Substrate imaging apparatus, substrate processing apparatus, substrate imaging method, and substrate processing method

Abstract

The invention provides a substrate imaging apparatus, a substrate processing apparatus, a substrate imaging method, and a substrate processing method. The substrate imaging apparatus includes an illumination unit, an imaging unit, and a control unit. The illumination unit emits illumination light to the upper surface of the substrate held by the substrate holding device. The image capturing unit captures an image of the upper surface of the substrate irradiated with the illumination light. On the basis of the output of the imaging unit, inspection image data indicating the state of at least a partial region of the upper surface of the substrate is acquired. The inspection image data corresponds to light of a wavelength absorbed by the substrate.

Description

Technical Field

[0001] This invention relates to a substrate imaging apparatus, a substrate processing apparatus, a substrate imaging method, and a substrate processing method. Background Technology

[0002] In various processing steps involving substrates, substrate inspection is performed. For example, in the substrate inspection apparatus described in Japanese Patent Application Publication No. 2018-36235, a strip of light larger than the diameter of the substrate in one direction is emitted downwards from a light-projecting section. In this state, the substrate to be inspected moves in a direction orthogonal to the first direction, passing below the light-projecting section. As a result, the strip of light sequentially illuminates various portions of the upper surface of the substrate. The strip of light is sequentially reflected by each portion of the substrate and received by a light-receiving section. Based on the amount of light received by the light-receiving section, image data representing an image of the entire upper surface of the substrate is generated. The substrate is inspected based on the generated image data. Summary of the Invention

[0003] During inspection, it is preferable to accurately determine the condition of the upper surface of the substrate (e.g., the presence or absence of defects, the film thickness distribution of the coating, or the presence or absence of a coating). That is, it is preferable that the image data used to inspect the upper surface of the substrate more accurately represents the condition of the upper surface of the substrate. However, depending on the type of substrate being inspected, it is sometimes impossible to obtain appropriate image data corresponding to the inspection of that substrate.

[0004] The purpose of this invention is to provide a substrate imaging apparatus, a substrate processing apparatus, a substrate imaging method, and a substrate processing method capable of performing appropriate inspections on the upper surface of a substrate according to the type of substrate.

[0005] According to one aspect of the present invention, a substrate imaging apparatus includes: an illumination unit that illuminates an illumination light onto an upper surface of a substrate; an imaging unit that captures images of the upper surface of the substrate illuminated by the illumination light; and a control unit that, based on the output of the imaging unit, acquires inspection image data representing the state of at least a portion of the upper surface of the substrate, the inspection image data corresponding to light of an absorption wavelength of the substrate.

[0006] According to another aspect of the present invention, a substrate processing apparatus includes: the substrate imaging apparatus described above; and an inspection unit that inspects the condition of the upper surface of the substrate based on inspection image data acquired by the substrate imaging apparatus.

[0007] Another aspect of the present invention provides a substrate imaging method comprising the following steps: irradiating an upper surface of a substrate with illumination light; imaging the upper surface of the substrate irradiated with the illumination light using an imaging unit; and obtaining inspection image data representing the state of at least a portion of the upper surface of the substrate based on the output of the imaging unit, the inspection image data corresponding to light of an absorption wavelength of the substrate.

[0008] Another aspect of the substrate processing method of the present invention includes: the substrate imaging method described above; and a step of inspecting the state of the upper surface of the substrate based on inspection image data obtained by the substrate imaging method.

[0009] According to the present invention, the upper surface of the substrate can be subjected to appropriate inspection corresponding to the type of substrate. Attached Figure Description

[0010] Figure 1 This is a perspective view of a substrate inspection apparatus according to an embodiment of the present invention.

[0011] Figure 2 It means Figure 1 A schematic side view of the internal structure of the substrate inspection device.

[0012] Figure 3 This is a top view of the silicon carbide substrate held by the rotating retainer, viewed from above.

[0013] Figure 4 This indicates that during the imaging of a silicon carbide substrate, light is shone onto the substrate from the illumination unit and guided to the light source. Figure 1 A diagram showing the travel state of each wavelength of white light from the camera lens.

[0014] Figure 5 This is an example of an R-image obtained by photographing a silicon carbide substrate.

[0015] Figure 6 This is an example of a G-image obtained by photographing a silicon carbide substrate.

[0016] Figure 7 This is an example of a B-image obtained by photographing a silicon carbide substrate.

[0017] Figure 8 It means Figure 1 A block diagram of the functional structure of the control unit.

[0018] Figure 9 It means by Figure 8 The flowchart of the shooting inspection process performed by the control department.

[0019] Figure 10 It means by Figure 8The flowchart of the shooting inspection process performed by the control department.

[0020] Figure 11 It means Figure 9 The flowchart shows an example of the inspection process in step S16.

[0021] Figure 12 It means possessing Figure 1 A schematic block diagram of an example of a substrate processing apparatus for a substrate inspection device. Detailed Implementation

[0022] Hereinafter, a substrate imaging apparatus, a substrate processing apparatus, a substrate imaging method, and a substrate processing method according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, substrate refers to substrates used in liquid crystal display devices or organic EL (Electro Luminescence) display devices, such as substrates for FPD (Flat Panel Display), semiconductor substrates, substrates for optical discs, substrates for magnetic disks, substrates for optical discs, substrates for photomasks, ceramic substrates, or substrates for solar cells.

[0023] In this embodiment, the substrate has a circular shape when viewed from above, except for the formation of the orientation plane or the notch. In the following description, the orientation plane and notch formed on the substrate for orientation confirmation will be referred to simply as a notch.

[0024] Furthermore, the substrate has a surface that serves as the circuit formation surface and a back surface that serves as the surface opposite to the circuit formation surface. In the following description, regardless of the surface and back surface of the substrate, the upward-facing surface of the substrate is referred to as the upper surface of the substrate, and the downward-facing surface of the substrate is referred to as the lower surface of the substrate.

[0025] 1. Structure of the substrate inspection device

[0026] The substrate imaging apparatus of this embodiment is assembled into a substrate inspection apparatus for inspecting the condition of the upper surface of a substrate. The substrate inspection apparatus will be described below.

[0027] Figure 1 This is a perspective view of a substrate inspection apparatus according to an embodiment of the present invention. Figure 2 It means Figure 1 A schematic side view of the internal structure of the substrate inspection apparatus 200. (See attached image.) Figure 1 As shown, the substrate inspection device 200 includes a housing 210, an illumination unit 220, a reflection unit 230, an imaging unit 240, a substrate holding device 250, a moving unit 260, an orientation detection unit 270, a control unit 280, and an operation unit 290.

[0028] The housing portion 210 has a rectangular box shape extending in one direction. A slit-shaped opening 211 for loading and unloading the substrate W is formed on the side of the housing portion 210. The illumination portion 220, the reflection portion 230, the imaging portion 240, the substrate holding device 250, the moving portion 260, and the orientation detection portion 270 are housed within the housing portion 210.

[0029] The lighting unit 220 according to this embodiment has one or more light sources (white light sources) that generate white light, and is formed to extend in a horizontal plane along a direction orthogonal to the long side direction of the housing unit 210.

[0030] Furthermore, the illumination unit 220 is disposed approximately at the center of the housing portion 210, emitting a strip of light larger than the diameter of the substrate W obliquely downwards. In the following description, the direction in which the illumination unit 220 extends in the horizontal plane (the direction of the short side of the housing portion 210) in the substrate inspection apparatus 200 is referred to as the first device direction D1. The direction in the horizontal plane orthogonal to the first device direction D1 (the direction of the long side of the housing portion 210) is referred to as the second device direction D2.

[0031] The white light emitted from the illumination unit 220 in this example includes light in the red wavelength region (red wavelength component), light in the green wavelength region (green wavelength component), and light in the blue wavelength region (blue wavelength component). In this embodiment, the wavelength region of the red light is 650 nm and its surrounding wavelength region (approximately 600 nm to 700 nm). The wavelength region of the green light is 550 nm and its surrounding wavelength region (approximately 500 nm to 580 nm). The wavelength region of the blue light is 450 nm and its surrounding wavelength region (approximately 400 nm to 490 nm).

[0032] The reflective portion 230 includes, for example, an elongated reflector, adjacent to the illumination portion 220 in the second device direction D2. Furthermore, the reflective portion 230 is disposed approximately at the center of the housing portion 210, extending parallel to the first device direction D1 and facing obliquely downwards.

[0033] The imaging unit 240 is positioned opposite the reflector of the reflecting unit 230 in the horizontal plane. The imaging unit 240 includes three imaging elements (241, 242, 243) and one or more condenser lenses 244.

