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

Abstract

The present invention provides a substrate imaging apparatus, a substrate processing apparatus, a substrate imaging method, and a substrate processing method that enable appropriate inspection of the upper surface of a substrate according to the type of substrate. [Solution] The substrate imaging device comprises an illumination unit 220, an imaging unit 240, and a control unit 280. The illumination unit 220 irradiates illumination light onto the upper surface of the substrate W held by the substrate holding device 250. The imaging unit 240 images the upper surface of the substrate irradiated with illumination light. Based on the output of the imaging unit 240, inspection image data showing the state of at least a portion of the upper surface of the substrate is acquired. The inspection image data corresponds to the wavelength of light absorbed by the substrate.

Description

Technical Field

[0001] The present invention relates to a substrate imaging device for imaging a substrate, a substrate processing device, a substrate imaging method, and a substrate processing method.

Background Art

[0002] In various processing steps for a substrate, inspection of the substrate is performed. For example, in the substrate inspection device described in Patent Document 1, a strip-shaped light larger than the diameter of the substrate in one direction is emitted downward from a light projecting unit. In this state, the substrate to be inspected is moved in a direction orthogonal to the one direction so as to pass below the light projecting unit. Thereby, the strip-shaped light is sequentially irradiated to each part of the upper surface of the substrate. The strip-shaped light is sequentially reflected by each part of the substrate and received by a light receiving unit. Based on the amount of light received by the light receiving unit, image data showing an image of the entire upper surface of the substrate is generated. Based on the generated image data, the substrate is inspected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In inspection, it is preferable that the state of the upper surface of the substrate (for example, the presence or absence of defects, the film thickness distribution of the coating film, or the presence or absence of the coating film, etc.) is accurately grasped. That is, it is preferable that the image data used for inspecting the upper surface of the substrate more accurately represents the state of the upper surface of the substrate. However, depending on the type of the substrate to be inspected, there may be cases where appropriate image data corresponding to the inspection of the substrate cannot be obtained.

[0005] The object of the present invention is to provide a substrate imaging apparatus, a substrate processing apparatus, a substrate imaging method, and a substrate processing method that enable appropriate inspection of the upper surface of a substrate according to the type of substrate. [Means for solving the problem]

[0006] A substrate imaging apparatus according to one aspect of the present invention comprises an illumination unit that irradiates the upper surface of a substrate with illumination light, an imaging unit that images the upper surface of the substrate irradiated with the illumination light, and a control unit that acquires inspection image data indicating the state of at least a portion of the upper surface of the substrate based on the output of the imaging unit, wherein the inspection image data corresponds to light of the absorption wavelength of the substrate.

[0007] A substrate processing apparatus according to another aspect of the present invention comprises a substrate imaging apparatus and an inspection unit that inspects the condition of the upper surface of a substrate based on inspection image data acquired by the substrate imaging apparatus.

[0008] A substrate imaging method according to yet another aspect of the present invention includes the steps of irradiating the upper surface of a substrate with illumination light, imaging the upper surface of the substrate irradiated with illumination light using an imaging unit, and acquiring inspection image data indicating the state of at least a portion of the upper surface of the substrate based on the output of the imaging unit, wherein the inspection image data corresponds to light of the absorption wavelength of the substrate.

[0009] A substrate processing method according to yet another aspect of the present invention includes the above-described substrate imaging method and 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. [Effects of the Invention]

[0010] According to the present invention, it becomes possible to perform appropriate inspections on the upper surface of a substrate according to the type of substrate. [Brief explanation of the drawing]

[0011] [Figure 1]This is a perspective view of the external appearance of a substrate inspection apparatus according to one embodiment of the present invention. [Figure 2] Figure 1 is a schematic side view showing the internal configuration of the circuit board inspection apparatus. [Figure 3] This is a plan view of a silicon carbide substrate held by a rotating support unit, as seen from above. [Figure 4] This figure shows the propagation of white light at different wavelengths as it is irradiated from the illumination unit onto the silicon carbide substrate and guided to the imaging unit shown in Figure 1 during imaging of the substrate. [Figure 5] This figure shows an example of an R image obtained by imaging a silicon carbide substrate. [Figure 6] This figure shows an example of a G image obtained by imaging a silicon carbide substrate. [Figure 7] This figure shows an example of a B image obtained by imaging a silicon carbide substrate. [Figure 8] This is a block diagram showing the functional configuration of the control unit in Figure 1. [Figure 9] Figure 8 is a flowchart showing the imaging inspection process performed by the control unit. [Figure 10] Figure 8 is a flowchart showing the imaging inspection process performed by the control unit. [Figure 11] Figure 9 is a flowchart showing an example of the inspection process in step S16. [Figure 12] This is a schematic block diagram showing an example of a substrate processing apparatus equipped with the substrate inspection device shown in Figure 1. [Modes for carrying out the invention]

[0012] Hereinafter, a substrate imaging device, a substrate processing device, a substrate imaging method, and a substrate processing method according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the substrate refers to a substrate for an FPD (Flat Panel Display) used in a liquid crystal display device, an organic EL (Electro Luminescence) display device, etc., a semiconductor substrate, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, a substrate for a solar cell, or the like.

[0013] In the present embodiment, the substrate has a circular shape in a plan view excluding the formation portions of the orientation flat or notch. In the following description, the cutouts for direction confirmation such as the orientation flat and notch formed on the substrate are simply collectively referred to as cutouts.

[0014] Further, the substrate has a front surface which is a circuit formation surface and a back surface which is a surface opposite to the circuit formation surface. In the following description, regardless of the front and back surfaces of the substrate, the upper-facing surface of the two surfaces of the substrate is called the upper surface of the substrate, and the lower-facing surface of the two surfaces of the substrate is called the lower surface of the substrate.

[0015] 1. Configuration of Substrate Inspection Device The substrate imaging device according to the present embodiment is incorporated in a substrate inspection device for inspecting the state of the upper surface of the substrate. The substrate inspection device will be described.

[0016] FIG. 1 is an external perspective view of a substrate inspection device according to an embodiment of the present invention. FIG. 2 is a schematic side view showing the internal configuration of the substrate inspection device 200 of FIG. 1. As shown in FIG. 1, the substrate inspection device 200 includes a housing portion 210, a lighting portion 220, a reflection portion 230, an imaging portion 240, a substrate holding device 250, a moving portion 260, a direction detection portion 270, a control portion 280, and an operation portion 290.

[0017] The housing 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 210. The illumination unit 220, the reflecting unit 230, the imaging unit 240, the substrate holding device 250, the moving unit 260, and the direction detection unit 270 are housed inside the housing 210.

[0018] The lighting unit 220 according to this embodiment is equipped with one or more light sources (white light sources) that generate white light, and is formed to extend in a direction perpendicular to the longitudinal direction of the housing unit 210 in a horizontal plane.

[0019] Furthermore, the illumination unit 220 is located approximately in the center of the housing unit 210 and emits a band-shaped light larger than the diameter of the substrate W diagonally downward. In the following description, the direction in which the illumination unit 220 extends in the horizontal plane (the short side of the housing unit 210) in the substrate inspection device 200 will be referred to as the first device direction D1. The direction perpendicular to the first device direction D1 in the horizontal plane (the long side of the housing unit 210) will be referred to as the second device direction D2.

[0020] 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 assumed to be 650 nm and its surrounding wavelength region (approximately 600 nm to 700 nm). The wavelength region of the green light is assumed to be 550 nm and its surrounding wavelength region (approximately 500 nm to 580 nm). The wavelength region of the blue light is assumed to be 450 nm and its surrounding wavelength region (approximately 400 nm to 490 nm).

[0021] The reflective section 230 includes, for example, a long mirror and is adjacent to the illumination section 220 in the second device direction D2. The reflective section 230 is also provided approximately in the center of the housing section 210 so as to extend parallel to the first device direction D1 and face diagonally downward.

