JP7314237B2 - Board imaging device and board imaging method - Google Patents

Description

The present disclosure relates to substrate imaging devices.

2. Description of the Related Art At present, in microfabrication of substrates (for example, semiconductor wafers), it is widely practiced to form uneven patterns on substrates using photolithography technology. For example, the process of forming a resist pattern on a semiconductor wafer includes forming a resist film on the surface of the wafer, exposing the resist film along a predetermined pattern, and developing the resist film after exposure by reacting it with a developer.

In recent years, an immersion exposure technique has been proposed as a technique for obtaining an extremely fine resist pattern with a line width of about 40 nm to 45 nm. When the resist film is subjected to liquid immersion exposure, the resist film is exposed while an exposure liquid (such as pure water) having a higher refractive index than air is supplied between the wafer and the projection lens for exposure.

By the way, in the process of surface treatment of a wafer, fine particles (foreign matter) may adhere to the surface (central portion or peripheral portion) of the wafer due to various causes. Most of the particles can be removed by washing the surface of the substrate with a cleaning liquid, but particles may still remain on the surface of the substrate. When a wafer on which particles are adhered is carried into an exposure machine, the exposure machine may be contaminated with the particles, and the shape of the particles may be transferred to a pattern other than the desired pattern when the subsequent wafer is exposed. In addition, if the exposure machine is contaminated with particles, it may take a long time to clean the exposure machine, resulting in a significant decrease in productivity. Furthermore, if defects (for example, cracks, chips, scratches, etc.) are present near the periphery of the wafer in the first place, the wafer cannot be properly processed. Therefore, Patent Documents 1 to 3 disclose a wafer inspection method including a step of capturing an image of the peripheral portion of the wafer using a plurality of cameras, a step of performing image processing on each captured image, and a step of grasping the state of the peripheral portion of the wafer based on the processed image after the image processing.

JP 2007-251143 A JP 2008-135583 A JP-A-11-339042

However, in the inspection methods of Patent Documents 1 to 3, in order to inspect a plurality of surfaces (for example, the upper surface and the end surface) in the vicinity of the peripheral edge of the wafer, each surface is individually imaged using a plurality of cameras. Therefore, a space for installing a plurality of cameras is required, which may increase the size of the device for inspecting the wafer and increase the cost of the device.

It is conceivable to inspect a plurality of surfaces near the periphery of the wafer while moving one camera. Also, since the moving speed of the camera is not so fast, it may take time to inspect the wafer.

Furthermore, when a plurality of cameras are used, a mechanism for assembling them is required in addition to the plurality of cameras, which complicates the configuration. Even when one camera is moved, a camera movement mechanism or the like is required in addition to the one camera, which complicates the configuration. Therefore, in the inspection methods of Patent Documents 1 to 3, the possibility of equipment troubles such as failure increases, and there is a concern that the inspection cannot be performed efficiently.

Therefore, the present disclosure describes a board imaging device that can reduce the size and cost while suppressing equipment troubles.

A substrate imaging device according to one aspect of the present disclosure includes a rotation holding part configured to hold and rotate a substrate, a mirror member having a reflecting surface that is inclined with respect to the rotation axis of the rotation holding part and faces an end surface and a peripheral area of the back surface of the substrate held by the rotation holding part, and a first light from the peripheral area of the front surface of the substrate held by the rotation holding part and a second light from the edge surface of the substrate held by the rotation holding part that is reflected by the mirror member. and a camera having an imaging device that receives input through the camera.

In the substrate imaging device according to one aspect of the present disclosure, the mirror member has a reflective surface that is inclined with respect to the rotation axis of the spin holder and that faces the end face and the peripheral region of the back surface of the substrate held by the spin holder. Further, in the substrate imaging device according to one aspect of the present disclosure, the first light from the peripheral region of the surface of the substrate held by the rotary holding unit and the second light from the end surface of the substrate held by the rotary holding unit are both input to the imaging device of the camera through the lens via the reflecting surface of the mirror member. Therefore, both the peripheral area of the surface of the substrate and the edge surface of the substrate are simultaneously imaged by one camera. Therefore, as a result of eliminating a plurality of cameras, a space for installing a plurality of cameras is also eliminated. Moreover, since a mechanism for moving the camera is not required, a space for installing the mechanism is also unnecessary. Thus, in the board imaging device according to one aspect of the present disclosure, the device configuration is extremely simplified. As a result, it is possible to reduce the size and cost of the substrate imaging device while suppressing equipment troubles.

The reflecting surface may be a curved surface that is recessed toward the side away from the end surface of the substrate held by the spin holder. In this case, the mirror image of the end face of the substrate reflected on the reflecting surface is larger than the real image. Therefore, a more detailed captured image of the end face of the substrate can be obtained. Therefore, by performing image processing on the captured image, it is possible to more accurately inspect the end surface of the substrate.

A substrate imaging device according to one aspect of the present disclosure may further include a focusing lens arranged in the middle of an optical path between the reflection of the second light from the reflecting surface of the mirror member and reaching the lens, and configured to align the imaging position of the end surface of the substrate with the imaging element. The optical path length of the second light reflected by the reflecting surface of the mirror member and reaching the lens is longer than the optical path length of the first light reaching the lens by the amount reflected by the mirror member. However, in this case, since the imaging position of the end surface of the substrate is aligned with the imaging device by the focusing lens, both the peripheral area of the surface of the substrate and the end surface of the substrate in the captured image become clear. Therefore, by performing image processing on the captured image, it is possible to more accurately inspect the end surface of the substrate.