[0034] The three imaging elements (241, 242, and 243) are, for example, a CCD (charge-coupled device) line sensor or a CMOS (complementary metal oxide semiconductor) line sensor. In the following description, when distinguishing the three line sensors provided with the imaging unit 240, these line sensors will be appropriately referred to as the first line sensor 241, the second line sensor 242, and the third line sensor 243.

[0035] exist Figure 2 In the diagram, a front view of the first line sensor 241, the second line sensor 242, and the third line sensor 243, viewed along the direction D2 of the second device, is shown within a dialog box with double-dotted lines. (See diagram for reference.) Figure 2 As shown in the dialog box, the first line sensor 241 has a structure in which multiple R pixels pa corresponding to red light are arranged in a line. The second line sensor 242 has a structure in which multiple G pixels pb corresponding to green light are arranged in a line. The third line sensor 243 has a structure in which multiple B pixels pc corresponding to blue light are arranged in a line.

[0036] With the imaging unit 240 housed within the housing 210, the first line sensor 241, the second line sensor 242, and the third line sensor 243 are respectively arranged in a vertical direction and extend parallel to the first device direction D1. Thus, the imaging unit 240 has a linear imaging area extending parallel to the first device direction D1.

[0037] As described above, the imaging unit 240 includes one or more condenser lenses 244. Figure 1 and Figure 2 The image shows a condenser lens 244. The focal depth of the imaging unit 240 is adjusted by one or more condenser lenses 244 so that, during imaging of the substrate W (described later), it is consistent with the length of the light travel path from the surface of the substrate W through the reflector 230 to the three imaging elements (241, 242, 243).

[0038] The substrate holding device 250 is, for example, a rotary chuck, including a drive unit 251 and a rotary holding part 252. The drive unit 251 is, for example, an electric motor, and has a rotation shaft 253. The rotary holding part 252 is mounted at the front end of the rotation shaft 253 of the drive unit 251, and adsorbs and holds the central region of the lower surface of the substrate W to be inspected. In addition, the rotary holding part 252 is driven to rotate about a vertical axis while the substrate W is adsorbed and held.

[0039] exist Figure 1 The top view of the rotation holding part 252 is shown within a dialog box with double-dotted lines. In this embodiment, the rotation holding part 252 is formed of, for example, resin, such as... Figure 1 As shown in the dialog box, it has a roughly circular plate shape. The diameter of the rotating holding part 252 is smaller than the diameter of the substrate W. Therefore, when the rotating holding part 252 holds the substrate W, the periphery of the substrate W does not overlap with the rotating holding part 252 when viewed from above.

[0040] The rotation holding portion 252 has a flat portion 252a that protrudes upward when the substrate W is not being held. The flat portion 252a is a circular flat surface that forms the upper surface of the rotation holding portion 252.

[0041] A plurality of suction holes 252b are formed dispersedly in the flat portion 252a (four in this example). An air suction system (not shown) is connected to the plurality of suction holes 252b. In addition, a plurality of protrusions 252c protruding upward are formed dispersedly in the flat portion 252a. Furthermore, an annular sealing protrusion 252d extending along the outer periphery of the rotating retaining portion 252 and protruding upward is formed in the flat portion 252a.

[0042] The heads of a plurality of screw components 252e are exposed approximately at the center of the flat portion 252a. The plurality of threaded components 252e are used to mount the rotating retainer 252 to... Figure 2 The component of the rotating shaft 253.

[0043] When the substrate W is held by the rotating holding portion 252, the substrate W is first placed on the rotating holding portion 252. At this time, the plurality of protrusions 252c and the sealing protrusions 252d contact the lower surface of the substrate W, and the substrate W is supported. In addition, a closed space is formed between the lower surface of the substrate W and the flat portion 252a of the rotating holding portion 252. In this state, the atmosphere in the closed space is drawn in through the plurality of suction holes 252b. As a result, the substrate W is held by adsorption on the rotating holding portion 252.

[0044] The moving part 260 includes a pair of guide members 261 and a moving retaining part 262. For example... Figure 1 As shown, a pair of guide members 261 are arranged along the first device direction D1 and extend along the second device direction D2. Figure 2 As shown, the movable holding part 262 is configured to move along a pair of guide members 261 in the second device direction D2 and the opposite direction while holding the substrate holding device 250. The movable holding part 262 moves while the substrate holding device 250 holds the substrate W, thereby allowing the substrate W to pass under the illumination part 220 and the reflection part 230. Consequently, the linear imaging area of ​​the imaging part 240 passes over one side of the substrate W.

[0045] The orientation detection unit 270 is, for example, a reflective photoelectric sensor including a light-emitting element and a light-receiving element. While the substrate W is rotated by the substrate holding device 250, it emits light toward the outer periphery of the substrate W and receives reflected light from the substrate W. The orientation detection unit 270 detects the cut in the substrate W based on the amount of light received from the reflected light. A transmissive photoelectric sensor can also be used as the orientation detection unit 270.

[0046] Control Unit 280 ( Figure 1 For example, it includes a CPU (central processing unit) and memory, or a microcomputer, and controls the lighting unit 220, the imaging unit 240, the substrate holding device 250, the moving unit 260, and the orientation detection unit 270. Details of the control unit 280 will be described later.

[0047] Operation Unit 290 ( Figure 1 For example, it includes a keyboard and indicator devices, configured to be operated by a user. By operating the operation unit 290, the user can input the type of a substrate W before inspecting it. In addition, by operating the operation unit 290, the user can set various operating conditions and inspection conditions of the substrate inspection device 200.

[0048] 2. The substrate inspection device 200 takes pictures of the substrate W.

[0049] The imaging operation of the substrate W in the substrate inspection apparatus 200 will be explained. The substrate W, which is to be inspected, is... Figure 1 The opening 211 is moved into the housing 210 and held by the substrate holding device 250.

[0050] Next, while rotating the substrate W via the substrate holding device 250, light is emitted from the direction detection unit 270 towards the periphery of the substrate W, and the reflected light is received by the direction detection unit 270. This detects the cut of the substrate W and determines its orientation. Based on this determination, the rotational position of the substrate W is adjusted so that the cut of the substrate W faces a predetermined direction.

[0051] Next, a strip of light is emitted obliquely downward from the illumination unit 220. In this state, the substrate W moves in the second device direction D2 via the moving part 260 so that the substrate W passes under the illumination unit 220. The illumination range of the light from the illumination unit 220 in the first device direction D1 is larger than the diameter of the substrate W. As a result, multiple portions of one side of the substrate W are sequentially illuminated by light from the illumination unit 220. The light reflected from the substrate W is further reflected by the reflecting part 230 and guided to the imaging part 240.

[0052] The three imaging elements (241, 242, 243) of the imaging unit 240 receive light reflected from one side of the substrate W at a predetermined sampling period, thereby sequentially imaging multiple portions of one side of the substrate W.

[0053] At this time, the multiple R pixels pa constituting the first linear sensor 241 respectively receive light in the red wavelength region and output pixel data representing the value corresponding to the amount of light received. Additionally, the multiple G pixels pb constituting the second linear sensor 242 respectively receive light in the green wavelength region and output pixel data representing the value corresponding to the amount of light received. Furthermore, the multiple B pixels pc constituting the third linear sensor 243 respectively receive light in the blue wavelength region and output pixel data representing the value corresponding to the amount of light received.

[0054] Hereinafter, the pixel data output from R pixel pa will be called R pixel data, the pixel data output from G pixel pb will be called G pixel data, and the pixel data output from B pixel pc will be called B pixel data.

[0055] Image data representing the entire surface of one side of the substrate W is generated based on multiple R-pixel data output from the imaging unit 240. Additionally, image data representing the entire surface of one side of the substrate W is generated based on multiple G-pixel data. Furthermore, image data representing the entire surface of one side of the substrate W is generated based on multiple B-pixel data.

[0056] Hereinafter, image data generated based on R pixel data will be referred to as R image data, and the image represented by R image data will be referred to as an R image. Similarly, image data generated based on G pixel data will be referred to as G image data, and the image represented by G image data will be referred to as a G image. Likewise, image data generated based on B pixel data will be referred to as B image data, and the image represented by B image data will be referred to as a B image. Furthermore, in the following explanations, unless there is a need to distinguish between R image data, G image data, and B image data, they will be simply referred to as image data.

[0057] Using at least one of the R image data, G image data, and B image data generated as described above, the substrate W is inspected as described later. Then, the moving unit 260 returns the substrate W to a predetermined position, and the inspection is performed using the method described later. Figure 12 The conveying device 120 moves the substrate W through the opening 211 to the outside of the housing 210.

