Substrate processing apparatus and monitoring method

Abstract

To provide a technique capable of monitoring a monitoring object with high accuracy by suppressing influence of unnecessary reflection light.SOLUTION: A substrate processing apparatus 100 comprises: a chamber 10; a substrate holding part 20; an illumination part 71; a polarization filter 73; a filter driving part 74; a camera 70; and a control part 9. The illumination part 71 irradiates an imaging region including a monitoring object in the chamber 10 with illumination light. The filter driving part 74 rotates the polarization filter 73 to the rotation position according to the monitoring object in the imaging region and reduces unnecessary reflection light according to the monitoring object with the polarization filter 73. The camera 70 images the imaging region through the polarization filter 73 to generate photographed image data. The control part 9 controls the filter driving part 74 and monitors the monitoring object on the basis of photographed image data generated by the camera 70.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus and a monitoring 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 and resist coating. A widely used apparatus for performing substrate processing using these processing liquids is a substrate processing apparatus in which a substrate holder rotates the substrate in a horizontal position while ejecting the processing liquid from a nozzle onto the surface of the substrate. For example, the nozzle ejects the processing liquid from a processing position vertically opposite the center of the upper surface of the substrate. The processing liquid that lands in the center of the substrate spreads over the surface of the substrate due to centrifugal force caused by the rotation of the substrate. The processing liquid acts on the surface of the substrate, thereby processing the substrate.

[0003] In such substrate processing apparatuses, whether the nozzle position is appropriate is monitored. For example, in Patent Document 1, an imaging means such as a camera is provided to monitor the nozzle position.

[0004] In Patent Document 1, the camera is provided above the substrate holder. The camera captures an image of an imaging area including the substrate held by the substrate holder and the nozzle, and generates a captured image. In Patent Document 1, a reference image including the nozzle is set in advance, and the position of the nozzle is detected by matching the captured image captured by the camera with the reference image. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-173148 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to more appropriately process substrates, it is desirable to monitor not only the nozzle position but also various other objects within the substrate processing apparatus.

[0007] For example, the substrate holding unit includes a disk-shaped spin base provided below the substrate, and a plurality of chuck pins arranged in a line in the circumferential direction along the periphery of the substrate on the upper surface of the spin base. The substrate holding unit can hold the substrate when the plurality of chuck pins move to a holding position where they abut against the periphery of the substrate, and the substrate is released from its hold when the plurality of chuck pins move to a release position away from the periphery of the substrate.

[0008] If an abnormality occurs and the chuck pins cannot move to the holding position, the substrate holder cannot hold the substrate normally.

[0009] Therefore, it is conceivable that a camera captures an image of an imaging area including the chuck pin, generates captured image data, and an image processing unit monitors the position of the chuck pin based on the captured image data.

[0010] A camera generates a captured image by receiving light from an imaging area on its light-receiving surface. The captured image includes a visualized image of reflected light from the imaging area, but some of this reflected light is unnecessary for monitoring. For example, if the intensity of the reflected light from the imaging area is too high, objects within the imaging area will be obscured by the reflected light, reducing the visibility of the objects in the captured image. As a notable example, if the intensity of the reflected light is too high and pixel values ​​saturate, the image of the object within that area will become invisible. Such reflected light with too high intensity reduces monitoring accuracy, which is a problem.

[0011] Furthermore, if droplets of processing liquid are present in the imaging area, the light reflected from the droplets will be incident on the light receiving surface of the camera, and the droplets will also be captured in the captured image. For example, if droplets adhere to the chuck pin, the droplets will also be captured in the captured image. Such droplets can also reduce monitoring accuracy.

[0012] As described above, when reflected light of excessively high intensity and unwanted reflected light such as reflected light from droplets enter the light receiving surface of the camera, the influence of the unwanted reflected light on the captured image increases, resulting in a problem of reduced monitoring accuracy.

