TWI892313B - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

The present invention provides a substrate processing apparatus and method that can capture processing conditions around the substrate W while suppressing particle generation within a processing chamber. This allows for imaging with a focus over a wide area of the substrate's top surface. While processing liquid is supplied to the top surface of a rotating substrate W, a camera 84 captures the periphery of the substrate W. This allows for imaging of the processing conditions around the substrate W. The camera 84 is positioned outside the processing chamber 30. Therefore, particle generation caused by the camera 84 can be suppressed within the processing space 31 within the processing chamber 30. Furthermore, the use of a first reflecting mirror 81 allows imaging of the substrate W's periphery from directly above. This allows for imaging with a focus over a wide area of the substrate's top surface.

Description

Substrate processing device and substrate processing method

The present invention relates to a substrate processing apparatus and a substrate processing method, which process a substrate using a processing liquid.

During the manufacturing process of substrates such as semiconductor wafers, a process liquid is supplied to the top surface of the substrate while the substrate is rotated horizontally within a processing chamber. For example, Patent Document 1 describes a known substrate processing apparatus that performs this process.

[Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Publication No. 2019-140340

In this type of substrate processing apparatus, the processing liquid discharged toward the center of the substrate's top surface diffuses toward the substrate's periphery as the substrate rotates. The liquid film formed on the substrate's top surface gradually thins as it diffuses from the center toward the periphery. Consequently, a phenomenon known as "coverage break" may occur at the periphery of the substrate's top surface. A coverage break is a break in the liquid film, exposing the substrate's top surface. When a coverage break occurs, the processing liquid is unevenly applied to the substrate's top surface.

To monitor for coverage gaps, for example, one approach could be to supply processing liquid to the substrate while photographing the substrate's periphery with a camera. However, placing the camera inside the processing chamber could contaminate the substrate with particles generated by the camera. Furthermore, photographing the substrate from an oblique angle narrows the range within which the focus can be placed on the substrate's top surface.

The present invention was developed in light of the above-mentioned circumstances. Its purpose is to provide a substrate processing apparatus and method that can capture the processing conditions around the substrate while suppressing the generation of particles within the processing chamber. The imaging can also be performed with the focus focused on a wide area of the substrate's top surface.

In order to solve the above problems, the first aspect of the present invention is a substrate processing device for processing a substrate with a processing liquid, which comprises: a processing chamber having a partition wall and a window portion, wherein the partition wall divides a processing space for processing the substrate, and the window portion is provided at a portion of the partition wall; a holding portion for holding the substrate in a horizontal position in the processing chamber; a rotating mechanism for rotating the holding portion around a rotation axis extending in a vertical direction; and a processing liquid supply portion for supplying the processing liquid to the substrate held by the holding portion. The processing liquid supply unit forms a liquid film on the upper surface of the substrate; a first reflecting mirror is located inside the processing chamber and above the peripheral portion of the substrate held by the holding unit; a camera is located outside the processing chamber and images the peripheral portion of the substrate via the window and the first reflecting mirror; and a control unit controls the rotating mechanism, the processing liquid supply unit, and the camera; the control unit operates the rotating mechanism and the processing liquid supply unit while causing the camera to perform imaging.

The second aspect of the present invention is the substrate processing apparatus of the first aspect, further comprising: an illumination unit located outside the processing chamber and irradiating light toward the periphery of the substrate via the window and the first reflective mirror.

A third aspect of the present invention is the substrate processing apparatus of the second aspect, further comprising: a semi-reflective mirror located outside the processing chamber; the illumination unit is disposed on one of the two optical paths branched by the semi-reflective mirror; and the camera is disposed on the other of the two optical paths branched by the semi-reflective mirror.

A fourth aspect of the present invention is a substrate processing apparatus according to any one of the first to third aspects, wherein the substrate is a silicon wafer and the first reflective mirror is also a silicon wafer.

The fifth aspect of the present invention is the substrate processing apparatus of the fourth aspect, further comprising: a second reflective mirror located outside the processing chamber, the reflective surface of which is silver or aluminum; and the camera photographs the periphery of the substrate via the second reflective mirror, the window, and the first reflective mirror.

A sixth aspect of the present invention is a substrate processing apparatus according to any one of the first to fifth aspects, wherein the camera is an event-based camera.

A seventh aspect of the present invention is a substrate processing apparatus according to any one of the first to sixth aspects, further comprising a fan filter unit disposed above the processing chamber.

The eighth aspect of the present invention is the substrate processing apparatus according to any one of the first to seventh aspects, further comprising: a cup body that surrounds the substrate held by the holding portion within the processing chamber.

A ninth aspect of the present invention is a substrate processing apparatus according to any one of the first to eighth aspects, wherein the control unit detects the occurrence of coating discontinuities on the upper surface of the substrate based on imaging data obtained from the camera.

The tenth aspect of the present invention is a substrate processing method for processing a substrate with a processing liquid, wherein the following processes (a) and (b) are performed: (a) in a processing chamber having a partition wall that separates a processing space for processing the substrate, the substrate held in a horizontal position is rotated about a rotation axis extending in a vertical direction, while the processing liquid is supplied to the upper surface of the substrate. (a) forming a liquid film on the upper surface of the substrate; and (b) photographing the periphery of the substrate while performing the process (a). In the process (b), a camera located outside the processing chamber photographs the periphery of the substrate through a window provided in the partition wall and a first reflecting mirror located above the periphery of the substrate within the processing chamber.