[0022] The imaging unit 240 is positioned in the horizontal plane to face the mirror of the reflecting unit 230. The imaging unit 240 includes three image sensors (241, 242, 243) and one or more condensing lenses 244.

[0023] Each of the three image sensors (241, 242, 243) is, for example, a CCD (charge-coupled device) line sensor or a CMOS (complementary metal-oxide-semiconductor) line sensor. In the following description, when distinguishing between the three line sensors provided by the imaging unit 240, they will be referred to as the first line sensor 241, the second line sensor 242, and the third line sensor 243, as appropriate.

[0024] Figure 2 shows front views of the first line sensor 241, the second line sensor 242, and the third line sensor 243 as seen in the direction of the second device direction D2, within the dashed-dotted outline. As shown within the outline in Figure 2, the first line sensor 241 has a configuration in which multiple R pixels pa corresponding to red light are arranged on a single line. The second line sensor 242 has a configuration in which multiple G pixels pb corresponding to green light are arranged on a single line. The third line sensor 243 has a configuration in which multiple B pixels pc corresponding to blue light are arranged on a single line.

[0025] 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 arranged so as to be aligned vertically and extending parallel to the first device direction D1. As a result, the imaging unit 240 has a linear imaging area that extends parallel to the first device direction D1.

[0026] As described above, the imaging unit 240 includes one or more condensing lenses 244. Figures 1 and 2 show one condensing lens 244. The depth of field of the imaging unit 240 is adjusted by one or more condensing lenses 244 to match the length of the light path from the surface of the substrate W through the reflecting unit 230 to the three image sensors (241, 242, 243) when imaging the substrate W, which will be described later.

[0027] The substrate holding device 250 is, for example, a spin chuck and includes a drive device 251 and a rotating holding unit 252. The drive device 251 is, for example, an electric motor and has a rotating shaft 253. The rotating holding unit 252 is attached to the tip of the rotating shaft 253 of the drive device 251 and holds the central region of the lower surface of the substrate W to be inspected by suction. The rotating holding unit 252 is also driven to rotate around a vertical axis while holding the substrate W by suction.

[0028] In Figure 1, a plan view of the rotating holding part 252 is shown within the dashed-dotted nozzle. The rotating holding part 252 according to this embodiment is formed of, for example, resin and has a substantially disc shape as shown within the nozzle in Figure 1. 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 by suction, the peripheral edge of the substrate W does not overlap with the rotating holding part 252 in a plan view.

[0029] The rotating holding portion 252 has a flat portion 252a that is exposed upward when it is not holding the substrate W. The flat portion 252a is a circular flat surface that constitutes the upper surface of the rotating holding portion 252.

[0030] Multiple (four in this example) suction holes 252b are formed in a dispersed manner on the flat portion 252a. An intake system (not shown) is connected to the multiple suction holes 252b. In addition, multiple projections 252c that protrude upward are formed in a dispersed manner on the flat portion 252a. Furthermore, an annular sealing projection 252d is formed on the flat portion 252a that extends along the outer circumference of the rotating holding portion 252 and protrudes upward.

[0031] The heads of several (six in this example) screw members 252e are exposed in the approximate center of the flat portion 252a. The several (six in this example) screw members 252e are components for attaching the rotation holding portion 252 to the rotation shaft 253 in Figure 2.

[0032] When the substrate W is held by the rotating holding part 252, the substrate W is first placed on the rotating holding part 252. At this time, multiple protrusions 252c and sealing protrusions 252d come into contact with the lower surface of the substrate W, supporting the substrate W. A closed space is also formed between the lower surface of the substrate W and the flat part 252a of the rotating holding part 252. In this state, the atmosphere in the closed space is drawn in through multiple suction holes 252b. As a result, the substrate W is held on the rotating holding part 252 by suction.

[0033] The movable section 260 includes a pair of guide members 261 and a movable holding section 262. The pair of guide members 261 are arranged in a first device direction D1 and extend in a second device direction D2, as shown in Figure 1. The movable holding section 262 is configured to move along the pair of guide members 261 in the second device direction D2 and the opposite direction while holding the substrate holding device 250. As the movable holding section 262 moves while the substrate holding device 250 holds the substrate W, the substrate W passes below the illumination section 220 and the reflection section 230. As a result, the linear imaging area of ​​the imaging section 240 passes over one surface of the substrate W.

[0034] The direction 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 being rotated by the substrate holding device 250, the sensor emits light toward the outer periphery of the substrate W and receives reflected light from the substrate W. The direction detection unit 270 detects the notch in the substrate W based on the amount of reflected light received from the substrate W. A transmissive photoelectric sensor can also be used as the direction detection unit 270.

[0035] The control unit 280 (Figure 1) includes, for example, a CPU (Central Processing Unit) and memory, or a microcomputer, and controls the illumination unit 220, imaging unit 240, substrate holding device 250, moving unit 260, and direction detection unit 270. Details of the control unit 280 will be described later.

[0036] The control unit 290 (Figure 1) includes, for example, a keyboard and a pointing device, and is configured to be operable by the user. By operating the control unit 290, the user can input the type of a particular circuit board W before inspecting that board. In addition, by operating the control unit 290, the user can set various operating conditions and inspection conditions for the circuit board inspection device 200.

[0037] 2. Imaging of the substrate W by the substrate inspection device 200 The imaging operation of the substrate W in the substrate inspection apparatus 200 will now be described. The substrate W to be inspected is brought into the housing 210 through the opening 211 in Figure 1 and held by the substrate holding device 250.

[0038] Next, the substrate W is rotated by the substrate holding device 250, and light is emitted from the direction detection unit 270 to the periphery of the substrate W. The reflected light is then received by the direction detection unit 270. This allows the notches of the substrate W to be detected and the orientation of the substrate W to be determined. Based on this determination, the rotational position of the substrate W is adjusted so that the notches of the substrate W face a predetermined direction.

[0039] Next, a band of light is emitted from the illumination unit 220 diagonally downward. In this state, the substrate W is moved by the moving unit 260 in the second device direction D2 so that the substrate W passes below 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, light from the illumination unit 220 is sequentially illuminated on multiple parts of one surface of the substrate W. The light reflected from the substrate W is further reflected by the reflecting unit 230 and guided to the imaging unit 240.

[0040] Each of the three image sensors (241, 242, 243) of the imaging unit 240 receives light reflected from one surface of the substrate W at a predetermined sampling period, thereby sequentially imaging multiple portions of one surface of the substrate W.

[0041] At this time, each of the multiple R pixels pa constituting the first line sensor 241 receives light in the red wavelength region and outputs pixel data indicating a value corresponding to the amount of light received. In addition, each of the multiple G pixels pb constituting the second line sensor 242 receives light in the green wavelength region and outputs pixel data indicating a value corresponding to the amount of light received. Furthermore, each of the multiple B pixels pc constituting the third line sensor 243 receives light in the blue wavelength region and outputs pixel data indicating a value corresponding to the amount of light received.

[0042] Hereafter, pixel data output from R pixel pa will be referred to as R pixel data, pixel data output from G pixel pb will be referred to as G pixel data, and pixel data output from B pixel pc will be referred to as B pixel data.

[0043] Based on multiple R pixel data output from the imaging unit 240, image data showing the entire image on one surface of the substrate W is generated. Furthermore, based on multiple G pixel data, image data showing the entire image on one surface of the substrate W is generated. Finally, based on multiple B pixel data, image data showing the entire image on one surface of the substrate W is generated.