[0013] Therefore, an object of the present disclosure is to provide a technology that can suppress the influence of unwanted reflected light and monitor a monitoring target with higher accuracy. [Means for solving the problem]

[0014] A first aspect is a substrate processing apparatus comprising: a chamber; a substrate holder that holds a substrate; an illumination unit that irradiates an imaging area including a monitoring object in the chamber with illumination light; a polarizing filter that transmits light from the imaging area in accordance with the polarization state of the light; a filter drive unit that rotates the polarizing filter to a rotation position corresponding to the monitoring object and reduces unnecessary reflected light corresponding to the monitoring object with the polarizing filter; a camera that images the imaging area through the polarizing filter and generates captured image data; and a control unit that controls the filter drive unit and monitors the monitoring object based on the captured image data generated by the camera. The control unit determines the rotation position of the polarizing filter based on a plurality of captured image data generated by the camera capturing images of the imaging area while the filter driving unit sequentially rotates the polarizing filter. . A second aspect is the substrate processing apparatus according to the first aspect, wherein the control unit determines the rotation position based on the contrast of the plurality of captured image data or the number of contour lines in the plurality of captured image data. A third aspect is a substrate processing apparatus comprising: a chamber; a substrate holding unit that holds a substrate; an illumination unit that irradiates illumination light onto an imaging area including an object to be monitored within the chamber; a polarizing filter that transmits the light from the imaging area depending on the polarization state of the light; a filter drive unit that rotates the polarizing filter to a rotational position depending on the object to be monitored and causes the polarizing filter to reduce unwanted reflected light depending on the object to be monitored; a camera that images the imaging area through the polarizing filter and generates captured image data; and a control unit that controls the filter drive unit and monitors the object to be monitored based on the captured image data generated by the camera, wherein the illumination unit includes a plurality of unit illumination units, and the unit illumination unit that irradiates the illumination light among the plurality of unit illumination units is switched depending on the object to be monitored so as to enhance the effect of the polarizing filter in reducing the unwanted reflected light.

[0015] No. 4 The embodiment is 3 The substrate processing apparatus according to the aspect of the present invention includes a memory unit that pre-stores angle data indicating the rotational position of the polarizing filter corresponding to the object to be monitored, and the filter drive unit rotates the polarizing filter to the rotational position corresponding to the object to be monitored based on the angle data.

[0018] A fifth aspect is a substrate processing apparatus according to any one of the first to fourth aspects, wherein the filter driving unit rotates the polarizing filter to a first rotational position that reduces the unwanted reflected light within a first judgment area of ​​the captured image data used to monitor a first monitored object as the monitored object, and the control unit monitors the first monitored object based on the first judgment area of ​​the captured image data when the polarizing filter is positioned at the first rotational position, and the filter driving unit rotates the polarizing filter to a second rotational position that reduces the unwanted reflected light within a second judgment area of ​​the captured image data used to monitor a second monitored object as the monitored object, and the control unit monitors the second monitored object based on the second judgment area of ​​the captured image data when the polarizing filter is positioned at the second rotational position.

[0019] A sixth aspect is a substrate processing apparatus according to any one of the first to fourth aspects, wherein, when a first object is present in the imaging area, the filter drive unit rotates the polarizing filter to a first rotation position that reduces the unwanted reflected light from the first object, and the control unit monitors the monitored object based on the captured image data when the polarizing filter is located at the first rotation position and the first object is present in the imaging area, and when a second object is present in the imaging area, the filter drive unit rotates the polarizing filter to a second rotation position that reduces the unwanted reflected light from the second object, and the control unit monitors the monitored object based on the captured image data when the polarizing filter is located at the second rotation position and the second object is present in the imaging area.

[0020] A seventh aspect is a substrate processing apparatus according to any one of the first to sixth aspects, wherein the illumination unit is arranged vertically above the imaging area, and the camera is arranged outside the illumination unit relative to the imaging area in a planar view, and images the imaging area diagonally downward.

[0022] No. 8The aspect of the present invention is a monitoring method, comprising: a polarization adjustment step of rotating a polarizing filter, which is provided between an imaging area including a monitoring object in a chamber accommodating a substrate holder that holds a substrate, and a camera, and which transmits light from the imaging area in accordance with the polarization state of the light, to reduce unnecessary reflected light corresponding to the monitoring object with the polarizing filter; an imaging step of using the camera to capture an image of the imaging area through the polarizing filter while an illumination unit irradiates the imaging area with illumination light, and to generate captured image data; and a monitoring step of monitoring the monitoring object based on the captured image data generated by the camera. In the polarization adjustment step, the polarization filter is rotated sequentially, and the rotation position of the polarization filter is determined based on a plurality of pieces of captured image data generated by the camera capturing images of the imaging area. . [Effects of the Invention]

[0023] 1st and 2nd 8 According to this aspect, the filter drive unit rotates the polarizing filter in accordance with the object being monitored, causing the polarizing filter to reduce unwanted reflected light. This reduces the influence of unwanted reflected light on the captured image data generated by the camera. Therefore, the control unit can monitor the object being monitored with higher accuracy based on the captured image data. Moreover, there is no need to set angle data in advance.

