Substrate imaging apparatus, substrate imaging method and memory medium

Abstract

To provide a substrate imaging apparatus that is easy to calibrate.SOLUTION: A substrate imaging apparatus 50 comprises a chuck 201 for holding a substrate W in a substrate processing apparatus 1 for processing the substrate W, a light source that irradiates the substrate W held by chuck 201 with the light, a camera for imaging the substrate W held by chuck 201, and a plurality of patches 600 fixed at different positions within the camera's field of view, reflecting light from the light source to the camera in different colors. The plurality of patches 600 is fixed to components permanently located within the substrate processing apparatus 1.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a substrate imaging device, a substrate imaging method, and a storage medium.

Background Art

[0002] Patent Document 1 discloses a calibration method for a WIS module. This calibration method can generate a multi-spectral band offset value using a test wafer having a thickness change or a color change of a predetermined pattern. The multi-spectral band offset value can be applied to the multi-spectral band value obtained from the substrate to generate calibrated RGB values that compensate for the difference in spectral responsiveness between camera systems included in a plurality of WIS modules.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a substrate imaging device that is easy to calibrate.

Means for Solving the Problems

[0005] A substrate imaging device according to an aspect of the present disclosure includes, in a substrate processing device that performs processing on a substrate, a chuck that holds the substrate, a light source that irradiates light onto the substrate held by the chuck, a camera that images the substrate held by the chuck, and a plurality of patches that are respectively fixed at different positions within the field of view of the camera and reflect light from the light source to the camera in different colors.

Effects of the Invention

[0006] According to the present disclosure, a substrate imaging apparatus that is easy to calibrate can be provided.

Brief Description of the Drawings

[0007]

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Embodiment for Carrying out the Invention

[0008] Hereinafter, a wafer processing system as a substrate processing apparatus according to the present embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0009] 〔Wafer Processing System〕 First, the configuration of the wafer processing system according to the present embodiment will be described. FIGS. 1 and 2 are a plan view and a front view schematically showing the outline of the configuration of the wafer processing system 1, respectively. In the present embodiment, a case where the wafer processing system 1 is a photolithography processing system that performs a resist film formation process and a development process on the wafer W will be described as an example.

[0010] As shown in FIG. 1, the wafer processing system 1 includes a cassette station 2 into which a cassette C containing a plurality of wafers W is loaded and unloaded, and a processing station 3 including a plurality of various processing apparatuses that perform predetermined processing on the wafer W. The wafer processing system 1 has a configuration in which the cassette station 2, the processing station 3, and an interface station 4 that transfers the wafer W between the cassette station 2, the processing station 3, and an exposure apparatus (not shown) adjacent to the opposite side of the processing station 3 are integrally connected. Although two processing stations 3 are provided between the cassette station 2 and the interface station 4 as shown in FIG. 1, one processing station 3 may be provided, or three or more processing stations 3 may be provided.

[0011] The cassette station 2 is provided with a plurality of cassette mounting tables 21, and wafer transfer devices 22 and 23. The cassette station 2 transfers the wafer W between the cassette C placed on the mounting table 12 and the processing station 3 by the wafer transfer device 22 or 23. For this purpose, the wafer transfer devices 22 and 23 are each provided with a drive mechanism in directions such as the X direction, Y direction, vertical direction, and rotation around the vertical axis (θ direction) as required, and may be provided with drive mechanisms in all directions. At least one of the wafer transfer devices 22 and 23 can transfer the cassette C and the wafer W, and can also perform the transfer operation of the wafer W with the processing station 3. The transfer operation of the wafer W with the processing station 3 means, for example, transferring the wafer W between the cassette C and the third block G3 provided with a transfer device accessible by the wafer transfer device 33 in the processing station 3 described later. The third block G3 may be provided with a plurality of transfer devices (not shown) arranged in the vertical direction.

[0012] Note that the cassette station 2 may be provided with an inspection device (not shown) for inspecting the wafer W at a position accessible by either of the wafer transfer devices 22 and 23.

[0013] The processing station 3 is provided with a plurality of blocks, for example, three blocks G1, G2, and G4 of the first, second, and fourth. Also, as shown in FIG. 2, a plurality of layers 31 including the first and second blocks G1 and G2 are stacked in the vertical direction. For example, the first block G1 is provided on the front side (the negative X direction side in FIG. 1) of the processing station 3, and the second block G2 is provided on the back side (the positive X direction side in FIG. 1) of the processing station 3. The fourth block G4 is provided on the interface station 4 side (the positive Y direction side in FIG. 1) of the processing station 3 or at the connection portion with another adjacent processing station 3. The fourth block G4 may be provided with a plurality of transfer devices arranged in the vertical direction. Also, the aforementioned third block G3 may be provided inside the processing station 3.

[0014] In the first block G1, a plurality of processing apparatuses, for example, a patterning film forming apparatus and a developing processing apparatus (not shown together) are arranged. As the patterning film forming apparatus, for example, in addition to a resist film forming apparatus, an antireflection film forming apparatus can be included. For example, a plurality of processing apparatuses are arranged side by side in the horizontal direction. Note that the number, arrangement, and type of these processing apparatuses can be arbitrarily selected.

[0015] In these patterning film forming apparatuses and developing processing apparatuses, for example, a predetermined processing liquid is supplied onto the wafer W, or a predetermined gas is supplied. In this way, in the patterning film forming apparatus, formation of a resist film used as a mask when forming a pattern of a lower layer film, and formation of an antireflection film or the like for efficiently performing light irradiation processing such as exposure processing are performed. On the other hand, in the developing processing apparatus, a part of the exposed resist film is removed to form an uneven shape as the mask.

[0016] For example, in the second block G2, heat treatment apparatuses (not shown) that perform heat treatment such as heating and cooling of the wafer W are provided side by side in the vertical and horizontal directions. Also, in the second block G2, although not shown, a hydrophobization processing apparatus that performs hydrophobization processing to enhance the adhesion between the resist liquid and the wafer W, and a peripheral exposure apparatus that exposes the outer peripheral portion of the wafer W are provided side by side in the vertical direction (Z direction in FIG. 2) and the horizontal direction. The number and arrangement of these heat treatment apparatuses, hydrophobization processing apparatuses, and peripheral exposure apparatuses can also be arbitrarily selected.

[0017] As shown in FIG. 1, in a region sandwiched between the first block G1 and the second block G2 in plan view, a wafer transfer region 32 is formed. In the wafer transfer region 32, for example, a wafer transfer apparatus 33 is arranged.

[0018] The wafer transfer device 33 has a transfer arm that is movable, for example, in the X direction, Y direction, θ direction, and vertical direction. The wafer transfer device 33 moves within the wafer transfer area 32 and can transfer the wafer W to predetermined devices within the surrounding first block G1, second block G2, third block G3, and fourth block G4. When there are multiple processing stations 3 as shown in FIG. 1, the wafer transfer device 33 provided in the processing station 3 located on the interface station 4 side can transfer the wafer W to predetermined devices within the fifth block G5, which will be described later, in addition to the first, second, and fourth blocks G1, G2, and G4.

[0019] For example, multiple wafer transfer devices 33 are arranged vertically. One wafer transfer device 33 can transfer the wafer W to a predetermined device located at the height of a plurality of upper layers 31 (see FIG. 2) among the plurality of vertically stacked layers 31. Another wafer transfer device 33 can transfer the wafer W to a predetermined device located at the height of a plurality of lower layers 31 below those layers 31. A plurality of wafer transfer areas 32 are provided to enable such transfer of the wafer W. Note that the number of wafer transfer devices 33 and the number of layers 31 corresponding to one wafer transfer device 33 can be arbitrarily selected, such as providing one wafer transfer device 33 for each layer 31.

[0020] Further, a shuttle transfer device (not shown) may be provided in the wafer transfer area 32 or the first block G1 or the second block G2. The shuttle transfer device linearly transfers the wafer W between a space adjacent to one side of the processing station 3 and another space adjacent to the opposite side.

[0021] The interface station 4 is provided with a fifth block G5 having a plurality of transfer devices, and wafer transfer devices 41 and 42. The interface station 4 transfers the wafer W using the wafer transfer device 41 or 42 between the fifth block G5 where the wafer W is transferred by the wafer transfer device 33 and the exposure device. For this purpose, the wafer transfer devices 41 and 42 are each provided with a drive mechanism in directions such as the X direction, Y direction, vertical direction, and rotation around the vertical axis (θ direction) as required, and may be provided with drive mechanisms in all directions. At least one of the wafer transfer devices 41 and 42 can support the wafer W and transfer the wafer W between the transfer device in the fifth block G5 and the exposure device.