A substrate imaging device according to one aspect of the present disclosure further includes an illumination unit having a light source and a light diffusion member that diffuses light from the light source in a first direction orthogonal to the optical axis thereof to generate diffused light. In this case, since the light from the light source is diffused in the first direction, the diffused light is incident on the edge surface of the substrate from various directions. Therefore, the edge surface of the substrate is uniformly illuminated as a whole. Therefore, it becomes possible to image the end face of the substrate more clearly.

The illumination unit may further include a light scattering member that scatters light from the light source to generate scattered light, and a cylindrical lens convex toward the light diffusion member that transmits the scattered light from the light scattering member to the light diffusion member, and the cylindrical lens may diffuse the light from the light source in a second direction orthogonal to both the optical axis and the first direction. In this case, the scattered light is diffused in the first and second directions, so that the diffused light is incident on the edge surface of the substrate from various directions. Therefore, the edge surface of the substrate is illuminated more uniformly as a whole. Therefore, it is possible to image the end surface of the substrate more clearly.

According to the board imaging device according to the present disclosure, it is possible to achieve miniaturization and cost reduction while suppressing equipment troubles.

FIG. 1 is a perspective view showing a substrate processing system. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a top view showing unit processing blocks (BCT block, HMCT block, COT block and DEV block). FIG. 4 is a cross-sectional view of the inspection unit viewed from above. FIG. 5 is a cross-sectional view of the inspection unit viewed from the side. FIG. 6 is a perspective view showing an inspection unit. FIG. 7 is a front perspective view of the peripheral imaging subunit. FIG. 8 is a rear perspective view of the peripheral imaging subunit. FIG. 9 is a top view of the peripheral imaging subunit. FIG. 10 is a side view of a two-plane imaging module. FIG. 11 is an exploded perspective view showing the lighting module. 12 is a cross-sectional view taken along line XII-XII of FIG. 11. FIG. 13 is a cross-sectional view taken along line XIII-XIII of FIG. 11. FIG. FIG. 14(a) is a photograph showing how the light from the light source passes through the light scattering member, FIG. 14(b) is a photograph showing how the light from the light source passes through the light scattering member and the cylindrical lens, and FIG. 14(c) is a photograph showing how the light from the light source passes through the light scattering member, the cylindrical lens, and the light diffusing member. FIG. 15(a) is a diagram for explaining the optical path when no focusing lens is present, and FIG. 15(b) is a diagram for explaining the optical path when the focusing lens is present. FIG. 16 is a perspective view showing a mirror member. FIG. 17 is a side view showing the mirror member. FIG. 18(a) is a diagram for explaining how the light from the illumination module is reflected by the mirror member, and FIG. 18(b) is a diagram for explaining how the light from the wafer is reflected by the mirror member. FIG. 19(a) shows a captured image when focused on the surface of the wafer when no focusing lens exists, FIG. 19(b) illustrates a captured image when focused on the edge of the wafer when no focusing lens exists, and FIG. FIG. 20 is a side view of the back imaging subunit. FIG. 21 is a block diagram showing main parts of the substrate processing system. FIG. 22 is a schematic diagram showing the hardware configuration of the controller.

Since the embodiments according to the present disclosure described below are examples for explaining the present invention, the present invention should not be limited to the following contents. In the following description, the same reference numerals will be used for the same elements or elements having the same functions, and redundant description will be omitted.

[Substrate processing system]
As shown in FIG. 1, a substrate processing system 1 (substrate processing apparatus) includes a coating and developing apparatus 2 (substrate processing apparatus) and a controller 10 (control section). The substrate processing system 1 is provided with an exposure device 3 . The exposure apparatus 3 includes a controller (not shown) that can communicate with the controller 10 of the substrate processing system 1 . The exposure device 3 is configured to transfer a wafer W (substrate) to and from the coating and developing device 2, and perform exposure processing (pattern exposure) of a photosensitive resist film formed on the surface Wa (see FIG. 10, etc.) of the wafer W. Specifically, an energy beam is selectively irradiated to an exposure target portion of a photosensitive resist film (photosensitive film) by a method such as liquid immersion exposure. Energy rays include, for example, ArF excimer laser, KrF excimer laser, g-line, i-line, or extreme ultraviolet (EUV).

The coating and developing device 2 performs processing for forming a photosensitive resist film or a non-photosensitive resist film (hereinafter collectively referred to as “resist film”) on the surface Wa of the wafer W before exposure processing by the exposure device 3 . The coating and developing device 2 performs development processing of the photosensitive resist film after the exposure processing of the photosensitive resist film by the exposure device 3 .

The wafer W may have a disk shape, or may have a plate shape such as a polygonal shape other than a circular shape. The wafer W may have a cutout portion that is partially cut out. The notch may be, for example, a notch (a U-shaped, V-shaped groove, etc.) or a linear portion extending linearly (so-called orientation flat). The wafer W may be, for example, a semiconductor substrate, a glass substrate, a mask substrate, an FPD (Flat Panel Display) substrate, or other various substrates. The diameter of the wafer W may be, for example, approximately 200 mm to 450 mm. When the edge of the wafer W is beveled (chamfered), the "surface" in this specification also includes the beveled portion of the wafer W viewed from the surface Wa side. Similarly, the “back surface” in this specification includes the bevel portion when viewed from the back surface Wb side of the wafer W (see FIG. 10, etc.). The "end surface" in this specification also includes a bevel portion when viewed from the end surface Wc side of the wafer W (see FIG. 10, etc.).