[0024] No. 4 According to this aspect, the rotation position can be determined by simple processing.

[0026] No. 2 According to this aspect, the unwanted reflected light is reduced, and thus the contrast and the number of contour lines are increased. Therefore, the influence of the unwanted reflected light on the captured image can be determined based on the contrast or the number of contour lines.

[0027] According to the fifth aspect, unwanted reflected light within the determination area of ​​the monitored object can be reduced in accordance with the monitored object, and the monitored object can be monitored based on the determination area in which unwanted reflected light is reduced, thereby enabling monitoring of the monitored object with high accuracy.

[0028] According to the sixth aspect, unwanted reflected light corresponding to an object present in the imaging area is reduced, so that the influence of unwanted reflected light on the captured image can be appropriately reduced.

[0029] According to the seventh aspect, the effect of reducing unwanted reflected light by the polarizing filter can be further enhanced.

[0030] No. 3 According to this aspect, the effect of reducing unwanted reflected light by the polarizing filter can be further improved depending on the monitored object. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus according to a first embodiment. [Figure 2] FIG. 2 is a plan view schematically illustrating an example of the configuration of a processing unit according to the first embodiment. [Figure 3] FIG. 2 is a longitudinal sectional view schematically showing an example of the configuration of a processing unit according to the first embodiment. [Figure 4] FIG. 2 is a diagram schematically illustrating an example of the configuration of a filter driving section. [Figure 5] FIG. 2 is a functional block diagram illustrating an example of an internal configuration of a control unit. [Figure 6] 1 is a flowchart showing an example of a flow of substrate processing. [Figure 7] FIG. 2 is a diagram schematically illustrating an example of a captured image. [Figure 8] FIG. 2 is a diagram schematically illustrating an example of a captured image. [Figure 9] 10 is a flowchart illustrating an example of a monitoring process. [Figure 10] 10 is a flowchart showing a specific example of a polarization adjustment process. [Figure 11] FIG. 10 is a diagram schematically illustrating the configuration of another embodiment of the processing unit. [Figure 12] FIG. 10 is a functional block diagram illustrating an example of an internal configuration of a control unit of a processing unit according to another embodiment. [Figure 13]10 is a flowchart illustrating an example of a monitoring process according to another embodiment. [Figure 14] FIG. 10 is a diagram schematically illustrating an example of the configuration of a substrate processing apparatus according to a second embodiment. [Figure 15] FIG. 2 is a diagram schematically illustrating an example of a captured image. DETAILED DESCRIPTION OF THE INVENTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 according to a first embodiment. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W 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 having 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 dilute hydrofluoric acid (DHF) solution. In the following description, the chemical solution, rinse solution, and organic solvent are collectively referred to as the "processing solution." Note 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Hereinafter, one of the twelve processing units 1 installed in the substrate processing apparatus 100 will be described.

[0043] <Processing unit> Fig. 2 is a plan view schematically showing an example of the configuration of the processing unit 1 according to the first embodiment. Fig. 3 is a vertical cross-sectional view schematically showing an example of the configuration of the processing unit 1 according to the first embodiment.

[0044] In the examples of Figures 2 and 3, the processing unit 1 includes a substrate holding part 20, a first nozzle 30, a second nozzle 60, a third nozzle 65, a guard part 40, a camera 70, a polarizing filter 73, and a filter driving part 74.

[0045] 2 and 3, the processing unit 1 also includes a chamber 10. 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. A processing space is formed in the space enclosed by the sidewall 11, the ceiling wall 12, and the floor wall 13. A loading / unloading port through which the main transport robot 103 loads and unloads the substrate W, and a shutter that opens and closes the loading / unloading port are provided in part of the sidewall 11 of the chamber 10 (all not shown). The chamber 10 houses a substrate holder 20, a first nozzle 30, a second nozzle 60, a third nozzle 65, and a guard unit 40.

[0046] 3, a fan filter unit (FFU) 14 is attached to the ceiling wall 12 of the chamber 10 to further purify the air in a clean room in which the substrate processing apparatus 100 is installed and supply the purified air to the processing space in 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 from the clean room and sending it into the chamber 10, and forms a downflow of purified air in the processing space in 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.