[0058] Here, the R image data, G image data, and B image data each contain multiple pixel values ​​representing multiple locations on the upper surface of the substrate W. The amount of light irradiated from the illumination unit 220 onto the substrate W is set such that the maximum value of the multiple pixel values ​​representing the central portion of the substrate in the generated R, G, and B images is close to a predetermined target pixel value. Furthermore, the amount of light can be set based on experiments or simulations, for example.

[0059] 3. Inspection of substrate W

[0060] In the aforementioned substrate inspection apparatus 200, at least one of the R image data, G image data, and B image data generated by photographing the substrate W is acquired as inspection image data according to a predetermined acquisition method. Based on this, various inspections can be performed using the acquired inspection image data.

[0061] (1) First inspection

[0062] The first inspection that can be performed by the substrate inspection apparatus 200 will be described. In this example, the substrate W to be inspected is a substrate W with a coating film such as a resist film formed thereon. In the first inspection, it is determined whether there are defects in the coating film formed on the substrate W.

[0063] The first inspection is performed as follows: First, image data representing the upper surface of a sample substrate without defects, and image data corresponding to the inspection image data, are prepared as sample image data. The sample image data can be generated by photographing the upper surface of the sample substrate using the substrate inspection apparatus 200, or by simulating the photographing of the sample substrate. Next, the upper surface of the substrate W to be inspected is photographed, and inspection image data of the substrate W to be inspected is obtained.

[0064] Next, based on the comparison between the pixel values ​​of the sample image data and the pixel values ​​of the inspection image data of the substrate W to be inspected, it is determined whether the substrate W to be inspected has defects. More specifically, the differences between the pixel values ​​of corresponding pixels in the sample image data and the inspection image data are calculated, and image data consisting of multiple calculated difference values ​​is generated as difference image data. Based on this, if the difference values ​​corresponding to each pixel in the difference image data are within a predetermined allowable range, the substrate W to be inspected is determined to be normal. That is, the substrate W is determined to be without defects. On the other hand, if the difference values ​​corresponding to each pixel in the difference image data are not within the predetermined allowable range, the substrate W to be inspected is determined to be abnormal. That is, the substrate W is determined to have defects.

[0065] (2) Second inspection

[0066] The second inspection that can be performed by the substrate inspection apparatus 200 will be described. In this example, the substrate W to be inspected is a substrate W with a coating film such as a resist film formed thereon. In the second inspection, it is determined whether there is unevenness in the coating film formed on the substrate W, that is, whether the distribution of the coating film thickness is within the allowable range.

[0067] The second inspection is performed as follows: First, the upper surface of the substrate W to be inspected is photographed to obtain inspection image data of the substrate W. Next, in the image represented by the inspection image data, it is determined whether there is a portion from the center of the substrate W to the outer periphery of the substrate W where the pixel value changes significantly by a proportion exceeding a predetermined threshold. Based on this, if a portion with a significant change in pixel value exists, it is determined that the substrate W has unevenness. On the other hand, if there is no portion with a significant change in pixel value, it is determined that the substrate W does not have unevenness.

[0068] (3) Third inspection

[0069] The third inspection, which can be performed by the substrate inspection apparatus 200, will be described. A coating film should ideally be formed on the substrate W after the coating film formation process. However, during the manufacturing process of the substrate W, due to human error or other reasons, a substrate W without a coating film may be mistakenly processed as having a coating film. In this example, the substrate W to be inspected is one that should have a coating film such as a resist film formed. The third inspection determines whether a coating film has been formed on the substrate W.

[0070] The third inspection is performed as follows: First, the upper surface of the substrate W to be inspected is photographed to obtain inspection image data of the substrate W. Next, it is determined whether the overall brightness of the image represented by the inspection image data is within a predetermined range. In this case, the overall brightness of the image can be represented by the sum of the pixel values ​​of all pixels in the image, or by the average of the pixel values ​​of all pixels in the image. Alternatively, the maximum, minimum, or average value of multiple pixels in the central part of the image can be used as the overall brightness of the image.

[0071] Based on this, if the overall brightness of the image represented by the inspection image data is within a predetermined range, it is determined that a coating film has been formed on the substrate W of the inspection object. On the other hand, if the overall brightness of the image represented by the inspection image data is not within a predetermined range, it is determined that a coating film has not been formed on the substrate W of the inspection object.

[0072] 4. Check image data

[0073] As for the types of substrates W that are subject to inspection, substrates W made of silicon and substrates W made of silicon carbide can be listed. Hereinafter, substrates W made of silicon will be appropriately referred to as silicon substrates, and substrates W made of silicon carbide will be appropriately referred to as silicon carbide substrates.

[0074] Figure 3This is a top view of the silicon carbide substrate held by the rotation holding part 252, viewed from above. The silicon carbide substrate is an orange, semi-transparent substrate. Therefore, when the silicon carbide substrate held by the rotation holding part 252 is viewed from above, as... Figure 3 As shown, a rotation-holding portion 252 exists in the central region of the lower surface of the silicon carbide substrate. Figure 3 In this embodiment, the silicon carbide substrate is visually perceived as an orange translucent substrate by the dot pattern. Furthermore, in this embodiment, a translucent substrate refers, for example, a substrate with a white light transmittance of approximately 20% or more and less than 100%. Additionally, an opaque substrate, as described later, refers, for example, a substrate with a white light transmittance of approximately 0% or more and less than 20%.

[0075] As described above, when the substrate W is a translucent substrate with a specific color, the substrate W readily absorbs light of a color that is complementary to that specific color. Therefore, in the substrate inspection apparatus 200, when photographing the silicon carbide substrate, a portion of the white light illuminating the substrate W from the illumination unit 220 and traveling inside the silicon carbide substrate is absorbed by the silicon carbide substrate.

[0076] Figure 4 This indicates that during the imaging of the silicon carbide substrate, the light is irradiated from the illumination unit 220 onto the substrate W and guided to... Figure 1 A diagram showing the travel of each wavelength of white light from the 240-degree camera module. (See diagram for reference.) Figure 4 As shown in the upper section, when photographing a silicon carbide substrate, white light is irradiated from the illumination unit 220 onto the upper surface of the silicon carbide substrate held by the substrate holding device 250. As described above, the white light in this embodiment includes light in the red wavelength region (red wavelength component), light in the green wavelength region (green wavelength component), and light in the blue wavelength region (blue wavelength component).

[0077] In this case, a portion of the red light, such as Figure 4 As shown by the solid arrow on the lower left, the red light is reflected from the upper surface of the silicon carbide substrate and guided to the imaging unit 240. The remaining portion of the red light travels inside the silicon carbide substrate and is reflected from the upper surface of the rotating holding part 252, then travels again inside the silicon carbide substrate and is guided to the imaging unit 240. Here, the red light has no complementary color relationship with the color of the silicon carbide substrate (orange). Therefore, the red light is hardly absorbed by the silicon carbide substrate during its travel inside the substrate.

[0078] A portion of green light, such as Figure 4As indicated by the single-dotted arrow in the center of the lower section, the green light is reflected from the upper surface of the silicon carbide substrate and guided to the reflective portion 230. The remaining portion of the green light travels inside the silicon carbide substrate and is reflected from the upper surface of the rotating holding portion 252, then travels again inside the silicon carbide substrate and is guided to the imaging portion 240. Here, like red, green has no complementary color relationship with the color of the silicon carbide substrate (orange). Therefore, the green light is hardly absorbed by the silicon carbide substrate during its travel inside the substrate.

[0079] like Figure 4 As indicated by the double-dotted arrow on the lower right side of the image, a portion of the blue light is reflected from the upper surface of the silicon carbide substrate and guided to the reflective portion 230. The remaining portion of the blue light travels inside the silicon carbide substrate and is reflected from the upper surface of the rotation holding portion 252, again traveling inside the silicon carbide substrate and being guided to the reflective portion 230. Here, blue and the color of the silicon carbide substrate (orange) are complementary colors. Therefore, most of the blue light traveling inside the silicon carbide substrate is absorbed by the silicon carbide substrate. Consequently, light in the blue wavelength range reflected from the upper surface of the rotation holding portion 252 hardly incident on the imaging portion 240.