According to the first to tenth aspects of the present invention, while a processing liquid is supplied to the top surface of a rotating substrate, the periphery of the substrate is photographed by a camera. This allows for capturing images of the processing status of the substrate periphery. The camera is located outside the processing chamber, thus suppressing the generation of camera-induced particles within the processing space within the chamber. Furthermore, by using a first reflecting mirror, the periphery of the substrate can be captured from directly above, enabling photography to focus on a wide area of the substrate's top surface.

In particular, according to the second aspect of the present invention, light can be irradiated directly onto the periphery of the substrate from above, enabling clearer images of the periphery. Furthermore, the illumination unit is located outside the processing chamber. Therefore, the generation of particles caused by illumination within the processing space within the processing chamber can be suppressed.

In particular, according to the third aspect of the present invention, the optical axis of the camera can be aligned with the optical axis of the lighting unit.

In particular, according to the fourth aspect of the present invention, the generation of particles caused by the first reflective mirror can be suppressed.

In particular, according to the fifth aspect of the present invention, the first reflective mirror located inside the processing chamber is made of a silicon wafer that is less susceptible to particle generation, while the second reflective mirror located outside the processing chamber is made of silver or aluminum, which has a high reflectivity. This reduces substrate contamination and allows for clear images of the substrate's periphery.

In particular, according to the sixth aspect of the present invention, by using an event camera, it is possible to capture high-speed motion of the substrate periphery while minimizing the amount of information in the captured data.

In particular, according to the seventh aspect of the present invention, a downward flow of clean air can be formed within the processing space of the processing chamber. However, when the fan-filter unit is installed above the processing chamber, it is difficult to install a camera there. However, according to the present invention, the camera can be placed on the side of the processing chamber and photograph the substrate from above via the first reflective mirror.

In particular, according to the eighth aspect of the present invention, the processing liquid that scatters from the substrate can be collected and recovered by using a cup. However, when the cup is arranged around the substrate, it is difficult to photograph the periphery of the substrate from an oblique angle. However, according to the present invention, by using the first reflective mirror, the periphery of the substrate can be photographed from directly above.

In particular, according to the ninth aspect of the present invention, it is possible to inspect the condition of coverage discontinuities that are likely to occur at the periphery of the substrate.

1: Substrate processing equipment

10: Indexer Block

11: Carrier loading section

12: 1st Transport Department

20: Processing Block

21: Buffer Zone

22: 2nd Transport Department

23: Processing unit

30: Processing Room

31: Processing Space

32: Next door

33: Window

34: Fan filter unit

35: Exhaust duct

40: Maintenance Department

41: Rotating base

42: Chuck pin

43: Chuck pin switching mechanism

50: Rotating mechanism

51: Motor cover

52: Rotary Motor

53: Support shaft

60: Treatment fluid supply unit

61: Spit out the nozzle

70: Cup body

71: Inner cup

72: Medium cup

73: Outer cup

80: Camera Department

81: 1st Reflector

82: Half-reflective mirror

83:Lighting Department

84: Camera

85: Second Reflector

90: Control Department

91: Processor

92: Memory

93: Memory

94: Display unit

121: Transport Route 1

122: The first transport robot

221: Second Transport Path

222: The second transport robot

321: Sidewall

322: Top plate

323: Bottom plate

530: Rotation axis

611: Nozzle Arm

612: Nozzle

613: Nozzle Motor

614: Liquid supply source

615:Piping

616: Pump

617: Valve

710: First guide plate

711: 1st drain tank

712: 2nd drain tank

713: 3rd drain tank

720: Second guide plate

730: 3rd guide plate

C: Carrier

D:Photographic data

L0: Optical Path

L1: Optical Path

L2: Optical Path

P1: Control Program

P2: Check program

W: substrate

S1~S6: Steps

S31~S35: Steps

Figure 1 is a plan view of the substrate processing apparatus.

Figure 2 is a plan view of the processing unit.

Figure 3 is a longitudinal cross-sectional view of the processing unit.

Figure 4 is a schematic diagram showing the liquid supply portion connected to the nozzle head.

Figure 5 is the control block diagram of the processing unit.

Figure 6 is a flow chart showing the substrate processing sequence.

Figure 7 is a flow chart showing the flow of monitoring processing for covering intermittent periods.

Figure 8 is a longitudinal cross-sectional view of the processing unit of the first variant.

The following describes the embodiments of the present invention in detail with reference to the drawings.

<1. Overall Structure of the Substrate Processing Device>

Figure 1 is a plan view of a substrate processing apparatus 1 according to one embodiment of the present invention. During the semiconductor wafer manufacturing process, substrate processing apparatus 1 supplies a processing liquid to the surface of a circular substrate W (silicon wafer) to process the surface of the substrate W. As shown in Figure 1 , substrate processing apparatus 1 includes an indexer block 10 and a processing block 20. Indexer block 10 and processing block 20 are arranged adjacent to each other on a horizontal surface.

