SUBSTRATE PROCESSING APPARATUS AND GUARD DETERMINATION METHOD

Abstract

To provide technology capable of detecting anomaly regarding a guard with higher accuracy.SOLUTION: A substrate processing device includes: a substrate holding part for holding a substrate; a liquid nozzle for supplying process liquid to a substrate being hold by the substrate holding part; a cylindrical guard surrounding the substrate holding part for accepting process liquid splashed from the peripheral edge of the substrate; a guard lifting mechanism for raising or lowering the guard; a camera 70 provided diagonally above the substrate holding part for generating a captured image by capturing an imaging region including the guard; and a control part 9 for outputting a control signal to the guard lifting mechanism for moving the guard to a predetermined height position and determining existence of anomaly regarding position or shape of the guard based on the captured image.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus and a guard determination method. [Background technology]

[0002] Conventionally, in manufacturing processes for semiconductor devices and the like, various processing liquids such as pure water, photoresist liquid, and etching liquid are supplied to substrates to perform various substrate processing processes such as cleaning processing and resist coating processing. As an apparatus for performing substrate processing using these processing liquids, a substrate processing apparatus that rotates the substrate in a horizontal position and ejects the processing liquid from a nozzle onto the surface of the substrate has been widely used.

[0003] In such substrate processing apparatuses, it is necessary to check whether or not a processing liquid is being discharged from the nozzles. As a method for determining whether or not a processing liquid is being discharged, for example, Patent Documents 1 and 2 propose providing an imaging means such as a camera to monitor the discharge of the processing liquid from the nozzles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-135679 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-173148 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to properly process a substrate, it is desirable to monitor not only the processing liquid but also many other monitoring targets.

[0006] For example, a substrate processing apparatus is provided with a guard for receiving processing liquid splashed from the periphery of a substrate. The guard has a cylindrical shape and can surround the substrate. The guard is provided so as to be able to rise and fall, and is lowered when the substrate is being loaded or unloaded. This makes it possible to avoid collision between the guard and a transport robot that loads or unloads the substrate into or from the substrate processing apparatus. When the processing liquid is supplied to the surface of the substrate, the guard rises. As the guard is raised, the upper peripheral edge of the guard is positioned above the substrate. Therefore, processing liquid splashed from the periphery of the substrate is received by the inner peripheral surface of the guard.

[0007] If an abnormality occurs and the guard cannot move to the appropriate position, it may become impossible to properly avoid a collision between the guard and the transport robot, or the guard may not be able to properly receive the processing liquid.

[0008] To detect such guard position abnormalities, an internal sensor in the guard lifting mechanism that raises and lowers the guard can be used. For example, if the guard lifting mechanism includes a power relay mechanism such as a ball screw mechanism and a power source such as a motor, an encoder that detects the motor's rotational position can be used to detect position abnormalities. However, if the motor loses synchronization or an abnormality occurs in the ball screw mechanism, the correspondence between the motor's rotational position and the guard position changes, reducing the accuracy of guard position detection. This also reduces the accuracy of guard position abnormality detection.

[0009] Furthermore, if the guard is deformed due to an abnormality, the transfer robot may collide with the hand, or the guard may not be able to properly receive the processing liquid.

[0010] Therefore, an object of the present disclosure is to provide a technology that can detect guard-related abnormalities with higher accuracy. [Means for solving the problem]

[0013] No. 1 The embodiment of a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image, and the control unit determines whether or not there is an abnormality based on a determination area in the captured image that includes a part of the guard,The judgment area includes a first judgment area and a second judgment area, and the first judgment area and the second judgment area are set on opposite sides of the minor axis of a virtual ellipse along the upper peripheral edge of the guard in the captured image, and the control unit determines that the guard is normal when it provisionally determines that the guard is normal in both the first judgment area and the second judgment area.

[0014] No. 2 The embodiment of a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image, and the control unit determines whether or not there is an abnormality based on a determination area in the captured image that includes a part of the guard, The determination area is set to an area that includes at least a portion of the upper peripheral edge of the guard when it is located at the predetermined height position, but does not include the substrate.

[0015] No. 3 The embodiment of a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image, and the control unit determines whether or not there is an abnormality based on a determination area in the captured image that includes a part of the guard, The specified height position is a guard standby position where the upper peripheral edge of the guard is lower than the upper surface of the spin base of the substrate holding part, which is vertically opposite the underside of the substrate, and the judgment area is set to an area that includes at least a portion of the peripheral portion of the upper peripheral edge of the guard when positioned at the specified height position, which is on the front side as seen from the camera.

[0016] No. 4 The embodiment of a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image, and the control unit determines whether or not there is an abnormality based on a determination area in the captured image that includes a part of the guard, The specified height position is a guard processing position where the upper edge of the guard is higher than the top surface of the substrate held by the substrate holding part, and the judgment area is set to an area that includes the innermost edge portion of the upper edge of the guard when positioned at the specified height position, as seen from the camera.

[0017] No. 5 The embodiment is 4 In this substrate processing apparatus, the control unit moves at least one of the multiple guards to the guard processing position, and the judgment area is set to an area that includes the upper peripheral portions of the multiple guards when the multiple guards are positioned at their respective guard processing positions.

[0018] No. 6The embodiment is 1 From 5 In a substrate processing apparatus according to any one of the above aspects, the control unit determines that the guard is normal when the similarity between the determination area and a normal reference image is equal to or greater than a threshold value, and the threshold value is set lower than the value of the similarity between the determination area of ​​the image captured when the guard is located at the predetermined height position and liquid droplets are attached to the guard and the reference image.

[0019] No. 7 The embodiment of a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holding part; a cylindrical guard for surrounding the substrate holding part and receiving the processing liquid splashed from the periphery of the substrate; a guard lifting mechanism for raising and lowering the guard; a camera disposed obliquely above the substrate holding part for capturing an image of an image capturing area including the guard to generate an image; and a control unit for outputting a control signal for moving the guard to a predetermined height position to the guard lifting mechanism and determining whether or not there is an abnormality in the position or shape of the guard based on a determination area in the image that includes a part of the guard. The guard The outer peripheral surface of the object part is included in the judgment area. Gas is supplied to the guard The part of the image Gas nozzle that blows off droplets attached to the surface and can.

[0020] No. 8 The embodiment of a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holding part; a cylindrical guard for surrounding the substrate holding part and receiving the processing liquid splashed from the periphery of the substrate; a guard lifting mechanism for raising and lowering the guard; a camera disposed obliquely above the substrate holding part for capturing an image of an image capturing area including the guard to generate an image; and a control unit for outputting a control signal for moving the guard to a predetermined height position to the guard lifting mechanism and determining whether or not there is an abnormality in the position or shape of the guard based on a determination area in the image that includes a part of the guard. A gas nozzle that supplies gas to the guard to blow off droplets adhering to the guard. and The control unit includes a first step of determining that the guard is normal when a similarity between the determination area and a normal reference image is equal to or greater than a second threshold value that is higher than a first threshold value; a second step of causing the gas nozzle to supply gas toward a portion of the guard that is captured in the determination area when the similarity is less than the second threshold value and equal to or greater than the first threshold value; a third step of causing the camera to capture an image of the capture area and generate the captured image after the second step; and a third step of determining whether the guard is normal based on the similarity between the determination area and the reference image in the captured image generated in the third step. and a fourth step of determining whether or not there is an abnormality based on the first threshold value. The first threshold value is set lower than a first value of the similarity between the reference image and the determination area of ​​the captured image taken when the guard is located at the predetermined height and there are liquid droplets on the captured portion of the guard, and the second threshold value is set lower than a second value of the similarity between the reference image and the determination area of ​​the captured image taken when the guard is located at the predetermined height and there are no liquid droplets on the captured portion of the guard, and higher than the first value.

[0023] No. 9 The embodiment of A guard determination method comprising: a guard lifting / lowering step of moving a cylindrical guard surrounding a substrate holding part for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard using a camera provided above the substrate holding part to generate an image; and a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image, wherein in the determination step, the presence or absence of the abnormality is determined based on a determination area in the captured image that includes a part of the guard, The judgment area includes a first judgment area and a second judgment area, and the first judgment area and the second judgment area are set on opposite sides of the minor axis of a virtual ellipse along the upper peripheral edge of the guard in the captured image, and in the judgment process, when it is provisionally determined that the guard is normal in both the first judgment area and the second judgment area, the guard is determined to be normal.

[0024] No. 10 The embodiment of A guard determination method comprising: a guard lifting / lowering step of moving a cylindrical guard surrounding a substrate holding part for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard using a camera provided above the substrate holding part to generate an image; and a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image, wherein in the determination step, the presence or absence of the abnormality is determined based on a determination area in the captured image that includes a part of the guard, The determination area is set to an area that includes at least a portion of the upper peripheral edge of the guard when it is located at the predetermined height position, but does not include the substrate.

[0025] No. 11 The embodiment of A guard determination method comprising: a guard lifting / lowering step of moving a cylindrical guard surrounding a substrate holding part for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard using a camera provided above the substrate holding part to generate an image; and a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image, wherein in the determination step, the presence or absence of the abnormality is determined based on a determination area in the captured image that includes a part of the guard, The specified height position is a guard standby position where the upper peripheral edge of the guard is lower than the upper surface of the spin base of the substrate holding part, which is vertically opposite the underside of the substrate, and the judgment area is set to an area that includes at least a portion of the peripheral portion of the upper peripheral edge of the guard when positioned at the specified height position, which is on the front side as seen from the camera.

[0026] No. 12 The embodiment of A guard determination method comprising: a guard lifting / lowering step of moving a cylindrical guard surrounding a substrate holding part for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard using a camera provided above the substrate holding part to generate an image; and a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image, wherein in the determination step, the presence or absence of the abnormality is determined based on a determination area in the captured image that includes a part of the guard, The specified height position is a guard processing position where the upper edge of the guard is higher than the top surface of the substrate held by the substrate holding part, and the judgment area is set to an area that includes the innermost edge portion of the upper edge of the guard when positioned at the specified height position, as seen from the camera.

[0027] No. 13 The embodiment is 12 In the guard raising / lowering process, at least one of the plurality of guards is moved to the guard processing position, and the judgment area is set to an area including the upper peripheral portions of the plurality of guards when the plurality of guards are positioned at their respective guard processing positions.

[0028] No. 14 The embodiment is 9 From 13 A guard judgment method according to any one of the above aspects, wherein in the judgment step, the guard is judged to be normal when the similarity between the judgment area and a normal reference image is equal to or greater than a threshold value, and the threshold value is set lower than the value of the similarity between the judgment area of ​​the image captured when the guard is located at the specified height position and liquid droplets are attached to the guard and the reference image.

[0029] No. 15 The embodiment of The guard determination method includes a guard lifting / lowering step of moving a cylindrical guard surrounding a substrate holding part for holding a substrate to a predetermined height position, an imaging step of capturing an image of an imaging area including the guard with a camera provided above the substrate holding part to generate a captured image, and a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on a determination area including a part of the guard in the captured image, Prior to the imaging step, the guard and a gas is supplied to the object portion of the guard, the object portion being imaged in the determination area. Droplets attached to Blow The method further includes a blowing gas supply step.