[0080] Figure 5 This is an example of an R-image obtained by photographing a silicon carbide substrate. Figure 6 This is an example of a G-image obtained by photographing a silicon carbide substrate. Figure 7 This is an example of a B-image obtained by photographing a silicon carbide substrate. Figures 5-7 The image on the left shows images of a silicon carbide substrate (R image, G image, and B image). The right side shows, graphically, the pixel values ​​corresponding to multiple segments along a straight line connecting two points p1 and p2 defined on the upper surface of the silicon carbide substrate. Figures 5-7 In the right part of the chart, the vertical axis represents the pixel value, and the horizontal axis represents the position between points p1 and p2 on the silicon carbide substrate.

[0081] like Figure 5 and Figure 6 As shown, the R and G images, in addition to the image of the upper surface of the silicon carbide substrate, also include an image representing the upper surface of the rotation holding portion 252 (typically an image of the protrusion 252c). The reason the R and G images include the image of the rotation holding portion 252 is that the red and green light reflected by the rotation holding portion 252 is not absorbed by the silicon carbide substrate and is incident on the imaging portion 240. Furthermore, the reason the R and G images include the image of the rotation holding portion 252 is that the depth of focus of the imaging portion 240 easily covers the area of ​​the upper surface of the rotation holding portion 252. Figure 5 and Figure 6In the right part of the diagram, hollow arrows indicate the pixel value changes corresponding to the protrusion 252c of the rotation holding part 252. The pixel value changes representing the shape of the upper surface of the rotation holding part 252 are a major cause of inspection defects such as misjudgment.

[0082] On the other hand, such as Figure 7 As shown, image B only includes the upper surface of the silicon carbide substrate and does not include an image showing the upper surface of the rotation holding part 252. The reason image B does not include an image of the rotation holding part 252 is that the blue light entering the silicon carbide substrate is absorbed by the silicon carbide substrate. Figure 7 In the right part of the chart, with Figure 5 and Figure 6 Unlike the previous example, the change in pixel value corresponding to the protrusion 252c of the rotation holding part 252 is not shown.

[0083] Based on these results, it is evident that if R-image data and G-image data are used when inspecting a silicon carbide substrate, the image from the rotating holding section 252 functions as noise, making accurate inspection impossible. Therefore, in the substrate inspection apparatus 200 of this embodiment, only B-image data is acquired as inspection image data when inspecting a silicon carbide substrate.

[0084] The silicon substrate is not transparent compared to the silicon carbide substrate. The front and back sides of the silicon substrate almost completely reflect the white light generated by the illumination unit 220. Therefore, the R-image data, G-image data, and B-image data obtained by photographing the silicon substrate do not contain any image components of the rotation holding unit 252. Therefore, in the substrate inspection apparatus 200 of this embodiment, when inspecting the silicon substrate, all three image data—R-image data, G-image data, and B-image data—are acquired as inspection image data.

[0085] 5. Functional structure of the control unit 280 of the substrate inspection device 200

[0086] Figure 8 It means Figure 1 A block diagram of the functional structure of the control unit 280. (See diagram below.) Figure 8 As shown, the control unit 280 includes an image capture control unit 281, an image data generation unit 282, a substrate characteristic determination unit 283, an inspection image data acquisition unit 284, an inspection storage unit 285, and an inspection unit 286 as functional units for capturing and inspecting the substrate W. These functional units are implemented by a CPU executing a computer program (a program for performing the image capture and inspection processing described later) stored in a memory or the like. Alternatively, the structure of some or all of the functional units of the control unit 280 can also be implemented using hardware such as electronic circuits.

[0087] The shooting control unit 281 controls the lighting unit 220, the shooting unit 240, the substrate holding device 250, the moving unit 260, and the orientation detection unit 270 to capture images of the housing unit 210. Figure 1 The substrate W of the imaging unit 240. In this case, the first line sensor 241, the second line sensor 242 and the third line sensor 243 of the imaging unit 240 sequentially output the R pixel data, G pixel data and B pixel data obtained by imaging to the control unit 280.

[0088] When the imaging unit 240 captures the substrate W, the image data generation unit 282 generates R image data based on the R pixel data output from the imaging unit 240. Furthermore, the image data generation unit 282 generates G image data based on the G pixel data output from the imaging unit 240. Additionally, the image data generation unit 282 generates B image data based on the B pixel data output from the imaging unit 240.

[0089] The storage unit 285 stores substrate characteristic information and inspection conditions. The substrate characteristic information includes information indicating the method for acquiring inspection image data corresponding to the characteristics of the substrate W to be inspected.

[0090] Here, a substrate W with a semi-transparent substrate that readily absorbs blue light compared to red and green light is called a B-absorbing substrate, and a substrate W with a semi-transparent substrate that readily absorbs green light compared to red and blue light is called a G-absorbing substrate. Furthermore, a substrate W with a semi-transparent substrate that readily absorbs red light compared to green and blue light is called an R-absorbing substrate, and an opaque substrate W that does not transmit white light is called an opaque substrate.

[0091] In this case, the aforementioned substrate characteristic information specifically includes information such as "when the substrate W to be inspected is a B-absorbing substrate, B image data is acquired as inspection image data." Additionally, the substrate characteristic information includes information such as "when the substrate W to be inspected is a G-absorbing substrate, G image data is acquired as inspection image data." Furthermore, the substrate characteristic information includes information such as "when the substrate W to be inspected is an R-absorbing substrate, R image data is acquired as inspection image data." Moreover, the substrate characteristic information includes information such as "when the substrate W to be inspected is an opaque substrate, R image data, G image data, and B image data are acquired as inspection image data, respectively."

[0092] The inspection conditions include the information required to inspect the substrate W using the inspection image data. For example, in the case of performing the first inspection described above, the inspection conditions include the allowable range of each differential value of the sample image data and the differential image data. Furthermore, in the case of performing the second inspection described above, the inspection conditions include a threshold for determining the amount of change in pixel values ​​in the inspection image data. Moreover, in the case of performing the third inspection, the inspection conditions include a predetermined range for determining the brightness of the image represented by the inspection image data.

[0093] In the substrate inspection apparatus 200, as described above, before inspecting a substrate W, information indicating the type of the substrate W is input based on the user's operation of the operation unit 290. The substrate characteristic determination unit 283 accepts the type of substrate W input from the operation unit 290. Based on this, the substrate characteristic determination unit 283 determines which of the above-mentioned B-absorbing substrate, G-absorbing substrate, R-absorbing substrate, and opaque substrate the accepted type of substrate W is.

[0094] This determination process can be implemented by the substrate characteristic determination unit 283 maintaining a table indicating which of the various substrates W belongs to: a B-absorbing substrate, a G-absorbing substrate, an R-absorbing substrate, or an opaque substrate. This table may include, for example, information such as "the substrate W made of silicon carbide is a B-absorbing substrate" and "the substrate W made of silicon is an opaque substrate." Alternatively, the aforementioned table may be stored in the inspection storage unit 285 instead of being maintained by the substrate characteristic determination unit 283.

[0095] Furthermore, based on the aforementioned determination results and the substrate characteristic information stored in the inspection storage unit 285, the substrate characteristic determination unit 283 determines the method for acquiring inspection image data when photographing a substrate W.

[0096] When photographing a substrate W, the inspection image data acquisition unit 284 receives R image data, G image data, and B image data from the image data generation unit 282. Furthermore, the inspection image data acquisition unit 284 acquires inspection image data from the received R image data, G image data, and B image data according to the inspection image data acquisition method determined by the substrate characteristic determination unit 283.

[0097] The inspection unit 286 inspects the substrate W based on the inspection conditions stored in the inspection storage unit 285 and the inspection image data acquired by the inspection image data acquisition unit 284. Furthermore, the inspection unit 286 outputs the inspection results to an external device, such as the substrate inspection apparatus 200. Figure 1 and Figure 8 In addition to the substrate inspection device 200 Figure 8 The structure other than the inspection section 286 is an example of a substrate imaging device.

[0098] 6. Photo inspection and processing

[0099] Figure 9 and Figure 10 It means by Figure 8 The flowchart shows the image inspection process performed by the control unit 280. Hereinafter, refer to... Figure 8 The imaging inspection process will be explained. The imaging inspection process is initiated, for example, by turning on the power to the board inspection device 200, or by the user issuing an instruction to the control unit 280 to start the inspection using the operation unit 290.

[0100] First, the substrate characteristic determination unit 283 determines whether the type of substrate W to be inspected has been entered (step S11). If the type of substrate W has not been entered, the substrate characteristic determination unit 283 repeats the process of step S11. On the other hand, when the type of substrate W is entered, the substrate characteristic determination unit 283 receives the entered information (type of substrate W) and determines whether the substrate W to be inspected is a B-absorbing substrate (step S12).