[0047] The substrate holder 20 holds the substrate W in a horizontal position (a position in which the normal is along the vertical direction) and rotates the substrate W around a rotation axis CX (see FIG. 3). The rotation axis CX is an axis that is along the vertical direction and passes through the center of the substrate W. The substrate holder 20 is also called a spin chuck. Note that FIG. 2 shows the substrate holder 20 in a state in which it is not holding a substrate.

[0048] 2 and 3, the substrate holding unit 20 includes a disk-shaped spin base 21 that is arranged in a horizontal position. The outer diameter of the disk-shaped spin base 21 is slightly larger than the diameter of the circular substrate W held by the substrate holding unit 20 (see FIG. 3). Thus, 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.

[0049] 2 and 3, 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 plurality of chuck pins 26 are arranged at equal intervals along a circumference corresponding to the peripheral edge of the circular substrate W. Each chuck pin 26 is provided so as to be 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 plurality of chuck pins 26 are driven in conjunction with each other by a link mechanism (not shown) housed in the spin base 21. The substrate holder 20 can hold the substrate W in a horizontal position close to the upper surface 21a above the spin base 21 by stopping the plurality of chuck pins 26 at their respective holding positions (see FIG. 3), and can release the substrate W from its holding by stopping the plurality of chuck pins 26 at their respective open positions.

[0050] 3, the upper end of a rotation shaft 24 extending along the rotation axis CX is connected to the lower surface of the spin base 21. A spin motor 22 that rotates the rotation shaft 24 is provided below the spin base 21. The spin motor 22 rotates the rotation shaft 24 about the rotation axis CX, thereby rotating the spin base 21 within a horizontal plane. As a result, the substrate W held by the chuck pins 26 also rotates about the rotation axis CX.

[0051] 3, a cylindrical cover member 23 is provided to surround the periphery of the spin motor 22 and the rotation shaft 24. The lower end of the cover member 23 is fixed to the floor wall 13 of the chamber 10, and the upper end reaches directly below the spin base 21. In the example of FIG. 3, a flange-shaped member 25 is provided at the upper end of the cover member 23, which extends outward from the cover member 23 almost horizontally and then bends downward.

[0052] 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 attached to the tip of a nozzle arm 32. The nozzle arm 32 extends horizontally, and its base end is connected to a nozzle support column 33. The nozzle support column 33 extends vertically and is rotatable about a vertical axis by an arm drive motor (not shown). As the nozzle support column 33 rotates, the first nozzle 30 moves in an arc between a nozzle processing position and a nozzle standby position in a space vertically above the substrate holder 20, as indicated by arrow AR34 in FIG. 2. The nozzle processing position is a position where the first nozzle 30 ejects a processing liquid onto the substrate W, e.g., 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 a processing liquid onto the substrate W, e.g., a position radially outward from the periphery of the substrate W. The radial direction here refers to the radial direction about the rotation axis CX. Figure 2 shows the first nozzle 30 positioned at the nozzle standby position, and Figure 3 shows the first nozzle 30 positioned at the nozzle operating position.

[0053] 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 is supplied from the processing liquid supply source 36 through the supply pipe 34 to the first nozzle 30, and is then ejected from an ejection port formed in the lower end surface of the first nozzle 30. The first nozzle 30 may be configured to be supplied with a plurality of types of processing liquid (including at least pure water).

[0054] The second nozzle 60 is attached to the tip of a nozzle arm 62, and the base end of the nozzle arm 62 is connected to a nozzle support column 63. A motor for driving the arm (not shown) rotates the nozzle support column 63, causing the second nozzle 60 to move in an arc in the space vertically above the substrate holding unit 20, as shown by arrow AR64. Similarly, the third nozzle 65 is attached to the tip of a nozzle arm 67, and the base end of the nozzle arm 67 is connected to a nozzle support column 68. A motor for driving the arm (not shown) rotates the nozzle support column 68, causing the third nozzle 65 to move in an arc in the space vertically above the substrate holding unit 20, as shown by arrow AR69.

[0055] Like the first nozzle 30, the second nozzle 60 and the third nozzle 65 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.

[0056] During liquid processing, the processing unit 1 rotates the substrate W using the substrate holder 20 while ejecting the 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 treated in accordance with the type of processing liquid.