Hereinafter, the arrangement direction of the indexer block 10 and the processing block 20 is referred to as the "front-back direction." Furthermore, the horizontal direction perpendicular to the front-back direction is referred to as the "left-right direction."

The indexer block 10 is used to load unprocessed substrates W from the outside and unload processed substrates W from the outside. As shown in Figure 1, the indexer block 10 includes a plurality (e.g., four) of carrier placement sections 11 and a first transfer section 12. The plurality of carrier placement sections 11 are arranged in a horizontal direction. Each carrier placement section 11 can be equipped with a carrier C for accommodating a plurality of substrates W. For example, a front-opening unified pod (FOUP) can be used as the carrier C.

The first transport unit 12 is located between the plurality of carrier loading units 11 and the processing block 20. The first transport unit 12 includes a first transport path 121 extending horizontally, and a first transport robot 122 disposed along the first transport path 121. The first transport robot 122 is movable horizontally along the first transport path 121.

The first transfer robot 122 has a hand that holds the substrate W and an arm that moves the hand. The first transfer robot 122 transports substrates W between the carrier C and the buffer area 21 (described below). Specifically, the first transfer robot 122 removes pre-processed substrates W from the carrier C and transports them to the buffer area 21. Also, the first transfer robot 122 removes processed substrates W from the buffer area 21 and transports them to the carrier C.

The processing block 20 processes multiple substrates W supplied from the indexer block 10. As shown in Figure 1, the processing block 20 includes a buffer zone 21, a second conveyor 22, and multiple processing units 23. The buffer zone 21 temporarily stores substrates W between the first conveyor 12 and the second conveyor 22. The buffer zone 21 can accommodate multiple substrates W simultaneously.

The second transport unit 22 includes a second transport path 221 extending in the front-to-back direction, and a second transport robot 222 mounted on the second transport path 221. The second transport robot 222 is movable in the front-to-back direction along the second transport path 221. The second transport robot 222 transports substrates W between the buffer area 21 and a plurality of processing units 23. Specifically, the second transport robot 222 removes pre-processed substrates W from the buffer area 21 and transports them to the processing units 23. Furthermore, the second transport robot 222 removes processed substrates W from the processing units 23 and transports them to the buffer area 21.

Furthermore, the processing block 20 may also have two or more second transport units 22. For example, second transport paths 221 may be arranged in multiple layers in the vertical direction, and a second transport robot 222 may be installed on each second transport path 221.

The processing units 23 are so-called single-wafer processing units that process substrates W one by one. Multiple processing units 23 are arranged on both sides of the second transport path 221. In the example shown in Figure 1 , two processing units 23 are arranged on the left side of the second transport path 221, and two processing units 23 are arranged on the right side of the second transport path 221. However, these multiple processing units 23 may also be arranged in multiple levels in the vertical direction. Multiple substrates W are processed simultaneously in each processing unit 23.

<2. Composition of the processing unit>

Next, the detailed structure of the processing unit 23 will be described. Below, one of the multiple processing units 23 included in the substrate processing apparatus 1 will be described, but the other processing units 23 also have the same structure.

Figure 2 is a plan view of processing unit 23. Figure 3 is a longitudinal cross-sectional view of processing unit 23. Processing unit 23 processes silicon wafers, or substrates W, using a processing liquid. As shown in Figures 2 and 3, processing unit 23 includes a processing chamber 30, a holding unit 40, a rotating mechanism 50, a processing liquid supply unit 60, a cup 70, an imaging unit 80, and a control unit 90.

The processing chamber 30 is a frame that forms a processing space 31, a single enclosed space for processing substrates W. The processing chamber 30 has a partition wall 32 that separates the processing space 31 from the outside. The partition wall 32 includes side walls 321 surrounding the sides of the processing space 31, a ceiling 322 covering the top of the processing space 31, and a bottom 323 covering the bottom of the processing space 31. The holding unit 40, rotating mechanism 50, processing liquid supply unit 60, cup 70, and a first reflective mirror 81 (described later) are housed within the processing chamber 30.

The portion of the sidewall 321 facing the second transport path 221 is provided with a loading/unloading port for loading and unloading substrates W into and out of the processing chamber 30, as well as a gate (not shown) for opening and closing the loading/unloading port. Furthermore, the processing chamber 30 has a window 33 in a portion of the sidewall 321. The window 33 is formed of a transparent resin such as polyvinyl chloride or glass. The boundary between the sidewall 321 and the window 33 is seamlessly sealed.

As shown in Figure 3, the processing chamber 30 includes a fan filter unit (FFU) 34. The FFU 34 is mounted on the ceiling 322. The FFU 34 includes a dust filter, such as a HEPA filter, and a fan that generates airflow. When the FFU 34 is activated, air from the clean room where the substrate processing apparatus 1 is located is drawn into the FFU 34, purified by the dust filter, and then supplied to the processing space 31 within the processing chamber 30. This creates a downward flow of cleaned air within the processing space 31 within the processing chamber 30.

Furthermore, an exhaust duct 35 is connected to a portion of the lower portion of the sidewall 321. Air supplied from the fan filter unit 34 forms a downward flow within the processing chamber 30 and is then exhausted to the outside of the processing chamber 30 through the exhaust duct 35.