[0030] No. 16 The embodiment of A guard determination method comprising: a guard lifting / lowering step of moving a cylindrical guard surrounding a substrate holding part for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard using a camera provided above the substrate holding part to generate an image; and a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image, wherein in the determination step, the presence or absence of the abnormality is determined based on a determination area in the captured image that includes a part of the guard, The determination process includes a first process of determining that the guard is normal when the similarity between the determination area and a normal reference image is equal to or greater than a second threshold value that is higher than a first threshold value; a second process of supplying gas to a portion of the guard that is captured in the determination area when the similarity is less than the second threshold value and equal to or greater than the first threshold value; a third process of using the camera to capture an image of the imaged area and generate the captured image after the second process; and a fourth process of determining whether or not there is an abnormality based on the similarity between the determination area of ​​the imaged image generated in the third process and the reference image, wherein the first threshold value is set lower than a first value of similarity between the reference image and the determination area of ​​the imaged image captured when the guard is located at the predetermined height position and liquid droplets are attached to the portion of the guard that is captured; and the second threshold value is set lower than a second value of similarity between the reference image and the determination area of ​​the imaged image captured when the guard is located at the predetermined height position and no liquid droplets are attached to the portion of the guard that is captured, but higher than the first value. [Effects of the Invention]

[0031] 1st and 2nd 9 According to this aspect, the presence or absence of an abnormality is determined based on a captured image including the guard, so that the presence or absence of an abnormality can be determined with higher accuracy.

[0032] Also, Since the configuration included in the area other than the judgment area does not affect the judgment, the presence or absence of an abnormality can be judged with higher accuracy.

[0033] Also, This can improve the accuracy of the determination. For example, if the guard is tilted, the guard may be provisionally determined to be normal in one of the first and second determination areas, but provisionally determined to be abnormal in the other. According to the third and thirteenth aspects, even in this case, the guard is correctly determined to be abnormal. This improves the accuracy of the determination.

[0034] No. 2 and 10 According to the aspect (3), since the substrate is not included, the accuracy of the determination is not affected by the presence or absence of the substrate, and the presence or absence of an abnormality can be determined with high accuracy.

[0035] No. 3 and 11 According to this aspect, it is easy to set the determination area to an area that does not include the substrate and that includes the upper peripheral edge of the guard.

[0036] No. 4 and 12 According to this aspect, it is easy to set the determination area to an area that does not include the substrate and that includes the upper peripheral edge of the guard.

[0037] No. 5 and 13 According to this aspect, the determination region is set to an area that includes the upper peripheral edges of the multiple guards, so that it is possible to determine whether or not there is an abnormality in the multiple guards.

[0038] No. 6 , th 7 , th 14 and 15According to this aspect, it is possible to suppress erroneous determination due to droplets.

[0039] No. 8 and 16 According to this aspect, if the similarity is less than the second threshold and greater than or equal to the first threshold, there is a possibility that no abnormality has occurred and that droplets are attached to the imaged portion. In this situation, gas is supplied to the imaged portion of the guard. Therefore, if droplets are attached to the imaged portion, the droplets are blown away by the gas. Then, in the third step, a captured image can be obtained in a state where no droplets are attached to the imaged portion, so that in the fourth step, the presence or absence of an abnormality can be determined with higher accuracy.

[0040] Furthermore, since gas is supplied in a situation where there is a possibility that droplets may be attached, the amount of gas consumed can be reduced. [Brief explanation of the drawings]

[0041] [Figure 1] FIG. 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus. [Figure 2] FIG. 2 is a plan view schematically illustrating an example of the configuration of a processing unit. [Figure 3] FIG. 2 is a longitudinal sectional view schematically illustrating an example of the configuration of a processing unit. [Figure 4] FIG. 2 is a functional block diagram illustrating an example of an internal configuration of a control unit. [Figure 5] 1 is a flowchart showing an example of a flow of substrate processing. [Figure 6] FIG. 2 is a diagram schematically illustrating an example of the state inside a processing unit during chemical liquid processing. [Figure 7] 10 is a flowchart illustrating an example of guard monitoring processing according to the first embodiment. [Figure 8] FIG. 2 is a diagram schematically illustrating an example of a captured image. [Figure 9] FIG. 2 is a diagram schematically illustrating an example of a captured image. [Figure 10] 10 is a flowchart showing an example of a more specific operation of a determination step. [Figure 11] 10A and 10B are diagrams illustrating an example of a captured image when the middle guard and the outer guard are stopped at their respective guard processing positions. [Figure 12] 10A and 10B are diagrams illustrating an example of a captured image when the inner guard, the middle guard, and the outer guard are stopped at their respective guard processing positions. [Figure 13] 10 is a diagram schematically illustrating an example of a captured image when droplets adhere to the outer peripheral surface of the guard portion. FIG. [Figure 14] 10 is a bar graph schematically showing the similarity as an experimental result. [Figure 15] FIG. 10 is a diagram illustrating an example of a configuration of a processing unit according to a second embodiment. [Figure 16] 10 is a flowchart illustrating an example of guard monitoring processing according to the second embodiment. [Figure 17] 10 is a flowchart showing a modified example of guard monitoring processing according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0042] Hereinafter, embodiments will be described with reference to the accompanying drawings. Note that the drawings are schematic, and for the sake of convenience, components may be omitted or simplified as appropriate. Furthermore, the relative sizes and positions of components shown in the drawings are not necessarily accurately depicted and may be changed as appropriate.

[0043] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0044] Furthermore, in the following description, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the ordering that may result from these ordinal numbers.

[0045] When expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless otherwise specified, the expressions not only strictly represent the positional relationship but also represent a state in which there is a relative displacement in terms of angle or distance within a range in which tolerance or equivalent functionality is obtained. When expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) are used, the expressions not only represent a state in which there is strict quantitative equality but also represent a state in which there is a difference in which tolerance or equivalent functionality is obtained, unless otherwise specified. When expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, the expressions not only represent a geometrically strict shape but also represent a shape with, for example, irregularities or chamfers within a range in which equivalent effects are obtained, unless otherwise specified. When the expressions "comprise," "include," "have," "includes," "includes," or "have" are used to describe one component, the expressions are not exclusive expressions that exclude the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0046] First Embodiment <Overall configuration of substrate processing equipment> FIG. 1 is a plan view schematically illustrating an example of the configuration of a substrate processing apparatus 100. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W to be processed one by one. The substrate processing apparatus 100 performs liquid processing on the substrates W using a chemical solution and a rinse solution such as pure water, and then performs a drying process. The substrate W is, for example, a semiconductor substrate and has a disk shape. Examples of the chemical solution include a mixed solution (SC1) of ammonia and hydrogen peroxide, a mixed aqueous solution (SC2) of hydrochloric acid and hydrogen peroxide, or a DHF solution (dilute hydrofluoric acid). In the following description, the chemical solution, rinse solution, organic solvent, etc. are collectively referred to as the "processing solution." It should be noted that the "processing solution" includes not only chemical solutions used in cleaning processes, but also chemical solutions for removing unnecessary films and chemical solutions for etching.

[0047] The substrate processing apparatus 100 includes a plurality of processing units 1, a load port LP, an indexer robot 102, a main transport robot 103, and a control unit 9.

[0048] The load port LP is an interface unit for loading and unloading substrates W between the substrate processing apparatus 100 and the outside. A container (also called a carrier) containing a plurality of unprocessed substrates W is loaded into the load port LP from the outside. The load port LP can hold a plurality of carriers. Each substrate W is removed from the carrier by the substrate processing apparatus 100, processed as described below, and then stored back in the carrier. The carrier containing the processed substrates W is then unloaded from the load port LP to the outside.

[0049] The carrier may be a FOUP (Front Opening Unified Pod) that stores the substrate W in a sealed space, a SMIF (Standard Mechanical Interface) pod, or an OC (Open Cassette) that exposes the substrate W to the outside air.

[0050] The indexer robot 102 transports the substrates W between each carrier held on the load port LP and the main transport robot 103. The main transport robot 103 transports the substrates W between each processing unit 1 and the indexer robot 102.

[0051] Each processing unit 1 performs liquid processing and drying processing on one substrate W. The substrate processing apparatus 100 according to this embodiment is provided with 12 processing units 1 of similar configuration. Specifically, four towers, each including three processing units 1 stacked vertically, are arranged around the main transport robot 103. FIG. 1 shows a schematic diagram of one of the processing units 1 stacked in three tiers. The number of processing units 1 in the substrate processing apparatus 100 is not limited to 12 and may be changed as appropriate.

[0052] The main transport robot 103 is installed in the center of four towers in which processing units 1 are stacked. The main transport robot 103 carries the substrates W to be processed received from the indexer robot 102 into each processing unit 1. The main transport robot 103 also carries out processed substrates W from each processing unit 1 and hands them over to the indexer robot 102. The control unit 9 controls the operation of each component of the substrate processing apparatus 100.

[0053] One of the twelve processing units 1 mounted on the substrate processing apparatus 100 will be described below, but the other processing units 1 have the same configuration except that the nozzle arrangements are different.

[0054] <Processing unit> Fig. 2 is a plan view schematically showing an example of the configuration of the processing unit 1. Fig. 3 is a vertical cross-sectional view schematically showing an example of the configuration of the processing unit 1.

[0055] The processing unit 1 includes, within a chamber 10, a spin chuck 20 which is an example of a substrate holding part, a first nozzle 30, a second nozzle 30A and a third nozzle 30B which are examples of liquid nozzles, a guard part 40 and a camera 70.

[0056] The chamber 10 includes a sidewall 11 extending in the vertical direction, a ceiling wall 12 that closes the upper side of the space enclosed by the sidewall 11, and a floor wall 13 that closes the lower side. The space enclosed by the sidewall 11, the ceiling wall 12, and the floor wall 13 forms a processing space. In addition, a part of the sidewall 11 of the chamber 10 is provided with a loading / unloading entrance through which the main transport robot 103 loads and unloads the substrate W, and a shutter that opens and closes the loading / unloading entrance (both not shown).

[0057] A fan filter unit (FFU) 14 is attached to the ceiling wall 12 of the chamber 10 to further purify the air within the clean room in which the substrate processing apparatus 100 is installed and supply the purified air to the processing space within the chamber 10. The fan filter unit 14 includes a fan and a filter (e.g., a HEPA (High Efficiency Particulate Air) filter) for taking in air within the clean room and sending it into the chamber 10, and forms a downflow of purified air in the processing space within the chamber 10. A punched plate with a large number of blow-out holes may be provided directly below the ceiling wall 12 to uniformly distribute the purified air supplied from the fan filter unit 14.

[0058] The spin chuck 20 holds the substrate W in a horizontal position (a position in which the normal is aligned vertically). The spin chuck 20 includes a disk-shaped spin base 21 fixed in a horizontal position to the upper end of a rotation shaft 24 extending vertically. A spin motor 22 that rotates the rotation shaft 24 is provided below the spin base 21. The spin motor 22 rotates the spin base 21 in a horizontal plane via the rotation shaft 24. A cylindrical cover member 23 is provided to surround the periphery of the spin motor 22 and the rotation shaft 24.

[0059] The outer diameter of the disk-shaped spin base 21 is slightly larger than the diameter of the circular substrate W held by the spin chuck 20. Therefore, the spin base 21 has an upper surface 21a that faces the entire lower surface of the substrate W to be held in the vertical direction.

[0060] A plurality of chuck pins 26 (four in this embodiment) are erected on the peripheral edge of the upper surface 21a of the spin base 21. The chuck pins 26 are arranged at equal intervals (at 90° intervals in the case of four chuck pins 26 as in this embodiment) along a circumference corresponding to the peripheral edge of the circular substrate W. Each chuck pin 26 is drivable between a holding position in contact with the peripheral edge of the substrate W and an open position spaced apart from the peripheral edge of the substrate W. The chuck pins 26 are driven in conjunction with each other by a link mechanism (not shown) housed in the spin base 21. The spin chuck 20 can hold the substrate W in a horizontal position close to the upper surface 21a above the spin base 21 by stopping the chuck pins 26 at their respective contact positions (see FIG. 3), and can release the substrate W by stopping the chuck pins 26 at their respective open positions.