[0022] A cleaning device for cleaning the surface of the wafer W and the above-described peripheral exposure device may be provided at a position accessible by either of the wafer transfer devices 41 and 42 within the interface station 4.

[0023] The inspection device may be provided in the cassette station 2 as described above, but may also be provided at a position accessible by any of the transfer arms (33, 41, 42 in FIG. 1 or FIG. 2) provided inside the processing station 3 and the interface station 4, respectively.

[0024] The above wafer processing system 1 is provided with a control device 100. The control device 100 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the wafer W in the wafer processing system 1. The program storage unit also stores a program for controlling the operation of the drive systems of the above various processing devices and transfer devices to realize the wafer processing in the wafer processing system 1. The above program may be recorded on a computer-readable storage medium H and installed from the storage medium H into the control device 100.

[0025] [Operation of Wafer Processing System] The wafer processing system 1 is configured as described above. Next, an example of wafer processing performed using the wafer processing system 1 configured as described above will be described.

[0026] First, a cassette C containing a plurality of wafers W is carried into the cassette station 2 of the wafer processing system 1 and placed on the cassette mounting table 21. Next, each wafer W in the cassette C is sequentially taken out by the wafer transfer device 22 or 23 and transferred to the transfer device of the third block G3.

[0027] The wafer W transferred to the transfer device of the third block G3 is supported by the wafer transfer device 33 and transferred to the hydrophobic treatment device provided in the second block G2, where hydrophobic treatment is performed. Next, the wafer W is transferred by the wafer transfer device 33 to the resist film forming device, and a resist film is formed on the wafer W. Then, the wafer W is transferred to the heat treatment device and pre-baked, and then transferred to the transfer device of the fifth block G5. When there are a plurality of processing stations 3 as shown in FIGS. 1 and 2, the wafer W is placed once on the transfer device of the fourth block G4 before being transferred to the transfer device of the fifth block G5, and then transferred between the plurality of wafer transfer devices 33. Also, the wafer W may be transferred by the wafer transfer device 33 to the peripheral exposure device as needed, and the peripheral portion of the wafer W may be exposed.

[0028] The wafer W transferred to the transfer device of the fifth block G5 is transferred to the exposure device by the wafer transfer devices 41 and 42 and exposed with a predetermined pattern. Note that the cleaning device may clean the wafer W before the exposure process.

[0029] The exposed wafer W is transferred to the transfer device of the fifth block G5 by the wafer transfer devices 41 and 42. Then, the wafer W is transferred to the heat treatment device by the wafer transfer device 33 and post-exposure baked.

[0030] The wafer W that has been subjected to the post-exposure baking process is transferred by the wafer transfer device 33 to a developing treatment device, where it is developed. After the development is completed, the wafer W is transferred by the wafer transfer device 33 to a heat treatment device 40, where it is subjected to a post-baking process.

[0031] Thereafter, the wafer W is transferred by the wafer transfer device 33 to a delivery device in the third block G3, and then transferred by the wafer transfer device 22 or 23 in the cassette station 2 to a cassette C on a predetermined cassette mounting table 21. In this manner, a series of photolithography steps is completed.

[0032] It should be noted that the wafer processing system of the present disclosure is not limited to the configuration and operation described above. For example, in the above embodiment, the wafer W is transferred between the interface station 4 and the exposure device, but it does not have to be directly connected to the exposure device. In that case, for example, the wafer W is transferred from the cassette station 2 to the processing station 3, where it is subjected to necessary processing, and then transferred back to the cassette station 2 to be taken out to the outside. Also, among the processing devices listed, those that are not required may not be provided, or processing may not be performed in those devices.

[0033] [Substrate imaging device] As described above, the wafer processing system 1 may include an inspection device. Hereinafter, the substrate imaging device 50 will be described as an example of the inspection device. The substrate imaging device includes a chuck for holding a substrate in a substrate processing apparatus (e.g., the wafer processing system 1) that processes the substrate, a light source for irradiating the substrate held by the chuck with light, and a camera for imaging the substrate held by the chuck.

[0034] The substrate imaging device 50 may further include a stage that supports the chuck, and an actuator that moves the chuck relative to the stage so that the entire surface of the substrate is within the field of view of the camera.

[0035] The substrate imaging device 50 may include a plurality of light sources and a plurality of cameras respectively corresponding to the plurality of light sources. For example, the substrate imaging device 50 may include a first light source, a first camera corresponding to the first light source, a second light source, and a second camera corresponding to the second light source. The first light source irradiates light onto the surface of the substrate held by the chuck. The first camera images the surface of the substrate held by the chuck. The first light source and the first camera are fixed to the stage, for example. The actuator may move the chuck with respect to the stage so that the entire area of the surface of the substrate is within the field of view of the first camera.

[0036] The second light source irradiates light onto at least the periphery of the substrate held by the chuck. The second camera images the periphery of the substrate held by the chuck. The second light source and the second camera are fixed to the stage, for example. The substrate imaging device 50 may include a mirror that reflects light from the substrate to the second camera. For example, the mirror reflects light from the periphery of the substrate to the second camera.

[0037] For example, as shown in FIGS. 3 to 5, the substrate imaging device 50 includes a housing 10, a rotation holding subunit 200 (rotation holding unit), a surface imaging subunit 300, a peripheral imaging subunit 400, and a back surface imaging subunit 500. Each of the subunits 200 to 500 is disposed within the housing 10. An inlet / outlet 11 for carrying the wafer W into and out of the housing 10 is formed in one end wall of the housing 10.

[0038] The rotation holding subunit 200 includes a chuck 201, a stage 210, actuators 202 and 203, and a guide rail 204. The chuck 201 holds the wafer W (substrate) within the wafer processing system 1. The chuck 201 is, for example, a suction chuck that holds the wafer W substantially horizontally by suction or the like. The shape of the chuck 201 (suction chuck) is not particularly limited, and may be circular, for example. The size of the chuck 201 may be smaller than that of the wafer W.

[0039] Stage 210 supports chuck 201. For example, stage 210 is fixed to the bottom of housing 10 inside housing 10. Actuator 202 is, for example, an electric motor and rotates chuck 201 with respect to stage 210. That is, actuator 202 rotates wafer W held by chuck 201. Actuator 202 may include an encoder for detecting the rotational position of chuck 201. In this case, the imaging positions of each surface of wafer W by each imaging subunit 300, 400, 500 can be associated with the rotational position. When wafer W has a notch, the posture of wafer W can be specified based on the notch discriminated by each imaging subunit 300, 400, 500 and the rotational position detected by the encoder.

[0040] Actuator 203 is, for example, a linear actuator and moves chuck 201 along guide rail 204 with respect to stage 210. That is, actuator 203 conveys wafer W held by chuck 201 between one end side and the other end side of guide rail 204. Accordingly, wafer W held by chuck 201 is movable between a first position near loading / unloading port 11 and a second position near peripheral imaging subunit 400 and back surface imaging subunit 500. Guide rail 204 extends linearly (for example, in a straight line) inside housing 10. As shown in FIG. 5, the fact that stage 210 supports chuck 201 includes supporting chuck 201 via guide rail 204, actuator 203, etc. In FIG. 5, stage 210 has a recess opened upward, and inside the recess, supports chuck 201 via guide rail 204 and actuator 203 (see FIG. 4).

[0041] The surface imaging sub-unit 300 includes a camera 310 and an illumination module 320. The camera 310 and the illumination module 320 constitute a set of imaging modules. The camera 310 includes a lens and an imaging element (for example, a CCD image sensor, a CMOS image sensor, etc.). The camera 310 faces the illumination module 320 (illumination unit).

[0042] The camera 310 and the illumination module 320 are located above the wafer W held by the chuck 201 and are fixed to the stage 210. The fixation here means that the relative position is invariant, so, for example, being fixed to the housing 10 is also included in being fixed to the stage 210. The same applies hereinafter. The camera 310 is separated from the illumination module 320 in the moving direction of the chuck 201 (the extending direction of the guide rail 204) by the actuator 203.