[0044] Hereinafter, image data generated based on R pixel data will be referred to as R image data, and images represented by R image data will be called R images. Similarly, image data generated based on G pixel data will be referred to as G image data, and images represented by G image data will be called G images. Furthermore, image data generated based on B pixel data will be referred to as B image data, and images represented by B image data will be called B images. In the following explanation, when it is not necessary to distinguish between R image data, G image data, and B image data, they will simply be referred to as image data.

[0045] 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. After that, the substrate W is returned to its predetermined position by the moving unit 260, and the substrate W is transported out of the housing unit 210 through the opening 211 by the transport device 120 shown in Figure 12, which will be described later.

[0046] Here, each of the R image data, G image data, and B image data includes multiple pixel values ​​representing images of multiple positions on the upper surface of the substrate W. The amount of light irradiated onto the substrate W from the illumination unit 220 is set so that the maximum value of the multiple pixel values ​​representing the center of the substrate in the generated R, G, and B images approaches a predetermined target pixel value. The setting of the light amount may be based on experiments or simulations, for example.

[0047] 3. Inspection of substrate W In the above-described substrate inspection apparatus 200, at least one of the R image data, G image data, and B image data generated by imaging the substrate W is acquired as inspection image data according to a predetermined acquisition method. Based on the acquired inspection image data, multiple types of inspections can be performed.

[0048] (1) First examination The first inspection that can be performed by the substrate inspection device 200 will be described. In this example, the substrate W to be inspected is assumed to be a substrate W on which a coating film such as a resist film is formed. In the first inspection, it is determined whether or not there are defects in the coating film formed on the substrate W.

[0049] The first inspection is basically performed as follows. First, image data representing the top surface of a defect-free sample substrate and corresponding to the inspection image data is prepared as sample image data. The sample image data may be generated by imaging the top surface of the sample substrate using the substrate inspection device 200, or by simulating the imaging of the sample substrate. Subsequently, the top surface of the substrate W to be inspected is imaged, and inspection image data of the substrate W to be inspected is acquired.

[0050] Next, the presence or absence of defects in the substrate W is determined based on a comparison of the pixel values ​​of each pixel in the sample image data with the pixel values ​​of each pixel in the inspection image data of the substrate W being inspected. More specifically, the difference between the pixel values ​​of corresponding pixels in the sample image data and the inspection image data is calculated, and image data composed of the calculated difference values ​​is generated as differential image data. If the difference values ​​corresponding to each pixel in the differential image data are within a predetermined tolerance range, the substrate W being inspected is determined to be normal. In other words, it is determined that the substrate W is free of defects. On the other hand, if the difference values ​​corresponding to each pixel in the differential image data are not within a predetermined tolerance range, the substrate W being inspected is determined to be abnormal. In other words, it is determined that the substrate W has defects.

[0051] (2) Second examination A second inspection that can be performed by the substrate inspection device 200 will be described. In this example, the substrate W to be inspected is assumed to be a substrate W on which a coating film such as a resist film is formed. In the second inspection, it is determined whether or not there is unevenness in the coating film formed on the substrate W, that is, whether or not the thickness distribution of the coating film is within an acceptable range.

[0052] The second inspection is basically performed as follows: First, the top surface of the substrate W to be inspected is imaged, and inspection image data of the substrate W is acquired. Next, it is determined whether there are any areas in the image represented by the inspection image data where the pixel values ​​change significantly from the center of the substrate W to the outer edge of the substrate W, exceeding a predetermined threshold ratio. If there are areas where the pixel values ​​change significantly, it is determined that the substrate W is uneven. On the other hand, if there are no areas where the pixel values ​​change significantly, it is determined that the substrate W is not uneven.

[0053] (3) Third examination A third inspection that can be performed by the substrate inspection device 200 will be described. A substrate W that has undergone the coating film formation process should inherently have a coating film formed on it. However, in the manufacturing process of the substrate W, due to human error or other reasons, a substrate W without a coating film may be mistakenly treated as having a coating film. In this example, the substrate W to be inspected is assumed to be a substrate W on which a coating film such as a resist film should be formed. The third inspection determines whether or not a coating film is formed on the substrate W.

[0054] The third inspection is basically performed as follows: First, the top surface of the substrate W to be inspected is imaged, and inspection image data of the substrate W is acquired. Next, it is determined whether the overall brightness of the image represented by the inspection image data falls within a predetermined range. In this case, the overall brightness of the image may be represented by the sum of the pixel values ​​of all pixels in the image, or by the average value 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 may be used as the overall brightness of the image.

[0055] Furthermore, if the overall brightness of the image represented by the inspection image data falls within a predetermined range, it is determined that a coating film is formed on the substrate W being inspected. On the other hand, if the overall brightness of the image represented by the inspection image data falls outside a predetermined range, it is determined that no coating film is formed on the substrate W being inspected.

[0056] 4. Examination image data The types of substrates W to be inspected include silicon substrates W and silicon carbide substrates W. Hereinafter, silicon substrates W will be referred to as silicon substrates, and silicon carbide substrates W will be referred to as silicon carbide substrates.

[0057] Figure 3 is a plan view of the silicon carbide substrate held by the rotating holding part 252, viewed from above. The silicon carbide substrate is an orange translucent substrate. Therefore, when viewing the silicon carbide substrate held by the rotating holding part 252 from above, it can be seen that the rotating holding part 252 is located in the central region of the lower surface of the silicon carbide substrate, as shown in Figure 3. In Figure 3, the dot pattern indicates that the silicon carbide substrate is visible as an orange translucent substrate. In this embodiment, a translucent substrate refers to, for example, a substrate with a white light transmittance of approximately 20% or more and 100% or less. Furthermore, an opaque substrate, as described later, refers to, for example, a substrate with a white light transmittance of approximately 0% or more and less than 20%.

[0058] As described above, if the substrate W is a translucent substrate having a specific color, the substrate W readily absorbs light of a color complementary to that specific color. Therefore, when a silicon carbide substrate is imaged in the substrate inspection apparatus 200, a portion of the white light irradiated onto the substrate W from the illumination unit 220 and propagating into the silicon carbide substrate is absorbed by the silicon carbide substrate.

[0059] Figure 4 is a diagram showing the propagation state of white light at each wavelength, which is irradiated from the illumination unit 220 onto the substrate W during imaging of the silicon carbide substrate and guided to the imaging unit 240 in Figure 1. As shown in the upper part of Figure 4, during imaging of the 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. 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), as described above.

[0060] In this case, some of the red light is reflected from the upper surface of the silicon carbide substrate and guided to the imaging unit 240, as shown by the solid arrow in the lower left of Figure 4. The remaining red light travels through the interior of the silicon carbide substrate, is reflected from the upper surface of the rotating holding unit 252, and then travels through the interior of the silicon carbide substrate again and is guided to the imaging unit 240. Here, red is not a complementary color to the color of the silicon carbide substrate (orange). Therefore, the red light is hardly absorbed by the silicon carbide substrate while traveling through it.

[0061] A portion of the green light is reflected from the upper surface of the silicon carbide substrate and guided to the reflector 230, as shown by the dashed arrow in the lower center of Figure 4. The remaining green light travels through the interior of the silicon carbide substrate, is reflected from the upper surface of the rotating holder 252, and then travels through the interior of the silicon carbide substrate again and is guided to the imaging unit 240. Here, green, like red, is not a complementary color to the color of the silicon carbide substrate (orange). Therefore, the green light is hardly absorbed by the silicon carbide substrate while traveling through it.

[0062] A portion of the blue light is reflected from the upper surface of the silicon carbide substrate and guided to the reflector 230, as shown by the dashed arrow in the lower right of Figure 4. The remaining blue light travels through the interior of the silicon carbide substrate, is reflected from the upper surface of the rotating holder 252, and then travels through the interior of the silicon carbide substrate again and is guided to the reflector 230. Here, blue is the complementary color to the color of the silicon carbide substrate (orange). Therefore, most of the blue light traveling through the interior of the silicon carbide substrate is absorbed by the silicon carbide substrate. Consequently, very little blue wavelength light reflected from the upper surface of the rotating holder 252 enters the imaging unit 240.