[0061] The cover member 23 that covers the spin motor 22 has its lower end fixed to the floor wall 13 of the chamber 10 and its upper end reaching directly below the spin base 21. A flange-shaped member 25 is provided at the upper end of the cover member 23, which projects outward from the cover member 23 almost horizontally and then bends downward. With the spin chuck 20 holding the substrate W by means of a plurality of chuck pins 26, the spin motor 22 rotates the rotation shaft 24, thereby rotating the substrate W about a rotation axis CX that runs vertically through the center of the substrate W. The driving of the spin motor 22 is controlled by the control unit 9.

[0062] The first nozzle 30 ejects a processing liquid toward the substrate W to supply the processing liquid to the substrate W. In the example of FIG. 2, the first nozzle 30 is configured by attaching an ejection head 31 to the tip of a nozzle arm 32. The base end of the nozzle arm 32 is fixedly connected to a nozzle base 33. The nozzle base 33 is rotatable about a vertical axis by a motor (not shown). As the nozzle base 33 rotates, the first nozzle 30 moves in an arc between a nozzle processing position and a nozzle standby position in the space above the spin chuck 20, as indicated by arrow AR34 in FIG. 2. The nozzle processing position is a position where the first nozzle 30 ejects the processing liquid onto the substrate W, for example, a position vertically opposite the center of the substrate W. The nozzle standby position is a position where the first nozzle 30 does not eject the processing liquid onto the substrate W, for example, a position radially outward from the periphery of the substrate W. The radial direction here refers to a radial direction about the rotation axis CX.

[0063] 3, the first nozzle 30 is connected to a processing liquid supply source 36 via a supply pipe 34. The processing liquid supply source 36 includes a tank that stores the processing liquid. A valve 35 is provided on the supply pipe 34. When the valve 35 is opened, the processing liquid supply source 36 supplies the processing liquid to the first nozzle 30 through the supply pipe 34, and the processing liquid is ejected from the ejection port of the first nozzle 30. Note that the first nozzle 30 may be configured to be supplied with a plurality of types of processing liquid (including at least pure water).

[0064] In addition to the first nozzle 30, the processing unit 1 of this embodiment is also provided with a second nozzle 30A and a third nozzle 30B. The second nozzle 30A and the third nozzle 30B of this embodiment have the same configuration as the first nozzle 30. That is, the second nozzle 30A is configured by attaching a discharge head 31A to the tip of a nozzle arm 32A. The second nozzle 30A moves in an arc in the space above the spin chuck 20 as indicated by arrow AR64 by a nozzle base 33A connected to the base end of the nozzle arm 32A. Similarly, the third nozzle 30B is configured by attaching a discharge head 31B to the tip of a nozzle arm 32B. The third nozzle 30B moves in an arc in the space above the spin chuck 20 as indicated by arrow AR69 by attaching a nozzle base 33B connected to the base end of the nozzle arm 32B.

[0065] Like the first nozzle 30, the second nozzle 30A and the third nozzle 30B are each connected to a processing liquid supply source (not shown) via a supply pipe (not shown). Each supply pipe is provided with a valve, and the supply / stop of the processing liquid is switched by opening and closing the valve. The number of nozzles provided in the processing unit 1 is not limited to three, and may be one or more.

[0066] In liquid processing, the processing unit 1 rotates the substrate W using the spin chuck 20 while ejecting a processing liquid from, for example, the first nozzle 30 toward the upper surface of the substrate W. The processing liquid that has landed on the upper surface of the substrate W spreads over the upper surface of the substrate W due to centrifugal force caused by the rotation and is scattered from the periphery of the substrate W. This liquid processing allows the upper surface of the substrate W to be processed in accordance with the type of processing liquid.

[0067] The guard portion 40 is a member for receiving the processing liquid splashed from the periphery of the substrate W. The guard portion 40 has a cylindrical shape surrounding the spin chuck 20 and includes, for example, a plurality of guards that can be raised and lowered independently of each other. In the example of Fig. 3, the multiple guards are shown as an inner guard 41, a middle guard 42, and an outer guard 43. The guards may also be called processing cups.

[0068] The inner guard 41 surrounds the periphery of the spin chuck 20 and has a shape that is substantially rotationally symmetrical with respect to the rotation axis CX that passes through the center of the substrate W held by the spin chuck 20. The inner guard 41 integrally includes a bottom portion 44 that is annular in plan view, a cylindrical inner wall portion 45 that rises upward from the inner peripheral edge of the bottom portion 44, a cylindrical outer wall portion 46 that rises upward from the outer peripheral edge of the bottom portion 44, a first guide portion 47 that rises from the bottom portion 44 between the inner wall portion 45 and the outer wall portion 46 and extends obliquely upward toward the center (in the direction approaching the rotation axis CX of the substrate W held by the spin chuck 20) ​​while describing a smooth arc at its upper end, and a cylindrical middle wall portion 48 that rises upward from the bottom 44 between the first guide portion 47 and the outer wall portion 46.

[0069] The inner wall portion 45 is formed to have a length such that it can be housed with an appropriate gap between the cover member 23 and the flange-shaped member 25 when the inner guard 41 is in its most raised position. The middle wall portion 48 is formed to have a length such that it can be housed with an appropriate gap between a second guide portion 52 (described later) of the middle guard 42 and the processing liquid separation wall 53 when the inner guard 41 and the middle guard 42 are in their closest positions.

[0070] The first guide portion 47 has an upper end portion 47b that extends obliquely upward toward the center (toward the rotation axis CX of the substrate W) while describing a smooth arc. A waste groove 49 is formed between the inner wall portion 45 and the first guide portion 47 to collect and discard used processing liquid. A circular inner recovery groove 50 is formed between the first guide portion 47 and the middle wall portion 48 to collect and recover used processing liquid. A circular outer recovery groove 51 is formed between the middle wall portion 48 and the outer wall portion 46 to collect and recover a different type of processing liquid from the inner recovery groove 50.

[0071] A liquid exhaust mechanism (not shown) is connected to the waste groove 49 to discharge the processing liquid collected in the waste groove 49 and to forcibly exhaust the air inside the waste groove 49. For example, four liquid exhaust mechanisms are provided at equal intervals around the circumference of the waste groove 49. In addition, recovery mechanisms (both not shown) are connected to the inner recovery groove 50 and the outer recovery groove 51 to recover the processing liquid collected in the inner recovery groove 50 and the outer recovery groove 51 to recovery tanks provided outside the processing unit 1. The bottoms of the inner recovery groove 50 and the outer recovery groove 51 are inclined at a slight angle with respect to the horizontal, and the recovery mechanism is connected to the lowest point. This allows the processing liquid that has flowed into the inner recovery groove 50 and the outer recovery groove 51 to be smoothly recovered.

[0072] The middle guard 42 surrounds the periphery of the spin chuck 20 and has a shape that is substantially rotationally symmetrical with respect to the rotation axis CX that passes through the center of the substrate W held by the spin chuck 20. The middle guard 42 integrally includes a second guide portion 52 and a cylindrical processing liquid separation wall 53 connected to the second guide portion 52.

[0073] The second guide portion 52 is located outside the first guide portion 47 of the inner guard 41 and has a lower end portion 52a that is cylindrical and coaxial with the lower end portion of the first guide portion 47, and an upper end portion 52b that extends obliquely upward toward the center (toward the rotation axis CX of the substrate W) while drawing a smooth arc from the upper end of the lower end portion 52a. When the inner guard 41 and the middle guard 42 are in the closest position, the lower end portion 52a is accommodated in the inner recovery groove 50 with an appropriate gap maintained between the first guide portion 47 and the middle wall portion 48. Furthermore, the upper end portion 52b is arranged to overlap the upper end portion 47b of the first guide portion 47 of the inner guard 41 in the vertical direction, and when the inner guard 41 and the middle guard 42 are in the closest position, it is in close proximity to the upper end portion 47b of the first guide portion 47 with a very small gap maintained. Although different from FIG. 3, a folded portion formed by folding the tip of the upper end portion 52b downward may be provided. The folded portion has a length that allows it to overlap the tip of the upper end portion 47b of the first guide portion 47 in the horizontal direction when the inner guard 41 and the middle guard 42 are in the closest position.

[0074] The upper end 52b of the second guide portion 52 is formed so that its thickness increases downward, and the processing liquid separation wall 53 has a cylindrical shape that extends downward from the outer peripheral edge of the lower end of the upper end 52b. The processing liquid separation wall 53 is accommodated in the outer recovery groove 51 with an appropriate gap maintained between the middle wall portion 48 and the outer guard 43 when the inner guard 41 and the middle guard 42 are closest to each other.

[0075] The outer guard 43 surrounds the periphery of the spin chuck 20 outside the second guide portion 52 of the middle guard 42 and has a shape that is substantially rotationally symmetrical with respect to the rotation axis CX that passes through the center of the substrate W held on the spin chuck 20. This outer guard 43 functions as a third guide portion. The outer guard 43 has a lower end portion 43a that is cylindrical and coaxial with the lower end portion 52a of the second guide portion 52, and an upper end portion 43b that extends obliquely upward from the upper end of the lower end portion 43a toward the center (in the direction approaching the rotation axis CX of the substrate W) while describing a smooth arc.

[0076] When the inner guard 41 and the outer guard 43 are in the closest position, the lower end 43a is accommodated in the outer recovery groove 51 with an appropriate gap maintained between the processing liquid separation wall 53 of the middle guard 42 and the outer wall portion 46 of the inner guard 41. The upper end 43b is arranged to overlap the second guide portion 52 of the middle guard 42 in the vertical direction, and when the middle guard 42 and the outer guard 43 are in the closest position, it is in close proximity to the upper end 52b of the second guide portion 52 with a very small gap maintained. Although different from FIG. 3 , a folded portion formed by folding the tip of the upper end 43b downward may be provided. The folded portion is formed to overlap the folded portion of the second guide portion 52 in the horizontal direction when the middle guard 42 and the outer guard 43 are in the closest position.

[0077] The inner guard 41, the middle guard 42, and the outer guard 43 can be raised and lowered by a guard lifting mechanism 61, a guard lifting mechanism 62, and a guard lifting mechanism 63, respectively. Hereinafter, the guard lifting mechanisms 61 to 63 may be collectively referred to as a guard lifting mechanism 60.

[0078] The guard lifting mechanism 60 raises and lowers the inner guard 41, middle guard 42, and outer guard 43 between their respective guard processing positions and guard standby positions so that they do not collide with each other. The guard processing position is a position where the upper edge of the target guard to be raised and lowered is above the upper surface of the substrate W, and the guard standby position is a position where the upper edge of the target guard is below the upper surface 21a of the spin base 21. The upper edge here refers to the annular portion that forms the upper opening of the target guard. In the example of FIG. 3, the inner guard 41, middle guard 42, and outer guard 43 are located at the guard standby positions.

[0079] The partition plate 15 is provided around the guard portion 40 to divide the inner space of the chamber 10 into upper and lower portions. The partition plate 15 may have through-holes or notches that penetrate in the thickness direction. In this embodiment, through-holes are formed to pass support shafts that support the nozzle base 33 of the first nozzle 30, the nozzle base 33A of the second nozzle 30A, and the nozzle base 33B of the third nozzle 30B. The outer peripheral edge of the partition plate 15 is connected to the side wall 11 of the chamber 10. In addition, the edge portion of the partition plate 15 that surrounds the guard portion 40 is formed into a circular shape with a diameter larger than the outer diameter of the outer guard 43. Therefore, the partition plate 15 does not obstruct the raising and lowering of the outer guard 43.

[0080] An exhaust duct 18 is provided in a portion of the side wall 11 of the chamber 10, near the floor wall 13. The exhaust duct 18 is connected in communication with an exhaust mechanism (not shown). Of the clean air supplied from the fan filter unit 14 and flowing down through the chamber 10, the air that passes between the guard part 40 and the partition plate 15 is discharged from the exhaust duct 18 to the outside of the apparatus.