[0043] The illumination module 320 includes a half mirror 321 and a light source 322. The half mirror 321 is located below the light source 322, transmits the light from the light source 322 downward, and reflects the light from below toward the camera 310. The length of the half mirror 321 in the direction intersecting (for example, orthogonal) to the extending direction of the guide rail 204 (hereinafter referred to as the "width direction") is larger than the diameter of the wafer W.

[0044] The light source 322 is an example of the first light source and irradiates light onto the surface Wa of the wafer W held by the chuck 201. The light includes, for example, electromagnetic waves in a plurality of visible wavelength bands. For example, the light includes electromagnetic waves in a plurality of wavelength bands in the range of about 400 nm to 700 nm. For example, the light includes at least a wavelength band visible as red, a wavelength band visible as green, and a wavelength band visible as blue. The same applies hereinafter to the light from other light sources.

[0045] For example, the light source 322 is located above the half mirror 321 and emits light downward. The light emitted from the light source 322 passes through the half mirror 321 and irradiates the surface Wa of the wafer W located below the half mirror 321. In the width direction, the light source 322 may be longer than the half mirror 321. In this case, the surface Wa of the wafer W is irradiated with light over the entire length of the half mirror 321 in the width direction.

[0046] The camera 310 is an example of the first camera and images the surface Wa of the wafer W held by the chuck 201. For example, the camera 310 forms an image of the light from the surface Wa of the wafer W reflected by the half mirror 321. In the width direction, the field of view of the camera 310 may be larger than the length of the half mirror 321. As described above, the length of the half mirror 321 in the width direction is larger than the diameter of the wafer W. Therefore, at least the entire area of the wafer W in the width direction falls within the field of view of the camera 310. When the actuator 203 moves the chuck 201, the portion of the surface Wa of the wafer W that falls within the field of view of the camera 310 changes along the extending direction of the guide rail 204. Thereby, it becomes possible to bring the entire surface Wa of the wafer W within the field of view of the camera 310. The data of the captured image captured by the camera 310 is transmitted to the control device 100.

[0047] As shown in FIGS. 3 to 6, the peripheral imaging sub-unit 400 includes a camera 410 (imaging means), an illumination module 420, and a mirror member 430. The camera 410, the illumination module 420 (illumination unit), and the mirror member 430 constitute a set of imaging modules. The camera 410 includes a lens 411 and one imaging element 412 (for example, a CCD image sensor, a CMOS image sensor, etc.). The camera 410 faces the illumination module 420.

[0048] The camera 410 and the illumination module 420 are located above the wafer W held by the chuck 201 and are fixed to the stage 210. The camera 410 is separated from the illumination module 320 along the horizontal direction.

[0049] The illumination module 420 includes a half mirror 424 and a light source 421. The half mirror 424 is located below the light source 421, transmits the light from the light source 421 downward, and reflects the light from below toward the camera 410. As shown in FIG. 6, the illumination module 420 includes a light source 421 and a half mirror 424. The half mirror 424 is located below the light source 421. The half mirror 424 transmits the light from the light source 421 downward and reflects the reflected light from below to the camera 410.

[0050] The light source 421 irradiates light onto the surface Wa (the peripheral region Wd of the surface Wa) of the periphery of the wafer W held by the chuck 201. For example, the light source 421 is located above the half mirror 424 and emits light downward. The light emitted from the light source 421 passes through the half mirror 424 and irradiates the peripheral region Wd of the surface Wa located below the half mirror 424.

[0051] The camera 410 images the peripheral region Wd of the surface Wa of the wafer W held by the chuck 201. For example, the camera 410 forms an image of the light from the peripheral region Wd of the surface Wa reflected by the half mirror 424 on the imaging element 412. The data of the captured image captured by the camera 410 is transmitted to the control device 100.

[0052] The mirror member 430 is an example of the above mirror and reflects the light from the wafer W to the camera 410. For example, the mirror member 430 is located below the illumination module 420. The light from the peripheral end surface Wc of the wafer W is reflected to the camera 410. The mirror member 430 includes a main body 431 and a reflecting surface 432. The main body 431 is constituted by an aluminum block. The main body 431 faces at least the peripheral region Wd of the back surface Wb of the wafer W and the periphery (the peripheral end surface Wc) of the wafer W.

[0053] The reflecting surface 432 is formed on the body 431 on the surface facing the peripheral region Wd of the back surface Wb and the end surface Wc. The reflecting surface 432 is curved in a concave shape so as to face the peripheral region Wd of the back surface Wb and the end surface Wc.

[0054] By the mirror member 430, the light source 421 becomes an example of the second light source, and irradiates light to at least the periphery of the wafer W held by the chuck 201. For example, at least a part of the light emitted from the light source 421 and transmitted through the half mirror 424 is reflected by the reflecting surface 432 of the mirror member 430 so as to face the end surface Wc, and irradiates the end surface Wc.

[0055] By the mirror member 430, the camera 410 becomes an example of the second camera, and images at least the periphery of the wafer W held by the chuck 201. For example, the mirror member 430 reflects the light from the periphery of the wafer W to the camera 410. For example, the reflected light of 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, and enters the camera 410. On the other hand, the reflected light reflected from the peripheral region Wd of the front surface Wa of the wafer W is not directed to the reflecting surface 432 of the mirror member 430 but is reflected again by the half mirror 424 and enters the camera 410. The camera 410 causes the light incident from the end surface Wc through the reflecting surface 432 and the light incident from the peripheral region Wd of the front surface Wa without passing through the reflecting surface 432 to form images at different positions on the imaging element 412.

[0056] As shown in FIG. 7, the back surface imaging subunit 500 includes a camera 510 (imaging means) and an illumination module 520 (illumination unit). The camera 510 and the illumination module 520 constitute a set of imaging modules. The camera 510 includes a lens 511 and one imaging element 512 (for example, a CCD image sensor, a CMOS image sensor, etc.). The camera 510 faces the illumination module 520 (illumination unit).

[0057] The camera 510 and the illumination module 520 are positioned below the wafer W held by the chuck 201 and are fixed to the stage 210. The camera 510 is separated from the illumination module 520 along the horizontal direction.

[0058] The illumination module 520 includes a half mirror 521 and a light source 522. The half mirror 521 is positioned above the light source 522, transmits the light from the light source 522 upward, and reflects the light from the information toward the camera 510.

[0059] The light source 522 irradiates light onto the back surface Wb (the peripheral region Wd of the back surface Wb) of the wafer W held by the chuck 201. For example, the light source 522 is positioned below the half mirror 521 and emits light upward. The light emitted from the light source 522 passes through the half mirror 521 and irradiates the peripheral region Wd of the back surface Wb positioned above the half mirror 521.

[0060] The camera 510 images the peripheral region Wd of the back surface Wb of the wafer W held by the chuck 201. For example, the camera 510 forms an image of the light from the peripheral region Wd of the back surface Wb reflected by the half mirror 521 on the imaging element 512. The data of the captured image captured by the camera 510 is transmitted to the control device 100.

[0061] 〔Configuration for calibration〕 In the substrate imaging apparatus exemplified above, the light emitted from each light source is reflected by the wafer W and enters the camera. Hereinafter, the light reflected by the wafer W is referred to as "reflected light" to distinguish it from the light before reflection. Further, the portion of the wafer W where the light is reflected is referred to as the "reflection site". The intensity distribution of a plurality of wavelength bands in the reflected light can vary depending on the characteristics of the reflection site. Therefore, the intensity distribution of a plurality of wavelength bands in the reflected light appears as color in the image captured by the camera. For this reason, the color of the reflection site in the image captured by the camera represents the characteristics of the reflection site. For example, the color of the surface Wa of the wafer W in the image captured by the camera 310 represents the characteristics of the film formed on the surface Wa of the wafer W. Utilizing this, it is possible to evaluate the characteristics of the reflection site based on the color of the reflection site.

[0062] The color of the reflected light from the same reflection site can vary depending on the individual differences of the light sources and the individual differences of the cameras. Therefore, even for images obtained from exactly the same reflection site, the color of the reflection site can vary among a plurality of substrate imaging apparatuses 50. Also, an image obtained from exactly the same reflection site can change over time due to deterioration over time of the substrate imaging apparatus 50 (for example, deterioration of the light source), etc. In order to evaluate the characteristics of the reflection site with high reliability based on the color of the reflection site, it is necessary to take measures against variations among a plurality of substrate imaging apparatuses 50 and changes over time in one substrate imaging apparatus 50.