[0063] Figure 5 shows an example of an R image obtained by imaging a silicon carbide substrate. Figure 6 shows an example of a G image obtained by imaging a silicon carbide substrate. Figure 7 shows an example of a B image obtained by imaging a silicon carbide substrate. In Figures 5 to 7, the left portion shows images of the silicon carbide substrate (R image, G image, and B image). The right portion shows a graph of pixel values ​​corresponding to multiple points on the straight line connecting two points p1 and p2 defined on the upper surface of the silicon carbide substrate. In the graphs on the right portion of Figures 5 to 7, the vertical axis represents the pixel value, and the horizontal axis represents the position between points p1 and p2 on the silicon carbide substrate.

[0064] As shown in Figures 5 and 6, the R and G images include an image of the top surface of the silicon carbide substrate, as well as an image of the top surface of the rotating holder 252 (typically an image of the protrusion 252c). The inclusion of the rotating holder 252 in the R and G images is due to the fact that the red and green light reflected by the rotating holder 252 is incident on the imaging unit 240 without being absorbed by the silicon carbide substrate. Furthermore, the inclusion of the rotating holder 252 in the R and G images also contributes to the fact that the depth of field of the imaging unit 240 easily covers the area of ​​the top surface of the rotating holder 252. In the graphs on the right side of Figures 5 and 6, the portion of the pixel value change corresponding to the protrusion 252c of the rotating holder 252 is indicated by a white arrow. The portion of the pixel value change representing the shape of the top surface of the rotating holder 252 can lead to inspection errors such as misidentification of defects.

[0065] On the other hand, as shown in Figure 7, image B includes only an image of the top surface of the silicon carbide substrate and does not include an image showing the top surface of the rotation-holding unit 252. This absence of an image of the rotation-holding unit 252 in image B is due to the absorption of blue light entering the silicon carbide substrate by the silicon carbide substrate. Unlike the examples in Figures 5 and 6, the graph in the right portion of Figure 7 does not show changes in pixel values ​​corresponding to the protrusion 252c of the rotation-holding unit 252.

[0066] These results show that when R image data and G image data are used to inspect a silicon carbide substrate, the image from the rotating holding unit 252 acts as noise, making accurate inspection impossible. Therefore, in the substrate inspection apparatus 200 according to this embodiment, only B image data is acquired as inspection image data when inspecting a silicon carbide substrate.

[0067] Unlike a silicon carbide substrate, a silicon substrate is not transparent. The front and back surfaces 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 imaging the silicon substrate do not contain any image components from the rotation holding unit 252. Consequently, in the substrate inspection apparatus 200 according to this embodiment, when inspecting a silicon substrate, all three image data—R image data, G image data, and B image data—are acquired as inspection image data.

[0068] 5. Functional configuration of the control unit 280 of the substrate inspection device 200 Figure 8 is a block diagram showing the functional configuration of the control unit 280 in Figure 1. As shown in Figure 8, the control unit 280 includes an imaging 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 imaging and inspecting the substrate W. These functional units are realized by the CPU executing a computer program (a program for performing the imaging inspection process described later) stored in memory or the like. Note that some or all of the functional units of the control unit 280 may be realized by hardware such as electronic circuits.

[0069] The imaging control unit 281 controls the illumination unit 220, imaging unit 240, substrate holding device 250, moving unit 260, and direction detection unit 270 so that the substrate W being transported into the housing unit 210 (Figure 1) is imaged. 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 R pixel data, G pixel data, and B pixel data obtained by imaging to the control unit 280.

[0070] The image data generation unit 282 generates R image data based on the R pixel data output from the imaging unit 240 when the imaging unit 240 is imaging the substrate W. The image data generation unit 282 also generates G image data based on the G pixel data output from the imaging unit 240. Furthermore, the image data generation unit 282 generates B image data based on the B pixel data output from the imaging unit 240.

[0071] The inspection memory unit 285 stores substrate characteristic information and inspection conditions, etc. The substrate characteristic information includes information indicating how to acquire inspection image data according to the characteristics of the substrate W to be inspected.

[0072] Here, a translucent substrate W that has the characteristic of absorbing blue light more readily than red and green light is called a B-absorbing substrate, and a translucent substrate W that has the characteristic of absorbing green light more readily than red and blue light is called a G-absorbing substrate. Furthermore, a translucent substrate W that has the characteristic of absorbing red light more readily than 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.

[0073] In this case, the above substrate characteristic information specifically includes the information that "if the substrate W to be inspected is a B-absorbing substrate, B image data will be acquired as the inspection image data." The substrate characteristic information also includes the information that "if the substrate W to be inspected is a G-absorbing substrate, G image data will be acquired as the inspection image data." The substrate characteristic information also includes the information that "if the substrate W to be inspected is an R-absorbing substrate, R image data will be acquired as the inspection image data." Furthermore, the substrate characteristic information includes the information that "if the substrate W to be inspected is an opaque substrate, R image data, G image data, and B image data will be acquired as inspection image data, respectively."

[0074] The inspection conditions include information necessary to inspect the substrate W using inspection image data. For example, when the first inspection described above is performed, the inspection conditions include the tolerance range for each difference value in the sample image data and the difference image data. When the second inspection described above is performed, the inspection conditions include a threshold for determining the amount of change in pixel values ​​in the inspection image data. Furthermore, when the third inspection described above is performed, the inspection conditions include a predetermined range for determining the brightness of the image represented by the inspection image data.

[0075] In the substrate inspection apparatus 200, as described above, before inspecting a substrate W, information indicating the type of substrate W is input based on the user's operation of the operation unit 290. The substrate characteristic determination unit 283 receives the type of substrate W input from the operation unit 290. Then, the substrate characteristic determination unit 283 determines whether the received type of substrate W is one of the above-mentioned B-absorbing substrates, G-absorbing substrates, R-absorbing substrates, or opaque substrates.

[0076] This determination process can be achieved by the substrate characteristic determination unit 283 maintaining a table of known information indicating whether multiple types of substrates W are B-absorbing substrates, G-absorbing substrates, R-absorbing substrates, or opaque substrates. This table includes, for example, information such as "substrate W made of silicon carbide is a B-absorbing substrate" and "substrate W made of silicon is an opaque substrate." Note that instead of being maintained by the substrate characteristic determination unit 283, the above table may be stored in the inspection storage unit 285.

[0077] Furthermore, the substrate characteristic determination unit 283 determines how to acquire inspection image data when imaging a substrate W, based on the above determination result and the substrate characteristic information stored in the inspection storage unit 285.

[0078] 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 when imaging a substrate W. The inspection image data acquisition unit 284 also 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.

[0079] 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. The inspection unit 286 also outputs the inspection results to an external device of the substrate inspection apparatus 200, for example. The configuration of the substrate inspection apparatus 200 shown in Figures 1 and 8, excluding the inspection unit 286 shown in Figure 8, is an example of a substrate imaging apparatus.

[0080] 6. Imaging and Inspection Processing Figures 9 and 10 are flowcharts showing the imaging inspection process performed by the control unit 280 in Figure 8. The imaging inspection process will be described below with reference to Figure 8. The imaging inspection process is started, for example, when the power to the substrate inspection device 200 is turned on, or when the user gives a command to the control unit 280 to start the inspection using the operation unit 290.

[0081] First, the substrate characteristic determination unit 283 determines whether or not the type of substrate W to be inspected has been entered (step S11). If the type of substrate W is not entered, the substrate characteristic determination unit 283 repeats the process in step S11. On the other hand, if the type of substrate W is entered, the substrate characteristic determination unit 283 receives the entered information (type of substrate W) and determines whether or not the substrate W to be inspected is a B absorption substrate (step S12).