[0081] The camera 70 is installed in the chamber 10 above the substrate W held by the spin chuck 20. In the example of Fig. 3, the camera 70 is installed above the partition plate 15. Also, in the example of Fig. 3, the camera 70 is located radially outward from the guard part 40. The radial direction here refers to the radial direction with respect to the rotation axis CX.

[0082] The camera 70 includes a solid-state imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and an optical system such as a lens. The camera 70 captures an image of an imaging area including the guard portion 40 from diagonally above. Here, the imaging area is set to an area including the entire periphery of the upper end periphery of the outer guard 43 when the outer guard 43 is positioned in the guard processing position (see also FIG. 9 , which will be described later). The camera 70 captures an image of the imaging area, generates captured image data (hereinafter simply referred to as the captured image), and outputs the captured image to the control unit 9.

[0083] 3, an illumination unit 71 is provided in the chamber 10 at a position above the partition plate 15. If the chamber 10 is a darkroom, the control unit 9 may control the illumination unit 71 so that the illumination unit 71 emits light when the camera 70 captures an image.

[0084] The hardware configuration of the control unit 9 is the same as that of a general computer. That is, the control unit 9 includes a data processing unit such as a CPU that performs various arithmetic processing, and a ROM ( Read The control unit 9 is configured to include a non-transitory storage unit such as a memory-only memory (RAM), and a temporary storage unit such as a random access memory (RAM), which is a readable and writable memory for storing various information. The CPU of the control unit 9 executes a predetermined processing program, whereby the control unit 9 controls each operating mechanism of the substrate processing apparatus 100, and processing in the substrate processing apparatus 100 progresses. The control unit 9 may be realized by a dedicated hardware circuit that does not require software to realize its functions.

[0085] 4 is a functional block diagram schematically showing an example of the internal configuration of the control unit 9. As shown in FIG. 4, the control unit 9 includes a guard determination unit 91 and a process control unit 92.

[0086] The process control unit 92 controls each component of the processing unit 1. Specifically, the process control unit 92 controls the spin motor 22, various valves such as the valve 35, the motors and nozzle lifting mechanisms of the nozzle bases 33, 33A, and 33B, the guard lifting mechanisms 61 to 63, the fan filter unit 14, and the camera 70. The process control unit 92 controls these components in accordance with a predetermined procedure, thereby enabling the processing unit 1 to process the substrate W. An example of a specific flow of processing the substrate W will be described in detail later.

[0087] The guard determination unit 91 determines whether or not there is an abnormality in the position or shape of the guard portion 40 based on the image captured by the camera 70. An example of a specific guard determination method will be described in detail later.

[0088] <An example of substrate processing flow> 5 is a flowchart showing an example of the flow of substrate processing. Initially, guard unit 40 stops at the guard standby position. That is, inner guard 41, middle guard 42, and outer guard 43 each stop at their guard standby positions (see FIG. 3). Note that although control unit 9 controls each component to perform predetermined operations described below, the following description focuses on each component itself as the subject of the operation.

[0089] First, the main transport robot 103 loads an unprocessed substrate W into the processing unit 1, and the spin chuck 20 holds the substrate W (step S1: loading and holding step). Initially, the guard part 40 is stopped at the guard standby position, so that collision between the hand of the main transport robot 103 and the guard part 40 can be avoided when the substrate W is loaded. When the substrate W is transferred to the spin chuck 20, the multiple chuck pins 26 move to their respective abutment positions, thereby holding the substrate W.

[0090] Next, the spin motor 22 starts rotating the substrate W (step S2: rotation start step). Specifically, the spin motor 22 rotates the spin chuck 20, thereby rotating the substrate W held by the spin chuck 20.

[0091] Next, the processing unit 1 performs various liquid processes on the substrate W. In the example of Fig. 5, the processing unit 1 first performs chemical liquid processing (step S3: chemical liquid process). Fig. 6 is a diagram schematically showing an example of the state inside the processing unit 1 during chemical liquid processing.

[0092] First, the guard lifting mechanism 60 lifts one of the guards 41 to 43 that corresponds to the chemical solution to the guard processing position. The guard for the chemical solution is not particularly limited, but may be, for example, the outer guard 43. In this case, the guard lifting mechanism 60 stops the inner guard 41 and the middle guard 42 at their respective guard standby positions, and lifts the outer guard 43 to the guard processing position (see FIG. 6).

[0093] Next, the processing unit 1 supplies the chemical liquid to the substrate W. Here, it is assumed that the first nozzle 30 supplies the processing liquid. Specifically, the nozzle base 33 moves the first nozzle 30 to the nozzle processing position, and the valve 35 opens to eject the chemical liquid from the first nozzle 30 toward the substrate W. As a result, the chemical liquid spreads over the upper surface of the rotating substrate W and splashes from the periphery of the substrate W. The splashed chemical liquid is received by the inner peripheral surface of the guard portion 40 (e.g., outer guard 43). As the chemical liquid acts on the upper surface of the substrate W, processing according to the chemical liquid (e.g., cleaning processing) is performed on the substrate W. When the chemical liquid processing has been sufficiently performed, the processing unit 1 stops supplying the chemical liquid.

[0094] Next, the processing unit 1 performs a first rinse process on the substrate W (step S4: first rinse step). The guard lifting mechanism 60 adjusts the lifted state of the guard part 40 as necessary. That is, if the guard for the first rinse liquid is different from the guard for the chemical liquid, the guard lifting mechanism 60 moves the guard corresponding to the first rinse liquid among the guards 41 to 43 to the guard processing position. The guard for the first rinse liquid is not particularly limited, but may be the inner guard 41. In this case, the guard lifting mechanism 60 lifts the guards 41 to 43 to their respective guard processing positions.

[0095] Next, the first nozzle 30 ejects a first rinse liquid toward the upper surface of the substrate W. The first rinse liquid is, for example, pure water. The first rinse liquid spreads over the upper surface of the rotating substrate W, washing away the chemical liquid on the substrate W, and splashes from the periphery of the substrate W. The processing liquid (mainly the first rinse liquid) splashed from the periphery of the substrate W is received by the inner peripheral surface of the guard portion 40 (for example, the inner guard 41). When the first rinse process has been sufficiently performed, the processing unit 1 stops supplying the first rinse liquid.

[0096] Next, the processing unit 1 performs a second rinse process on the substrate W (step S5: second rinse step). The guard lifting mechanism 60 adjusts the lifted state of the guard part 40 as necessary. That is, if the guard for the second rinse liquid is different from the guard for the first rinse liquid, the guard lifting mechanism 60 moves the guard corresponding to the second rinse liquid among the guards 41 to 43 to the guard processing position.

[0097] Next, the first nozzle 30 ejects a second rinse liquid toward the upper surface of the substrate W. The second rinse liquid is a liquid having a smaller latent heat of vaporization than the first rinse liquid, such as isopropyl alcohol. The second rinse liquid spreads over the upper surface of the substrate W, washing away the first rinse liquid on the substrate W, and splashes from the periphery of the substrate W. The processing liquid (mainly the second rinse liquid) splashed from the periphery of the substrate W is received by the inner peripheral surface of the guard portion 40. When the second rinse process has been sufficiently performed, the processing unit 1 stops supplying the second rinse liquid and moves the first nozzle 30 to the nozzle standby position.

[0098] Next, the processing unit 1 performs a drying process on the substrate W (step S6: drying step). For example, the spin motor 22 increases the rotation speed of the substrate W to dry the substrate W (so-called spin drying). Even during the drying process, the processing liquid splashed from the periphery of the substrate W is received by the inner peripheral surface of the guard part 40. When the drying process is sufficiently completed, the spin motor 22 stops the rotation of the substrate W.

[0099] Next, the guard lifting mechanism 60 lowers the guard portion 40 to the guard standby position (step S7: guard lowering step). That is, the guard lifting mechanism 60 lowers the inner guard 41, the middle guard 42, and the outer guard 43 to their respective guard standby positions.

[0100] Next, the spin chuck 20 releases its hold on the substrate W, and the main transport robot 103 removes the substrate W from the processing unit 1 (step S8: release-holding and unloading step). Since the guard part 40 is stopped at the guard standby position when the substrate W is unloaded, it is possible to avoid collision between the hand of the main transport robot 103 and the guard part 40.

[0101] Through the above operations, the processing unit 1 can process the substrate W.

[0102] <Guard position> As is clear from the substrate processing operations described above, the guard section 40 moves to a height position appropriate for each process. Specifically, when the substrate W is being loaded or unloaded (steps S1 and S8), the guard section 40 is stopped at the guard standby position. This makes it possible to avoid collisions between the hand of the main transport robot 103 and the guard section 40. Furthermore, when various processing liquids are supplied to the substrate W (steps S3 to S5), the raised and lowered state of the guard section 40 is determined according to the type of processing liquid. This allows the processing liquid to be received by the guard of the guard section 40 appropriate for the type of processing liquid, allowing the processing liquid to be appropriately collected or discarded.

[0103] However, if the guard section 40 cannot move to an appropriate height position for each process, problems may occur. For example, if the guard section 40 does not stop at the guard standby position when the substrate W is being loaded or unloaded, the hand of the main transport robot 103 may collide with the guard section 40. Furthermore, if the guard appropriate for the type of processing liquid does not stop at the guard processing position when the processing liquid is being supplied, the processing liquid will not be collected or discarded appropriately.

[0104] <Guard monitoring processing> Therefore, in this embodiment, the processing unit 1 performs guard monitoring processing on the guard section 40. Fig. 7 is a flowchart showing an example of the guard monitoring processing according to the first embodiment. Below, an example of the guard monitoring processing will first be outlined, and then the example of the guard monitoring processing will be described in detail, broadly divided into a state where the guard section 40 is stopped at the guard standby position and a state where the guard section 40 is stopped at the guard processing position.

[0105] 7, first, the guard lifting mechanism 60 moves the guard part 40 to a predetermined height position (target height position) (step S11: guard lifting step). The guard lifting step corresponds to the movement of the guard part 40 performed in each of the above-mentioned chemical solution step (step S3), first rinse step (step S4), second rinse step (step S5), and guard lowering step (step S7).

[0106] Next, camera 70 captures an image of an imaging area including guard section 40 to generate a captured image, and outputs the captured image to control unit 9 (step S12: imaging process). FIGS. 8 and 9 are diagrams that schematically show examples of captured images. FIG. 8 shows a captured image captured when guards 41 to 43 of guard section 40 are stopped at their respective guard standby positions, and FIG. 9 shows a captured image captured when only outer guard 43 of guard section 40 is stopped at the guard processing position. When guard section 40 moves to the guard standby position in the guard lifting / lowering process, the captured image shown in FIG. 8 is generated in the imaging process, and when only outer guard 43 of guard section 40 moves to the guard processing position in the guard lifting / lowering process, the captured image shown in FIG. 9 is generated in the imaging process.

[0107] Next, the guard determination unit 91 of the control unit 9 determines whether or not there is an abnormality in the guard unit 40 based on the pixel values ​​of the captured image (step S13: determination step). Here, a normal captured image when the guard unit 40 is normally positioned at a predetermined height position is stored as reference image data (hereinafter simply referred to as a reference image) in a non-volatile non-temporary storage unit (for example, a memory) 93. Then, the guard determination unit 91 determines whether or not there is an abnormality in the guard unit 40 based on a comparison between the captured image and the reference image.

[0108] <Guard standby position> Here, a case where the guard section 40 moves to the guard standby position in the guard lifting / lowering process (step S11) will be described in detail. Specifically, a case where the guard lifting / lowering process corresponds to the movement of the guard section 40 performed in the guard lowering process (step S7) will be described in detail.