[0063] As a measure against variations among a plurality of substrate imaging apparatuses 50 and changes over time in one substrate imaging apparatus 50, calibration for correcting the color of the reflection site with known characteristics to be close to a predetermined reference color is effective. Frequent calibration is effective for improving reliability. However, for calibration, it is necessary to carry a sample substrate having a reflection site with known characteristics into the wafer processing system 1 instead of the wafer W. Therefore, it is difficult to perform frequent calibration at the movable site of the wafer processing system 1.

[0064] Therefore, the substrate imaging device 50 further includes a plurality of patches 600 that are respectively fixed at different positions within the field of view of the camera and reflect light from the light source to the camera in different colors. The plurality of patches 600 are fixed to members that are always present within the wafer processing system 1, and calibration of the camera can be performed without loading the calibration wafer W into the wafer processing system 1. Therefore, calibration is easy. For this reason, calibration can be easily performed at least during the intervals between processes on the wafer W, and the reliability of the information represented by the color can be easily maintained.

[0065] Being always present within the wafer processing system 1 means, for example, that it cannot be carried out of the wafer processing system 1 by the wafer processing system 1 itself. As described above, the wafer W can be carried out of the wafer processing system 1 by the wafer processing system 1 itself (for example, by the wafer transfer devices 22, 23, 33, etc.), so it is not always present within the wafer processing system 1. The components of each processing device cannot be carried out of the wafer processing system 1 by the wafer processing system 1 itself, so they are always present within the wafer processing system 1. Also, 22, 23, 23 can carry the wafer W out of the wafer processing system 1, but cannot carry themselves out of the wafer processing system 1, so they are always present within the wafer processing system 1.

[0066] Reflecting light to the camera in different colors means converting the light into reflected light with different distributions in a plurality of wavelength bands and reflecting it to the camera.

[0067] In the direction perpendicular to the wafer W, each of the plurality of patches 600 may be located between the back surface Wb of the wafer W held by the chuck 201 and the surface facing the back surface Wb of the wafer W. The plurality of patches 600 are less likely to interfere with the loading of the wafer W onto the chuck 201 and the unloading of the wafer W from the chuck 201.

[0068] For example, each of the plurality of patches 600 may be located below the back surface Wb of the wafer W held horizontally by the chuck 201. In the direction along the wafer W (e.g., the horizontal direction), the position of the wafer W and the positions of the plurality of patches 600 do not necessarily overlap. For example, the patch 600 may be located outside the region below the wafer W at a height lower than the back surface Wb of the wafer W held horizontally by the chuck 201. Even in such a case, in the direction perpendicular to the wafer W, it can be said that the patch 600 is located between the back surface Wb and the surface facing the back surface Wb.

[0069] The surfaces of the plurality of patches 600 and the surface Wa of the wafer W may both be located within the depth of field of the camera. The depth of field means the range in which the required resolution (e.g., the resolution required for color discrimination) can be maintained on a line along the optical axis center of the camera. Calibration can be performed without changing the focus position of the camera when imaging the wafer W and when imaging the plurality of patches 600.

[0070] The substrate imaging device 50 may include a plurality of patches 600 for each of the surface imaging subunit 300, the peripheral imaging subunit 400, and the back surface imaging subunit 500, or may include a plurality of patches 600 for any one of the surface imaging subunit 300, the peripheral imaging subunit 400, and the back surface imaging subunit 500. FIGS. 8 and 9 show a plurality of patches 600A provided for the surface imaging subunit 300 as an example of the plurality of patches 600.

[0071] As shown in FIGS. 8 and 9, the plurality of patches 600A may be fixed to the chuck 201 as a member that always exists in the wafer processing system 1. The surplus space in the chuck 201 can be used for the arrangement of the plurality of patches 600A.

[0072] When a plurality of patches 600A are provided on the chuck 201, the patches 600A can be moved along the extending direction of 204 by 203. Therefore, 203 may be moved so as to change the patch 600A that enters the field of view of the camera 310 among the plurality of patches 600A, at least when the chuck 201 does not hold the wafer W. A wider range can be utilized for the arrangement of the plurality of patches 600A.

[0073] For example, the chuck 201 has a facing surface 221 facing the back surface Wb of the wafer W and an annular support portion 222 protruding from the facing surface 221 and contacting the back surface Wb of the wafer W. The plurality of patches 600A are provided on the facing surface 221 within the support portion 222. For example, each of the plurality of patches 600A is arranged between the back surface Wb of the wafer W and the facing surface 221 within the support portion 222 and is fixed to the facing surface 221 by adhesion or fastening or the like. The plurality of patches 600A can be arranged in a wide range on the chuck 201 without interfering with the holding (for example, suction holding) of the wafer W by the chuck 201.

[0074] The chuck 201 may have a plurality of multiple support portions 222, and each of the plurality of support portions 222 may contact the back surface Wb of the wafer W. In this case, at least any one of the plurality of patches 600A may be provided on the facing surface 221 between the support portions 222. For example, in the examples of FIGS. 8 and 9, the chuck 201 has an innermost support portion 222, an intermediate support portion 222 surrounding the innermost support portion 222, and an outermost support portion 222 surrounding the intermediate support portion 222. Any one of the plurality of patches 600A is provided between the innermost support portion 222 (the first support portion) and the intermediate support portion 222 (the second support portion). Any other of the plurality of patches 600A is provided between the intermediate support portion 222 (the first support portion) and the outermost support portion 222 (the second support portion).

[0075] As shown in FIG. 10, each of the plurality of patches 600A has a base chip 610 and a coating 620. The base chip 610 is flat and has a front surface 611 and a back surface 612. The front surface 611 faces the camera 310. Note that facing the camera 310 means being visible from the camera 310, and it is not necessarily limited to facing (e.g., directly facing) the camera 310 along a straight line. The back surface 612 is the opposite surface of the front surface 611 and is fixed to the opposing surface 221 or the like.

[0076] The coating 620 is formed to cover the front surface 611. When the front surface 611 is covered by the coating 620, light can be reflected from the patch 600A to the camera 310 in a color correlated with the characteristics of the coating 620. For example, due to differences in the characteristics of the coating 620, the influence of the coating 620 on the distribution of a plurality of wavelength bands in the reflected light changes, so the color of the reflected light can be correlated with the characteristics of the coating 620.

[0077] By calibrating the relationship between the characteristics of the coating and the color, the characteristics of the coating formed on the wafer W can be represented with high reliability by the color of the wafer W in the image captured by the camera 310.

[0078] The coating may be an oxide film. Since the characteristics of the coating are less likely to change over time, highly reliable calibration can be repeated over a long period. The material of the base chip 610 may be the same as that of the wafer W. For example, the material of the base chip 610 may contain silicon. In this case, the coating may be a silicon oxide film.

[0079] The type of the oxide film can vary depending on the material of the base chip 610. Other examples of the oxide film include a titanium oxide film and a zinc oxide film.

[0080] Examples of the characteristics of the film 620 include, for example, its thickness. Due to differences in thickness, the light absorption characteristics and the like of the film 620 differ. Thus, each of the plurality of patches 600A can reflect light from the light source to the camera 310 in a color correlated with the thickness of the film 620. By calibrating the relationship between the thickness and color of the film, the thickness of the film formed on the wafer W can be represented with high reliability based on the color of the wafer W in the image captured by the camera 310.

[0081] Other examples of the characteristics of the film 620 include the line width and the like of the concavo-convex pattern engraved on the film 620. As illustrated in FIG. 11, the line width of the concavo-convex pattern is the width LW of the convex portion in the concavo-convex pattern 621 engraved on the film 620. Due to differences in the line width, the light scattering characteristics and the like by the film 620 differ. Thus, each of the plurality of patches 600A can reflect light from the light source to the camera 310 in a color correlated with the line width of the film 620. By calibrating the relationship between the line width of the concavo-convex pattern engraved on the film and the color, the line width of the concavo-convex pattern engraved on the film formed on the wafer W can be represented with high reliability based on the color of the wafer W in the image captured by the camera 310.

[0082] The member to which the plurality of patches 600A are fixed is not limited to the chuck 201. For example, as shown in FIGS. 12 and 13, the substrate imaging device 50 may further include an extension bracket 230 that projects outward from the outer periphery of the chuck 201 at a position farther from the back surface Wb of the wafer W than the chuck 201.