[0082] In step S12, if the substrate W to be inspected is a B-absorbing substrate, the substrate characteristic determination unit 283 determines how to acquire inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S13). In step S13, it is decided to acquire the B image data obtained by imaging as the inspection image data.

[0083] Subsequently, when the substrate W is brought into the substrate inspection device 200, the imaging control unit 281 controls each component (220, 240, 250, 260, 270) of the substrate inspection device 200 to irradiate the substrate W with illumination light (step S14).

[0084] 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). Subsequently, 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).

[0085] In step S15, it has already been determined through the processing in step S13 that the image data necessary for acquiring the inspection image data is B image data. Therefore, only B image data may be generated.

[0086] Next, the inspection unit 286 performs inspection processing 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 (step S16). The inspection processing in step S16 corresponds to at least one of the first inspection, second inspection, and third inspections described above. After the completion of step S16, the imaging inspection process ends.

[0087] 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 or not the substrate W to be inspected is a G-absorbing substrate (step S21).

[0088] In step S21, if the substrate W to be inspected is a G-absorbing substrate, the substrate characteristic determination unit 283 determines how to acquire inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S22). In step S22, it is decided to acquire the G image data obtained by imaging as the inspection image data. Subsequently, the same processes as steps S14 and S15 described above are performed in steps S23 and S24, respectively. Note that in step S24, it has already been determined by the processing in step S22 that the image data necessary for acquiring the inspection image data is G image data. Therefore, only G image data may be generated.

[0089] Next, the inspection image data acquisition unit 284 acquires the G image data as inspection image data according to the acquisition method determined by the substrate characteristic determination unit 283 (step S25). After that, the process proceeds to step S16.

[0090] 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 or not the substrate W to be inspected is an R-absorbing substrate (step S31).

[0091] In step S31, if the substrate W to be inspected is an R-absorbing substrate, the substrate characteristic determination unit 283 determines how to acquire inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S32). In step S32, it is decided to acquire the R image data obtained by imaging as the inspection image data. Subsequently, the same processes as steps S14 and S15 described above are performed in steps S33 and S34, respectively. Note that in step S34, it has already been determined by the process in step S22 that the image data necessary for acquiring the inspection image data is R image data. Therefore, only R image data may be generated.

[0092] Next, the inspection image data acquisition unit 284 acquires the 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 S16.

[0093] In step S31 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). The substrate characteristic determination unit 283 also determines how to acquire inspection image data based on the substrate characteristic information stored in the inspection storage unit 285 (step S42). In step S42, it is decided to acquire the R image data, G image data, and B image data obtained by imaging as inspection image data, respectively. Subsequently, the same processes as steps S14 and S15 above are performed in steps S43 and S44, respectively.

[0094] Next, the inspection image data acquisition unit 284 acquires R image data, G image data, and B image data as inspection image data, respectively, according to the acquisition method determined by the substrate characteristic determination unit 283 (step S45). After that, the process proceeds to step S16.

[0095] Figure 11 is a flowchart showing an example of the inspection process in step S16 of Figure 9. Here, an example of the inspection process corresponding to the first inspection described above will be explained. In the following explanation, it will be assumed that in the initial state, the inspection storage unit 285 in Figure 8 stores sample image data corresponding to the substrate W to be inspected as an inspection condition.

[0096] As shown in Figure 11, when the process corresponding to the first inspection is started, the inspection unit 286 reads sample image data from the inspection conditions in the inspection storage unit 285 (step S51).

[0097] Next, the inspection unit 286 generates differential image data based on the read sample image data and the inspection image data acquired in any of steps S16, S25, S35, or S45 in Figures 9 and 10 (step S52).

[0098] 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 tolerance range (step S53). If the difference value corresponding to each pixel of the differential image data is within a predetermined tolerance 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 a predetermined tolerance range, the inspection unit 286 determines that the substrate W to be inspected is abnormal (step S55). After processing in step S54 or step S55, the inspection process ends.

[0099] 7. Effects (a) In the above-described substrate inspection apparatus 200, illumination light consisting of white light is shone onto the upper surface of the substrate W, and the upper surface of the substrate W is imaged 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 used for inspecting the substrate W is acquired.

[0100] The method for acquiring inspection image data is determined so that, when the substrate W to be inspected is a translucent 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, if the substrate W to be inspected is a silicon carbide substrate, B image data 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 that includes reflections of surrounding materials on the substrate W. As a result, it becomes possible to perform appropriate inspection of the top surface of the substrate W according to the type of substrate W.

[0101] (b) Furthermore, the method for acquiring inspection image data is determined so that, 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. This makes it possible to inspect the top surface of the substrate W using more inspection image data when the substrate W is an opaque substrate. Therefore, inspection accuracy is improved.

[0102] (c) In the above-described substrate inspection apparatus 200, the substrate characteristic determination unit 283 receives input of the type of substrate W and determines whether the received type of substrate W is a B-absorbing substrate, a G-absorbing substrate, an R-absorbing substrate, or an opaque substrate. The substrate characteristic determination unit 283 also determines the method for acquiring inspection image data based on the determination result. Therefore, the user does not need to perform complicated setting work regarding the method for acquiring inspection image data.

[0103] (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 pitch of the multiple pixels in each line sensor denser, inspection image data with higher resolution can be acquired.

[0104] 8. Substrate processing apparatus equipped with a substrate inspection device 200 Figure 12 is a schematic block diagram showing an example of a substrate processing apparatus equipped with the substrate inspection apparatus 200 shown in Figure 1. As shown in Figure 12, the substrate processing apparatus 100 is provided adjacent to the exposure apparatus 300 and includes the substrate inspection apparatus 200, as well as a control device 110, a transport device 120, a coating processing unit 130, a developing processing unit 140, and a heat processing unit 150.

[0105] The control device 110 includes, for example, a CPU and memory, or a microcomputer, and controls the operation of the transport device 120, the coating processing unit 130, the developing processing unit 140, and the heat processing unit 150. The control device 110 also gives commands to the control unit 280 (Figure 1) of the substrate inspection device 200 to inspect the surface condition of one side of the substrate W (to perform the imaging inspection process described above).

[0106] The transport device 120 transports the substrate W between the coating processing unit 130, the developing processing unit 140, the heat processing unit 150, the substrate inspection device 200, and the exposure device 300. The coating processing unit 130 forms a resist film on one surface of the untreated substrate W (coating process). After the coating process, the substrate W with the resist film formed is subjected to exposure processing in the exposure device 300. The developing processing unit 140 develops the substrate W by supplying a developer solution to the substrate W after exposure processing by the exposure device 300. The heat processing unit 150 performs heat processing on the substrate W before and after the coating process by the coating processing unit 130, the developing process by the developing processing unit 140, and the exposure process by the exposure device 300.

[0107] The coating processing unit 130 may also form an anti-reflective film on the substrate W. In this case, the heat processing unit 150 may be provided with a processing unit for performing adhesion strengthening treatment to improve the adhesion between the substrate W and the anti-reflective film. The coating processing unit 130 may also form a resist cover film on the substrate W to protect the resist film formed on the substrate W.

[0108] The substrate inspection device 200 inspects the substrate W after coating by the coating processing unit 130 and before exposure by the exposure device 300. Alternatively, the substrate inspection device 200 inspects the substrate W after coating by the coating processing unit 130 and after exposure by the exposure device 300. Alternatively, the substrate inspection device 200 may inspect the substrate W after coating by the coating processing unit 130, after exposure by the exposure device 300, and after development by the development processing unit 140.