[0109] First, in the guard lifting / lowering process, the processing control unit 92 of the control unit 9 outputs control signals to the guard lifting / lowering mechanisms 61-63. These control signals are signals for moving the guards 41-43 to their respective guard standby positions. In response to the control signals, the guard lifting / lowering mechanisms 61-63 move the guards 41-43 to their respective guard standby positions.

[0110] At this time, if the guard lifting mechanism 60 can normally move the guard section 40 to the guard standby position, it is possible to avoid a collision between the hand of the main transport robot 103 and the guard section 40 in the next hold release carry-out process (step S8). On the other hand, if the guard section 40 cannot normally move to the guard standby position due to factors such as an abnormality in the guard lifting mechanism 60, the hand of the transport robot may collide with the guard section 40.

[0111] Therefore, the processing unit 1 sequentially performs an imaging step (step S12) and a determination step (step S13) before the main transport robot 103 starts to move the hand (i.e., before the carry-out process). Note that the actual guard monitoring process is realized by the imaging step and the determination step.

[0112] In the imaging step, a captured image shown in Fig. 8 is generated. In the example of Fig. 8, the captured image includes the entire upper surface of the processed substrate W and a part of the outer guard 43 stopped at the guard standby position. In the example of Fig. 8, only the outer guard 43 of the guard section 40 is included in the captured image, and the inner guard 41 and the middle guard 42 are not included.

[0113] Here, the guard determination unit 91 determines whether or not there is an abnormality in the outer guard 43 based on the captured image. stand-by This is because, if the outer guard 43 is positioned at this position, it is possible to avoid a collision between the hand of the main transport robot 103 and the guard section 40. In other words, the guard determination section 91 only needs to determine whether or not there is an abnormality in the outer guard 43, and the captured image does not need to include the inner guard 41 and the middle guard 42.

[0114] The guard determination unit 91 determines whether or not there is an abnormality in the outer guard 43 by comparing the captured image with a reference image for the standby position. The reference image for the standby position is a normal captured image captured by the camera 70 when the outer guard 43 normally stops at the guard standby position, and is stored in advance in the storage unit 93.

[0115] In the example of Fig. 8, at least one determination area R1 is set in the captured image. The determination area R1 is set to an area that includes a portion of the outer guard 43 (specifically, a portion of the upper periphery) when the outer guard 43 is normally positioned at the guard standby position. In the example of Fig. 8, the determination area R1 is set to an area that includes the portion of the upper periphery of the outer guard 43 that is on the near side as seen from the camera 70. In other words, the determination area R1 is set in the captured image below the major axis LA1 of a virtual ellipse E1 along which the upper periphery of the outer guard 43 follows.

[0116] 8, the determination area R1 is set in an area that does not include the substrate W. The distance between the periphery of the substrate W and the upper periphery of the outer guard 43 is wider below the major axis LA1 of the ellipse E1, so if the determination area R1 is set below the major axis LA1, it is easy to set the determination area R1 in an area that does not include the substrate W and that includes the upper periphery of the outer guard 43.

[0117] 8, a first judgment region R11 and a second judgment region R12 are set as the judgment region R1. The first judgment region R11 and the second judgment region R12 are set on opposite sides of the minor axis SA1 of the ellipse E1.

[0118] As reference images for the standby position, a first reference image M11 of the same area as the first determination area R11 and a second reference image M12 of the same area as the second determination area R12 are stored in advance in the storage unit 93.

[0119] 10 is a flowchart showing an example of a more specific operation of the determination step (step S13). First, the guard determination unit 91 calculates a similarity DS1 between the first determination region R11 and the first reference image M11 (hereinafter referred to as a first similarity) based on pixel values ​​in the first determination region R11 and pixel values ​​in the first reference image M11 (step S131). The similarity is not particularly limited, and may be a known similarity such as the sum of squared differences of pixel values, the sum of absolute differences of pixel values, normalized cross-correlation, or zero-mean normalized cross-correlation. When the similarity is normalized cross-correlation or zero-mean normalized cross-correlation, the similarity takes a value between −1.0 and 1.0.

[0120] Next, the guard determination unit 91 calculates the similarity DS2 between the second determination area R12 and the second reference image M12 (hereinafter also referred to as the second similarity) based on the pixel values ​​in the second determination area R12 and the pixel values ​​in the second reference image M12 (step S132). If these similarities are high, it is considered that the outer guard 43 is stopped normally at the guard standby position.

[0121] Next, the guard determination unit 91 determines whether both the first similarity DS1 and the second similarity DS2 are equal to or greater than a specified threshold value Ref (step S133). That is, the guard determination unit 91 determines whether it has been provisionally determined that the outer guard 43 is normally stopped at the guard standby position in both the provisional determination result based on the pixel values ​​of the first determination region R11 and the provisional determination result based on the pixel values ​​of the second determination region R12.

[0122] When both the first similarity DS1 and the second similarity DS2 are equal to or greater than the threshold value Ref, the guard determination unit 91 determines that the outer guard 43 is normally stopped at the guard standby position (step S134). In other words, the guard determination unit 91 determines that the outer guard 43 is normal when it provisionally determines that the outer guard 43 is normal in both the first determination region R11 and the second determination region R12.

[0123] On the other hand, when at least one of the first similarity DS1 and the second similarity DS2 is less than the threshold value Ref, the guard determination unit 91 determines that an abnormality has occurred with the outer guard 43 (step S135). In other words, the guard determination unit 91 determines that the outer guard 43 is not normally positioned at the guard standby position. When the guard determination unit 91 detects an abnormality, the processing unit 1 may interrupt the processing, and may further notify the user of the occurrence of the abnormality by a notification unit (not shown) (for example, a display).

[0124] As described above, the guard monitoring process can detect an abnormality in the outer guard 43. When an abnormality is detected, the main transport robot 103 can halt the start of the unloading process of the substrate W. This makes it possible to avoid a collision between the hand of the main transport robot 103 and the guard part 40.

[0125] Although the guard monitoring process before the substrate W is unloaded has been described above, the processing unit 1 may also perform a similar guard monitoring process before the substrate W is loaded. Delivery and Retention The imaging step (step S12) and the determination step (step S13) may be performed immediately before the substrate W is loaded in the step (step S1). Even if an abnormality is detected in the determination step immediately before the substrate W is loaded, the main transport robot 103 can stop the start of the loading process of the substrate W. This makes it possible to avoid collision between the hand of the main transport robot 103 and the guard part 40.

[0126] In this embodiment, as described above, the guard determination unit 91 directly determines whether or not there is an abnormality based on a captured image including the guard unit 40. Therefore, even if an abnormality such as loss of synchronization occurs in the guard lifting mechanism 60, it can properly determine whether or not there is an abnormality in the outer guard 43. In other words, the guard determination unit 91 can determine whether or not there is an abnormality with higher accuracy.

[0127] 8, a determination region R1 is set in only a portion of the captured image, and the guard determination unit 91 determines whether or not there is an abnormality based on pixel values ​​within this determination region R1. In other words, components included in the captured image outside the determination region R1 are not used in the determination. Therefore, the guard determination unit 91 can avoid the influence of these components on the determination results, and can determine whether or not there is an abnormality with higher accuracy.

[0128] 8, the determination region R1 is set to an area in the captured image that does not include the substrate W. Before the substrate W is loaded into the processing unit 1, the spin chuck 20 does not yet hold the substrate W, so the captured image taken at this time naturally does not include the substrate W. On the other hand, before the substrate W is unloaded from the processing unit 1, the spin chuck 20 holds the substrate W, so the captured image taken at this time includes the substrate W, as illustrated in FIG. 8. In this way, the two captured images differ from each other in terms of the presence or absence of the substrate W.

[0129] However, since the determination area R1 set in the captured image does not include the substrate W, the presence or absence of such a substrate W does not affect the determination. Therefore, even if a common determination area R1 and a common reference image for the standby position are used when the substrate W is carried in and when it is carried out, the guard determination unit 91 can appropriately determine whether or not there is an abnormality.

[0130] 8, a first judgment region R11 and a second judgment region R12 are set as the judgment region R1. When the guard judgment unit 91 provisionally judges that the outer guard 43 is normal in both the first judgment region R11 and the second judgment region R12, the guard judgment unit 91 judges that the outer guard 43 is normal.

[0131] For comparison, a case will be described in which the presence or absence of an abnormality in the outer guard 43 is determined only in the first determination region R11. In this case, if the guard portion 40 tilts due to factors such as an abnormality in the guard lifting / lowering mechanism 60, an erroneous determination may occur. For example, if the guard lifting / lowering mechanism 63 supports and raises and lowers the lower end of the outer guard 43 at multiple points, a malfunction at one point will cause the outer guard 43 to tilt. In this case, the upper peripheral edge of the outer guard 43 will tilt relative to the horizontal plane.

[0132] When the outer guard 43 is tilted in this way, even if the first judgment region R11 is similar to the first reference image M11, the second judgment region R12 may deviate from the second reference image M12. In this case, if the guard judgment unit 91 judges whether or not there is an abnormality based only on the first judgment region R11, it may erroneously judge that the outer guard 43 is normal. In other words, an abnormality may not be detected.

[0133] In contrast, if the guard determination unit 91 determines the presence or absence of an abnormality using both the first determination region R11 and the second determination region R12, such erroneous determination can be suppressed. In other words, the guard determination unit 91 can determine the presence or absence of an abnormality with higher determination accuracy.

[0134] 8, the first determination area R11 and the second determination area R12 are set on opposite sides of the minor axis SA1 of the virtual ellipse E1, which makes it easier for the guard determination unit 91 to detect an abnormality caused by the tilt of the outer guard 43.

[0135] <Guard processing position> Next, a detailed description will be given of the case where the guard part 40 moves to the guard processing position in the guard lifting / lowering step (step S11). That is, a detailed description will be given of the case where the guard lifting / lowering step corresponds to the movement of the guard part 40 performed in any one of the chemical step (step S3), the first rinse step (step S4), and the second rinse step (step S5).

[0136] First, in the guard lifting / lowering process, the guard lifting / lowering mechanism 60 moves the guards 41-43 appropriately depending on the type of processing liquid, as described above. Here, only the outer guard 43 is assumed to be raised to the guard processing position. That is, the processing control unit 92 of the control unit 9 outputs control signals to the guard lifting / lowering mechanisms 61-63, respectively, for raising only the outer guard 43 to the guard processing position. The guard lifting / lowering mechanism 60 moves the guards 41-43 appropriately in response to the control signals.

[0137] If the guard lifting mechanism 60 can move the guards 41 to 43 normally, then when the next processing liquid is supplied, the processing liquid splashed from the periphery of the substrate W will be received by the appropriate guard and collected or discarded. On the other hand, if the guards 41 to 43 cannot move normally due to factors such as an abnormality in the guard lifting mechanism 60, the processing liquid will not be properly received by the appropriate guard.

[0138] Therefore, before supplying the next processing liquid, the processing unit 1 performs an imaging step (step S12) and a determination step (step S13). For example, in chemical liquid processing, the processing unit 1 performs the imaging step and the determination step before supplying the chemical liquid to the substrate W.

[0139] In the imaging step, a captured image shown in Fig. 9 is generated. In the example of Fig. 9, the captured image includes the entire upper peripheral edge of the outer guard 43 that stops at the guard processing position. In the example of Fig. 9, the upper surface of the substrate W is also included in the captured image, but the front peripheral edge is blocked by the outer guard 43. Therefore, in the captured image of Fig. 9, the front peripheral portion of the upper peripheral edge of the guard part 40 is continuous with the substrate W in the vertical direction.