As shown in FIGS. 1 to 3, the coating and developing apparatus 2 includes a carrier block 4, a processing block 5, and an interface block 6. FIG. Carrier block 4, processing block 5 and interface block 6 are arranged horizontally.

The carrier block 4 has a carrier station 12 and a loading/unloading section 13, as shown in FIGS. A carrier station 12 supports a plurality of carriers 11 . Carrier 11 accommodates at least one wafer W in a sealed state. A side surface 11a of the carrier 11 is provided with an opening/closing door (not shown) for loading and unloading the wafer W. As shown in FIG. The carrier 11 is detachably installed on the carrier station 12 so that the side surface 11a faces the loading/unloading section 13 side.

The loading/unloading section 13 is located between the carrier station 12 and the processing block 5 . The loading/unloading section 13 has a plurality of opening/closing doors 13a. When the carrier 11 is placed on the carrier station 12, the opening/closing door of the carrier 11 faces the opening/closing door 13a. By simultaneously opening the opening/closing door 13a and the opening/closing door on the side surface 11a, the inside of the carrier 11 and the inside of the carrying-in/carrying-out section 13 communicate with each other. The carry-in/carry-out section 13 incorporates a transfer arm A1. The transfer arm A 1 takes out the wafer W from the carrier 11 and transfers it to the processing block 5 , receives the wafer W from the processing block 5 and returns it into the carrier 11 .

The processing block 5 has unit processing blocks 14 to 17, as shown in FIGS. The unit processing blocks 14 to 17 are arranged in the order of unit processing block 17, unit processing block 14, unit processing block 15, and unit processing block 16 from the floor side. The unit processing blocks 14 to 17, as shown in FIG. 3, have a liquid processing unit U1, a thermal processing unit U2, and an inspection unit U3.

The liquid processing unit U1 is configured to supply the surface Wa of the wafer W with various processing liquids. The thermal processing unit U2 is configured to heat the wafer W using, for example, a hot plate, and cool the heated wafer W using, for example, a cooling plate to perform thermal processing. The inspection unit U3 is configured to inspect each surface of the wafer W (front surface Wa, rear surface Wb, and end surface Wc) (details will be described later).

The unit processing block 14 is a lower layer film forming block (BCT block) configured to form a lower layer film on the surface Wa of the wafer W. As shown in FIG. The unit processing block 14 incorporates a transfer arm A2 for transferring the wafer W to each of the units U1 to U3 (see FIG. 2). The liquid processing unit U1 of the unit processing block 14 applies the coating liquid for forming the lower layer film onto the surface Wa of the wafer W to form a coating film. The heat treatment unit U2 of the unit processing block 14 performs various heat treatments associated with the formation of the lower layer film. A specific example of the heat treatment is heat treatment for curing the coating film to form the underlying film. An example of the underlayer film is an antireflection (SiARC) film.

The unit processing block 15 is an intermediate film (hard mask) forming block (HMCT block) configured to form an intermediate film on the underlying film. The unit processing block 15 incorporates a transfer arm A3 for transferring the wafer W to each of the units U1 to U3 (see FIG. 2). The liquid processing unit U1 of the unit processing block 15 applies a coating liquid for forming an intermediate film onto the lower layer film to form a coating film. The heat treatment unit U2 of the unit processing block 15 performs various heat treatments associated with the formation of the intermediate film. A specific example of the heat treatment is heat treatment for curing the coating film to form the intermediate film. Examples of intermediate films include SOC (Spin On Carbon) films and amorphous carbon films.

The unit processing block 16 is a resist film forming block (COT block) configured to form a thermosetting resist film on the intermediate film. The unit processing block 16 incorporates a transfer arm A4 for transferring the wafer W to each of the units U1 to U3 (see FIG. 2). The liquid processing unit U1 of the unit processing block 16 applies a coating liquid (resist agent) for forming a resist film onto the intermediate film to form a coating film. The heat treatment unit U2 of the unit processing block 16 performs various heat treatments associated with the formation of the resist film. A specific example of the heat treatment includes heat treatment (PAB: Pre Applied Bake) for curing the coating film to form a resist film.

The unit processing block 17 is a development processing block (DEV block) configured to develop the exposed resist film. The unit processing block 17 incorporates a transfer arm A5 for transferring the wafer W to each of the units U1 to U3 and a direct transfer arm A6 for transferring the wafer W without going through these units (see FIG. 2). The liquid processing unit U1 of the unit processing block 17 supplies a developing liquid to the exposed resist film to develop the resist film. The liquid processing unit U1 of the unit processing block 17 supplies a rinse liquid to the resist film after development to wash away dissolved components of the resist film together with the developer. Thereby, the resist film is partially removed to form a resist pattern. The thermal processing unit U2 of the unit processing block 16 performs various types of thermal processing associated with development processing. Specific examples of the heat treatment include heat treatment before development (PEB: Post Exposure Bake), heat treatment after development (PB: Post Bake), and the like.

A shelf unit U10 is provided on the side of the carrier block 4 in the processing block 5, as shown in FIGS. The shelf unit U10 extends from the floor surface to the unit processing block 15, and is partitioned into a plurality of vertically aligned cells. A lifting arm A7 is provided near the shelf unit U10. The elevating arm A7 elevates the wafer W between the cells of the shelf unit U10.