[0057] The guard section 40 is a member for receiving processing liquid splashed from the periphery of the substrate W. The guard section 40 has a cylindrical shape surrounding the substrate holding section 20 and includes, for example, multiple guards that can be raised and lowered independently of each other. The guards may also be called processing cups. In the example of FIG. 3, the multiple guards are an inner guard 41, a middle guard 42, and an outer guard 43. Each of the guards 41 to 43 surrounds the periphery of the substrate holding section 20 and has a shape that is approximately rotationally symmetrical with respect to the rotation axis CX.

[0058] In the example shown in FIG. 3 , the inner guard 41 integrally includes a bottom portion 44, an inner wall portion 45, an outer wall portion 46, a first guide portion 47, and a middle wall portion 48. The bottom portion 44 has an annular shape in a plan view. The inner wall portion 45 and the outer wall portion 46 have cylindrical shapes and are respectively provided on the inner and outer peripheral edges of the bottom portion 44. The first guide portion 47 has a cylindrical tubular portion 47a provided on the bottom portion 44 between the inner wall portion 45 and the outer wall portion 46 and extending vertically upward from the upper end of the tubular portion 47a and approaching the rotation axis CX as it extends vertically upward. The middle wall portion 48 has a cylindrical shape and is provided on the bottom portion 44 between the first guide portion 47 and the outer wall portion 46.

[0059] When the guards 41 to 43 are raised (see the imaginary lines in FIG. 3), the processing liquid splashed from the periphery of the substrate W is received by the inner peripheral surface of the first guide portion 47, flows down along the inner peripheral surface, and is received in the waste groove 49. The waste groove 49 is an annular groove formed by the inner wall portion 45, the first guide portion 47, and the bottom portion 44. A liquid exhaust mechanism (not shown) is connected to the waste groove 49 to discharge the processing liquid and to forcibly exhaust the air from the inside of the waste groove 49.

[0060] 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. The second guide portion 52 has a cylindrical tubular portion 52a and an inclined portion 52b that approaches the rotation axis CX as it extends vertically upward from the upper end of the tubular portion 52a. The inclined portion 52b is located vertically above the inclined portion 47b of the inner guard 41 and is arranged to overlap with the inclined portion 47b in the vertical direction. The tubular portion 52a is housed in an annular inner recovery groove 50. The inner recovery groove 50 is a groove formed by the first guide portion 47, the middle wall portion 48, and the bottom portion 44.

[0061] When only the guards 42 and 43 are raised, the processing liquid from the periphery of the substrate W is received by the inner peripheral surface of the second guide portion 52 , flows down along the inner peripheral surface, and is received in the inner recovery groove 50 .

[0062] The processing liquid separation wall 53 has a cylindrical shape, and its upper end is connected to the second guide part 52. The processing liquid separation wall 53 is housed in an annular outer recovery groove 51. The outer recovery groove 51 is a groove formed by the middle wall part 48, the outer wall part 46, and the bottom part 44.

[0063] The outer guard 43 is located outside the middle guard 42 and functions as a third guide section that guides the treatment liquid to the outer recovery groove 51. The outer guard 43 integrally includes a cylindrical portion 43a and an inclined portion 43b that approaches the rotation axis CX as it extends vertically upward from the upper end of the cylindrical portion 43a. The cylindrical portion 43a is housed within the outer recovery groove 51, and the inclined portion 43b is located vertically above the inclined portion 52b and is arranged to overlap the inclined portion 52b in the vertical direction.

[0064] When only the outer guard 43 is raised, the processing liquid from the periphery of the substrate W is received by the inner peripheral surface of the outer guard 43 , flows down along the inner peripheral surface, and is received in the outer recovery groove 51 .

[0065] The inner recovery groove 50 and the outer recovery groove 51 are connected to recovery mechanisms (both not shown) for recovering the processing liquid into a recovery tank provided outside the processing unit 1.

[0066] The guards 41 to 43 can be raised and lowered by a guard lifting mechanism 55. The guard lifting mechanism 55 raises and lowers the guards 41 to 43 between their respective guard processing positions and guard standby positions so that the guards 41 to 43 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 guards 41 to 43 are located at the guard standby position. The guard lifting mechanism 55 includes, for example, a ball screw mechanism and a motor or an air cylinder.

[0067] 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 and cutouts (not shown) that penetrate in the thickness direction, and in this embodiment, through-holes are formed to allow the nozzle support columns 33, 63, and 68 to pass through. The outer peripheral edge of the partition plate 15 is connected to the side wall 11 of the chamber 10. The inner peripheral edge 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.