[0109] In the substrate processing apparatus 100 described above, for example, the operating conditions for each component are set as a processing recipe for each lot of a predetermined number of substrates W. The processing recipe may include information indicating the type of substrate W to be processed. In this case, the substrate characteristic determination unit 283 of the substrate inspection apparatus 200 shown in Figure 8 may determine whether the substrate W to be inspected is a B-absorbing substrate, a G-absorbing substrate, an R-absorbing substrate, or an opaque substrate by receiving the processing recipe from the control device 110 shown in Figure 12.

[0110] 9. Other Embodiments (a) The illumination unit 220 according to the above embodiment includes a white light source that generates white light, but the present invention is not limited thereto. The illumination unit 220 may also include a red light source that generates red light, a green light source that generates green light, and a blue light source that generates blue light instead of a white light source. In this case, the imaging unit 240 may be composed of a monochrome image sensor.

[0111] In this case, when the substrate characteristic determination unit 283 acquires only one image data from among the R image data, G image data, and B image data as inspection image data, it may control the illumination unit 220 as shown by the dotted arrow in Figure 8, and selectively drive the light source of the color corresponding to that one image data. This control suppresses unnecessary energy consumption in the illumination unit 220.

[0112] (b) The imaging unit 240 according to the above embodiment is composed of three line sensors (241 to 243), but the present invention is not limited thereto. The imaging unit 240 may be composed of a color image sensor in which a plurality of R pixels pa, a plurality of G pixels pb, and a plurality of B pixels pc are arranged in a Bayer array. Alternatively, the imaging unit 240 may have a configuration that includes a monochrome image sensor and a color filter switching device that switches the wavelength of light incident on the image sensor. Alternatively, the imaging unit 240 may be composed of a plurality of monochrome image sensors and a plurality of color filters corresponding to each of the plurality of monochrome image sensors.

[0113] (c) In the imaging inspection process according to the above embodiment, steps S21 to S25 and S31 to S35 are performed assuming the presence of a G-absorbing substrate and an R-absorbing substrate. However, if there is no substrate W corresponding to the G-absorbing substrate and the R-absorbing substrate, steps S21 to S25 and S31 to S35 may not be performed.

[0114] (d) In the substrate inspection apparatus 200 according to the above embodiment, the substrate holding device 250 moves relative to the fixed illumination unit 220, reflection unit 230, and imaging unit 240 in order to image the entire upper surface of the substrate W, but the present invention is not limited thereto.

[0115] The illumination unit 220, the reflective unit 230, and the imaging unit 240 may be configured to be movable in a second device direction D2 relative to the substrate holding device 250 while maintaining their relative positional relationship. In this case, the substrate W may be imaged by moving the illumination unit 220, the reflective unit 230, and the imaging unit 240 in a second device direction D2 relative to the fixed substrate holding device 250.

[0116] (e) In the substrate inspection apparatus 200 according to the above embodiment, the inspection image data consists 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 be generated so as to correspond to multiple parts of the substrate W, respectively.

[0117] For example, if the substrate W to be inspected is a translucent substrate, the rotating holding part 252, which is covered by the depth of field of the imaging unit 240, is likely to appear in the image obtained by imaging. However, components located far from the substrate W are unlikely to appear in the image obtained by imaging if they are far outside the depth of field of the imaging unit 240.

[0118] Therefore, for the portion of the substrate W that overlaps with the rotating holding portion 252 in a plan view, the inspection image data is the image data corresponding to the light absorbed by the substrate W (one of the R image data, G image data, and B image data). On the other hand, for the portion of the substrate W that is separated from the rotating holding portion 252 in a plan view, the R image data, G image data, and B image data are used as the inspection image data.

[0119] This makes it possible, for example, to perform appropriate inspections of the central region of the top surface of the substrate W with suppressed degradation of accuracy, and to perform more accurate and detailed inspections of the outer region of the top surface of the substrate W that surrounds the central region of the top surface of the substrate W.

[0120] (f) In the substrate inspection apparatus 200 according to the above embodiment, when the substrate W to be inspected is a translucent substrate, one of the R image data, G image data, and B image data is acquired as inspection image data, but the present invention is not limited thereto. When the substrate W to be inspected is a translucent substrate, the R image data, G image data, and B image data may be acquired as inspection image data.

[0121] In this case, in order to suppress the decrease in inspection accuracy due to reflections from the rotation holding unit 252, it is preferable that the inspection conditions stored in the substrate characteristic determination unit 283 are adjusted for each image data.

[0122] For example, the inspection image data corresponding to light absorbed by substrate W is adjusted to have stricter inspection conditions. Conversely, the inspection image data corresponding to light not absorbed by substrate W is adjusted to have looser inspection conditions. Specifically, for inspection image data corresponding to wavelengths of light absorbed by substrate W, the "tolerance range for each difference value in the difference image data" used in the first inspection described above is set to be small. Conversely, for inspection image data corresponding to light not absorbed by substrate W, the "tolerance range for each difference value in the difference image data" used in the first inspection described above is set to be large.

[0123] In these cases, inspection results based on inspection image data corresponding to the light absorbed by the substrate W can be treated as highly reliable inspection results. Furthermore, inspection results based on inspection image data corresponding to the light not absorbed by the substrate W can be treated as supplementary inspection results.

[0124] (g) In the substrate inspection apparatus 200 according to the above embodiment, when the substrate W to be inspected is a translucent substrate, one of the R image data, G image data, and B image data is acquired as inspection image data, but the present invention is not limited thereto. When the substrate W to be inspected is a translucent substrate, image data obtained by combining two or more of the R image data, G image data, and B image data may be acquired as inspection image data.

[0125] In this case, the inspection image data is defined as image data corresponding to the light absorbed by the substrate W, and the component of the image data corresponding to the wavelength of light absorbed by the substrate W is greater than the component of the image data corresponding to the wavelength of light not absorbed by the substrate W. As a result, the component of the image data corresponding to the light absorbed by the substrate W is preferentially used for inspecting the substrate W. Therefore, the decrease in inspection accuracy due to reflections of surrounding materials of the substrate W during imaging of the substrate W is reduced.

[0126] 10. Correspondence between each part of the embodiment and each component of the claim The following describes examples of the correspondence between each component of the claim and each component of the embodiment. Various other elements having the configuration or function described in the claim can also be used as each component of the claim.

[0127] In the above embodiment, 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 configuration of the substrate inspection apparatus 200 excluding 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.

[0128] Furthermore, an example of the first wavelength is one of the wavelengths of red light, green light, and blue light that is absorbed by the substrate W, and the pixel data corresponding to that one wavelength of light is an example of the first data. An example of the second wavelength is the remaining wavelength of red light, green light, and blue light that is not absorbed by the substrate W, and the pixel data corresponding to the remaining wavelength of light is an example of the second data.

[0129] Furthermore, the operating mode of the control unit 280 during processing steps S14-S16, S23-S25, and S33-S35 in Figures 9 and 10 is an example of the first mode, the operating mode of the control unit 280 during processing steps S43-S45 in Figure 10 is an example of the second mode, the substrate characteristic determination unit 283 is an example of a substrate characteristic determination unit, the first device direction D1 is an example of a first direction, the second device direction D2 is an example of a second direction, the moving unit 260 is an example of a moving unit, the inspection unit 286 is an example of an inspection unit, and the substrate inspection device 200 and the substrate processing device 100 are examples of substrate processing devices.

[0130] 11. Summary of Embodiments (Paragraph 1) The substrate imaging device relating to Paragraph 1 is An illumination unit that shines illumination light onto the top surface of the circuit board, An imaging unit that images the upper surface of the substrate irradiated with the illumination light, The system includes a control unit that acquires inspection image data indicating 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 corresponds to light of the absorption wavelength of the substrate.