A shelf unit U11 is provided on the interface block 6 side in the processing block 5 . The shelf unit U11 extends from the floor surface to the upper part of the unit processing block 17, and is partitioned into a plurality of vertically aligned cells.

The interface block 6 incorporates a transfer arm A8 and is connected to the exposure device 3. FIG. The transfer arm A8 is configured to take out the wafer W from the shelf unit U11, transfer it to the exposure apparatus 3, receive the wafer W from the exposure apparatus 3, and return it to the shelf unit U11.

A controller 10 partially or wholly controls the substrate processing system 1 . Details of the controller 10 will be described later. The controller 10 can transmit and receive signals to and from the controller of the exposure apparatus 3, and the substrate processing system 1 and the exposure apparatus 3 are controlled by cooperation between the controllers.

[Configuration of inspection unit]
Next, the inspection unit U3 will be described in more detail with reference to FIGS. 4 to 20. FIG. As shown in FIGS. 4 to 6, the inspection unit U3 has a housing 100, a rotation holding subunit 200 (rotation holding section), a front surface imaging subunit 300, a peripheral edge imaging subunit 400 (board imaging device), and a rear surface imaging subunit 500. Each subunit 200 to 500 is arranged within the housing 100 . One end wall of the housing 100 is formed with a loading/unloading port 101 for loading and unloading the wafer W into the housing 100 and out of the housing 100 .

The rotary holding subunit 200 includes a holding table 201 , actuators 202 and 203 and guide rails 204 . The holding table 201 is, for example, a suction chuck that holds the wafer W substantially horizontally by suction or the like. The shape of the holding table 201 (suction chuck) is not particularly limited, but may be circular, for example. The size of the holding table 201 may be smaller than the wafer W.

The actuator 202 is, for example, an electric motor, and drives the holding table 201 to rotate. That is, the actuator 202 rotates the wafer W held on the holding table 201 . Actuator 202 may include an encoder for detecting the rotational position of holding table 201 . In this case, the imaging position of each surface of the wafer W by each of the imaging subunits 300, 400, and 500 can be associated with the rotational position. If the wafer W has a notch, the attitude of the wafer W can be specified based on the notch determined by each imaging subunit 300, 400, 500 and the rotational position detected by the encoder.

The actuator 203 is, for example, a linear actuator, and moves the holding base 201 along the guide rails 204 . That is, the actuator 203 conveys the wafer W held on the holding table 201 between one end side and the other end side of the guide rail 204 . Therefore, the wafer W held by the holding table 201 can be moved between a first position closer to the loading/unloading port 101 and a second position closer to the edge imaging subunit 400 and the backside imaging subunit 500 . The guide rail 204 extends linearly (for example, linearly) within the housing 100 .

The surface imaging subunit 300 includes a camera 310 (imager) and an illumination module 320 . Camera 310 and lighting module 320 constitute a set of imaging modules. The camera 310 includes a lens and one imaging device (eg, CCD image sensor, CMOS image sensor, etc.). The camera 310 faces an illumination module 320 (illumination section).

Illumination module 320 includes a half mirror 321 and a light source 322 . The half mirror 321 is arranged in the housing 100 at an angle of approximately 45° with respect to the horizontal direction. The half mirror 321 is positioned above the intermediate portion of the guide rail 204 so as to cross the extending direction of the guide rail 204 when viewed from above. The half mirror 321 has a rectangular shape. The length of the half mirror 321 is greater than the diameter of the wafer W.

The light source 322 is positioned above the half mirror 321 . Light source 322 is longer than half mirror 321 . The light emitted from the light source 322 passes entirely through the half mirror 321 and is irradiated downward (toward the guide rail 204 side). The light passing through the half mirror 321 is reflected by an object located below the half mirror 321 , is reflected again by the half mirror 321 , passes through the lens of the camera 310 , and enters the imaging element of the camera 310 . That is, the camera 310 can capture an image of an object existing in the irradiation area of the light source 322 via the half mirror 321 . For example, when the holding table 201 holding the wafer W is moved along the guide rail 204 by the actuator 203 , the camera 310 can image the surface Wa of the wafer W passing through the irradiation area of the light source 322 . Data of the captured image captured by the camera 310 is transmitted to the controller 10 .

The peripheral imaging subunit 400 includes a camera 410 (imaging means), an illumination module 420, and a mirror member 430, as shown in FIGS. 4-10. The camera 410, illumination module 420 (illumination section), and mirror member 430 constitute a set of imaging modules. The camera 410 includes a lens 411 and one imaging device 412 (eg, CCD image sensor, CMOS image sensor, etc.). Camera 410 faces illumination module 420 .

The illumination module 420 is arranged above the wafer W held by the holding table 201, as shown in FIGS. The lighting module 420 includes a light source 421 , a light scattering member 422 and a holding member 423 . 11 to 13, the light source 421 is composed of, for example, a housing 421a and a plurality of LED point light sources 421b arranged in the housing 421a. The plurality of LED point light sources 421b are arranged in a row along the radial direction of the wafer W. As shown in FIG.