The holding unit 40 holds the substrate W in a horizontal position within the processing chamber 30. Specifically, the holding unit 40 holds the substrate W with its normal oriented in the vertical direction. As shown in Figures 2 and 3, the holding unit 40 includes a circular rotating base 41 and a plurality of chuck pins 42. The chuck pins 42 are arranged at equal angular intervals on the outer periphery of the top surface of the rotating base 41. The substrate W is held by the chuck pins 42 with the patterned surface facing upward. Each chuck pin 42 contacts the lower surface and outer edge of the substrate W. The chuck pins 42 support the substrate W above the top surface of the rotating base 41, separated by a slight gap.

A chuck pin switching mechanism 43 is installed within the rotating base 41 to switch the positions of the chuck pins 42. The chuck pin switching mechanism 43 switches the chuck pins 42 between a holding position and a release position. Here, the holding position refers to a position that holds the substrate W. Furthermore, the release position refers to a position where the substrate W is no longer held.

The rotating mechanism 50 is used to rotate the holding portion 40. It is housed within a motor housing 51 located below the rotating base 41. As shown by the dashed line in Figure 3, the rotating mechanism 50 includes a rotating motor 52 and a support shaft 53. The support shaft 53 extends vertically, with its lower end connected to the rotating motor 52 and its upper end fixed to the center of the lower surface of the rotating base 41. When the rotating motor 52 is driven, the support shaft 53 rotates about a rotation axis 530 passing through its axis. Consequently, the holding portion 40 and the substrate W held therein also rotate along with the support shaft 53 about the rotation axis 530.

The processing liquid supply unit 60 supplies processing liquid to the upper surface of the substrate W held by the holding unit 40. The processing liquid supply unit 60 includes a discharge nozzle 61. As shown in Figures 2 and 3, the discharge nozzle 61 includes a nozzle arm 611, a nozzle head 612, and a nozzle motor 613. The nozzle head 612 is located at the tip of the nozzle arm 611. The nozzle motor 613 drives the nozzle arm 611 to rotate horizontally around the base of the nozzle arm 611. This allows the nozzle head 612 to move between a processing position above the substrate W held by the holding unit 40 (the position indicated by the two-dot chain in Figure 2) and a retracted position further outward from the cup 70 (the position indicated by the solid line in Figure 2).

Figure 4 schematically illustrates the liquid supply unit connected to the nozzle head 612. The nozzle head 612 is connected to a liquid supply source 614, which stores the processing liquid, via a pipe 615. A pump 616 and a valve 617 are installed along the pipe 615. When the nozzle head 612 is positioned at the processing position, valve 617 is opened and pump 616 is activated. This causes the processing liquid to be supplied from the liquid supply source 614 through the pipe 615 to the nozzle head 612. The processing liquid is then discharged from the nozzle head 612 toward the top surface of the substrate W.

The processing unit 23 discharges a processing liquid from the nozzle head 612 toward the center of the top surface of the substrate W while the substrate W is rotated by the rotation mechanism 50. The centrifugal force generated by the rotation of the substrate W causes the processing liquid to spread from the center toward the periphery of the substrate W, thereby forming a film of processing liquid on the top surface of the substrate W.

Examples of treatment liquids include DHF (dilute hydrofluoric acid), SPM (a mixture of sulfuric acid and hydrogen peroxide), SC-1 (a mixture of ammonia, hydrogen peroxide, and pure water), SC-2 (a mixture of hydrochloric acid, hydrogen peroxide, and pure water), or pure water (deionized water). However, the type of treatment liquid is not limited, and treatment liquids other than those listed above may also be used.

Furthermore, a plurality of discharge nozzles 61 may be provided in one processing unit 23. Furthermore, the processing unit 23 may further include a nozzle for supplying the processing liquid toward the lower surface of the substrate W.

The cup 70 collects the treated liquid after use. As shown in Figure 3, the cup 70 comprises an inner cup 71, a middle cup 72, and an outer cup 73. The inner cup 71 has a first annular guide plate 710 surrounding the retaining portion 40. The middle cup 72 has a second annular guide plate 720 located outside and above the first guide plate 710. The outer cup 73 has a third annular guide plate 730 located outside and above the second guide plate 720.

The inner cup 71, middle cup 72, and outer cup 73 can be independently raised and lowered by a lifting mechanism (not shown). When the processing liquid supply unit 60 supplies processing liquid to the substrate W, at least one of the first guide plate 710, the second guide plate 720, and the third guide plate 730 surrounds the substrate W held by the holding unit 40.

The bottom of the inner cup 71 extends below the middle cup 72 and outer cup 73. Furthermore, on the upper surface of the bottom, a first drain groove 711, a second drain groove 712, and a third drain groove 713 are provided in order from the inside.

The processing liquid ejected from the nozzle head 612 of the processing liquid supply unit 60 forms a liquid film on the upper surface of the substrate W. The liquid is then scattered outward by the centrifugal force generated by the rotation of the substrate W. The processing liquid scattered from the substrate W is then collected by one of the first guide plate 710, the second guide plate 720, and the third guide plate 730. The processing liquid collected by the first guide plate 710 is discharged outside the processing unit 23 through the first drain trough 711. The processing liquid collected by the second guide plate 720 is discharged outside the processing unit 23 through the second drain trough 712. The processing liquid collected by the third guide plate 730 is discharged outside the processing unit 23 through the third drain trough 713.