[0083] For example, the extension bracket 230 projects outward from the outer periphery of the chuck 201 over the entire circumference below the chuck 201. The extension bracket 230 may be fixed to the chuck 201. In this case, 202 rotates the extension bracket 230 together with the chuck 201 and moves the extension bracket 230 together with the chuck 201.

[0084] At least any one of the plurality of patches 600A may be fixed to the surface (upper surface) of the extension bracket 230. In the illustrated example, all of the plurality of patches 600A are fixed to the surface of the extension bracket 230. More extensively, the plurality of patches can be arranged.

[0085] The extension bracket 230 does not necessarily have to protrude from the outer periphery of the chuck 201 over the entire circumference. For example, as shown in FIG. 14, it may partially protrude from the outer periphery of the chuck 201. In FIG. 14, the extension bracket 230 protrudes in four directions perpendicular to each other, but is not limited thereto.

[0086] At least any one of the plurality of patches 600A may be fixed at a position not hidden by the wafer W held by the chuck 201. Calibration can be performed immediately before imaging the wafer W to further improve the reliability of the information represented by the color.

[0087] At least any one of the plurality of patches 600A may be fixed to the stage 210 as a member that always exists in the wafer processing system 1. For example, as shown in FIG. 15, the plurality of patches 600A may be fixed to the stage 210 so as to be arranged along the field of view 311 of the camera 310. The surplus space on the stage 210 can be used for the arrangement of the plurality of patches 600A.

[0088] As shown in FIG. 16, the substrate imaging device 50 may have a plurality of patches 600B provided for the peripheral imaging subunit 400 as an example of the plurality of patches 600. Each of the plurality of patches 600B is configured in the same manner as each of the plurality of patches 600A. The plurality of patches 600B may be fixed to the mirror member 430 as a member that always exists in the wafer processing system 1. By using the surplus space in the mirror member 430, the plurality of patches 600B for the imaging system passing through the mirror member 430 can be arranged.

[0089] For example, a plurality of patches 600B are fixed to a portion of the reflective surface 432 that faces the back surface Wb of the wafer W. A portion of the reflective surface 432 that faces the back surface Wb is not used to reflect light from the end surface Wc to the camera 410. Therefore, a plurality of patches 600B can be arranged without affecting the image of the end surface Wc.

[0090] The configuration of the substrate imaging device 50 shown above can be appropriately changed. For example, in addition to the plurality of patches 600A for the camera 310 and the plurality of patches 600B for the camera 410, the substrate imaging device 50 may have a plurality of patches 600 for the camera 510. The substrate imaging device 50 may not have a dedicated chuck 201 and actuators 202 and 203, and may be configured to image the wafer W held by the hand 34 of the wafer transfer device 33. When the hand 34 is included in the substrate imaging device 50 in this way, the plurality of patches 600A may be fixed to the hand 34 as a member that always exists in the wafer processing system 1, as shown in FIG. 17.

[0091] The substrate imaging device 50 may include a control device 100. The control device 100 causes the camera 310 to image a plurality of patches 600A to obtain a calibration image, generates correction data for the calibration image so as to approximate the respective colors of the plurality of patches 600A in the calibration image to a predetermined reference color, causes the camera 310 to image a substrate to obtain a substrate image, and corrects the substrate image based on the correction data.

[0092] In the substrate imaging device 50, the color reproducibility for the same substrate can be easily improved. Also, the color reproducibility can be improved among a plurality of substrate imaging devices 50. For example, in one substrate imaging device 50, after acquiring and correcting a substrate image by the above-described procedure, when acquiring and correcting the substrate image again after a long period of time, the color reproducibility is improved by generating correction data at each timing. Further, in each of the plurality of substrate imaging devices 50, by using correction data generated for the same reference color, the color reproducibility among the plurality of substrate imaging devices 50 is improved.

[0093] The control device 100 may be further configured to cause the camera 410 to image a plurality of patches 600B to acquire a calibration image, generate correction data for the calibration image so as to approximate the color of each of the plurality of patches 600A in the calibration image to a predetermined reference color, cause the camera 410 to image a substrate to acquire a substrate image, and correct the substrate image based on the correction data.

[0094] When a plurality of patches 600 are provided for the camera 510, the control device 100 may further execute a similar procedure for the camera 510. Since the description related to the camera 310, the description related to the camera 410, and the description related to the camera 510 overlap, the description related to the camera 410 and the description related to the camera 510 will be omitted below.

[0095] For example, as shown in FIG. 18, the control device 100 includes, as functional components (hereinafter referred to as "function blocks"), a reference color storage unit 111, a calibration unit 112, a correction data storage unit 113, a substrate image processing unit 114, and a substrate image storage unit 115. The reference color storage unit 111 stores the above-described reference color. For example, the reference color storage unit 111 stores a plurality of reference colors respectively associated with the plurality of patches 600. For example, in the reference color storage unit 111, the plurality of reference colors are associated with identification information of any of the plurality of patches 600.

[0096] The calibration unit 112 causes the camera 310 to image a plurality of patches 600A to obtain a calibration image, and generates correction data for the calibration image so as to approximate the color of each of the plurality of patches 600A in the calibration image to a predetermined reference color. For example, the calibration unit 112 generates correction data representing the relationship between the intensity before correction and the intensity after correction for each wavelength band, and stores it in the correction data storage unit 113. The calibration unit 112 may perform statistical processing on a plurality of calibration images repeatedly imaged by the camera 310, and generate correction data based on the statistical processing result.

[0097] The substrate image processing unit 114 causes the camera 310 to image a substrate to obtain a substrate image, and corrects the substrate image based on the correction data. For example, the substrate image processing unit 114 corrects the intensity for each wavelength band so as to match the relationship between the intensity before correction and the intensity after correction represented by the correction data. The substrate image processing unit 114 stores the corrected substrate image in the substrate image storage unit 115.

[0098] The control device 100 may further include, as functional blocks, a calibration image processing unit 116 and a regeneration determination unit 117. After generating the correction data, the calibration image processing unit 116 causes the camera 310 to image a plurality of patches 600A to re-acquire a calibration image, and corrects the re-acquired calibration image based on the correction data. The regeneration determination unit 117 determines whether regeneration of the correction data is necessary based on the difference between the color of each of the plurality of patches 600A in the corrected calibration image and the reference color. For example, the regeneration determination unit 117 determines that regeneration of the correction data is necessary when the difference between the color of at least any one of the plurality of patches 600A and the reference color exceeds a predetermined threshold. When it is determined by the regeneration determination unit 117 that regeneration of the correction data is necessary, the calibration unit 112 regenerates the correction data. It is possible to maintain the reliability of the information represented by the color while suppressing the execution frequency of calibration.

[0099] As shown in FIG. 19, the control device 100 may further include, as functional blocks, a correlation model storage unit 121, a film thickness calculation unit 122, and a line width calculation unit 123. The correlation model storage unit 121 stores a correlation model that is pre-generated to represent the relationship between a reference color and the characteristics of the film. For example, the correlation model storage unit 121 stores a correlation model (hereinafter referred to as the "film thickness correlation model") that is pre-generated to represent the relationship between the reference color and the thickness of the film. The correlation model storage unit 121 may store a correlation model (hereinafter referred to as the "line width correlation model") that is pre-generated to represent the relationship between the reference color and the line width. The correlation model storage unit 121 may store both the film thickness correlation model and the line width correlation model, or may store either one of them.

[0100] The film thickness calculation unit 122 calculates the thickness distribution of the film formed on the wafer W based on the corrected substrate image stored in the substrate image storage unit 115 and the film thickness correlation model stored in the correlation model storage unit 121. By calculating based on the corrected substrate image and the correlation model, the correlation model can be shared among the plurality of substrate imaging devices 50, and the film thickness distribution can be calculated with high reliability by each substrate imaging device 50. The line width calculation unit 123 calculates the line width distribution of the film formed on the wafer W based on the corrected substrate image stored in the substrate image storage unit 115 and the line width correlation model stored in the correlation model storage unit 121. By calculating based on the corrected substrate image and the correlation model, the correlation model can be shared among the plurality of substrate imaging devices 50, and the line width distribution can be calculated with high reliability by each substrate imaging device 50. The control device 100 may include both the film thickness calculation unit 122 and the line width calculation unit 123, or may include either one of them.