The light scattering member 422 is connected to the light source 421 so as to overlap the light source 421, as shown in FIGS. 7-13. As shown in FIGS. 11 to 13, the light scattering member 422 is formed with a through hole 422a extending in the direction in which the light source 421 and the light scattering member 422 overlap. The inner wall surface of the through hole 422a is mirror-finished. As a method for mirror finishing, for example, electroless nickel plating is applied to the inner wall surface to form a plated film 422b on the inner wall surface. Accordingly, when the light from the light source 421 enters the through hole 422a of the light scattering member 422, the incident light is irregularly reflected by the plating film 422b as shown in FIGS. As a result, scattered light is generated in the light scattering member 422 (see FIG. 14(a)).

The holding member 423 is connected to the light scattering member 422 so as to overlap the light scattering member 422, as shown in FIGS. As shown in FIGS. 10 to 13, the holding member 423 is formed with a through hole 423a and a cross hole 423b that crosses the through hole 423a. The through hole 423a extends in the direction in which the light scattering member 422 and the holding member 423 overlap. The cross hole 423b extends from one side surface of the holding member 423 toward the through hole 423a along a direction orthogonal to the through hole 423a. The cross hole 423b is connected so as to communicate with the through hole 423a.

The holding member 423 internally holds a half mirror 424, a cylindrical lens 425, a light diffusing member 426, and a focusing lens 427, as shown in FIGS. As shown in FIGS. 10 and 12, the half mirror 424 is arranged at the intersection of the through-hole 423a and the cross-hole 423b while being inclined at approximately 45° with respect to the horizontal direction. The half mirror 424 has a rectangular shape.

The cylindrical lens 425 is arranged between the holding member 423 and the half mirror 424, as shown in FIGS. 10-13. The cylindrical lens 425 is a convex cylindrical lens protruding toward the half mirror 424, as shown in FIGS. The axis of the cylindrical lens 425 extends in the direction in which the plurality of LED point light sources 421b are arranged. When the scattered light from the light scattering member 422 enters the cylindrical lens 425, the scattered light is expanded along the circumferential direction of the cylindrical surface of the cylindrical lens 425 (see FIG. 14B).

The light diffusing member 426 is arranged between the cylindrical lens 425 and the half mirror 424, as shown in FIGS. The light diffusion member 426 is a sheet member having a rectangular shape, and diffuses the light transmitted through the cylindrical lens 425 . As a result, diffused light is generated in the light diffusion member 426 (see FIG. 14(c)). For example, the light diffusion member 426 may have an isotropic diffusion function that diffuses incident light in all directions on the surface of the light diffusion member 426, or an anisotropic diffusion function that diffuses incident light in the axial direction of the cylindrical lens 425 (direction perpendicular to the circumferential direction of the cylindrical surface of the cylindrical lens 425).

Focusing lens 427 is positioned within cross-hole 423b as shown in FIGS. The focusing lens 427 is not particularly limited as long as it has a function of changing the combined focal length with the lens 411 . The focusing lens 427 is, for example, a rectangular parallelepiped lens.

Here, when only the lens 411 is used, as shown in FIG. 15A, the light from point A near the lens 411 passes through the lens 411 and converges on the image sensor 412, while the light from point B far from the lens 411 passes through the lens 411 and converges at a position shifted from the image sensor 412 (behind the image sensor 412). Therefore, the image at point A tends to be captured clearly on the image pickup device 412 , but the image at point B tends to be blurred on the image pickup device 412 . On the other hand, if the focusing lens 427 exists, the light from the point B far from the lens 411 is refracted by the focusing lens 427 and converges on the image sensor 412 through the lens 411, as shown in FIG. 15(b). Due to the presence of the focusing lens 427, when an image at point B is viewed through the focusing lens 427, the image appears to exist at point C on the same plane as point A. Therefore, when viewed from the lens 411, the position of point A and the apparent position of point B (position of point C) are both at the same distance from the lens 411, so the light from points A and B both converge on the imaging device 412. Therefore, both the images at the points A and B are clearly captured on the imaging device 412 . The above description also applies to the case where the focusing lens 427 is a bifocal lens having two portions with different refractive powers in one lens.

The mirror member 430 is arranged below the lighting module 420 as shown in FIGS. The mirror member 430 includes a main body 431 and a reflective surface 432, as shown in FIGS. The main body 431 is composed of an aluminum block.

As shown in FIGS. 7, 13 and 17, when the wafer W held by the holding table 201 is at the second position, the reflecting surface 432 faces the edge Wc of the wafer W held by the holding table 201 and the peripheral edge region Wd of the back surface Wb. The reflecting surface 432 is inclined with respect to the rotation axis of the holding base 201 . The reflecting surface 432 is mirror-finished. For example, the reflective surface 432 may be attached with a mirror sheet, may be aluminum-plated, or may be vapor-deposited with an aluminum material.

Reflective surface 432 is a curved surface recessed toward the side away from end surface Wc of wafer W held on holding table 201 . That is, the mirror member 430 is a concave mirror. Therefore, when the end face Wc of the wafer W is reflected on the reflecting surface 432, its mirror image is magnified more than the real image. The radius of curvature of the reflecting surface 432 may be, for example, approximately 10 mm to 30 mm. The opening angle θ (see FIG. 17) of the reflecting surface 432 may be about 100° to 150°. The opening angle θ of the reflecting surface 432 is the angle formed by two planes circumscribing the reflecting surface 432 .