Thus, the processing unit 23 has multiple processing liquid discharge paths. Therefore, it can recover the processing liquid supplied to the substrate W separately by type. Therefore, it can also dispose of or recycle the recovered processing liquid according to the properties of each processing liquid.

The imaging unit 80 is a mechanism for capturing images of the periphery of a substrate W being processed by a processing liquid. As shown in Figures 2 and 3 , the imaging unit 80 includes a first reflecting mirror 81, a semi-reflecting mirror 82, an illumination unit 83, and a camera 84.

The first reflective mirror 81 is located within the processing chamber 30. It is positioned vertically above the periphery of the substrate W held by the holder 40. Furthermore, the first reflective mirror 81 is positioned at the same height as the window 33. The first reflective mirror 81 is positioned at an angle of approximately 45° with respect to both the vertical and horizontal directions to reflect light traveling vertically upward from the periphery of the substrate W toward the window 33 and then horizontally.

The first reflective mirror 81 is located in the processing space 31 within the processing chamber 30. Therefore, if a mirror with a reflective surface made of a metal such as silver, aluminum, iron, or copper is used as the first reflective mirror 81, there is a risk of contamination of the substrate W by metal particles. Therefore, a silicon wafer, for example, can be used as the first reflective mirror 81. Since silicon wafers have a mirror surface, they can be used as a reflective mirror. Furthermore, using a silicon wafer as the first reflective mirror 81 can suppress the generation of particles caused by the first reflective mirror 81.

The semi-reflective mirror 82 is located outside the processing chamber 30. It is positioned near the outside of the window 33. The first mirror 81, the window 33, and the semi-reflective mirror 82 are aligned horizontally. The semi-reflective mirror 82 splits the optical path L0 connecting the first mirror 81 and the semi-reflective mirror 82 into two optical paths, L1 and L2.

The illumination unit 83 is located outside the processing chamber 30. It is positioned on optical path L1, one of the two optical paths L1 and L2 branched by the semi-reflective mirror 82. The illumination unit 83 irradiates the periphery of the substrate W with illumination light for imaging. The illumination unit 83 includes a light source such as an LED. When the camera 84 is capturing images, the light source of the illumination unit 83 emits light. This light then irradiates the semi-reflective mirror 82 from the illumination unit 83. The illumination light is reflected by the semi-reflective mirror 82, passes through the window 33, and enters the processing chamber 30. Furthermore, within the processing chamber 30, the illumination light is reflected by the first reflective mirror 81 and irradiates the periphery of the substrate W held by the holding unit 40.

Camera 84 is located outside the processing chamber 30. It is positioned on optical path L2, the other of the two optical paths L1 and L2 branched by the half mirror 82. Camera 84 includes an imaging element such as a CCD or CMOS. When the nozzle head 612 discharges processing liquid onto the surface of the substrate W, illumination light is emitted from the illumination unit 83 while the camera 84 captures the image. Illumination light reflected from the periphery of the upper surface of the substrate W is reflected by the first reflection mirror 81, passes through the window 33 and the half mirror 82, and enters the camera 84. The camera 84 then captures an image of the periphery of the substrate W as image data D. The captured image data D is output from the camera 84 to the control unit 90.

In camera 84, for example, an event camera is used. A general camera used for motion picture photography (frame-based camera) outputs photographic data arranged in chronological order, and the photographic data is a frame image having brightness value information of a plurality of pixels. In contrast, an event camera outputs photographic data D (event data), which is composed only of information of pixels whose brightness values have changed. Therefore, the amount of information of the photographic data D output from the event camera is smaller than the amount of information of the photographic data output from the frame camera. Therefore, if an event camera is used, the acquisition and transmission of the photographic data D can be performed at a higher speed than when a frame camera is used. Furthermore, an event camera can acquire image data D at shorter intervals than the frame intervals of a frame camera. For example, an event camera can acquire image data D every several microseconds. Therefore, using an event camera can capture high-speed motion around the periphery of a substrate W.

As described above, the half mirror 82, lighting unit 83, and camera 84 are positioned outside the processing chamber 30. Specifically, the half mirror 82, lighting unit 83, and camera 84 are positioned outside the processing space 31, which is a single, enclosed space where substrates W are positioned. This configuration prevents corrosion of the half mirror 82, lighting unit 83, and camera 84 from the effects of the processing liquid. Furthermore, it prevents particles generated by the half mirror 82, lighting unit 83, and camera 84 from adhering to substrates W within the processing space 31.

The half mirror 82, lighting unit 83, and camera 84 can be located either within the second transport path 221 or outside the processing block 20. However, if the half mirror 82, lighting unit 83, and camera 84 are located within the second transport path 221, the entire imaging unit 80 can be housed inside the outer wall of the processing block 20. This reduces the footprint of the substrate processing apparatus 1.

The control unit 90 is an information processing device that controls the aforementioned components of the processing unit 23. Figure 5 is a control block diagram of the processing unit 23. As schematically shown in Figure 5, the control unit 90 is composed of a computer having a processor 91 such as a CPU, a memory 92 such as RAM, and a storage unit 93 such as a hard drive.

