of the pixel values in the divided region may be used as the feature amount.

In the above example, the divided regions are obtained by dividing a predetermined region in the image of the peripheral portion of the substrate in any of directions in the circumferential direction and the radial direction, but may be obtained by dividing the predetermined region in both the circumferential direction and the radial direction.

The range in which the feature amount is acquired, that is, the predetermined region includes only any of the front peripheral edge region and the rear peripheral edge region of the wafer W, but may include both the front peripheral edge region and the rear peripheral edge region.

When the predetermined region includes both the front and rear peripheral regions of the wafer W, the front and rear divided regions may be provided in the same manner, and when it is determined that there is an abnormality in both the front divided region and the rear divided region located on the rear side of the divided region, the inspection may be failed.

In addition, when the determination is made by the determination unit 212 so that only the peripheral edge area of the front surface of the wafer W is included in the predetermined area and there is a divided area determined to have an abnormality, the additional determination may be made by the determination unit 212 so that only the peripheral edge area of the back surface of the wafer W is included in the predetermined area. When the determination is made by the determination unit 212 so that only the peripheral edge area of the back surface of the wafer W is included in the predetermined area and there is a divided area determined to have an abnormality, the additional determination may be made by the determination unit 212 so that only the peripheral edge area of the front surface of the wafer W is included in the predetermined area.

When such an addition determination is performed, the addition determination may be performed by dividing the divided region on the back side of the divided region determined to have an abnormality in the previous determination by steps.

The predetermined region may include not only the peripheral edge region of the front surface and/or the back surface of the wafer W but also the side end surface of the wafer.

The predetermined region may be set such that the chamfer is excluded from the predetermined region based on the detection result of the edge of the wafer W or the like. Further, the predetermined region may be set so that only the following portions are included in the predetermined region based on the detection result of the edge of the wafer W and the like: the portion on the outer side of the portion on which the chamfer is formed is included.

In contrast to the above example, a histogram of pixel values in a divided region of the captured peripheral image may be extracted as the feature amount of the divided region. In this case, the determination unit 212 determines that there is an abnormality when, for example, a pixel value whose frequency deviation from the frequency of the reference peripheral image is equal to or greater than a predetermined value exists in the divided region to be determined.

The predetermined region in the image of the peripheral portion of the substrate, the number of divisions of the predetermined region, and the size of each divided region are set by a user, for example. In this setting, a reference peripheral image or the like may be displayed on a display unit (not shown).

A wafer W having no abnormality in the peripheral edge portion may be produced, and a reference peripheral edge image may be generated based on an imaging result obtained by imaging the wafer W by the inspection apparatus 63. In addition, the photolithography process may be performed on a plurality of wafers W (for example, several substrate groups) with respect to the reference edge image, and in the process, each wafer W may be imaged by the inspection apparatus 63, and the reference edge image may be generated based on the imaging result. In this case, the reference edge image may be generated by averaging pixel values of the captured edge images of the plurality of wafers, or the captured edge images of the plurality of wafers may be displayed on the display unit, and the captured edge image serving as the reference edge image may be selected from the displayed captured edge images.

As for the setting of the "threshold value", "predetermined range", and specific color component relating to the feature amount, a plurality of pieces of lithography processing are actually performed in the same manner as described above, and the pixel values of the captured peripheral image obtained based on the imaging result at that time are displayed, and the like, and the user performs the setting based on the display result. These "threshold values" and the like may be automatically set based on the feature amount of the reference peripheral image.

In addition, the reference peripheral image may not be set or selected, and only the feature values of the respective divided regions of the reference peripheral image may be set.

The mounting position of the inspection device 63 is not limited to the block G4, and may be mounted on any block among the blocks G1 to G3.

In the above description, the inspection target peripheral image is an image obtained based on the imaging result of the inspection device 63 in the substrate processing system 1. However, the inspection target peripheral image may be an image obtained based on the imaging result of an inspection device or an imaging device outside the substrate processing system 1.

In the above description, the resist film formed on the wafer W in the process of manufacturing the semiconductor device is inspected, but the technique according to the present disclosure can be applied to other inspections performed when various processes related to the manufacturing process of the semiconductor device are performed.

The embodiments disclosed herein are considered to be illustrative in all respects, rather than restrictive. The above-described embodiments may be omitted, replaced, or modified in various ways without departing from the scope of the appended claims and the gist thereof.

The following configuration also falls within the technical scope of the present disclosure.

(1) A substrate inspection method for inspecting a substrate, the substrate inspection method comprising the steps of:

a feature value acquisition step of acquiring a feature value of each of a plurality of divided regions in an image of a peripheral portion of the substrate to be inspected, the divided regions being obtained by dividing a predetermined region in the image of the peripheral portion of the substrate; and

and a determination step of performing a predetermined determination regarding inspection of the peripheral edge portion of the substrate based on the acquisition result in the feature amount acquisition step.

In the above (1), a predetermined region in the inspection target peripheral image is divided into divided regions, and for each of the divided regions, a determination regarding the inspection of the peripheral portion of the substrate is performed based on the feature amount of the divided region. Therefore, macroscopic abnormalities such as large-scale coating defects can be accurately detected.

(2) In the substrate inspection method according to the above (1), in the determination step, the predetermined determination is performed based on the acquisition result in the feature amount acquisition step and the feature amount of the divided region in a reference peripheral image, which is an image of the peripheral portion of the substrate that is a reference of the predetermined determination.

(3) In the substrate inspection method described in (1) or (2), the feature amount is an average value of pixel values in the divided region.

(4) The substrate inspection method according to any one of above (1) to (3), wherein the feature amount is a standard deviation of pixel values in the divided regions.

(5) The substrate inspection method according to any one of items in items (1) to (4), wherein the feature amount is a histogram of pixel values in the divided region.

(6) The substrate inspection method according to any one of items in items (3) to (5), wherein the feature amount is an amount related to a pixel value of a specific color.

(7) The substrate inspection method according to any one of items in items (1) to (6), wherein the divided region is a region obtained by dividing the predetermined region in a radial direction of the substrate.

(8) The substrate inspection method according to any one of items in items (1) to (7), wherein the divided region is a region obtained by dividing the predetermined region in a circumferential direction of the substrate.

(9) The substrate inspection method according to any one of items above (1) to (8), further comprising an imaging step of imaging a peripheral edge portion of the substrate,

the inspection target peripheral image is an image of the peripheral portion of the substrate obtained based on the imaging result in the imaging step.

(10) A substrate inspection apparatus for inspecting a substrate, the apparatus comprising:

a feature value acquisition unit that acquires a feature value of each of a plurality of divided regions in an inspection target peripheral image, which is an image of the peripheral portion of the substrate obtained as a result of the imaging of the inspection target by the imaging unit, the divided regions being obtained by dividing a predetermined region in the image of the peripheral portion of the substrate; and

and a determination unit that performs a predetermined determination regarding inspection of the peripheral edge portion of the substrate based on the acquisition result obtained by the feature amount acquisition unit.