In the illumination module 420, the light emitted from the light source 421 is scattered by the light scattering member 422, expanded by the cylindrical lens 425, further diffused by the light diffusion member 426, and then passed through the half mirror 424 as a whole to be irradiated downward. The diffused light that has passed through the half mirror 424 is reflected by the reflecting surface 432 of the mirror member 430 located below the half mirror 424 . When the wafer W held by the pedestal 201 is at the second position, the reflected light of the diffused light reflected by the reflecting surface 432 irradiates mainly the end surface Wc of the wafer W (if the edge of the wafer W has a bevel, especially the upper end of the bevel portion) and the peripheral edge region Wd of the surface Wa, as shown in FIGS.

The reflected light reflected from the peripheral area Wd of the surface Wa of the wafer W does not face the reflecting surface 432 of the mirror member 430, but is reflected again by the half mirror 424 (see FIG. 18B). On the other hand, the reflected light reflected from the end surface Wc of the wafer W is sequentially reflected by the reflecting surface 432 of the mirror member 430 and the half mirror 424, sequentially passes through the focusing lens 427 and the lens 411 of the camera 410, and enters the imaging element 412 of the camera 410. Therefore, the optical path length of light reaching the imaging element 412 of the camera 410 from the end surface Wc of the wafer W is longer than the optical path length of light reaching the imaging element 412 of the camera 410 from the peripheral region Wd of the surface Wa of the wafer W. The optical path difference between these optical paths may be, for example, about 1 mm to 10 mm. In this manner, both the light from the peripheral region Wd of the surface Wa of the wafer W and the light from the end surface Wc of the wafer W are input to the imaging element 412 of the camera 410 . That is, when the wafer W held by the holding table 201 is at the second position, the camera 410 can image both the peripheral region Wd of the surface Wa of the wafer W and the end surface Wc of the wafer W. FIG. Data of the captured image captured by the camera 410 is transmitted to the controller 10 .

When the peripheral region Wd of the surface Wa of the wafer W is focused without the focusing lens 427 present, due to the existence of the optical path difference, the peripheral region Wd of the surface Wa of the wafer W tends to appear sharply, but the end surface Wc of the wafer W tends to appear blurred in the captured image captured by the camera 410 (see FIG. 19A). On the other hand, when the end surface Wc of the wafer W is focused without the focusing lens 427 present, due to the presence of the optical path difference, the edge region Wd of the surface Wa of the wafer W tends to be blurred in the captured image captured by the camera 410, although the end surface Wc of the wafer W appears clearly (see FIG. 19B). However, since the focusing lens 427 exists between the reflected light reflected by the reflecting surface 432 of the mirror member 430 and the lens 411, even if the optical path difference exists, the imaging position of the end surface Wc of the wafer W matches the imaging element 412 (see FIG. 15B). Therefore, in the captured image captured by the camera 410, both the peripheral region Wd of the surface Wa of the wafer W and the end surface Wc of the wafer W are clearly captured (see FIG. 19(c)).

The back imaging subunit 500 includes a camera 510 (imaging means) and an illumination module 520 (illumination section), as shown in FIGS. Camera 510 and illumination module 520 constitute a set of imaging modules. The camera 510 includes a lens 511 and one imaging element 512 (eg, CCD image sensor, CMOS image sensor, etc.). The camera 510 faces an illumination module 520 (illumination section).

The lighting module 520 is arranged below the lighting module 420 and below the wafer W held on the holding table 201 . The illumination module 520 includes a half mirror 521 and a light source 522, as shown in FIG. The half mirror 521 is arranged at an angle of approximately 45° with respect to the horizontal direction. The half mirror 521 has a rectangular shape.

The light source 522 is positioned below the half mirror 521 . Light source 522 is longer than half mirror 521 . The light emitted from the light source 522 passes through the half mirror 521 as a whole and is irradiated upward. The light passing through the half mirror 521 is reflected by an object located above the half mirror 521 , is reflected again by the half mirror 521 , passes through the lens 511 of the camera 510 , and enters the imaging element 512 of the camera 510 . That is, the camera 510 can capture an image of an object existing in the irradiation area of the light source 522 via the half mirror 521 . For example, the camera 510 can image the rear surface Wb of the wafer W when the wafer W held by the holding table 201 is at the second position. Data of the captured image captured by the camera 510 is transmitted to the controller 10 .

[Controller configuration]
As shown in FIG. 21, the controller 10 has, as functional modules, a reading section M1, a storage section M2, a processing section M3, and an instruction section M4. These functional modules are simply the functions of the controller 10 divided into a plurality of modules for convenience, and do not necessarily mean that the hardware constituting the controller 10 is divided into such modules. Each functional module is not limited to being realized by executing a program, but may be realized by a dedicated electric circuit (for example, a logic circuit) or an integrated circuit (ASIC: Application Specific Integrated Circuit) that integrates this.

A reading unit M1 reads a program from a computer-readable recording medium RM. The recording medium RM records a program for operating each part of the substrate processing system 1 . The recording medium RM may be, for example, a semiconductor memory, an optical recording disk, a magnetic recording disk, or a magneto-optical recording disk.

The storage unit M2 stores various data. The storage unit M2 stores, for example, a program read from the recording medium RM by the reading unit M1, data of captured images captured by the cameras 310, 410, and 510, various data (so-called processing recipes) for processing the wafer W, setting data input by an operator via an external input device (not shown), and the like.