[0140] The guard determination unit 91 determines whether or not there is an abnormality in the guard unit 40 (here, the outer guard 43) based on the captured image and the reference image for the processing position. The reference image for the processing position is a normal captured image captured by the camera 70 when the guard unit 40 (here, only the outer guard 43) is stopped normally at the guard processing position, and is stored in advance in the storage unit 93.

[0141] In the example of Fig. 9, at least one determination area R2 is set in the captured image. The determination area R2 is set to an area that includes a part of the upper periphery of the outer guard 43 when it is positioned in the normal guard processing position. In the example of Fig. 9, the determination area R2 is set to an area that includes the innermost portion of the upper periphery of the outer guard 43 as seen from the camera 70. In other words, the determination area R2 is set in the captured image above the major axis LA1 of the imaginary ellipse E1 along which the upper periphery of the outer guard 43 fits.

[0142] 9, the determination area R2 is set in an area that does not include the substrate W. The distance between the periphery of the substrate W and the upper peripheral edge of the outer guard 43 is wider above the major axis LA1 of the ellipse E1, so if the determination area R2 is set above the major axis LA1, it is easy to set the determination area R2 in an area that does not include the substrate W and that includes the upper peripheral edge of the outer guard 43.

[0143] 9, a first judgment region R21 and a second judgment region R22 are set as the judgment region R2. The first judgment region R21 and the second judgment region R22 are set on opposite sides of the minor axis SA1 of the ellipse E1.

[0144] As reference images for the processing position, a first reference image M21 of the same area as the first determination area R21 and a second reference image M22 of the same area as the second determination area R22 are stored in advance in the storage unit 93.

[0145] An example of a specific operation of the determination step (step S13) is the same as that shown in the flowchart in Fig. 10. First, the guard determination unit 91 calculates a first similarity DS1 between the first determination region R21 and the first reference image M21 based on pixel values ​​in the first determination region R21 and pixel values ​​in the first reference image M21 (step S131). Next, the guard determination unit 91 calculates a second similarity DS2 between the second determination region R22 and the second reference image M22 based on pixel values ​​in the second determination region R22 and pixel values ​​in the second reference image M22 (step S132).

[0146] Next, the guard determination unit 91 determines whether both the first similarity DS1 and the second similarity DS2 are equal to or greater than a specified threshold value Ref (step S133). When both the first similarity DS1 and the second similarity DS2 are equal to or greater than the threshold value Ref, the guard determination unit 91 determines that the outer guard 43 is normally positioned at the guard processing position (step S134). When at least one of the first similarity DS1 and the second similarity DS2 is less than the threshold value Ref, the guard determination unit 91 determines that an abnormality has occurred with the outer guard 43 (step S135). When the guard determination unit 91 detects an abnormality, the processing unit 1 may interrupt the processing, and may further notify the user of the occurrence of the abnormality by a notification unit (not shown) (for example, a display).

[0147] As described above, the guard monitoring process can detect an abnormality in the guard section 40. When an abnormality is detected by the guard monitoring process, the processing unit 1 can halt the start of supplying the next processing liquid. This prevents the next processing liquid from being received by another guard, and prevents the processing liquid from mixing into the recovery line or the drainage line.

[0148] While the above specific example describes a case where only the outer guard 43 is stopped at the guard processing position, the same applies when the inner guard 41 or the middle guard 42 is stopped at the guard processing position. FIG. 11 is a diagram schematically illustrating an example of a captured image when the middle guard 42 and the outer guard 43 are stopped at their respective guard processing positions. This captured image also includes a portion of the middle guard 42 stopped at the guard processing position. Specifically, the innermost portion of the upper edge of the middle guard 42 as viewed from the camera 70 appears directly below the upper edge of the outer guard 43 in the captured image. The determination region R2 is set to an area that includes both the upper edge of the outer guard 43 and the upper edge of the middle guard 42 when they are normally positioned at the guard processing position. In the example of FIG. 11, the first determination region R21 and the second determination region R22 each include a portion of the upper edge of the outer guard 43 and a portion of the upper edge of the middle guard 42.

[0149] In this case, the reference image for the processing position is a normally captured image that includes the outer guard 43 and middle guard 42 that have stopped properly at the guard processing position. In the example of Fig. 11, a first reference image M31 of the same area as the first determination area R21 and a second reference image M32 of the same area as the second determination area R22 are shown, and these are pre-stored in the storage unit 93. Each of the first reference image M31 and the second reference image M32 includes both a portion of the upper edge periphery of the outer guard 43 and a portion of the upper edge periphery of the middle guard 42 that have stopped properly at the guard processing position.

[0150] The specific operation in the determination step (step S13) is the same as in Fig. 10. However, the first reference image M31 is used instead of the first reference image M21, and the second reference image M32 is used instead of the second reference image M22.

[0151] The same applies when the inner guard 41, the middle guard 42, and the outer guard 43 stop at their respective guard processing positions. Fig. 12 is a diagram schematically showing an example of a captured image when the inner guard 41, the middle guard 42, and the outer guard 43 stop at their respective guard processing positions. The determination region R2 (first determination region R21 and second determination region R22) is set to an area that includes a portion of the upper peripheral edge of the guards 41 to 43 when they are normally positioned at the guard processing position. The first reference image M41 and the second reference image M42 for the processing position are normally captured images that include a portion of the upper peripheral edge of the guards 41 to 43 that have normally stopped at the guard processing position, and these are stored in advance in the storage unit 93.

[0152] The specific operation in the determination step (step S13) is the same as in Fig. 10. However, the first reference image M41 is used instead of the first reference image M21, and the second reference image M42 is used instead of the second reference image M22.

[0153] As described above, the determination region R2 is preferably set to an area that includes part of the upper periphery of the guards 41 to 43 when they are normally positioned at the guard processing position. This allows the guard determination unit 91 to determine the presence or absence of an abnormality using the common determination region R2 when at least one of the guards 41 to 43 is stopped at the guard processing position (FIGS. 9, 11, and 12).

[0154] As described above, the guard determination unit 91 directly detects abnormalities related to the guard unit 40 based on the captured image including the guard unit 40 captured by the camera 70. Therefore, even if an abnormality such as loss of synchronization occurs in the guard lifting mechanism 60, the abnormality of the guard unit 40 can be determined with high accuracy.

[0155] In the above example, the determination area R2 is set to only a part of the captured image, and the guard determination unit 91 determines whether or not there is an abnormality based on the pixel values ​​within this determination area R2. This prevents the influence of components other than the determination area R2 on the determination, and allows the guard determination unit 91 to determine whether or not there is an abnormality with higher accuracy.

[0156] In the above example, the determination region R2 is set to an area that does not include the substrate W in the captured image. Incidentally, the guard section 40 may move to the guard processing position not only during liquid processing of the substrate W but also, for example, during cleaning processing inside the chamber 10 (hereinafter referred to as chamber cleaning processing). For example, when cleaning the inner circumferential surfaces of the guards 41 to 43, the guards 41 to 43 are raised to the guard processing position as appropriate. Even in such cases, it is desirable for the processing unit 1 to perform guard monitoring processing. Such chamber cleaning processing may be performed without a substrate W being loaded into the processing unit 1. In this case, the substrate W is naturally not included in the captured image. On the other hand, in the guard monitoring processing for liquid processing, the substrate W is included in the captured image, as exemplified in FIGS. 9, 11, and 12. Thus, the captured images for the liquid processing and the chamber cleaning processing differ from each other in terms of the presence or absence of the substrate W.

[0157] However, since the determination area R2 set in the captured image does not include the substrate W, the presence or absence of such a substrate W does not affect the determination. Therefore, even if a common determination area R2 and a common reference image for the processing position are used for each of the liquid processing and the chamber cleaning processing, the guard determination unit 91 can appropriately determine the presence or absence of an abnormality in the guard unit 40.

[0158] In the above example, a first judgment region R21 and a second judgment region R22 are set as the judgment region R2. The guard judgment unit 91 determines that the guard unit 40 is normal when it provisionally determines that the guard unit 40 is normal in both the first judgment region R21 and the second judgment region R22. Therefore, even if the guard unit 40 is tilted due to factors such as an abnormality in the guard lifting / lowering mechanism 60, the guard judgment unit 91 can determine the presence or absence of an abnormality with higher accuracy. Furthermore, the first judgment region R21 and the second judgment region R22 are set on opposite sides of the minor axis SA1 of the ellipse E1. Therefore, the guard judgment unit 91 can easily detect an abnormality caused by the tilt of the guard unit 40.

[0159] Furthermore, the predetermined height position (target height position) of the guard part 40 that moves in each process may be changed as appropriate due to changes in specifications, etc. However, according to this embodiment, by appropriately changing the determination area and reference image, it is possible to detect an abnormality in the guard part 40 according to the height position without changing the hardware configuration of the processing unit 1.

[0160] <Threshold Ref> As described above, during substrate processing, the processing liquid is supplied to the substrate W, which may cause the processing liquid to splash within the chamber 10, resulting in droplets of the processing liquid adhering to the outer peripheral surface of the guard unit 40. In this case, as will be described in detail below, the guard determination unit 91 may make an erroneous determination. FIG. 13 is a diagram schematically illustrating an example of a captured image when droplets L1 are adhering to the outer peripheral surface of the guard unit 40. In the example of FIG. 13, multiple droplets L1 are adhering to the outer peripheral surface of the outer guard 43 of the guard unit 40, and droplets L1 are also included in the first determination region R11 and the second determination region R12. Therefore, the first similarity DS1 between the first determination region R11 and the first reference image M11 and the second similarity DS2 between the second determination region R12 and the second reference image M12 may be lower than the threshold value Ref. In this case, even though the guard unit 40 is properly stopped at the guard standby position, the guard determination unit 91 may erroneously determine that the guard unit 40 is not properly stopped at the guard standby position. That is, the guard determination unit 91 erroneously detects an abnormality in the guard unit 40.

[0161] Therefore, the determination region R1 is set to suppress such erroneous detection. Specifically, the determination region R1 is set so that the guard area occupied by the outer guard 43 in the determination region R1 is small. For example, in the example shown in FIG. 13, the outline of the first determination region R11 has a rectangular shape consisting of a bottom side, a right side side, a left side side, and a top side. The first determination region R11 is set so that the upper edge of the outer guard 43 intersects with the bottom side and the right side. This allows the guard area to be smaller than when the upper edge of the outer guard 43 intersects both sides of the first determination region R11. This reduces the proportion of droplets L1 within the determination region R1, thereby suppressing the influence of droplets L1 on the determination. The same applies to the second determination region R12.

[0162] Next, we aim to suppress erroneous determinations by setting a threshold value Ref. In this embodiment, similarities were investigated through experiments. FIG. 14 is a bar graph schematically showing similarities as experimental results. In the experiment, the camera 70 generated captured images in each of the following three states, and the control unit 9 calculated a first similarity DS1 between the first determination region R11 and the first reference image M11 and a second similarity DS2 between the second determination region R12 and the second reference image M12.

[0163] In the first state, no liquid droplets L1 are attached to the outer peripheral surface of the guard part 40, and the guard part 40 is normally stopped at the guard standby position (see FIG. 8). In the second state, liquid droplets L1 are attached to the outer peripheral surface of the guard part 40, but the guard part 40 is normally stopped at the guard standby position (see FIG. 13). In the third state, no liquid droplets L1 are attached to the outer peripheral surface of the guard part 40, and the guard part 40 is stopped while shifted from the guard standby position. As a specific example, in the third state, the height position of the upper end peripheral portion of the outer guard 43 is the same as or slightly lower than the height position of the upper surface 21a of the spin base 21. In addition, here, in each of the first to third states, the camera 70 captured images multiple times, and the control unit 9 calculated the first similarity DS1 and the second similarity DS2 each time.