[0101] In step S12, if the substrate W to be inspected is a B-absorbing substrate, the substrate characteristic determination unit 283 determines the method for acquiring the inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S13). In step S13, it is determined that the B-image data obtained by taking a picture will be acquired as the inspection image data.

[0102] Subsequently, when the substrate W is moved into the substrate inspection apparatus 200, the imaging control unit 281 illuminates the substrate W with illumination light by controlling the various components (220, 240, 250, 260, 270) of the substrate inspection apparatus 200 (step S14).

[0103] Furthermore, the image data generation unit 282 generates R image data, G image data, and B image data based on the output from the imaging unit 240 (step S15). Then, the inspection image data acquisition unit 284 acquires the B image data as inspection image data according to the acquisition method determined by the substrate characteristic determination unit 283 (step S16).

[0104] Furthermore, in step S15, it has already been determined through the processing in step S13 that the image data required to obtain the inspection image data is B image data. Therefore, it is also possible to generate only B image data.

[0105] Next, the inspection unit 286 performs inspection processing (step S17) based on the inspection conditions stored in the inspection storage unit 285 and the inspection image data acquired by the inspection image data acquisition unit 284. The inspection processing in step S17 corresponds to at least one of the first inspection, second inspection, and third inspection described above. After step S17 is completed, the image inspection processing ends.

[0106] In step S12 above, if the substrate W to be inspected is not a B absorbing substrate, the substrate characteristic determination unit 283 determines whether the substrate W to be inspected is a G absorbing substrate (step S21).

[0107] In step S21, if the substrate W to be inspected is a G-absorbing substrate, the substrate characteristic determination unit 283 determines the method for acquiring the inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S22). In step S22, it is determined that the G-image data obtained by capturing an image will be acquired as the inspection image data. Then, steps S23 and S24, which are the same as steps S14 and S15 described above, are performed. Furthermore, in step S24, it has already been determined through the processing in step S22 that the image data required to acquire the inspection image data is G-image data. Therefore, it is also possible to generate only the G-image data.

[0108] Next, the image data acquisition unit 284 acquires G image data as inspection image data according to the acquisition method determined by the substrate characteristic determination unit 283 (step S25). Then, the process proceeds to step S16.

[0109] In step S21 above, if the substrate W to be inspected is not a G-absorbing substrate, the substrate characteristic determination unit 283 determines whether the substrate W to be inspected is an R-absorbing substrate (step S31).

[0110] In step S31, if the substrate W to be inspected is an R-absorbing substrate, the substrate characteristic determination unit 283 determines the method for acquiring the inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S32). In step S32, it is determined that the R-image data obtained by capturing an image will be acquired as the inspection image data. Then, steps S33 and S34, which are the same as steps S14 and S15 described above, are performed. Furthermore, in step S34, it has already been determined through the processing in step S32 that the image data required to acquire the inspection image data is R-image data. Therefore, it is also possible to generate only the R-image data.

[0111] Next, the image data acquisition unit 284 acquires R image data as inspection image data according to the acquisition method determined by the substrate characteristic determination unit 283 (step S35). After that, the process proceeds to step S17.

[0112] In step S31 described above, if the substrate W to be inspected is not an R-absorbing substrate, the substrate characteristic determination unit 283 determines that the substrate W to be inspected is an opaque substrate (step S41). Furthermore, the substrate characteristic determination unit 283 determines the method for acquiring inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S42). In step S42, it is determined that R-image data, G-image data, and B-image data obtained through imaging will be acquired as inspection image data. Then, steps S43 and S44, which are the same as steps S14 and S15 described above, are performed.

[0113] Next, the image data acquisition unit 284 acquires R image data, G image data, and B image data as inspection image data according to the acquisition method determined by the substrate characteristic determination unit 283 (step S45). After that, the process proceeds to step S17.

[0114] Figure 11 It means Figure 9 A flowchart of an example of the inspection process in step S16. Here, an example of the inspection process corresponding to the first inspection described above is explained. In the following description, in the initial state, Figure 8 The inspection storage unit 285 stores sample image data corresponding to the substrate W to be inspected as inspection conditions.

[0115] like Figure 11 As shown, when the processing corresponding to the first inspection begins, the inspection unit 286 reads the sample image data according to the inspection conditions of the inspection storage unit 285 (step S51).

[0116] Next, the inspection unit 286, based on the read sample image data and in... Figure 9 and Figure 10 The inspection image data obtained in any one of steps S16, S25, S35, and S45 is used to generate differential image data (step S52).

[0117] Next, the inspection unit 286 determines, based on the inspection conditions stored in the inspection storage unit 285, whether the difference value corresponding to each pixel of the differential image data is within a predetermined allowable range (step S53). Therefore, if the difference value corresponding to each pixel of the differential image data is within the predetermined allowable range, the inspection unit 286 determines that the substrate W to be inspected is normal (step S54). On the other hand, if the difference value corresponding to each pixel of the differential image data is not within the predetermined allowable range, the inspection unit 286 determines that the substrate W to be inspected is abnormal (step S55). After the processing in step S54 or step S55, the inspection process ends.

[0118] 7. Effects

[0119] (a) In the substrate inspection apparatus 200 described above, illumination light consisting of white light is irradiated onto the upper surface of the substrate W, and the upper surface of the substrate W is photographed by the imaging unit 240. Based on the output of the imaging unit 240, R image data, G image data, and B image data are generated. Based on the R image data, G image data, and B image data, inspection image data for inspecting the substrate W is obtained.

[0120] The method for acquiring inspection image data is determined as follows: when the substrate W to be inspected is a semi-transparent substrate that absorbs light of a specific wavelength, image data corresponding to the wavelength of light absorbed by the substrate W is acquired as inspection image data. Specifically, when the substrate W to be inspected is a silicon carbide substrate, image data B corresponding to the blue light absorbed by the silicon carbide substrate is acquired as inspection image data. This prevents the use of inspection image data containing images of peripheral components of the substrate W. As a result, an appropriate inspection corresponding to the type of substrate W can be performed on the upper surface of the substrate W.

[0121] (b) Furthermore, the method for acquiring inspection image data is determined to be as follows: when the substrate W to be inspected is an opaque substrate, all image data generated by imaging is acquired as inspection image data. Specifically, when the substrate W to be inspected is a silicon substrate, all R image data, G image data, and B image data generated by imaging are acquired as inspection image data. Therefore, when the substrate W is an opaque substrate, more inspection image data can be used to inspect the upper surface of the substrate W. Thus, inspection accuracy is improved.

[0122] (c) In the substrate inspection apparatus 200 described above, the substrate characteristic determination unit 283 accepts input of the type of substrate W and determines whether the accepted substrate W is a B-absorbing substrate, a G-absorbing substrate, an R-absorbing substrate, or an opaque substrate. Furthermore, based on the determination result, the substrate characteristic determination unit 283 determines the method for acquiring inspection image data. Therefore, the user does not need to perform complicated setup procedures regarding the method for acquiring inspection image data.

[0123] (d) The imaging unit 240 described above includes a first line sensor 241, a second line sensor 242, and a third line sensor 243. In each line sensor, multiple pixels are arranged in the first device direction D1. Therefore, by making the arrangement spacing of the multiple pixels in each line sensor denser, inspection image data with higher resolution can be obtained.

[0124] 8. A substrate processing apparatus having a substrate inspection device 200

[0125] Figure 12 It means possessing Figure 1A schematic block diagram of an example of a substrate processing apparatus of a substrate inspection apparatus 200. (See diagram for reference.) Figure 12 As shown, the substrate processing apparatus 100 is arranged adjacent to the exposure apparatus 300, and includes a substrate inspection apparatus 200, as well as a control device 110, a conveying device 120, a coating processing unit 130, a developing processing unit 140, and a heat treatment unit 150.

[0126] The control device 110, for example, includes a CPU and memory, or a microcomputer, to control the operation of the conveying device 120, the coating processing unit 130, the developing processing unit 140, and the heat treatment unit 150. Additionally, the control device 110 communicates with the control unit 280 of the substrate inspection device 200. Figure 1 It issues an instruction to inspect the surface condition of one side of the substrate W (for performing the above-mentioned photographic inspection process).

[0127] The conveying device 120 conveys the substrate W between the coating processing unit 130, the developing processing unit 140, the heat treatment unit 150, the substrate inspection device 200, and the exposure device 300. The coating processing unit 130 forms a resist film on one side of the untreated substrate W (coating process). The substrate W with the resist film formed after coating processing is exposed in the exposure device 300. The developing processing unit 140 develops the substrate W by supplying a developer to the substrate W exposed by the exposure device 300. The heat treatment unit 150 heat-treats the substrate W before and after the coating process in the coating processing unit 130, the developing process in the developing processing unit 140, and the exposure process in the exposure device 300.