[0131] In this substrate imaging device, illumination light is shone onto the top surface of the substrate, and the top surface of the substrate is imaged by the imaging unit. Inspection image data is acquired based on the output of the imaging unit.

[0132] Depending on the type of substrate being inspected, a portion of the illumination light may be reflected from the top surface of the substrate and enter the imaging unit, while the remaining portion of the illumination light may pass through the substrate. In this case, the illumination light that has passed through the substrate may be reflected from the surface of the peripheral components located below the substrate, pass through the substrate again, and enter the imaging unit. Therefore, the image data generated based on the output of the imaging unit may represent both the top surface of the substrate and the peripheral components. Such image data cannot accurately capture the condition of the top surface of the substrate.

[0133] When illumination light passes through the substrate, if the remaining portion of the illumination light is absorbed by the substrate, the amount of light reflected by surrounding materials and incident on the imaging unit will be reduced. As a result, image data can be obtained that shows the top surface of the substrate and does not show surrounding materials.

[0134] Therefore, in the above-described substrate imaging device, the inspection image data showing 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 is the wavelength of light that the substrate can absorb. As a result, it becomes possible to perform appropriate inspections of the upper surface of the substrate according to the type of substrate.

[0135] (Paragraph 2) In the substrate imaging apparatus relating to Paragraph 1, The substrate imaging device is The substrate further comprises 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 illumination light onto the upper surface of the substrate held by the holding unit, The imaging unit images the upper surface of the substrate held by the holding unit, At least a portion of the upper surface of the substrate may include an area that overlaps with the holding portion in a plan view.

[0136] In this case, the substrate is held by the retaining part, which is in contact with the bottom surface of the substrate. At this time, the retaining part is separated from the top surface of the substrate by the thickness of the substrate, but the thickness of the substrate is relatively small. That is, the distance between the top surface of the substrate and the retaining part is relatively small. Therefore, the retaining part is likely to be located within the depth of field of the imaging unit. Consequently, when the substrate is imaged with light that passes through the substrate but is not absorbed by the substrate, the retaining part will be captured in the image of the substrate obtained by that imaging.

[0137] In contrast, in the above configuration, the illumination light includes light of the absorption wavelength of the substrate. Furthermore, the inspection image data corresponds to light of the absorption wavelength of the substrate. In addition, at least a portion of the upper surface of the substrate includes an area that overlaps with the holding portion in a plan view. This suppresses the inclusion of images of the holding portion in the image shown by the inspection image data. In other words, it prevents the acquisition of inspection image data that includes reflections of the holding portion.

[0138] (Article 3) In the substrate imaging apparatus relating to Article 2, The illumination unit is configured to irradiate the upper surface of the substrate with light having a first wavelength and light having a second wavelength, simultaneously or selectively, as illumination light. The imaging unit is configured to generate first data corresponding to light of the first wavelength by imaging the substrate irradiated with light of the first wavelength, and to generate second data corresponding to light of the second wavelength by imaging the substrate irradiated with light of the second wavelength. The control unit may operate in a first mode in which, when the substrate transmits the illumination light and absorbs the first wavelength of light more readily than the second wavelength of light, it controls the illumination unit and the imaging unit to irradiate the upper surface of the substrate with light containing at least the first wavelength of light among the first and second wavelengths of light as illumination light, and generates image data as inspection image data in which the components of the first data are greater than the components of the second data.

[0139] According to the above configuration, for example, light of a first wavelength is irradiated onto the upper surface of the substrate as illumination light. In this case, first data corresponding to the light of the first wavelength is generated. Furthermore, for example, light of a second wavelength is irradiated onto the upper surface of the substrate as illumination light. In this case, second data corresponding to the light of the second wavelength is generated.

[0140] If the substrate transmits illumination light and absorbs light of the first wavelength more readily than light of the second wavelength, then the inspection image data will contain more of the first data component than the second data component. As a result, it becomes possible to perform appropriate inspections of the top surface of the substrate according to the type of substrate.

[0141] (Article 4) In the substrate imaging apparatus relating to Article 3, The control unit may generate image data consisting of the first data as the inspection image data when the first mode is in operation.

[0142] In this case, if the substrate transmits illumination light and absorbs light of the first wavelength more readily than light of the second wavelength, the image data generated by the first data is considered the inspection image data. Therefore, appropriate inspection according to the type of substrate becomes possible with simple processing.

[0143] (Article 5) In a substrate imaging apparatus relating to Article 3 or Article 4, The control unit may operate in a second mode in which, when the upper surface of the substrate does not transmit light of the first wavelength and light of the second wavelength, it controls the illumination unit and the imaging unit to irradiate the upper surface of the substrate with light of the first wavelength and light of the second wavelength as illumination light, and generates image data consisting of the first data and image data consisting of the second data as inspection image data, respectively.

[0144] If the top surface of the substrate does not transmit illumination light, most of the illumination light is reflected and incident on the imaging unit. This generates image data that accurately shows the condition of the top surface of the substrate. The appearance of the top surface of the substrate may change depending on the wavelength of the illumination light. In the above substrate imaging device, light of a first wavelength and light of a second wavelength can be used as 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.

[0145] Therefore, by using image data corresponding to the first wavelength of light and image data corresponding to the second wavelength of light, it becomes possible to perform a more accurate and detailed inspection of the condition of the top surface of the substrate.

[0146] (Paragraph 6) In the substrate imaging apparatus relating to Paragraph 5, The substrate imaging device is The system further includes a substrate characteristic determination unit that determines whether the substrate transmits the illumination light and absorbs light of the first wavelength more readily than light of the second wavelength, or whether the substrate does not transmit light of the first wavelength or light of the second wavelength. The control unit, The first mode is operated when the substrate transmits the illumination light and absorbs light of the first wavelength more readily than light of the second wavelength. The second mode may be operated if the substrate is a substrate that does not transmit light of the first wavelength and light of the second wavelength.

[0147] In this case, the control unit's mode is determined based on the results of the circuit board's characteristics assessment. Therefore, the user does not need to perform complicated setup procedures to determine the control unit's mode.

[0148] (Paragraph 7) In the substrate imaging apparatus relating to Paragraph 6, The first wavelength mentioned above is the wavelength of blue light, The second wavelength mentioned above is the wavelength of red or green light. The substrate characteristic determination unit is When the substrate is made of silicon carbide, it is determined that the substrate transmits the illumination light and absorbs light of the first wavelength more readily than light of the second wavelength. If the substrate is made of silicon, it may be determined that the substrate is a substrate that does not transmit light of the first wavelength and light of the second wavelength.

[0149] A silicon carbide substrate is an orange, translucent substrate that transmits light of red, green, and blue wavelengths. Furthermore, a silicon carbide substrate has an orange color and absorbs blue wavelength light more readily than red and green wavelength light. According to the above configuration, when the substrate is made of silicon carbide, the inspection image data obtained contains more of the first data component corresponding to blue light than the second data component corresponding to red or green light.

[0150] A silicon substrate is an opaque substrate with a mirror-like outer surface that does not transmit light of red, green, and blue wavelengths. According to the above configuration, 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 either red or green is acquired as inspection image data.

[0151] (Article 8) In a substrate imaging apparatus relating to any one of Articles 2 to 7, The imaging unit is A first line sensor is provided so as to extend parallel to a first direction, and is capable of outputting a signal indicating the amount of light of the first wavelength received as first data by receiving light of the first wavelength. The system includes a second line sensor that is provided to extend parallel to the first direction and is capable of outputting a signal indicating the amount of light of the second wavelength received as the second data by receiving light of the second wavelength, The substrate imaging device is The device may further include a moving part that moves at least one of the holding part and the imaging part such that the substrate held by the holding part moves relative to the imaging part in a second direction parallel to the upper surface of the substrate and intersecting the first direction.