[0164] According to the experimental results, the minimum value of the first similarity DS1 and the second similarity DS2 in the first state was similarity value sd1 (approximately 0.99). The minimum value of the first similarity DS1 and the second similarity DS2 in the second state was similarity value sd2 (approximately 0.93), which was lower than similarity value sd1. The maximum value of the first similarity DS1 and the second similarity DS2 in the third state was similarity value sd3 (less than approximately 0.5), which was lower than similarity value sd2.

[0165] In other words, when droplet L1 is attached to the outer peripheral surface of guard part 40, if guard part 40 is stopped normally at the guard standby position, the similarity may become less than similarity value sd1, but will not become less than similarity value sd2. Furthermore, if the height position of the upper edge part of outer guard 43 is equal to or lower than the height position of upper surface 21a of spin base 21, collision between the hand of main transport robot 103 and guard part 40 can be avoided.

[0166] Therefore, it is preferable to set the threshold value Ref to a value (hereinafter referred to as the first threshold value Ref1) that is lower than the similarity value sd2 (corresponding to the first value) and higher than the similarity value sd3. This allows the guard determination unit 91 to determine that the guard unit 40 is normal even in the second state. This makes it possible to avoid erroneous detection of an abnormality in the second state.

[0167] Furthermore, when the upper peripheral edge of the outer guard 43 is located higher than the upper surface 21a of the spin base 21, the guard determination unit 91 can appropriately detect an abnormality in the guard unit 40. Therefore, collision between the hand of the main transport robot 103 and the guard unit 40 can be appropriately avoided.

[0168] <Shape abnormality> Although the above example has been described focusing on an abnormality related to the position of the guard portion 40, the guard determination unit 91 can also detect an abnormality when an abnormality occurs in the shape of the guard portion 40. This is because if an abnormality occurs in the shape of the guard portion 40 included in the captured image, the similarity between the captured image and the reference image decreases, and the guard determination unit 91 can detect an abnormality in the guard portion 40 by the above-mentioned determination based on the similarity.

[0169] For example, if the outer guard 43 is provisionally determined to be normal in the first determination region R11 and provisionally determined to be abnormal in the second determination region R12, there is a possibility that an abnormality has occurred in the shape of the upper edge portion of the outer guard 43. The guard determination unit 91 can also detect such abnormal shapes.

[0170] <Second embodiment> FIG. 15 is a diagram schematically illustrating an example of the configuration of a processing unit 1 according to the second embodiment. Compared to the first embodiment, the processing unit 1 further includes a gas nozzle 80. The gas nozzle 80 is provided in the chamber 10. The outlet of the gas nozzle 80 faces the guard part 40, and the gas nozzle 80 ejects gas from the outlet toward the guard part 40 to blow away droplets L1 adhering to the guard part 40. The flow rate of the gas is set to a value sufficient to blow away the droplets L1. The flow rate of the gas is set to, for example, about 50 L (liters) / min or more and 150 L / min or less.

[0171] The gas nozzle 80 is connected to a gas supply source 83 via a gas supply pipe 81. The gas supply source 83 includes a cylinder that stores gas. A valve 82 is provided on the gas supply pipe 81. The valve 82 opens and closes the flow path of the gas supply pipe 81. When the valve 82 is opened, the gas supply source 83 supplies gas to the gas nozzle 80 through the gas supply pipe 81. The gas includes, for example, an inert gas. As the inert gas, for example, at least one of a rare gas such as argon gas and nitrogen gas can be used.

[0172] The gas nozzle 80 may discharge gas onto portions of the guard member 40 that are reflected in the determination region R1 and the determination region R2 (hereinafter referred to as the "image portions"). A plurality of gas nozzles 80 may be provided corresponding to the plurality of image portions of the guard member 40. The gas nozzle 80 may be immobile within the chamber 10, or may be movable by a gas nozzle movement mechanism (not shown) to various positions where gas can be supplied to each image portion. The gas nozzle movement mechanism is not particularly limited, but may have an arm rotation mechanism similar to that of the first nozzle 30, or may have a linear motion mechanism including a ball screw mechanism and a motor. The gas nozzle 80 may also be attached to the ejection head 31 at the tip of the nozzle arm 32. In this case, the gas nozzle 80 moves integrally with the first nozzle 30. Alternatively, the gas nozzle 80 may be attached to the ejection head 31A at the tip of the nozzle arm 32A, or to the ejection head 31B at the tip of the nozzle arm 32B.

[0173] 16 is a flowchart showing an example of guard monitoring processing according to the second embodiment. First, as in step S11, the guard lifting / lowering mechanism 60 moves the guard unit 40 to a predetermined height position (step S31: guard lifting / lowering process). Here, the guard lifting / lowering mechanism 60 moves the guard unit 40 to a guard standby position, which is the predetermined height position.

[0174] Next, the processing unit 1 ejects gas from the gas nozzle 80 toward the imaged portion of the guard part 40 (step S32: gas supply step). Specifically, the gas nozzle 80 ejects gas toward the imaged portion that appears in the determination region R1. Therefore, even if liquid droplets L1 adhere to the imaged portion, the liquid droplets L1 are blown away by the gas. When a predetermined time, which is set to be a time sufficient to blow away the liquid droplets L1, has elapsed since the start of gas ejection, the processing unit 1 stops supplying gas from the gas nozzle 80. The predetermined time is set to be, for example, 0.1 seconds or more and 30 seconds or less.

[0175] Next, similarly to step S12, the camera 70 captures an image of the imaging area to generate a captured image, and outputs the captured image to the control unit 9 (step S33: imaging step). Since the liquid droplets L1 adhering to the imaged portion are blown away by the immediately preceding gas supply step, the determination region R1 of the captured image contains almost no or no liquid droplets L1.

[0176] Next, similar to step S13, the guard determination unit 91 determines whether or not there is an abnormality in the guard unit 40 based on pixel values ​​within the determination region R1 of the captured image (step S34: determination step). Because the determination region R1 contains almost no or no liquid droplets L1, the guard determination unit 91 can determine whether or not there is an abnormality with higher accuracy. Note that it is not necessary to use the first threshold value Ref1 shown in FIG. 14 as the threshold value Ref; it is preferable to use a value (hereinafter referred to as the second threshold value Ref2) that is lower than the similarity value sd1 (corresponding to the second value) and higher than the similarity value sd2 (corresponding to the first value) as the threshold value Ref.

[0177] When the guard lifting mechanism 60 moves the guard section 40 to the guard processing position in the guard lifting step (step S31), the gas nozzle 80 may supply gas toward the portion of interest shown in the determination region R2 in the gas supply step (step S32). As a result, the determination region R2 of the image obtained in the subsequent imaging step (step S33) contains almost no or no droplets L1. This allows the guard determination unit 91 to determine the presence or absence of an abnormality with higher accuracy in the determination step (step S34).

[0178] <Modification> If the processing unit 1 discharges gas from the gas nozzle 80 every time a guard monitoring process is performed, the amount of gas consumed increases. Here, it is intended to reduce the amount of gas consumed.

[0179] 17 is a flowchart showing a modified example of the guard monitoring process according to the second embodiment. As will be described in detail later, the first threshold value Ref1 and the second threshold value Ref2 higher than the first threshold value Ref1, as shown in FIG. 14, are appropriately used as the threshold value Ref.

[0180] First, similarly to step S11, the guard lifting mechanism 60 moves the guard portion 40 to a predetermined height position (step S41). Here, it is assumed that the guard lifting mechanism 60 moves the guard portion 40 to the guard standby position.

[0181] Next, similarly to step S12, the camera 70 captures an image of the imaging area to generate a captured image, and outputs the captured image to the control unit 9 (step S42).

[0182] Next, similar to step S131, the guard judgment unit 91 of the control unit 9 calculates a first similarity DS1 between the first judgment area R11 of the captured image and the first reference image M11 (step S43), and similar to step S132, calculates a second similarity DS2 between the second judgment area R12 of the captured image and the second reference image M12 (step S44).

[0183] Next, the guard determination unit 91 determines whether both the first similarity DS1 and the second similarity DS2 are equal to or greater than a second threshold value Ref2 that is higher than the first threshold value Ref1 (step S45). If both the first similarity DS1 and the second similarity DS2 are equal to or greater than the second threshold value Ref2, the guard determination unit 91 determines that the guard unit 40 is normal (step S46, corresponding to the first step).

[0184] When at least one of the first similarity DS1 and the second similarity DS2 is less than the second threshold value Ref2, there is a possibility that an abnormality has occurred or that a liquid droplet L1 has adhered.

[0185] Therefore, the guard determination unit 91 determines whether or not at least one of the first similarity DS1 and the second similarity DS2 is less than the first threshold value Ref1 (step S47). If at least one of the first similarity DS1 and the second similarity DS2 is less than the first threshold value Ref1, it is highly likely that an abnormality has occurred, and therefore the guard determination unit 91 determines that an abnormality has occurred (step S48).

[0186] On the other hand, when both the first similarity DS1 and the second similarity DS2 are equal to or greater than the first threshold value Ref1, it is highly likely that the liquid droplet L1 is attached, and therefore the gas nozzle 80 supplies gas to the portion of the guard part 40 that is reflected in the determination region R1 (step S49, corresponding to the second step). As a result, even if the liquid droplet L1 is attached to the portion, it is possible to blow away the liquid droplet L1 with the gas.

[0187] Next, the camera 70 captures an image of the imaging area to generate a captured image, and outputs the captured image to the control unit 9 (step S50, corresponding to the third step).

[0188] Next, the guard determination unit 91 determines whether or not there is an abnormality in the guard unit 40 based on the captured image generated in step S50 and the reference image (corresponding to the fourth step). More specifically, first, the guard determination unit 91 calculates a first similarity DS1 (step S51) as in step S131, and calculates a second similarity DS2 (step S52) as in step S132.

[0189] Next, the guard determination unit 91 determines whether both the first similarity DS1 and the second similarity DS2 are equal to or greater than the second threshold value Ref2 (step S53). When both the first similarity DS1 and the second similarity DS2 are equal to or greater than the second threshold value Ref2, the guard determination unit 91 determines that the guard unit 40 is normal (step S46).

[0190] On the other hand, when at least one of the first similarity DS1 and the second similarity DS2 is less than the second threshold value Ref2, the guard determination unit 91 determines whether the number of determinations made in step S46 as NO (negative) is equal to or greater than a specified number n (step S54). If the number of determinations is less than n, the gas supply step (step S49) is executed again. That is, since it is possible that a single gas supply step is insufficient to blow away the droplets L1, the gas supply step is executed again.

[0191] When the number of determinations is equal to or greater than the number n, the guard determination unit 91 determines that an abnormality has occurred in the guard unit 40 (step S48). That is, the guard determination unit 91 determines that an abnormality has occurred if at least one of the first similarity DS1 and the second similarity DS2 after the liquid droplets L1 have been blown away in the gas supply process n times is less than the second threshold value Ref2.

[0192] As described above, according to the modified example, the gas supply step (step S49) is performed when at least one of the first similarity DS1 and the second similarity DS2 is less than the second threshold value Ref2 (step S45: NO) and when both the first similarity DS1 and the second similarity DS2 are equal to or greater than the first threshold value Ref1 (step S47: NO). In other words, the processing unit 1 performs the gas supply step in a situation where there is a high possibility that the droplet L1 is attached to the object portion of the guard part 40. Therefore, the gas can be used effectively while reducing the amount of gas consumed.

[0193] 17, the gas supplying step (step S49) can be performed n times, but n may be set to 1. In this case, step S54 is unnecessary.

[0194] Although the guard determination method and the substrate processing apparatus 100 have been described in detail above, the above description is merely illustrative in all respects and is not intended to be limiting. It is understood that countless variations not illustrated can be envisioned without departing from the scope of this disclosure. The configurations described in the above embodiments and variations can be combined or omitted as appropriate as long as they are not mutually inconsistent.