The memory unit 93 stores a control program P1 and an inspection program P2. The control program P1 is a computer program used to control the operation of various components of the processing unit 23 in order to execute the processing of substrates W in the processing unit 23. The inspection program P2 is a computer program used to monitor the processing status of substrates W based on the image data D obtained from the camera 84.

As shown in Figure 5, the control unit 90 is communicatively connected to the fan filter unit 34, chuck pin switching mechanism 43, rotary motor 52, nozzle motor 613, pump 616, valve 617, cup 70 lifting mechanism, lighting unit 83, and camera 84, via wired or wireless communication. Furthermore, the control unit 90 is electrically connected to a display unit 94, such as a liquid crystal display. The control unit 90 controls the operation of each of the aforementioned components according to the control program P1 and the test program P2 stored in the memory unit 93. This allows the processing of steps S1-S6 and steps S31-S35, described below, to be performed.

<3. Operation of the Substrate Processing Device>

Next, the processing of the substrate W in the processing unit 23 will be described. FIG6 is a flow chart showing the processing sequence of the substrate W.

When processing a substrate W in the processing unit 23, the second transfer robot 222 first loads the substrate W into the processing chamber 30 (step S1). Once loaded into the processing chamber 30, the substrate W is held horizontally by the plurality of chuck pins 42 of the holding portion 40. The rotation mechanism 50 then drives the rotation motor 52, causing the substrate W to begin rotating (step S2). Specifically, the support shaft 53, the rotation base 41, the plurality of chuck pins 42, and the substrate W held by the chuck pins 42 rotate about the rotation shaft 530.

Next, the processing liquid supply unit 60 supplies the processing liquid toward the substrate W (step S3). In step S3, the nozzle motor 613 drives the nozzle head 612 toward the processing position facing the top surface of the substrate W. The nozzle head 612, positioned at the processing position, then discharges the processing liquid toward the top surface of the rotating substrate W. The processing liquid diffuses from the center of the top surface of the substrate W toward the periphery, forming a liquid film covering the top surface of the substrate W.

Furthermore, in step S3, the discharge nozzle 61 may be swung horizontally at the processing position while discharging the processing liquid from the discharge nozzle 61.

When the prescribed supply of processing liquid is complete, the processing liquid supply unit 60 stops discharging the processing liquid from the nozzle head 612. The nozzle motor 613 then drives the nozzle head 612 from the processing position to the retreat position. The rotation mechanism 50 then increases the rotational speed of the rotation motor 52, accelerating the rotation of the substrate W. Consequently, the processing liquid film formed on the upper surface of the substrate W is flung toward the outer side of the substrate W, thereby drying the substrate W (step S4).

When the drying process of the substrate W is complete, the rotation mechanism 50 stops the rotation motor 52, halting the rotation of the substrate W (step S5). The holder 40 then releases the substrate W from its grip using the plurality of chuck pins 42. The second transfer robot 222 then removes the processed substrate W from the holder 40 and carries it out of the processing chamber 30 (step S6).

Each processing unit 23 sequentially performs the above-mentioned steps S1 to S6 on the plurality of substrates W being transported.

<4. Regarding surveillance with intermittent coverage>

During the processing in step S3, the processing liquid ejected from the nozzle head 612 toward the center of the top surface of substrate W is diffused toward the periphery due to the rotation of substrate W. The liquid film formed on the top surface of substrate W gradually thins as it diffuses from the center toward the periphery. Therefore, during the processing in step S3, the liquid film may be interrupted at the periphery of substrate W, partially exposing the top surface of substrate W. This phenomenon is known as "coverage discontinuity." When coverage discontinuity occurs, the processing liquid is applied unevenly to the top surface of substrate W.

Therefore, the control unit 90 has the function of supplying the processing liquid from the processing liquid supply unit 60 to the upper surface of the substrate W while monitoring the occurrence of coating discontinuities based on the image data D obtained by the camera 84. This monitoring process is described below with reference to the flowchart in Figure 7.

In step S3, the control unit 90 first determines whether the nozzle head 612 has started discharging the treatment liquid (step S31). If the treatment liquid has not started discharging (step S31: No), the control unit 90 continues to wait for the nozzle head 612 to start discharging the treatment liquid. Then, if the treatment liquid supply starts (step S31: Yes), the control unit 90 starts imaging with the camera 84 (step S32).

The camera 84 captures the periphery of the substrate W held by the holder 40 via the half mirror 82, the window 33, and the first mirror 81. The field of view of the camera 84 can be set to encompass, for example, a 30 mm radius from the outer edge of the substrate W. The camera 84 outputs the acquired image data D to the control unit 90. The control unit 90 then receives the image data D sequentially output from the camera 84 (step S33).

The periphery of the substrate W rotates at high speed. Therefore, when coverage discontinuities occur on the periphery of the substrate W, the area where they occur also moves at high speed. Furthermore, the time it takes for a coverage discontinuity to occur can be very short. For example, the time it takes for a coverage discontinuity to occur can be as short as a few millimeters. However, using an event camera as the camera 84 allows for the acquisition of image data D at short intervals. This allows for accurate capture of coverage discontinuities occurring on the periphery of the substrate W. Furthermore, the image data D output from the event camera consists solely of information about pixels experiencing changes in brightness. Therefore, the control unit 90 can process the image data D at high speed while simultaneously processing the substrate W.