[0152] In this case, by moving at least one of the holding unit and the imaging unit in a second direction, image data corresponding to a first wavelength is generated based on the output of the first line sensor. In addition, image data corresponding to a second wavelength is generated based on the output of the second line sensor.

[0153] In the first line sensor, multiple pixels (photodetectors) that receive light having a first wavelength are arranged parallel to the first direction. In the second line sensor, multiple pixels (photodetectors) that receive light having a second wavelength are arranged parallel to the first direction. Therefore, by increasing the density of the arrangement pitch of the multiple pixels in each line sensor in the direction parallel to the first direction, inspection image data with higher resolution can be acquired.

[0154] (Paragraph 9) The substrate processing apparatus relating to Paragraph 9 is: A substrate imaging device relating to any one of paragraphs 1 to 8, The system includes an inspection unit that inspects the condition of the upper surface of the substrate based on inspection image data acquired by the substrate imaging device.

[0155] The substrate inspection device includes the substrate imaging device described above. This makes it possible to perform appropriate inspections of the top surface of the substrate according to the type of substrate.

[0156] (Paragraph 10) The substrate imaging method relating to Paragraph 10 is: The steps include irradiating the top surface of the circuit board with illumination light, The steps include: capturing an image of the upper surface of the substrate irradiated with the illumination light using an imaging unit; The step includes acquiring inspection image data showing 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 corresponds to light of the absorption wavelength of the substrate.

[0157] In this substrate imaging method, illumination light is shone onto the top surface of the substrate, and the top surface of the substrate is imaged by the imaging unit. Inspection image data is acquired based on the output of the imaging unit.

[0158] Depending on the type of substrate being inspected, a portion of the illumination light may be reflected from the top surface of the substrate and enter the imaging unit, while the remaining portion of the illumination light may pass through the substrate. In this case, the illumination light that has passed through the substrate may be reflected from the surface of the peripheral components located below the substrate, pass through the substrate again, and enter the imaging unit. Therefore, the image data generated based on the output of the imaging unit may represent both the top surface of the substrate and the peripheral components. Such image data cannot accurately capture the condition of the top surface of the substrate.

[0159] When illumination light passes through the substrate, if the remaining portion of the illumination light is absorbed by the substrate, the amount of light reflected by surrounding materials and incident on the imaging unit will be reduced. As a result, image data can be obtained that shows the top surface of the substrate and does not show surrounding materials.

[0160] Therefore, in the above substrate imaging method, the inspection image data showing 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 is the wavelength of light that the substrate can absorb. As a result, it becomes possible to perform appropriate inspections of the upper surface of the substrate according to the type of substrate.

[0161] (Paragraph 11) The substrate processing method relating to Paragraph 11 is: The substrate imaging method relating to item 10, The method includes the step of inspecting the condition of the upper surface of the substrate based on the inspection image data acquired by the substrate imaging method described above.

[0162] The substrate inspection method includes the substrate imaging method described above. This makes it possible to perform appropriate inspections of the top surface of the substrate according to the type of substrate. [Explanation of Symbols]

[0163] 100...Substrate processing device, 110...Control device, 120...Transfer device, 130...Coating processing device, 140...Developing processing device, 150...Heat processing device, 200...Substrate inspection device, 210...Housing, 211...Opening, 220...Illumination unit, 230...Reflective unit, 240...Imaging unit, 241...First line sensor, 242...Second line sensor, 243...Third line sensor, 244...Concentrating lens, 250...Substrate holding device, 251...Drive device, 252...Rotation holding unit, 252a...Flat unit, 252b...Suction hole, 252c …Protrusion, 252d…Seal projection, 252e…Screw member, 253…Rotation axis, 260…Movement part, 261…Guide member, 262…Movement holding part, 270…Direction detection part, 280…Control unit, 281…Imaging control unit, 282…Image data generation unit, 283…Substrate characteristic determination unit, 284…Inspection image data acquisition unit, 285…Inspection storage unit, 286…Inspection unit, 290…Operation unit, 300…Exposure device, D1…First device direction, D2…Second device direction, W…Substrate, pa…R pixel, pb…G pixel, pc…B pixel

Claims

1. An illumination unit that shines illumination light onto the top surface of the circuit board, An imaging unit that images the upper surface of the substrate irradiated with the illumination light, The system includes a control unit that acquires inspection image data indicating 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 corresponds to light of the absorption wavelength of the substrate, and is captured by a substrate imaging device.

2. The substrate further comprises 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 illumination light onto the upper surface of the substrate held by the holding unit, The imaging unit images the upper surface of the substrate held by the holding unit, The substrate imaging apparatus according to claim 1, wherein at least a portion of the upper surface of the substrate includes a region that overlaps with the holding portion in a plan view.

3. The illumination unit is configured to irradiate the upper surface of the substrate with light having a first wavelength and light having a second wavelength, simultaneously or selectively, as illumination light. The imaging unit is configured to generate first data corresponding to light of the first wavelength by imaging the substrate irradiated with light having the first wavelength, and to generate second data corresponding to light of the second wavelength by imaging the substrate irradiated with light having the second wavelength. The substrate imaging apparatus according to claim 2, wherein the control unit operates in a first mode in which, when the substrate transmits the illumination light and absorbs the first wavelength of light more readily than the second wavelength of light, the illumination unit and the imaging unit irradiate the upper surface of the substrate with light including at least the first wavelength of light among the first wavelength of light and the second wavelength of light as the illumination light, and generates image data in which the components of the first data are greater than the components of the second data as the inspection image data.

4. The substrate imaging apparatus according to claim 3, wherein the control unit generates image data consisting of the first data as the inspection image data when the first mode is in operation.

5. The substrate imaging apparatus according to claim 3 or 4, wherein the control unit operates in a second mode in which, when the upper surface of the substrate does not transmit light of the first wavelength and light of the second wavelength, the illumination unit and the imaging unit are controlled to irradiate the upper surface of the substrate with light of the first wavelength and light of the second wavelength as illumination light, and image data consisting of first data and image data consisting of second data are generated as inspection image data, respectively.

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

7. The first wavelength mentioned above is the wavelength of blue light, The second wavelength is the wavelength of red or green light, The substrate characteristic determination unit is When the substrate is made of silicon carbide, it is determined that the substrate transmits the illumination light and absorbs light of the first wavelength more readily than light of the second wavelength. The substrate imaging apparatus according to claim 6, wherein, when the substrate is made of silicon, it is determined that the substrate is a substrate that does not transmit light of the first wavelength and light of the second wavelength.

8. The imaging unit is A first line sensor is provided so as to extend parallel to the first direction, and is capable of outputting a signal indicating the amount of light of the first wavelength received as first data by receiving light of the first wavelength. The system includes a second line sensor that is provided to extend parallel to the first direction and is capable of outputting a signal indicating the amount of light of the second wavelength received as the second data by receiving light of the second wavelength, The substrate imaging device is A substrate imaging apparatus according to any one of claims 2 to 4, further comprising a moving part for moving at least one of the holding part and the imaging part such that the substrate held by the holding part moves relative to the imaging part in a second direction parallel to the upper surface of the substrate and intersecting the first direction.

9. A substrate imaging apparatus according to claim 1 or 2, A substrate processing apparatus comprising: an inspection unit that inspects the condition of the upper surface of a substrate based on inspection image data acquired by the substrate imaging device.

10. The steps include irradiating the top surface of the circuit board with illumination light, The steps include: capturing an image of the upper surface of the substrate irradiated with the illumination light using an imaging unit; The step includes acquiring inspection image data showing 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 corresponds to light of the absorption wavelength of the substrate, and the substrate imaging method.

11. The substrate imaging method according to claim 10, A substrate processing method comprising the step of inspecting the condition of the upper surface of a substrate based on inspection image data acquired by the substrate imaging method described above.

Images