[0195] For example, the imaging step and the determination step of the guard monitoring process may be performed multiple times at predetermined time intervals during at least one of the periods during loading / unloading, liquid processing, and drying processing of the substrate W. In other words, the processing unit 1 may continuously perform the monitoring process for the guard part 40 during the period. [Explanation of symbols]

[0196] 1 Processing Unit 20 Substrate holder (spin chuck) 21 Spinbase 21a Top side 30 Liquid nozzle (first nozzle) 41 Guard (inner guard) 42 Guard (Medium Guard) 43 Guard (Outer Guard) 30A Liquid Nozzle (Second Nozzle) 30B Liquid nozzle (third nozzle) 80 Gas Nozzle 9 Control Unit 70 Camera 100 Substrate processing apparatus E1 ellipse DS1 similarity (first similarity) DS2 similarity (second similarity) M11, M21, M31, M41 Reference Image (1st Reference Image) M12, M22, M32, M42 Reference Image (Second Reference Image) R1,R2 Judgment area R11,R21 1st judgment area R12,R22 2nd judgment area Ref1 threshold, first threshold Ref2 Second threshold (threshold) S11 Guard lifting process S12 Imaging process S13 Judgment process SA1 short axis W substrate

Claims

1. A substrate holder for holding a substrate; a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holder; a cylindrical guard that surrounds the substrate holder and catches the processing liquid that splashes from the periphery of the substrate; a guard lifting mechanism that lifts and lowers the guard; a camera that is provided obliquely above the substrate holding portion and captures an image of an imaging area including the guard to generate a captured image; a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position, and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image; Equipped with the control unit determines the presence or absence of the abnormality based on a determination region in the captured image that includes a part of the guard; the determination region includes a first determination region and a second determination region; the first determination area and the second determination area are set on opposite sides of a minor axis of an imaginary ellipse along an upper peripheral edge portion of the guard in the captured image, The control unit determines that the guard is normal when it provisionally determines that the guard is normal in both the first determination region and the second determination region.

2. A substrate holding part that holds a substrate; a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holder; a cylindrical guard that surrounds the substrate holder and catches the processing liquid that splashes from the periphery of the substrate; a guard lifting mechanism that lifts and lowers the guard; a camera that is provided obliquely above the substrate holding portion and captures an image of an imaging area including the guard to generate a captured image; a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position, and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image; Equipped with the control unit determines the presence or absence of the abnormality based on a determination region in the captured image that includes a part of the guard; In the substrate processing apparatus, the determination area is set to an area that includes at least a part of an upper peripheral edge of the guard when the guard is positioned at the predetermined height position, but does not include the substrate.

3. A substrate holding part that holds a substrate; a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holder; a cylindrical guard that surrounds the substrate holder and catches the processing liquid that splashes from the periphery of the substrate; a guard lifting mechanism that lifts and lowers the guard; a camera that is provided obliquely above the substrate holding portion and captures an image of an imaging area including the guard to generate a captured image; a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position, and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image; Equipped with the control unit determines the presence or absence of the abnormality based on a determination region in the captured image that includes a part of the guard; the predetermined height position is a guard standby position in which an upper edge portion of the guard is lower than an upper surface of a spin base of the substrate holding unit that faces a lower surface of the substrate in the vertical direction; A substrate processing apparatus, wherein the determination area is set to an area including at least a portion of the peripheral portion of the upper end of the guard when positioned at the predetermined height position, the peripheral portion being on the front side as seen from the camera.

4. A substrate holding part that holds a substrate; a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holder; a cylindrical guard that surrounds the substrate holder and catches the processing liquid that splashes from the periphery of the substrate; a guard lifting mechanism that lifts and lowers the guard; a camera that is provided obliquely above the substrate holding portion and captures an image of an imaging area including the guard to generate a captured image; a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position, and determines whether or not there is an abnormality in the position or shape of the guard based on the captured image; Equipped with the control unit determines the presence or absence of the abnormality based on a determination region in the captured image that includes a part of the guard; the predetermined height position is a guard processing position where an upper edge of the guard is higher than an upper surface of the substrate held by the substrate holding part; The substrate processing apparatus, wherein the determination area is set to an area including a peripheral portion of the upper end of the guard when the guard is positioned at the predetermined height position, the peripheral portion being on the far side as seen from the camera.

5. 5. The substrate processing apparatus according to claim 4, The control unit moves at least one of the plurality of guards to the guard processing position, The substrate processing apparatus, wherein the determination area is set to an area including the upper peripheral edges of the plurality of guards when the plurality of guards are positioned at the respective guard processing positions.

6. 6. The substrate processing apparatus according to claim 1, the control unit determines that the guard is normal when a similarity between the determination region and a normal reference image is equal to or greater than a threshold value; A substrate processing apparatus, wherein the threshold value is set lower than the value of the similarity between the determination area of ​​the image captured when the guard is positioned at the specified height position and droplets are attached to the guard and the reference image.

7. A substrate holding part that holds a substrate; a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holder; a cylindrical guard that surrounds the substrate holder and catches the processing liquid that splashes from the periphery of the substrate; a guard lifting mechanism that lifts and lowers the guard; a camera that is provided obliquely above the substrate holding portion and captures an image of an imaging area including the guard to generate a captured image; a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position, and determines whether or not there is an abnormality in the position or shape of the guard based on a determination area that includes a part of the guard in the captured image; a gas nozzle including an outer peripheral surface of the guard, supplying gas to a target portion of the guard that is imaged in the determination area to blow off droplets adhering to the target portion of the guard; A substrate processing apparatus comprising:

8. A substrate holding part that holds a substrate; a liquid nozzle for supplying a processing liquid to the substrate held by the substrate holder; a cylindrical guard that surrounds the substrate holder and catches the processing liquid that splashes from the periphery of the substrate; a guard lifting mechanism that lifts and lowers the guard; a camera that is provided obliquely above the substrate holding portion and captures an image of an imaging area including the guard to generate a captured image; a control unit that outputs a control signal to the guard lifting mechanism to move the guard to a predetermined height position, and determines whether or not there is an abnormality in the position or shape of the guard based on a determination area that includes a part of the guard in the captured image; a gas nozzle that supplies gas to the guard to blow off droplets adhering to the guard; Equipped with The control unit a first step of determining that the guard is normal when a similarity between the determination region and a normal reference image is equal to or greater than a second threshold value that is higher than a first threshold value; a second step of supplying gas from the gas nozzle toward a portion of the guard that is captured in the determination area when the degree of similarity is less than the second threshold value and equal to or greater than the first threshold value; a third step of causing the camera to capture an image of the imaging area and generate the captured image after the second step; a fourth step of determining whether or not the abnormality exists based on the similarity between the determination region of the captured image generated in the third step and the reference image; Run the first threshold value is set to be lower than a first value of the similarity between the reference image and the determination area of ​​the captured image captured when the guard is located at the predetermined height position and droplets are attached to the captured portion of the guard, The second threshold value is set to be lower than a second value of the similarity between the judgment area of ​​the captured image taken when the guard is located at the specified height position and no liquid droplets are attached to the subject portion of the guard and the reference image, and higher than the first value.

9. A guard raising / lowering step of moving a cylindrical guard surrounding a substrate holding portion for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard by a camera provided above the substrate holding portion to generate a captured image; a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image; Equipped with In the determination step, the presence or absence of the abnormality is determined based on a determination region in the captured image that includes a part of the guard, the determination region includes a first determination region and a second determination region; the first determination area and the second determination area are set on opposite sides of a minor axis of an imaginary ellipse along an upper peripheral edge portion of the guard in the captured image, A guard determination method, wherein in the determination step, the guard is determined to be normal when it is provisionally determined that the guard is normal in both the first determination region and the second determination region.

10. A guard raising / lowering step of moving a cylindrical guard surrounding a substrate holding portion for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard by a camera provided above the substrate holding portion to generate a captured image; a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image; Equipped with In the determination step, the presence or absence of the abnormality is determined based on a determination region in the captured image that includes a part of the guard, A guard determination method, wherein the determination area is set to an area that includes at least a portion of the upper edge of the guard when it is located at the predetermined height position, but does not include the substrate.

11. A guard raising / lowering step of moving a cylindrical guard surrounding a substrate holding portion for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard by a camera provided above the substrate holding portion to generate a captured image; a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image; Equipped with In the determination step, the presence or absence of the abnormality is determined based on a determination region in the captured image that includes a part of the guard, the predetermined height position is a guard standby position in which an upper edge portion of the guard is lower than an upper surface of a spin base of the substrate holding unit that faces a lower surface of the substrate in the vertical direction; A guard judgment method in which the judgment area is set to an area that includes at least a portion of the peripheral portion of the upper end of the guard when positioned at the specified height position, the peripheral portion being on the front side as seen from the camera.

12. A guard raising / lowering step of moving a cylindrical guard surrounding a substrate holding portion for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard by a camera provided above the substrate holding portion to generate a captured image; a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image; Equipped with In the determination step, the presence or absence of the abnormality is determined based on a determination region in the captured image that includes a part of the guard, the predetermined height position is a guard processing position where an upper edge of the guard is higher than an upper surface of the substrate held by the substrate holding part; A guard determination method in which the determination area is set to an area including the innermost peripheral portion of the upper edge of the guard when it is located at the predetermined height position, as seen from the camera.

13. The guard determination method according to claim 12, In the guard lifting / lowering step, at least one of the plurality of guards is moved to the guard processing position, A guard determination method, wherein the determination area is set to an area including the upper peripheral edges of the plurality of guards when the plurality of guards are positioned at the respective guard processing positions.

14. 14. The guard determination method according to claim 9, further comprising: In the determination step, when a similarity between the determination region and a normal reference image is equal to or greater than a threshold value, the guard is determined to be normal; A guard determination method in which the threshold value is set lower than the value of the similarity between the determination area of ​​the captured image taken when the guard is located at the specified height position and liquid droplets are attached to the guard and the reference image.

15. A guard raising / lowering step of moving a cylindrical guard surrounding a substrate holding portion for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard by a camera provided above the substrate holding portion to generate a captured image; a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on a determination area including a part of the guard in the captured image; Equipped with The guard determination method further includes a gas supplying step, prior to the imaging step, of supplying gas to an imaged portion of the guard, including the outer peripheral surface thereof, that is imaged in the determination area, to blow away droplets adhering to the imaged portion of the guard.

16. A guard raising / lowering step of moving a cylindrical guard surrounding a substrate holding portion for holding a substrate to a predetermined height position; an imaging step of capturing an image of an imaging area including the guard by a camera provided above the substrate holding portion to generate a captured image; a determination step of determining whether or not an abnormality has occurred in the position or shape of the guard based on the captured image; Equipped with In the determination step, the presence or absence of the abnormality is determined based on a determination region in the captured image that includes a part of the guard, The determination step includes: a first step of determining that the guard is normal when a similarity between the determination region and a normal reference image is equal to or greater than a second threshold value that is higher than a first threshold value; a second step of supplying gas to a portion of the guard that is captured in the determination area when the degree of similarity is less than the second threshold value and equal to or greater than the first threshold value; a third step of capturing an image of the imaging area with the camera to generate the captured image after the second step; a fourth step of determining whether or not the abnormality exists based on the similarity between the determination region of the captured image generated in the third step and the reference image; Equipped with the first threshold value is set to be lower than a first value of the similarity between the reference image and the determination area of ​​the captured image captured when the guard is located at the predetermined height position and droplets are attached to the captured portion of the guard, A guard determination method in which the second threshold value is set lower than a second value of the similarity between the determination area of ​​the captured image taken when the guard is located at the specified height position and no droplets are attached to the subject portion of the guard and the reference image, and higher than the first value.

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