The control unit 90 checks the presence of cover discontinuities based on the image data D acquired from the camera 84 (step S34). Specifically, if the image data D contains no portions with varying brightness values, or if the portions with varying brightness values do not meet predetermined conditions, the control unit 90 determines that cover discontinuities have not occurred. Alternatively, if the image data D contains portions with varying brightness values that meet predetermined conditions, the control unit 90 determines that cover discontinuities have occurred.

If the control unit 90 determines that no coating interruption has occurred (step S34: No), it continues to discharge the treatment liquid from the nozzle head 612 while repeating the inspection process of steps S33 and S34.

On the other hand, if it is determined that a coating gap has occurred (step S34: Yes), the control unit 90 outputs an alarm (step S35). The alarm output may be, for example, a message displayed on the display unit 94, a buzzer sound, or the lighting of a lamp. Furthermore, if a coating gap is determined to have occurred, the control unit 90 may also stop processing the substrate W.

As described above, in the substrate processing apparatus 1 , the controller 90 operates the rotating mechanism 50 and the processing liquid supply unit 60 to supply processing liquid to the upper surface of the rotating substrate W while simultaneously capturing images of the periphery of the substrate W using the camera 84 . This allows the camera to capture the occurrence of coating discontinuities around the periphery of the substrate W.

The camera 84 is positioned outside the processing chamber 30. This helps suppress the generation of particles caused by the camera 84 within the processing space 31 within the processing chamber 30. Furthermore, by using the first reflective mirror 81, the periphery of the substrate W can be photographed from directly above. This allows for a wider range of the substrate W's top surface to be captured with the focus aligned compared to photographing the substrate W from an oblique angle. Furthermore, by photographing the periphery of the substrate W from directly above, multiple locations on the periphery of the substrate W can be placed at an even distance from the camera 84. Furthermore, the illumination light emitted from the illumination unit 83 can also be directed directly above the substrate W via the first reflective mirror 81, enabling clearer images of the periphery of the substrate W.

In particular, when the fan filter unit 34 is installed above the processing chamber 30, as in the processing unit 23 of this embodiment, it is difficult to install the camera 84 and the illumination unit 83 above the processing chamber 30. However, if a first reflective mirror 81 is disposed within the processing chamber 30, the camera 84 and the illumination unit 83 can be positioned on the side of the processing chamber 30. This allows the substrate W to be photographed from above while illuminating the upper surface of the substrate W through the first reflective mirror 81.

Furthermore, when the cup 70 is positioned around the substrate W in the processing unit 23 of this embodiment, it is difficult to capture images of the periphery of the substrate W from an oblique angle. However, if a first reflective mirror 81 is positioned within the processing chamber 30, a camera 84 and an illumination unit 83 can be positioned on the side of the processing chamber 30. This allows the substrate W to be photographed from above while illuminating the upper surface of the substrate W through the first reflective mirror 81.

Furthermore, the coverage discontinuity can be eliminated by increasing the amount of treatment liquid supplied from the treatment liquid supply section 60 to the upper surface of the substrate W. However, when a large amount of treatment liquid is used, the cost of the treatment liquid increases, and the burden of liquid drainage on the environment increases. Therefore, it is preferable to set the supply amount of treatment liquid from the treatment liquid supply section 60 to the minimum amount that does not produce coverage discontinuity. In this regard, the processing unit 23 of this embodiment supplies the treatment liquid while monitoring the occurrence of coverage discontinuity. The control section 90 can also adjust the supply amount of treatment liquid from the treatment liquid supply section 60 to the substrate W according to the occurrence of coverage discontinuity. This allows an appropriate amount of processing liquid to be supplied to the upper surface of the substrate W.

<5. Variations>

While one embodiment of the present invention has been described above, the present invention is not limited to this embodiment. The following describes various variations, focusing on the differences from the above embodiment.

<5-1. First variant>

Figure 8 is a longitudinal cross-sectional view of the processing unit 23 according to the first modification. In the example of Figure 8 , the imaging unit 80 includes a second mirror 85 . The second mirror 85 is located outside the processing chamber 30 . The second mirror 85 is positioned on the optical path L2, on the camera 84 side of the two optical paths L1 and L2 branched by the half mirror 82 . The camera 84 captures the periphery of the substrate W through the second mirror 85 , the half mirror 82 , the window 33 , and the first mirror 81 .

Using the second reflective mirror 85 in this manner increases the flexibility of camera 84 placement. Furthermore, since the second reflective mirror 85 is located outside the processing chamber 30, it can use a reflective surface made of silver or aluminum with high reflectivity. Specifically, while the first reflective mirror 81 inside the processing chamber 30 is made of silicon wafers, which are less susceptible to particle generation, the second reflective mirror 85 outside the processing chamber 30 is made of silver or aluminum with high reflectivity. This allows for clear images of the periphery of the substrate W while minimizing contamination of the substrate W.