[0101] The substrate imaging device 50 may further include a temperature sensor 329 (see FIG. 5) that detects the temperature of the light source 322 and a temperature sensor 429 (see FIG. 6) that detects the temperature of the light source 421. As shown in FIG. 20, the control device 100 may further include a monitoring unit 131 and a temperature history storage unit 132 as functional blocks. The monitoring unit 131 records at least the transition of the detection result by the temperature sensor 329 from when a calibration image for the camera 310 is acquired. For example, the monitoring unit 131 periodically acquires the detection result by the temperature sensor 329 and stores it in the temperature history storage unit 132. The monitoring unit 131 may record at least the transition of the detection result by the temperature sensor 429 from when a calibration image for the camera 410 is acquired. For example, the monitoring unit 131 periodically acquires the detection result by the temperature sensor 429 and stores it in the temperature history storage unit 132. Based on the detection result recorded by the monitoring unit, the factor when the color reproducibility deteriorates can be quickly identified.

[0102] The control device 100 may further include a contamination detection unit 134 as a functional block. The contamination detection unit 134 detects the contamination of at least any one of the plurality of patches 600A based on the color relationship between the plurality of patches 600A in the calibrated calibration image. For example, the contamination detection unit 134 calculates the degree of deterioration of color reproducibility with respect to the reference color for each of the plurality of patches 600A, and may detect the contamination of any one of the plurality of patches 600A based on the variation in the degree of deterioration among the plurality of patches 600A. For example, when the variation in the degree of deterioration among the plurality of patches 600A exceeds a predetermined variation threshold, the contamination of the patch 600A that is the cause of the variation may be detected. The contamination detection unit 134 may notify the operator of the contamination detection result by, for example, displaying it on the user interface 195 described later.

[0103] The contamination detection unit 134 may detect the contamination of any one of the plurality of patches 600A based on the deterioration degree of color reproducibility and the temperature change stored in the temperature history storage unit 132. For example, even if it is shown that there is no change in the temperature of the light source 322 in the temperature change stored in the temperature history storage unit 132, the contamination detection unit 134 may detect the contamination of the patch 600A whose deterioration degree of color reproducibility exceeds a predetermined deterioration threshold. The regeneration determination unit 117 may determine whether regeneration of correction data is necessary based on the deterioration degree of color reproducibility and the temperature change stored in the temperature history storage unit 132. For example, when there is a correlation between the deterioration degree of color reproducibility and the temperature change stored in the temperature history storage unit 132, the regeneration determination unit 117 may determine that regeneration of correction data is necessary.

[0104] FIG. 21 is a block diagram illustrating the hardware configuration of the control device 100. As shown in FIG. 21, the control device 100 includes a circuit 190. The circuit 190 includes a processor 191, a memory 192, a storage 193, an image processing circuit 194, and a user interface 195.

[0105] The storage 193 includes, for example, one or more non-volatile storage media. Examples of non-volatile storage media include hard disk drives, solid state drives, flash memories, etc. The non-volatile storage media may include portable storage media such as optical disks. The storage 193 stores a program for causing the control device 100 to cause the camera 310 to capture a plurality of patches 600A to obtain a calibration image, generate correction data for the calibration image so as to approximate the colors of the plurality of patches 600A in the calibration image to predetermined reference colors, cause the camera 310 to capture a substrate to obtain a substrate image, and correct the substrate image based on the correction data. For example, the storage 193 stores a program for causing the control device 100 to configure each of the above-described functional blocks.

[0106] Memory 192 includes one or more volatile memory media. Examples of volatile memory media include random access memory. Memory 192 temporarily stores programs loaded from storage 193. Processor 191 includes one or more computing devices. Examples of computing devices include a CPU (Central Processing Unit), or a GPU (Graphics Processing Unit), etc. By executing the program loaded into memory 192, processor 191 causes control device 100 to configure each of the above-described functional blocks. Processor 191 may temporarily store the computation result in memory 192.

[0107] Image processing circuit 194 causes cameras 310, 410, 510 to perform imaging in response to a request from processor 191, and acquires the captured images from cameras 310, 410, 510. User interface 195 includes one or more input devices and one or more display devices. Examples of input devices include a keyboard or a mouse, etc. Examples of display devices include a liquid crystal monitor, etc. The input device may be incorporated into the display device to form a touch panel. User interface 195 acquires an input to one or more input devices and displays text, images, etc. on one or more display devices in response to a request from processor 191.

[0108] 〔Substrate Imaging Procedure〕 As an example of a substrate imaging method, a substrate imaging procedure executed by the control device 100 using the camera 310 is illustrated. This procedure includes irradiating light from the light source 322 onto a plurality of patches 600A fixed to members permanently present in the wafer processing system 1, causing the plurality of 60A to be imaged by the camera 310 to obtain a calibration image, generating correction data for the calibration image so that the respective colors of the plurality of patches 600A in the calibration image approach predetermined reference colors, loading the wafer W into the field of view of the camera 310 and holding it by the chuck 201, irradiating light from the light source onto the wafer W held by the chuck 201, causing the wafer W to be imaged by the camera 310 to obtain a substrate image, and correcting the substrate image based on the correction data.

[0109] As shown in FIG. 22, the control device 100 first executes steps S01 and S02. In step S01, the calibration unit 112 causes the camera 310 to image a plurality of patches 600A to obtain a calibration image. If all of the plurality of patches 600A do not simultaneously enter the field of view 311, the calibration image may be obtained while moving the chuck 201 by 203 so that all of the plurality of patches 600A enter the field of view 311. In step S02, the calibration unit 112 generates correction data for the calibration image so that the respective colors of the plurality of patches 600A in the calibration image approach predetermined reference colors.

[0110] Next, the control device 100 executes steps S03 and S04. In step S03, the substrate image processing unit 114 causes the camera 310 to image the substrate to obtain a substrate image. In step S04, the substrate image processing unit 114 corrects the substrate image based on the correction data and stores the corrected substrate image in the substrate image storage unit 115.

[0111] Next, the control device 100 executes step S05. In step S05, based on the corrected substrate image stored in the substrate image storage unit 115 and the film thickness correlation model stored in the correlation model storage unit 121, the film thickness calculation unit 122 calculates the thickness distribution of the film formed on the wafer W. The film thickness calculation unit 122 may display the calculation result on the user interface 195 or the like. Based on the corrected substrate image stored in the substrate image storage unit 115 and the line width correlation model stored in the correlation model storage unit 121, the line width calculation unit 123 may calculate the line width distribution of the film formed on the wafer W. The line width calculation unit 123 may display the calculation result on the user interface 195 or the like.

[0112] Next, the control device 100 executes step S06. In step S06, the calibration image processing unit 116 checks whether the current time is the re-acquisition timing of the calibration image. The re-acquisition timing of the calibration image is determined in advance.

[0113] In step S06, if it is determined that the current time is the re-acquisition timing of the calibration image, the control device 100 executes steps S07, S08, and S09. In step S07, the calibration image processing unit 116 causes the camera 310 to image a plurality of patches 600A to re-acquire the calibration image. In step S08, the calibration image processing unit 116 corrects the re-acquired calibration image based on the correction data. In step S09, the regeneration determination unit 117 determines whether regeneration of the correction data is necessary based on the difference between the color of each of the plurality of patches 600A in the corrected calibration image and the reference color.

[0114] In step S08, if it is determined that regeneration of the correction data is unnecessary, the control device 100 executes step S11. In step S11, the contamination detection unit 134 checks for the presence or absence of contamination of at least any one of the plurality of patches 600A based on the color relationship between the plurality of patches 600A in the corrected calibration image.

[0115] In step S11, when it is determined that there is contamination in at least any one of the plurality of patches 600A, the control device 100 executes step S12. In step S12, the contamination detection unit 134 notifies the operator of the contamination detection result by displaying it on the user interface 195 or the like. Thereafter, the control device 100 returns the process to step S03. In step S11, when it is determined that there is no contamination in any of the plurality of patches 600A, the control device 100 returns the process to step S03 without executing step S12. Thereafter, until it is determined in step S08 that regeneration of the correction data is necessary, acquisition, correction, and recording of the substrate image based on the generated correction data are repeated. In step S08, when it is determined that regeneration of the correction data is necessary, the control device 100 returns the process to step S01 to regenerate the correction data.

[0116] 〔Summary〕 The present disclosure includes the following configurations.