The processing unit M3 processes various data. The processing unit M3 generates signals for operating the liquid processing unit U1, the heat processing unit U2, and the inspection unit U3 (e.g., the rotation holding subunit 200, the cameras 310, 410, 510, and the lighting modules 320, 420, 520) based on various data stored in the storage unit M2, for example. Further, the processing unit M3 performs image processing on the data of the captured images captured by the cameras 310, 410, and 510, and determines whether or not the wafer W has defects or the like. When the processing unit M3 determines that the wafer W has a defect or the like, it generates a signal for stopping the processing of the wafer W. FIG.

The instruction unit M4 transmits the signal generated by the processing unit M3 to various devices.

The hardware of the controller 10 is composed of, for example, one or more control computers. The controller 10 has, for example, a circuit 10A shown in FIG. 22 as a hardware configuration. Circuit 10A may be comprised of electrical circuitry. Specifically, the circuit 10A has a processor 10B, a memory 10C (storage section), a storage 10D (storage section), a driver 10E, and an input/output port 10F. The processor 10B cooperates with at least one of the memory 10C and the storage 10D to execute a program and input/output signals via the input/output port 10F, thereby configuring each functional module described above. The memory 10C and storage 10D function as a storage unit M2. The driver 10E is a circuit that drives various devices of the substrate processing system 1, respectively. The input/output port 10F inputs and outputs signals between the driver 10E and various devices of the substrate processing system 1 (e.g., the rotating portion 21, the holding portion 22, the pumps 32 and 42, the valves 33 and 43, the heat treatment unit U2, the holding table 201, the actuators 202 and 203, the cameras 310, 410 and 510, the light sources 322, 421 and 522, etc.).

Although the substrate processing system 1 includes one controller 10 in this embodiment, it may include a controller group (control section) including a plurality of controllers 10 . When the substrate processing system 1 includes a controller group, each of the above functional modules may be realized by one controller 10, or may be realized by a combination of two or more controllers 10. When the controller 10 is composed of a plurality of computers (circuits 10A), each of the above functional modules may be implemented by one computer (circuits 10A), or by a combination of two or more computers (circuits 10A). The controller 10 may have multiple processors 10B. In this case, each of the above functional modules may be realized by one processor 10B, or may be realized by a combination of two or more processors 10B.

[Action]
In this embodiment, the mirror member 430 has a reflecting surface 432 which is inclined with respect to the rotation axis of the holding table 201 and faces the end surface Wc of the wafer W held by the holding table 201 and the peripheral edge region Wd of the back surface Wb. In this embodiment, both the light from the peripheral region Wd of the surface Wa of the wafer W held by the holding table 201 and the reflected light obtained by reflecting the light from the end surface Wc of the wafer W held by the holding table 201 by the reflecting surface 432 of the mirror member 430 are input to the imaging element 412 of the camera 410 through the lens 411. Therefore, both the peripheral region Wd of the surface Wa of the wafer W and the end face Wc of the wafer W are imaged by the single camera 410 at the same time. Therefore, as a result of eliminating a plurality of cameras, a space for installing a plurality of cameras is also eliminated. Moreover, since a mechanism for moving the camera 410 is not required, a space for installing the mechanism is also unnecessary. Thus, in this embodiment, the device configuration of the inspection unit U3 is extremely simplified. As a result, it is possible to reduce the size and cost of the inspection unit U3 while suppressing equipment troubles.

In this embodiment, the reflecting surface 432 is a curved surface recessed away from the end surface Wc of the wafer W held by the holding table 201 . Therefore, the mirror image of the end face Wc of the wafer W reflected on the reflecting surface 432 is larger than the real image. For example, when the reflecting surface 432 is not curved, the width of the end face Wc of the wafer W in the captured image is about 20 pixels. Therefore, a more detailed captured image of the end surface Wc of the wafer W can be obtained. As a result, the end face Wc of the wafer W can be inspected more accurately by image processing the captured image.

Incidentally, the optical path length of the light from the end surface Wc of the wafer W reflected by the reflecting surface 432 of the mirror member 430 to the lens 411 is longer than the optical path length of the light from the peripheral region Wd of the surface Wa of the wafer W to the lens 411 by the amount reflected by the mirror member 430. However, in this embodiment, the focusing lens 427 is arranged in the optical path from the end surface Wc of the wafer W to the lens 411 after being reflected by the reflecting surface 432 of the mirror member 430 . The focus adjustment lens 427 is configured to align the imaging position of the end surface Wc of the wafer W with the imaging element 412 . Therefore, since the imaging position of the edge surface Wc of the wafer W is aligned with the imaging element 412 by the focusing lens 427, both the peripheral region Wd of the surface Wa of the wafer W and the edge surface Wc of the wafer W in the captured image become clear. Therefore, the end surface Wc of the wafer W can be inspected more accurately by performing image processing on the captured image.

In the present embodiment, the illumination module 420 irradiates the reflective surface 432 of the mirror member 430 with diffused light so that the diffused light from the illumination module 420 is reflected by the reflective surface 432 of the mirror member 430 and reaches the end face Wc of the wafer W held on the holding table 201. Therefore, diffused light is incident on the end surface Wc of the wafer W from various directions. Therefore, the end surface Wc of the wafer W is illuminated uniformly as a whole. As a result, the end surface Wc of the wafer W can be imaged more clearly.