[0068] In the example of Figure 3, an exhaust duct 18 is provided in part of the side wall 11 of the chamber 10, near the floor wall 13. The exhaust duct 18 is connected to an exhaust mechanism (not shown). Of the clean air that flows down inside the chamber 10, the air that passes between the guard part 40 and the partition plate 15 is exhausted to the outside of the apparatus through the exhaust duct 18.

[0069] The camera 70 is used to monitor the state of an object to be monitored within the chamber 10. The object to be monitored includes, for example, at least one of the substrate holder 20, the first nozzle 30, the second nozzle 60, the third nozzle 65, and the guard unit 40. The camera 70 captures an image of an imaging area including the object to be monitored, generates captured image data (hereinafter simply referred to as a captured image), and outputs the captured image to the control unit 9. The control unit 9 monitors the state of the object to be monitored based on the captured image, as will be described in detail later.

[0070] 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. In the example of Fig. 3, the camera 70 is installed at an imaging position vertically above the substrate W held by the substrate holder 20. In the example of Fig. 3, the imaging position is set vertically above the partition plate 15 and radially outward from the guard part 40. The radial direction here refers to the radial direction with respect to the rotation axis CX.

[0071] In the example of FIG. 3, a recessed portion (hereinafter referred to as a recessed wall portion 111) for accommodating the camera 70 is formed in the side wall 11 of the chamber 10. The recessed wall portion 111 has a shape that is recessed outward relative to the rest of the side wall 11. The camera 70 is accommodated inside the recessed wall portion 111. In the example of FIG. 3, a transparent member 72 is provided in front of the camera 70 in the imaging direction. The transparent member 72 has high translucency for the wavelength of light detected by the camera 70. Therefore, the camera 70 can image the imaging region within the processing space through the transparent member 72. In other words, the transparent member 72 is provided between the camera 70 and the imaging region. The transmittance of the transparent member 72 in the detection wavelength range of the camera 70 is, for example, 60% or more, preferably 80% or more. The transparent member 72 is formed of a transparent material such as quartz glass. In the example of FIG. 3, the transparent member 72 has a plate-like shape and, together with the recessed wall portion 111 of the side wall 11, forms an accommodation space for the camera 70. By providing the transparent member 72, the camera 70 can be protected from the processing liquid in the processing space and volatile components of the processing liquid.

[0072] The imaging area of ​​the camera 70 includes, for example, a portion of the substrate holding part 20 and the guard part 40. In the example of Fig. 3, the camera 70 captures an image of the imaging area obliquely downward from the imaging position. In other words, the imaging direction of the camera 70 is inclined vertically downward from the horizontal direction.

[0073] In the example of FIG. 3, the illumination unit 71 is provided at a position vertically above the partition plate 15. In the example of FIG. 3, the illumination unit 71 is provided radially outward of the guard unit 40 in a plan view, and as a more specific example, is provided inside the recessed wall portion 111. The illumination unit 71 includes a light source such as a light-emitting diode, and irradiates the imaging area with irradiation light. If the inside of the chamber 10 is a darkroom, the control unit 9 may control the illumination unit 71 so that the illumination unit 71 illuminates the imaging area when the camera 70 takes an image. The illumination light from the illumination unit 71 passes through the transparent member 72 and is irradiated into the processing space.

[0074] The polarizing filter 73 is provided between the camera 70 and the imaging region. In the example of FIG. 3, the polarizing filter 73 is also provided inside the recessed wall portion 111. The polarizing filter 73 transmits light from the imaging region according to the polarization state of the light. Specifically, the absorption axis and polarization axis of the polarizing filter 73 are perpendicular to each other, and the polarizing filter 73 absorbs the polarized component of the light incident on it that is aligned with the absorption axis and transmits the polarized component that is aligned with the polarization axis. The polarizing filter 73 may be a circular polarizing filter. The light reflected from the imaging region is incident on the light receiving surface of the camera 70 through the polarizing filter 73. In other words, the camera 70 captures the image of the imaging region through the polarizing filter 73.

[0075] The filter driver 74 rotates the polarizing filter 73 around a rotation axis Q2 that is aligned with the optical axis of the polarizing filter 73. This causes the absorption axis of the polarizing filter 73 to rotate around the rotation axis Q2. In the example of Figure 3, the rotation axis Q2 is also aligned with the imaging direction of the camera 70.