[0128] Furthermore, the coating processing unit 130 may also form an anti-reflective film on the substrate W. In this case, a processing unit for performing a bonding strengthening process may also be provided in the heat treatment unit 150 to improve the adhesion between the substrate W and the anti-reflective film. Additionally, the coating processing unit 130 may also form a resist coating film on the substrate W to protect the resist film formed on the substrate W.

[0129] The substrate inspection apparatus 200 inspects the substrate W after the coating process of the coating processing unit 130 and before the exposure process of the exposure apparatus 300. Alternatively, the substrate inspection apparatus 200 inspects the substrate W after the coating process of the coating processing unit 130 and the exposure process of the exposure apparatus 300. Alternatively, the substrate inspection apparatus 200 may also inspect the substrate W after the coating process of the coating processing unit 130, the exposure process of the exposure apparatus 300, and the development process of the development processing unit 140.

[0130] In the substrate processing apparatus 100 described above, for example, for each batch of a predetermined number of substrates W, the operating conditions of each component are set as a processing procedure. The processing procedure may, for example, include information indicating the type of substrate W to be processed. In this case, the substrate inspection apparatus 200... Figure 8 The substrate characteristic determination unit 283 can also be determined from... Figure 12 The control device 110 receives and processes the data to determine which of the substrates W to be inspected is a B-absorbing substrate, a G-absorbing substrate, an R-absorbing substrate, or an opaque substrate.

[0131] 9. Other implementation methods

[0132] (a) The illumination unit 220 described in the above embodiment includes a white light source that produces white light, but the present invention is not limited thereto. The illumination unit 220 may also include a red light source that produces red light, a green light source that produces green light, and a blue light source that produces blue light instead of a white light source. In this case, the imaging unit 240 may also be composed of a monochrome imaging element.

[0133] In this case, if the substrate characteristic determination unit 283 acquires only one of the R image data, G image data, and B image data as the inspection image data, such as... Figure 8 As indicated by the dashed arrow, the illumination unit 220 can be controlled to selectively drive a light source of a color corresponding to the image data. This control suppresses unnecessary energy consumption in the illumination unit 220.

[0134] (b) The imaging unit 240 in the above embodiment is composed of three line sensors (241-243), but the present invention is not limited thereto. The imaging unit 240 may also be composed of a plurality of R pixels pa, a plurality of G pixels pb, and a plurality of B pixels pc arranged in a Bayer array. Alternatively, the imaging unit 240 may have a structure including a monochrome imaging element and a color filter switching device for switching the wavelength of light incident on the imaging element. Alternatively, the imaging unit 240 may also be composed of a plurality of monochrome imaging elements and a plurality of color filters corresponding to the plurality of monochrome imaging elements.

[0135] (c) In the imaging and inspection process of the above embodiment, assuming the presence of a G-absorbing substrate and an R-absorbing substrate, steps S21 to S25 and S31 to S35 are performed. However, if there is no substrate W equivalent to the G-absorbing substrate and the R-absorbing substrate, steps S21 to S25 and S31 to S35 may not be performed.

[0136] (d) In the substrate inspection apparatus 200 of the above embodiment, in order to photograph the entire upper surface of the substrate W, the substrate holding device 250 moves relative to the fixed illumination part 220, reflection part 230 and imaging part 240, but the present invention is not limited thereto.

[0137] The illumination unit 220, the reflector 230, and the imaging unit 240 can also be configured to maintain their relative positions and be movable relative to the substrate holding device 250 in the second device direction D2. In this case, the substrate W can also be imaged by moving the illumination unit 220, the reflector 230, and the imaging unit 240 relative to the fixed substrate holding device 250 in the second device direction D2.

[0138] (e) In the substrate inspection apparatus 200 of the above embodiment, the inspection image data is composed of any one of R image data, G image data, and B image data representing the entire substrate W, but the present invention is not limited thereto. The inspection image data may also be generated in a manner that corresponds to multiple parts of the substrate W respectively.

[0139] For example, when the substrate W to be inspected is a semi-transparent substrate, the rotating holding part 252, which is covered by the focal depth of the imaging unit 240, is likely to appear in the image obtained by imaging. However, if the part located at a position separate from the substrate W is significantly deviated from the focal depth of the imaging unit 240, it is difficult to appear in the image obtained by imaging.

[0140] Therefore, for the portion of the substrate W that overlaps with the rotation holding portion 252 when viewed from above, image data (any one of R image data, G image data, and B image data) corresponding to the light absorbed by the substrate W is used as inspection image data. On the other hand, for the portion of the substrate W that deviates from the rotation holding portion 252 when viewed from above, R image data, G image data, and B image data are used as inspection image data.

[0141] Thus, for example, it is possible to perform appropriate inspections on the central region of the upper surface of the substrate W with reduced accuracy, and to perform more accurate and detailed inspections on the outer region of the upper surface of the substrate W surrounding the central region of the upper surface of the substrate W.

[0142] (f) In the substrate inspection apparatus 200 of the above embodiment, when the substrate W to be inspected is a semi-transparent substrate, one of the R image data, G image data, and B image data is acquired as the inspection image data, but the present invention is not limited thereto. When the substrate W to be inspected is a semi-transparent substrate, R image data, G image data, and B image data may also be acquired as the inspection image data.

[0143] In this case, in order to suppress the decrease in inspection accuracy caused by the reflection of the rotation holding part 252, it is preferable to adjust the inspection conditions stored in the substrate characteristic determination part 283 for each image data.

[0144] For example, the inspection image data corresponding to light absorbed by the substrate W is adjusted to make the inspection conditions more stringent. Conversely, the inspection image data corresponding to light not absorbed by the substrate W is adjusted to make the inspection conditions more lenient. Specifically, for the inspection image data corresponding to the wavelength of light absorbed by the substrate W, the allowable range of each difference value of the differential image data used in the first inspection is set to be smaller. Conversely, for the inspection image data corresponding to light not absorbed by the substrate W, the allowable range of each difference value of the differential image data used in the first inspection is set to be larger.

[0145] In these cases, inspection results based on inspection image data corresponding to light absorbed by the substrate W can be processed as highly reliable inspection results. Furthermore, inspection results based on inspection image data corresponding to light not absorbed by the substrate W can be processed as supplementary inspection results.

[0146] (g) In the substrate inspection apparatus 200 of the above embodiment, when the substrate W to be inspected is a semi-transparent substrate, one of the R image data, G image data, and B image data is acquired as the inspection image data, but the present invention is not limited thereto. When the substrate W to be inspected is a semi-transparent substrate, image data composed of two or more of the R image data, G image data, and B image data may also be acquired as the inspection image data.

[0147] In this case, among the image data being inspected, the component corresponding to the wavelength of the light absorbed by the substrate W is more abundant than the component corresponding to the wavelength of the light not absorbed by the substrate W. Therefore, the component of the image data corresponding to the light absorbed by the substrate W is preferentially used for inspecting the substrate W. Consequently, the reduction in inspection accuracy caused by the reflection of peripheral components of the substrate W during image capture can be reduced.

[0148] 10. Correspondence between the various parts of the implementation method and the constituent elements of the scope of the claimed patent protection.

[0149] Hereinafter, examples of the correspondence between the constituent elements of the scope of patent protection and the constituent elements of the implementation method will be described. Various other elements having the structure or function described in the scope of patent protection may also be used as constituent elements of the scope of patent protection.

[0150] In the above embodiments, the illumination unit 220 is an example of an illumination unit, the imaging unit 240 is an example of an imaging unit, the control unit 280 and the inspection image data acquisition unit 284 are examples of control units, the structure in the substrate inspection apparatus 200 other than the inspection unit 286 is an example of a substrate imaging apparatus, and the substrate holding device 250 is an example of a holding unit.

[0151] Furthermore, the wavelength of one of the wavelengths of red light, green light, and blue light that is absorbed by the substrate W is an example of a first wavelength, and the pixel data corresponding to the wavelength of one light is an example of first data. The wavelength of the remaining light that is not absorbed by the substrate W among the wavelengths of red light, green light, and blue light is an example of a second wavelength, and the pixel data corresponding to the wavelength of the remaining light is an example of second data.

[0152] in addition, Figure 9 and Figure 10 The operation mode of the control unit 280 in steps S14-S16, S23-S25, and S33-S35 is an example of the first mode. Figure 10 In the processing steps S43 to S45, the operation mode of the control unit 280 is an example of the second mode, the substrate characteristic determination unit 283 is an example of the substrate characteristic determination unit, the first device direction D1 is an example of the first direction, the second device direction D2 is an example of the second direction, the moving unit 260 is an example of the moving unit, the inspection unit 286 is an example of the inspection unit, and the substrate inspection device 200 and the substrate processing device 100 are examples of the substrate processing device.