[0117] (1) In a substrate processing apparatus 1 that performs processing on a substrate W, a chuck 201 that holds the substrate W, light sources 322, 421, 522 that irradiate light on the substrate W held by the chuck 201, cameras 310, 410, 510 that image the substrate W held by the chuck 201, and a plurality of patches 600 that are fixed at different positions within the fields of view of the cameras 310, 410, 510 and reflect light from the light sources 322, 421, 522 to the cameras 310, 410, 510 in different colors, wherein the plurality of patches 600 are fixed to members that always exist within the substrate processing apparatus 1, a substrate imaging apparatus 50. According to this substrate imaging apparatus 50, calibration of the cameras 310, 410, 510 can be executed without loading a calibration substrate W into the substrate processing apparatus 1. Therefore, calibration is easy. For this reason, calibration can be easily executed at least during the intervals between substrate W processing, and the reliability of the information represented by color can be easily maintained.

[0118] (2) Each of the plurality of patches 600 has a base chip 610 having a surface facing the cameras 310, 410, 510, and a film 620 formed on the surface of the base chip 610, and reflects light from the light sources 322, 421, 522 to the cameras 310, 410, 510 in a color correlated with the characteristics of the film 620, the substrate imaging device 50 according to (1). By calibrating the relationship between the characteristics of the film 620 and the color, the characteristics of the film 620 formed on the substrate W can be represented with high reliability according to the color of the substrate W in the image captured by the cameras 310, 410, 510.

[0119] (3) The film 620 is an oxide film, the substrate imaging device 50 according to (2). Since the characteristics of the film 620 hardly change over time, highly reliable calibration can be repeated over a long period.

[0120] (4) Each of the plurality of patches 600 reflects light from the light sources 322, 421, 522 to the cameras 310, 410, 510 in a color correlated with the thickness of the film 620, the substrate imaging device 50 according to (2) or (3). By calibrating the relationship between the thickness of the film 620 and the color, the thickness of the film 620 formed on the substrate W can be represented with high reliability according to the color of the substrate W in the image captured by the cameras 310, 410, 510.

[0121] (5) Each of the plurality of patches 600 reflects light from the light sources 322, 421, 522 to the cameras 310, 410, 510 in a color correlated with the line width of the uneven pattern 621 engraved on the film 620, the substrate imaging device 50 according to (2) or (3). By calibrating the relationship between the line width of the uneven pattern 621 engraved on the film 620 and the color, the line width of the uneven pattern 621 engraved on the film 620 formed on the substrate W can be represented with high reliability according to the color of the substrate W in the image captured by the cameras 310, 410, 510.

[0122] (6) In a direction perpendicular to the substrate W, each of the plurality of patches 600 is located between the back surface of the substrate W and the surface facing the back surface of the substrate W, and the substrate imaging device 50 according to any one of (1) to (5). The plurality of patches 600 are less likely to interfere with the loading of the substrate W onto the chuck 201 and the unloading of the substrate W from the chuck 201.

[0123] (7) The substrate imaging device 50 according to (6), wherein the surfaces of the plurality of patches 600 and the surface of the substrate W are both located within the depth of field of the cameras 310, 410, and 510. Calibration can be performed without changing the focal position of the cameras 310, 410, and 510 when imaging the substrate W and when imaging the plurality of chucks 201.

[0124] (8) The substrate imaging device 50 according to any one of (1) to (7), wherein the plurality of patches 600 are fixed to the chuck 201 as members that always exist within the substrate processing apparatus 1. The surplus space in the chuck 201 can be used for arranging the plurality of patches 600.

[0125] (9) The substrate imaging device 50 according to (8), further comprising a stage 210 that supports the chuck 201, and actuators 202 and 203 that move the chuck 201 relative to the stage 210 so that the entire surface of the substrate W is within the field of view of the cameras 310, 410, and 510, and the actuators 202 and 203 move the chuck 201 to change the patch 600 that enters the field of view of the cameras 310, 410, and 510 among the plurality of patches 600 at least when the chuck 201 is not holding the substrate W. A wider range can be used for arranging the plurality of patches 600.

[0126] (10) The chuck 201 has a facing surface 221 facing the back surface of the substrate W and an annular support portion 222 protruding from the facing surface 221 and contacting the back surface of the substrate W. At least one of the plurality of patches 600 is provided on the facing surface 221 within the support portion 222, and the substrate imaging device 50 described in (8). A plurality of patches 600 can be arranged over a wide range in the chuck 201 without interfering with the holding of the substrate W.

[0127] (11) The substrate imaging device 50 described in (8) further includes an extension bracket 230 that projects outward from the outer periphery of the chuck 201 at a position farther from the back surface of the substrate W than the chuck 201, and at least one of the plurality of patches 600 is fixed to the extension bracket 230 as a member that always exists within the substrate processing apparatus 1. A plurality of patches 600 can be arranged over a wider range.

[0128] (12) At least one of the plurality of patches 600 is fixed at a position not hidden by the substrate W held by the chuck 201, and the substrate imaging device 50 according to any one of (1) to (11). Calibration can be performed immediately before imaging the substrate W, and the reliability of the information represented by color can be further improved.

[0129] (13) The substrate imaging device 50 described in (12) further includes a stage 210 that supports the chuck 201, and actuators 202 and 203 that move the chuck 201 relative to the stage 210 so that the entire surface of the substrate W is within the fields of view of the cameras 310, 410, and 510. At least one of the plurality of patches 600 is fixed to the stage 210 as a member that always exists within the substrate processing apparatus 1. The surplus space on the stage 210 can be used for arranging the plurality of patches 600.

[0130] (14) The substrate imaging apparatus 50 according to any one of (1) to (13), further comprising a mirror 430 that reflects light from the substrate W to the cameras 310, 410, and 510, and at least one of the plurality of patches 600 being fixed to the mirror 430 as a member that always exists within the substrate processing apparatus 1. By utilizing the surplus space in the mirror 430, a plurality of patches 600 for the imaging system passing through the mirror 430 can be arranged.

[0131] (15) The substrate imaging apparatus 50 according to any one of (1) to (14), further comprising a calibration unit 112 that causes the cameras 310, 410, and 510 to image a plurality of patches 600 to obtain a calibration image, and generates correction data for the calibration image so that the respective colors of the plurality of patches 600 in the calibration image approach a predetermined reference color, and a substrate image processing unit 114 that causes the cameras 310, 410, and 510 to image the substrate W to obtain a substrate W image, and corrects the substrate W image based on the correction data. In one substrate imaging apparatus 50, the color reproducibility for the same substrate W can be easily improved. Also, the color reproducibility can be improved among a plurality of substrate imaging apparatuses 50.

[0132] (16) The substrate imaging apparatus 50 according to (15), further comprising temperature sensors 329 and 429 that detect the temperatures of the light sources 322, 421, and 522, and a monitoring unit 131 that records the transition of the detection results by the temperature sensors 329 and 429 at least from when the calibration image is obtained. Based on the detection results recorded by the monitoring unit 131, the factor when the color reproducibility deteriorates can be quickly specified.

[0133] (17) After generating the correction data, the calibration image processing unit 116 causes the cameras 310, 410, and 510 to image a plurality of patches 600 to re-acquire the calibration image, and corrects the re-acquired calibration image based on the correction data. The substrate imaging apparatus 50 according to (15) or (16) further includes a regeneration determination unit 117 that determines whether regeneration of the correction data is necessary based on the difference between the color of each of the plurality of patches 600 in the corrected calibration image and the reference color. It is possible to maintain the reliability of the information represented by the color while suppressing the execution frequency of calibration.

[0134] (18) After generating the correction data, the calibration image processing unit 116 causes the cameras 310, 410, and 510 to image a plurality of patches 600 to re-acquire the calibration image, and corrects the re-acquired calibration image based on the correction data. The substrate imaging apparatus 50 according to any one of (15) to (17) further includes a contamination detection unit 134 that detects contamination of at least any one of the plurality of patches 600 based on the color relationship between the plurality of patches 600 in the corrected calibration image. It is possible to suppress a decrease in reliability due to contamination of the plurality of patches 600.

[0135] (19) The substrate imaging apparatus 50 according to any one of (15) to (18) further includes a film thickness calculation unit 122 that calculates the thickness distribution of the film 620 formed on the substrate W based on the correlation model generated in advance so as to represent the relationship between the reference color and the thickness of the film 620, and the corrected substrate W image. By using the corrected substrate W image and the correlation model, it is possible to calculate the film thickness distribution with high reliability for each substrate imaging apparatus 50 while sharing the correlation model among the plurality of substrate imaging apparatuses 50.