In this embodiment, light emitted from the light source 421 is scattered by the light scattering member 422 , expanded by the cylindrical lens 425 , and further diffused by the light diffusion member 426 . Therefore, diffused light is incident on the end surface Wc of the wafer W from various directions. Therefore, the end surface Wc of the wafer W is illuminated uniformly as a whole. As a result, the end surface Wc of the wafer W can be imaged more clearly.

[Other embodiments]
Although the embodiments according to the present disclosure have been described in detail above, various modifications may be made to the above embodiments within the scope of the gist of the present invention. For example, the reflecting surface 432 may be inclined with respect to the rotation axis of the holding table 201 and face the edge Wc of the wafer W held by the holding table 201 and the peripheral edge region Wd of the back surface Wb, and may have a shape other than a curved surface (for example, a flat surface).

Perimeter imaging subunit 400 may not include focusing lens 427 .

The peripheral imaging subunit 400 may not include any of the light scattering member 422 , the cylindrical lens 425 and the light diffusing member 426 .

The inspection unit U3 may be arranged in the shelf units U10 and U11. For example, the inspection unit U3 may be provided in a cell positioned corresponding to the unit processing blocks 14 to 17 of the shelf units U10 and U11. In this case, the wafer W is directly transferred to the inspection unit U3 while being transported by the arms A1 to A8.

REFERENCE SIGNS LIST 1 substrate processing system (substrate processing apparatus) 2 coating and developing apparatus (substrate processing apparatus) 10 controller (control unit) 14 to 17 unit processing block 200 rotation holding subunit (rotation holding unit) 201 holding base 300 front surface imaging subunit 400 peripheral edge imaging subunit (substrate imaging device) 500 rear surface imaging subunit 310, 410, 510 camera 411, 511 lens 41 2, 512... Imaging device 320, 420, 520... Illumination module (illumination unit) 322, 421, 522... Light source 422... Light scattering member 425... Cylindrical lens 426... Light diffusion member 427... Focus adjustment lens 430... Mirror member 432... Reflective surface M2... Storage unit M3... Processing unit RM... Recording medium U3... Inspection unit W... Wafer (substrate) Wa... Surface , Wb... back surface, Wc... end face, Wd... peripheral area.

Claims (4)

a housing having a loading/unloading port for loading and unloading substrates;
a rotation holding unit that is housed in the housing and holds and rotates the substrate;
a first imaging unit that is housed in the housing and captures an image of the surface of the substrate held by the rotation holding unit;
a second imaging unit that is housed in the housing and captures an image of a peripheral area and an end face of the surface of the substrate held by the rotation holding unit;
a driving device capable of driving the rotation holding unit ;
The second imaging unit is arranged on the back side with respect to the loading/unloading port,
The driving device is configured to reciprocate the rotation holding unit between a first position closer to the loading/unloading port and a second position closer to the second imaging unit,
The first imaging unit has a first camera and a first mirror member arranged in a state inclined with respect to the horizontal direction,
The first camera is configured to capture an image of the surface of the substrate via the first mirror member while the driving device moves the rotation holding unit between the first position and the second position,
The second imaging unit includes a second camera, a second mirror member including a reflective surface inclined with respect to the rotation axis of the rotation holding unit, and a third mirror member arranged in a state inclined with respect to a horizontal direction and reflecting at least the reflected light from the second mirror member,
The reflective surface is configured to face the edge surface of the substrate and the peripheral edge region of the back surface of the substrate when the rotation holding unit holding the substrate is at the second position,
The substrate imaging device, wherein the second camera is configured to capture an image of a peripheral edge region and an end surface of the surface of the substrate via the third mirror member when the rotation holding unit holding the substrate is at the second position. 2. The substrate imaging device according to claim 1 , further comprising a third imaging unit that is housed in said housing and that captures an image of the back surface of said substrate held by said rotation holding unit. further comprising a third imaging unit housed within the housing;
The third imaging unit has a third camera and a fourth mirror member arranged in a state inclined with respect to the horizontal direction,
2. The substrate imaging apparatus according to claim 1 , wherein the third camera is configured to image the back surface of the substrate via the fourth mirror member when the rotation holding unit holding the substrate is at the second position. A substrate imaging method using a substrate imaging device comprising: a housing having a loading/unloading port for carrying a substrate in and out; a rotation holding unit housed in the housing for holding and rotating the substrate; a first imaging unit housed in the housing ; a second imaging unit housed in the housing;
The second imaging unit is arranged on the back side with respect to the loading/unloading port,
The first imaging unit has a first camera and a first mirror member arranged in a state inclined with respect to the horizontal direction,
The second imaging unit includes a second camera, a second mirror member including a reflecting surface inclined with respect to the rotation axis of the rotation holding unit, and a third mirror member arranged in a state inclined with respect to a horizontal direction and reflecting at least the reflected light from the second mirror member,
a step of capturing an image of the surface of the substrate by the first camera via the first mirror member while the driving device moves the rotation holding unit between a first position closer to the loading/unloading port and a second position closer to the second imaging unit while the substrate is held by the rotation holding unit;
a step of capturing an image of a peripheral area and an end surface of the surface of the substrate by the second camera via the third mirror member when the rotation holding unit holds the substrate and the rotation holding unit holding the substrate is at the second position ;
In the step of imaging the peripheral edge area and the edge surface of the front surface of the substrate, the substrate imaging method is such that when the rotation holding unit holding the substrate is at the second position, the reflecting surface faces the edge area of the substrate and the peripheral edge area of the back surface of the substrate.

Images