[0153] 11. Summary of Implementation Methods

[0154] (First item) The substrate imaging device of the first item includes:

[0155] The illumination unit illuminates the upper surface of the substrate;

[0156] The imaging unit, which images the upper surface of the substrate illuminated by the illumination light; and

[0157] The control unit, based on the output of the imaging unit, acquires inspection image data representing the state of at least a portion of the upper surface of the substrate.

[0158] The inspection image data corresponds to the light absorbed by the substrate at a specific wavelength.

[0159] In this substrate imaging apparatus, illumination light is shone onto the upper surface of the substrate, and the upper surface of the substrate is imaged using an imaging unit. Based on the output of the imaging unit, inspection image data is obtained.

[0160] Depending on the type of substrate being inspected, sometimes a portion of the illumination light is reflected from the upper surface of the substrate and incident on the imaging unit, while the remainder is transmitted through the substrate. In this case, the illumination light transmitted from the substrate may be reflected by the surface of peripheral components of the substrate located below it, and then pass through the substrate again to the imaging unit. Therefore, the image data generated based on the output of the imaging unit may represent the peripheral components along with the upper surface of the substrate. In such image data, it is impossible to accurately determine the state of the upper surface of the substrate.

[0161] If the remaining portion of the illumination light is absorbed by the substrate when it is transmitted from the substrate, the amount of light reflected by the surrounding components and incident on the imaging unit is reduced. As a result, image data showing the upper surface of the substrate but not the surrounding components can be obtained.

[0162] Therefore, in the aforementioned substrate imaging apparatus, the inspection image data representing the state of at least a portion of the upper surface of the substrate corresponds to light of the substrate's absorption wavelength. The substrate's absorption wavelength refers to the wavelength of light that the substrate can absorb. As a result, appropriate inspection corresponding to the type of substrate can be performed on the upper surface of the substrate.

[0163] (Second item) In the substrate imaging apparatus mentioned in the first item,

[0164] The substrate imaging device further includes a holding part that adsorbs and holds the lower surface of the substrate.

[0165] The illumination light includes light of the absorption wavelength of the substrate.

[0166] The illumination unit irradiates the upper surface of the substrate held by the holding unit with the illumination light.

[0167] The imaging unit captures images of the upper surface of the substrate held by the holding unit.

[0168] The region of at least a portion of the upper surface of the substrate includes the region that overlaps with the retaining portion when viewed from above.

[0169] In this case, with the substrate held by the holding part, the holding part is in contact with the lower surface of the substrate. At this time, the holding part is separated from the upper surface of the substrate by a relatively small amount of substrate thickness. That is, the distance between the upper surface of the substrate and the holding part is relatively small. Therefore, the holding part is easily located within the focal depth range of the imaging part. Therefore, when the substrate is photographed using light transmitted from the substrate and not absorbed by the substrate, the holding part is captured in the image of the substrate obtained by this photograph.

[0170] In contrast, in the above structure, the illumination light includes light of the absorption wavelength of the substrate. Furthermore, the inspection image data corresponds to the light of the absorption wavelength of the substrate. Moreover, at least a portion of the upper surface of the substrate includes a region that overlaps with the holding portion when viewed from above. Therefore, images containing the holding portion are suppressed in the image represented by the inspection image data. That is, inspection image data containing the image of the holding portion is prevented from being acquired.

[0171] (Third item) In the substrate imaging device mentioned in the second item,

[0172] The illumination unit is configured to simultaneously or selectively illuminate the upper surface of the substrate with light having a first wavelength and light having a second wavelength.

[0173] The imaging unit is configured to generate first data corresponding to the first wavelength of light by imaging the substrate irradiated with light having the first wavelength, and to generate second data corresponding to the second wavelength of light by imaging the substrate irradiated with light having the second wavelength.

[0174] When the substrate transmits the illumination light and absorbs the first wavelength light more easily than the second wavelength light, the control unit controls the illumination unit and the imaging unit to operate in a first mode: illuminating the upper surface of the substrate with light containing at least the first wavelength light of the first wavelength and the second wavelength light, and generating image data containing more components of the first data than the second data as the inspection image data.

[0175] According to the above structure, for example, light of a first wavelength is used as illumination light to irradiate the upper surface of the substrate. In this case, first data corresponding to the first wavelength of light is generated. Alternatively, for example, light of a second wavelength is used as illumination light to irradiate the upper surface of the substrate. In this case, second data corresponding to the second wavelength of light is generated.

[0176] When the substrate transmits illumination light and absorbs light of the first wavelength more readily than light of the second wavelength, image data containing more components of the first data than the second data is obtained as inspection image data. As a result, appropriate inspection corresponding to the type of substrate can be performed on the upper surface of the substrate.

[0177] (Fourth item) In the substrate imaging device mentioned in the third item,

[0178] When the control unit operates in the first mode, it can also generate image data composed of the first data as the inspection image data.

[0179] In this case, where the substrate transmits illumination light but readily absorbs the first wavelength of light compared to the second wavelength, the image data generated based on the first data is used as inspection image data. Therefore, appropriate inspection corresponding to the type of substrate can be performed with simple processing.

[0180] (Fifth item) In the substrate imaging apparatus covered in the third or fourth item,

[0181] When the upper surface of the substrate does not transmit light of the first wavelength and light of the second wavelength, the control unit controls the illumination unit and the imaging unit to operate in a second mode: the first wavelength and light of the second wavelength are used as illumination light to irradiate the upper surface of the substrate, and image data composed of the first data and image data composed of the second data are generated as inspection image data, respectively.

[0182] When the upper surface of the substrate does not allow illumination light to pass through, most of the illumination light is reflected and incident on the imaging unit. This generates image data that accurately represents the state of the upper surface of the substrate. The state of the upper surface of the substrate sometimes changes depending on the wavelength of the illumination light. In the above-described substrate imaging apparatus, both a first wavelength and a second wavelength of light can be used as the illumination light. Furthermore, image data corresponding to the first wavelength of light and image data corresponding to the second wavelength of light are generated as inspection image data, respectively.

[0183] Therefore, by using image data corresponding to light of the first wavelength and image data corresponding to light of the second wavelength, the condition of the upper surface of the substrate can be inspected more accurately and in greater detail.

[0184] (Sixth item) In the substrate imaging device mentioned in the fifth item,

[0185] The substrate imaging apparatus further includes a substrate characteristic determination unit, which determines whether the substrate is a substrate that transmits the illumination light and more easily absorbs the first wavelength light compared to the second wavelength light, or whether the substrate is a substrate that does not transmit either the first wavelength light or the second wavelength light.

[0186] The control unit operates in the first mode when the substrate is a substrate that transmits the illumination light and more easily absorbs the first wavelength light compared to the second wavelength light, and operates in the second mode when the substrate is a substrate that does not transmit light of either the first wavelength or the second wavelength light.

[0187] In this case, the mode of the control unit is determined based on the characteristics of the substrate. Therefore, the user does not need to perform complicated settings to determine the mode of the control unit.

[0188] (Seventh) In the substrate imaging apparatus mentioned in the sixth item,

[0189] The first wavelength is the wavelength of blue light.

[0190] The second wavelength is the wavelength of red or green light.

[0191] The substrate characteristic determination unit determines that, if the substrate is made of silicon carbide, the substrate is a substrate that allows the illumination light to pass through and that more easily absorbs the first wavelength light than the second wavelength light; if the substrate is made of silicon, the substrate is a substrate that does not allow the first wavelength light or the second wavelength light to pass through.

[0192] The substrate made of silicon carbide is an orange, semi-transparent substrate that allows light of red, green, and blue wavelengths to pass through. Furthermore, because the silicon carbide substrate is orange, it readily absorbs blue wavelength light compared to red and green wavelengths. Based on this structure, when the substrate is made of silicon carbide, image data containing more components of the first data corresponding to blue than the second data corresponding to red or green wavelengths is obtained as inspection image data.

[0193] The silicon substrate is an opaque substrate with an outer surface, similar to a mirror, preventing the transmission of light of red, green, and blue wavelengths. Based on this structure, when the substrate is made of silicon, image data consisting of first data corresponding to blue is acquired as inspection image data. Additionally, image data consisting of second data corresponding to red or green is acquired as inspection image data.