[0136] The substrate imaging apparatus 50 according to any one of (15) to (19), further comprising a line width calculation unit 123 that calculates the line width distribution of the uneven pattern 621 engraved on the film 620 formed on the substrate W based on a correlation model generated in advance so as to represent the relationship between the reference color and the line width, and the corrected substrate W image. By being based on the corrected substrate W image and the correlation model, it is possible to calculate the line width distribution with high reliability in each substrate imaging apparatus 50 while sharing the correlation model among a plurality of substrate imaging apparatuses 50.

[0137] (21) Irradiating a plurality of patches 600 fixed to members constantly present in the substrate processing apparatus 1 with light from the light sources 322, 421, 522, imaging the plurality of patches 600 with the cameras 310, 410, 510 to obtain a calibration image, generating correction data for the calibration image so as to approximate the respective colors of the plurality of patches 600 in the calibration image to a predetermined reference color, loading the substrate W into the fields of view of the cameras 310, 410, 510 and holding it by the chuck 201, irradiating the substrate W held by the chuck 201 with light from the light sources 322, 421, 522, imaging the substrate W with the cameras 310, 410, 510 to obtain a substrate W image, and correcting the substrate W image based on the correction data. A method for imaging the substrate W including these steps.

[0138] (22) A computer-readable storage medium storing a program for causing a device to execute the substrate W imaging method according to (21).

[0139] Although the embodiments have been described above, the present disclosure is not necessarily limited to the above-described embodiments, and various modifications are possible without departing from the gist thereof. The plurality of patches 600 may be integrated. For example, the plurality of patches 600 may be integrated side by side in a row. In this case, the color of the reflected light by the plurality of patches 600 may gradually change from one end to the other end of the arrangement of the plurality of patches 600. For example, the color of the reflected light by the plurality of patches 600 may have a gradation as it goes from one end to the other end.

[0140] Although a semiconductor wafer has been exemplified as an example of the substrate, the present invention is not limited thereto. For example, the substrate may be a glass substrate. Further, although the case where the fluid is a gas has been mainly exemplified, the fluid may be a liquid. Even when the fluid is a liquid, the Schlieren effect can be obtained, and thus it is possible to visualize the distribution of the fluid flow by the above-described configuration.

Explanation of Reference Numerals

[0141] 1... substrate processing apparatus, 50... substrate imaging apparatus, W... substrate, 201... chuck, 221... opposing surface, 222... support portion, 600... patch, 610... base chip, 620... film, 621... uneven pattern, 230... extension bracket, 210... stage, 430... mirror, 202, 203... actuator, 112... calibration unit, 114... substrate image processing unit, 116... calibration image processing unit, 117... regeneration determination unit, 122... film thickness calculation unit, 123... line width calculation unit, 329, 429... temperature sensor, 131... monitoring unit, 134... contamination detection unit, 310, 410, 510... camera.

Claims

1. In a substrate processing apparatus that performs processing on a substrate, a chuck that holds the substrate, a light source that irradiates light onto the substrate held by the chuck, a camera that images the substrate held by the chuck, a plurality of patches that are respectively fixed at different positions within the field of view of the camera and reflect light from the light source to the camera in different colors, and comprising the plurality of patches are fixed to a member that always exists within the substrate processing apparatus, a substrate imaging device.

2. Each of the plurality of patches has a base chip having a surface facing the camera, and a coating formed on the surface of the base chip, and comprising reflects light from the light source to the camera in a color correlated with the characteristics of the coating, the substrate imaging device according to claim 1.

3. The coating is an oxide film, the substrate imaging device according to claim 2.

4. Each of the plurality of patches reflects light from the light source to the camera in a color correlated with the thickness of the coating, the substrate imaging device according to claim 2 or 3.

5. Each of the plurality of patches reflects light from the light source to the camera in a color correlated with the line width of the uneven pattern engraved on the coating, the substrate imaging device according to claim 2 or 3.

6. In a direction perpendicular to the substrate, each of the plurality of patches is located between the back surface of the substrate and the surface facing the back surface of the substrate, the substrate imaging device according to any one of claims 1 to 3.

7. The surfaces of the plurality of patches and the surface of the substrate are both located within the depth of focus of the camera, the substrate imaging device according to claim 6.

8. The plurality of patches are fixed to the chuck as a member that always exists within the substrate processing apparatus, the substrate imaging device according to any one of claims 1 to 3.

9. a stage that supports the chuck, an actuator that moves the chuck relative to the stage so that the entire area of the surface of the substrate enters the field of view of the camera, and further comprising the actuator moves the chuck so as to change the patch that enters the field of view of the camera among the plurality of patches, at least in a state where the chuck is not holding the substrate, the substrate imaging device according to claim 8.

10. The chuck has a facing surface facing the back surface of the substrate, An annular support portion that protrudes from the facing surface and contacts the back surface of the substrate; having; at least one of the plurality of patches is provided on the facing surface within the support portion; The substrate imaging device according to claim 8.

11. Further comprising an extension bracket that projects outward from the outer periphery of the chuck at a position farther from the back surface of the substrate than the chuck; at least one of the plurality of patches is fixed to the extension bracket as a member that always exists within the substrate processing apparatus; The substrate imaging device according to claim 8.

12. At least one of the plurality of patches is fixed at a position that is not hidden by the substrate held by the chuck; The substrate imaging device according to any one of claims 1 to 3.

13. A stage that supports the chuck; An actuator that moves the chuck relative to the stage so that the entire surface of the substrate is within the field of view of the camera; further comprising; at least one of the plurality of patches is fixed to the stage as a member that always exists within the substrate processing apparatus; The substrate imaging device according to claim 12.

14. Further comprising a mirror that reflects light from the substrate to the camera; at least one of the plurality of patches is fixed to the mirror as a member that always exists within the substrate processing apparatus; The substrate imaging device according to any one of claims 1 to 3.

15. A calibration unit that causes the camera to image the plurality of patches to obtain a calibration image, and generates correction data for the calibration image so that the colors of the plurality of patches in the calibration image approach predetermined reference colors; A substrate image processing unit that causes the camera to image the substrate to obtain a substrate image, and corrects the substrate image based on the correction data; further comprising; The substrate imaging device according to any one of claims 1 to 3.

16. A temperature sensor that detects the temperature of the light source; A monitoring unit that records at least the transition of the detection results by the temperature sensor since the calibration image was obtained; further comprising; The substrate imaging device according to claim 15.

17. After generating the correction data, causing the camera to image the plurality of patches to reacquire the calibration image, and correcting the reacquired calibration image based on the correction data, a calibration image processing unit; A regeneration determination unit that determines whether regeneration of the correction data is necessary based on the difference between the color of each of the plurality of patches in the corrected calibration image and the reference color; Further comprising: The substrate imaging apparatus according to claim 15.

18. After generating the correction data, causing the camera to image the plurality of patches to reacquire the calibration image, and correcting the reacquired calibration image based on the correction data, a calibration image processing unit; A contamination detection unit that detects contamination of at least any one of the plurality of patches based on the color relationship between the plurality of patches in the corrected calibration image; Further comprising: The substrate imaging apparatus according to claim 15.

19. Further comprising a film thickness calculation unit that calculates the thickness distribution of the film formed on the substrate based on a correlation model generated in advance so as to represent the relationship between the reference color and the film thickness, and the corrected substrate image; The substrate imaging apparatus according to claim 15.

20. Further comprising a line width calculation unit that calculates the line width distribution of the uneven pattern engraved on the film formed on the substrate based on a correlation model generated in advance so as to represent the relationship between the reference color and the line width, and the corrected substrate image; The substrate imaging apparatus according to claim 15.

21. Irradiating light from a light source onto a plurality of patches fixed to a member constantly present in the substrate processing apparatus, imaging the plurality of patches with a camera to acquire a calibration image; Generating correction data for the calibration image so as to bring the color of each of the plurality of patches in the calibration image closer to a predetermined reference color; Loading a substrate into the field of view of the camera and holding it by a chuck; Irradiating light from the light source onto the substrate held by the chuck, imaging the substrate with the camera to acquire a substrate image; Correcting the substrate image based on the correction data; A substrate imaging method including:

22. A computer-readable storage medium storing a program for causing an apparatus to execute the substrate imaging method according to claim 21.

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