<5-2. Other variations>

In the above embodiment, the imaging unit 80 includes a half mirror 82. Using the half mirror 82 allows the optical axis of the illumination unit 83 to align with the optical axis of the camera 84. However, the imaging unit 80 does not need to include the half mirror 82. The illumination unit 83 may also emit illumination light from a position slightly offset from the optical path L0 between the camera 84 and the first reflector 81.

In the above embodiment, a silicon wafer is used as the first reflector 81. However, the first reflector 81 is not limited to a silicon wafer. For example, the first reflector 81 may be a conventional reflector having a reflective surface made of silver or aluminum molded with transparent resin.

In the above embodiment, one first reflective mirror 81 is disposed in the processing chamber 30. However, two or more first reflective mirrors 81 may be disposed in the processing chamber 30. Furthermore, the camera 84 may capture the periphery of the upper surface of the substrate W through a plurality of first reflective mirrors 81.

Furthermore, in the above embodiment, an event camera is used as camera 84. However, a frame-based camera or a high-speed camera may be used instead of the event camera.

Furthermore, in the above embodiment, the control unit 90 has been described as detecting coverage discontinuities, which are likely to occur around the periphery of the substrate W. However, the control unit 90 can also detect events other than coverage discontinuities based on the image data D output from the camera 84.

Furthermore, the various elements in the above-mentioned embodiments or variations may be arbitrarily combined within the scope of no contradiction.

23: Processing unit

30: Processing Room

31: Processing Space

32: Next door

33: Window

34: Fan filter unit

35: Exhaust duct

40: Maintenance Department

41: Rotating base

42: Chuck pin

43: Chuck pin switching mechanism

50: Rotating mechanism

51: Motor cover

52: Rotary Motor

53: Support shaft

60: Treatment fluid supply unit

61: Spit out the nozzle

70: Cup body

71: Inner cup

72: Medium cup

73: Outer cup

80: Camera Department

81: 1st Reflector

82: Half-reflective mirror

83:Lighting Department

84: Camera

90: Control Department

321: Sidewall

322: Top plate

323: Bottom plate

530: Rotation axis

611: Nozzle Arm

612: Nozzle

710: First guide plate

711: 1st drain tank

712: 2nd drain tank

713: 3rd drain tank

720: Second guide plate

730: 3rd guide plate

D:Photographic data

L0: Optical Path

L1: Optical Path

L2: Optical Path

W: substrate

Claims (10)

A substrate processing apparatus processes a substrate using a processing liquid. The apparatus comprises: a processing chamber having a partition wall and a window portion, wherein the partition wall defines a processing space for processing the substrate, and the window portion is provided in a portion of the partition wall; a holding portion for holding the substrate in a horizontal position within the processing chamber; a rotating mechanism for rotating the holding portion about a rotation axis extending in a vertical direction; a processing liquid supply portion for supplying processing liquid to the upper surface of the substrate held by the holding portion to form a liquid film on the upper surface of the substrate; a first reflecting mirror located within the processing chamber and above the periphery of the substrate held by the holding portion; A camera located outside the processing chamber and configured to capture images of the periphery of the substrate through the window and the first reflective mirror; and a control unit configured to control the rotating mechanism, the processing liquid supply unit, and the camera. The control unit controls the camera while operating the rotating mechanism and the processing liquid supply unit. The substrate processing apparatus of claim 1 further comprises: An illumination unit located outside the processing chamber and irradiating light toward a peripheral portion of the substrate via the window and the first reflective mirror. The substrate processing apparatus of claim 2 further comprises: a semi-reflecting mirror located outside the processing chamber; the illumination unit is disposed on one of the two optical paths branched by the semi-reflecting mirror; the camera is disposed on the other of the two optical paths branched by the semi-reflecting mirror. The substrate processing apparatus of claim 1, wherein: the substrate is a silicon wafer, and the first reflective mirror is also a silicon wafer. The substrate processing apparatus of claim 4 further comprises: a second reflective mirror located outside the processing chamber, the reflective surface of the mirror being silver or aluminum; the camera photographs the periphery of the substrate via the second reflective mirror, the window, and the first reflective mirror. The substrate processing apparatus of claim 1, wherein: the camera is an event camera. The substrate processing apparatus of claim 1 further comprises: A fan filter unit disposed above the processing chamber. The substrate processing apparatus of claim 1 further comprises: A cup body, located within the processing chamber and surrounding the substrate held by the holding portion. The substrate processing apparatus of any one of claims 1 to 8, wherein the control unit detects the occurrence of coverage discontinuities on the upper surface of the substrate based on imaging data obtained from the camera. A substrate processing method is a method for treating a substrate with a processing liquid. The method comprises performing the following processes (a) and (b): (a) rotating the substrate held in a horizontal position about a rotation axis extending in a vertical direction within a processing chamber having a partition wall defining a processing space for processing the substrate, while supplying a processing liquid to the upper surface of the substrate, thereby forming a liquid film on the upper surface of the substrate; and (b) photographing the peripheral portion of the substrate while performing the process (a). In the above process (b), a camera located outside the processing chamber captures the periphery of the substrate through a window and a first reflecting mirror. The window is provided in the partition wall, and the first reflecting mirror is located above the periphery of the substrate within the processing chamber.