[0194] (Item 8) In any of the items 2 to 7, the substrate imaging apparatus

[0195] The camera unit includes:

[0196] A first-line sensor, configured to extend parallel to a first direction, is capable of receiving light of the first wavelength and outputting a signal representing the amount of light received at the first wavelength as the first data; and

[0197] A second line sensor, configured to extend parallel to the first direction, is capable of receiving light of the second wavelength and outputting a signal representing the amount of light received at the second wavelength as the second data.

[0198] The substrate imaging apparatus further includes a moving part that moves at least one of the holding part and the imaging part to move the substrate held by the holding part relative to the imaging part in a second direction that is parallel to the upper surface of the substrate and intersects the first direction.

[0199] In this case, by moving at least one of the holding part and the imaging part in the second direction, image data corresponding to the first wavelength is generated based on the output of the first linear sensor. Additionally, image data corresponding to the second wavelength is generated based on the output of the second linear sensor.

[0200] In the first line sensor, multiple pixels (light-receiving elements) that receive light having a first wavelength are arranged parallel to each other along a first direction. Similarly, in the second line sensor, multiple pixels (light-receiving elements) that receive light having a second wavelength are arranged parallel to each other along the first direction. Therefore, by making the arrangement of the multiple pixels in each line sensor more dense in a direction parallel to the first direction, inspection image data with higher resolution can be obtained.

[0201] (Item 9) The substrate processing apparatus covered by Item 9 includes:

[0202] The substrate imaging device involved in any one of items 1 through 8; and

[0203] The inspection unit inspects the condition of the upper surface of the substrate based on the inspection image data obtained by the substrate imaging device.

[0204] This substrate inspection apparatus includes the aforementioned substrate imaging device. Therefore, it is possible to perform appropriate inspections on the upper surface of the substrate, corresponding to the type of substrate.

[0205] (Item 10) The substrate imaging method involved in Item 10 includes the following steps:

[0206] Illumination light is shone onto the upper surface of the substrate;

[0207] The upper surface of the substrate, illuminated by the illumination light, is photographed using the imaging unit; and

[0208] Based on the output of the imaging unit, inspection image data representing the state of at least a portion of the upper surface of the substrate is obtained.

[0209] The inspection image data corresponds to the light absorbed by the substrate at a specific wavelength.

[0210] In this substrate imaging method, illumination light is shone onto the upper surface of the substrate, and an imaging unit is used to image the upper surface of the substrate. Based on the output of the imaging unit, inspection image data is obtained.

[0211] Depending on the type of substrate being inspected, sometimes a portion of the illumination light is reflected from the upper surface of the substrate and incident on the imaging unit, while the remainder is transmitted through the substrate. In this case, the illumination light transmitted from the substrate may be reflected by the surface of peripheral components of the substrate located below it, and then pass through the substrate again to the imaging unit. Therefore, the image data generated based on the output of the imaging unit may represent the peripheral components along with the upper surface of the substrate. In such image data, it is impossible to accurately determine the state of the upper surface of the substrate.

[0212] If the remaining portion of the illumination light is absorbed by the substrate when it is transmitted from the substrate, the amount of light reflected by the surrounding components and incident on the imaging unit is reduced. As a result, image data showing the upper surface of the substrate but not the surrounding components can be obtained.

[0213] Therefore, in the above-described substrate imaging method, the inspection image data representing the state of at least a portion of the upper surface of the substrate corresponds to light of the substrate's absorption wavelength. The substrate's absorption wavelength refers to the wavelength of light that the substrate can absorb. As a result, appropriate inspections corresponding to the type of substrate can be performed on the upper surface of the substrate.

[0214] (Item 11) The substrate processing method involved in Item 11 includes:

[0215] The substrate imaging method involved in item 10; and

[0216] The step of inspecting the condition of the upper surface of the substrate based on the inspection image data obtained by the substrate imaging method.

[0217] This substrate inspection method includes the substrate imaging method described above. Therefore, it is possible to perform appropriate inspections on the upper surface of the substrate, corresponding to the type of substrate.

Claims

1. A substrate imaging device, characterized in that, have: The illumination unit illuminates the upper surface of the substrate; The imaging unit, which images the upper surface of the substrate illuminated by the illumination light; and The control unit, based on the output of the imaging unit, acquires inspection image data representing the state of at least a portion of the upper surface of the substrate. The inspection image data corresponds to the light absorbed by the substrate at a specific wavelength.

2. The substrate imaging apparatus according to claim 1, characterized in that, The substrate imaging device further includes a holding part that adsorbs and holds the lower surface of the substrate. The illumination light includes light of the absorption wavelength of the substrate. The illumination unit irradiates the upper surface of the substrate held by the holding unit with the illumination light. The imaging unit captures images of the upper surface of the substrate held by the holding unit. The region of at least a portion of the upper surface of the substrate includes the region that overlaps with the retaining portion when viewed from above.

3. The substrate imaging apparatus according to claim 2, characterized in that, The illumination unit is configured to simultaneously or selectively illuminate the upper surface of the substrate with light having a first wavelength and light having a second wavelength. The imaging unit is configured to generate first data corresponding to the first wavelength of light by imaging the substrate irradiated with light having the first wavelength, and to generate second data corresponding to the second wavelength of light by imaging the substrate irradiated with light having the second wavelength. When the substrate transmits the illumination light and absorbs the first wavelength light more easily than the second wavelength light, the control unit controls the illumination unit and the imaging unit to operate in a first mode: illuminating the upper surface of the substrate with light containing at least the first wavelength light of the first wavelength and the second wavelength light, and generating image data containing more components of the first data than the second data as the inspection image data.

4. The substrate imaging apparatus according to claim 3, characterized in that, When the control unit operates in the first mode, it generates image data composed of the first data as the inspection image data.

5. The substrate imaging apparatus according to claim 3 or 4, characterized in that, When the upper surface of the substrate does not transmit light of the first wavelength and light of the second wavelength, the control unit controls the illumination unit and the imaging unit to operate in a second mode: the first wavelength and light of the second wavelength are used as illumination light to irradiate the upper surface of the substrate, and image data composed of the first data and image data composed of the second data are generated as inspection image data, respectively.

6. The substrate imaging apparatus according to claim 5, characterized in that, The substrate imaging apparatus further includes a substrate characteristic determination unit, which determines whether the substrate is a substrate that transmits the illumination light and more easily absorbs the first wavelength light compared to the second wavelength light, or whether the substrate is a substrate that does not transmit either the first wavelength light or the second wavelength light. The control unit operates in the first mode when the substrate is a substrate that transmits the illumination light and more easily absorbs the first wavelength light compared to the second wavelength light, and operates in the second mode when the substrate is a substrate that does not transmit light of either the first wavelength or the second wavelength light.

7. The substrate imaging apparatus according to claim 6, characterized in that, The first wavelength is the wavelength of blue light. The second wavelength is the wavelength of red or green light. The substrate characteristic determination unit determines that, if the substrate is made of silicon carbide, the substrate is a substrate that allows the illumination light to pass through and that more easily absorbs the first wavelength light than the second wavelength light; if the substrate is made of silicon, the substrate is a substrate that does not allow the first wavelength light or the second wavelength light to pass through.

8. The substrate imaging apparatus according to any one of claims 2 to 7, characterized in that, The camera unit includes: A first-line sensor, configured to extend parallel to a first direction, is capable of receiving light of the first wavelength and outputting a signal representing the amount of light received at the first wavelength as the first data; and The second line sensor, which is configured to extend parallel to the first direction, is capable of receiving light of the second wavelength and outputting a signal representing the amount of light received at the second wavelength as the second data. The substrate imaging apparatus further includes a moving part that moves at least one of the holding part and the imaging part to move the substrate held by the holding part relative to the imaging part in a second direction that is parallel to the upper surface of the substrate and intersects the first direction.

9. A substrate processing apparatus, characterized in that, have: The substrate imaging apparatus according to any one of claims 1 to 8; and The inspection unit inspects the condition of the upper surface of the substrate based on inspection image data obtained by the substrate imaging device.

10. A method for photographing a substrate, characterized in that, Includes the following steps: Illumination light is shone onto the upper surface of the substrate; The upper surface of the substrate, illuminated by the illumination light, is photographed using the imaging unit; and Based on the output of the imaging unit, inspection image data representing the state of at least a portion of the upper surface of the substrate is obtained. The inspection image data corresponds to the light absorbed by the substrate at a specific wavelength.

11. A substrate processing method, characterized in that, include: The substrate imaging method according to claim 10; as well as The step of inspecting the condition of the upper surface of the substrate based on the inspection image data obtained by the substrate imaging method.

Images