[0076] FIG. 4 is a diagram schematically illustrating an example of the configuration of the filter driver 74. The filter driver 74 includes a case 741, a rotary holder 742, and a rotation mechanism 743. The case 741 has a ring-shaped outer shape surrounding the rotation axis Q2. The rotary holder 742 holds the periphery of the polarizing filter 73 and is housed in the case 741 so as to be rotatable about the rotation axis Q2. The rotation mechanism 743 rotates the rotary holder 742 relative to the case 741. In the example shown in FIG. 4, the rotation mechanism 743 includes a power transmission mechanism 744 and a motor 745. The motor 745 is controlled by the control unit 9. The motor 745 transmits a rotational force to the rotary holder 742 via the power transmission mechanism 744, causing the rotary holder 742 to rotate relative to the case 741. The power transmission mechanism 744 has, for example, an external gear that meshes with multiple teeth formed on the outer circumferential surface of the rotary holding member 742. When the motor 745 rotates the external gear, the rotary holding member 742 that meshes with the external gear rotates. When the rotation mechanism 743 rotates the rotary holding member 742, the polarizing filter 73 held by the rotary holding member 742 rotates around the rotation axis Q2.

[0077] As will be described later, the filter driver 74 rotates the polarizing filter 73 around the rotation axis Q2 in accordance with the unwanted reflected light from the imaging area, thereby reducing the unwanted reflected light with the polarizing filter 73. The unwanted reflected light here refers to light reflected from the imaging area, and is reflected light that can reduce the monitoring accuracy of the monitored object. Specific examples of unwanted reflected light will be described later.

[0078] The hardware configuration of the control unit 9 is the same as that of a general computer. That is, the control unit 9 is configured to include a data processing unit such as a CPU that performs various arithmetic processing, a non-temporary storage unit such as a ROM (Read Only Memory) that is a read-only memory that stores a basic program, and a temporary storage unit such as a RAM (Random Access Memory) that is a readable and writable memory that stores various information. When the CPU of the control unit 9 executes a predetermined processing program, the control unit 9 controls each operating mechanism of the substrate processing apparatus 100, and processing in the substrate processing apparatus 100 progresses. Note that the control unit 9 may be realized by a dedicated hardware circuit that does not require software to realize its functions.

[0079] 5 is a functional block diagram schematically showing an example of the internal configuration of the control unit 9. As shown in FIG. 5, the control unit 9 includes a polarization control unit 91, a monitoring processing unit 92, and a processing control unit 93.

[0080] The polarization control unit 91 outputs a control signal to the filter driving unit 74 (more specifically, the motor 745) to cause the filter driving unit 74 to rotate the polarization filter 73. The detailed operation of the polarization control unit 91 will be described later.

[0081] The monitoring processing unit 92 monitors the state of the monitoring object based on the captured image from the camera 70. The detailed operation of the monitoring processing unit 92 will also be explained later.

[0082] The process control unit 93 controls each component of the processing unit 1. More specifically, the process control unit 93 controls the spin motor 22, various valves such as the valve 35, arm drive motors that rotate each of the nozzle support columns 33, 63, and 68, the guard lifting mechanism 55, the fan filter unit 14, and the camera 70. The process control unit 93 controls these components in accordance with a predetermined procedure, thereby enabling the processing unit 1 to process the substrate W.

[0083] <An example of substrate processing flow> Here, an example of a specific flow of processing the substrate W will be briefly described. Fig. 6 is a flowchart showing an example of the flow of substrate processing. Initially, the guards 41 to 43 each stop at a guard standby position, and the nozzles 30, 60, 65 each stop at a nozzle standby position. Note that although the control unit 9 controls each component to perform a predetermined operation described below, the following description will focus on each component itself as the subject of the operation.

[0084] First, the main transport robot 103 loads an unprocessed substrate W into the processing unit 1, and the substrate holding part 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 handed over to the substrate holding part 20, the multiple chuck pins 26 move to their respective holding positions, thereby holding the substrate W.

[0085] Next, the spin motor 22 starts rotating the substrate W (step S2: rotation start step). Specifically, the spin motor 22 rotates the spin base 21, thereby rotating the substrate W held by the substrate holder 20.

[0086] Next, the processing unit 1 performs various liquid treatments on the substrate W (step S3: liquid treatment step). For example, the processing unit 1 performs chemical liquid treatment. First, the guard lifting mechanism 55 raises one of the guards 41 to 43 that corresponds to the chemical liquid to the guard treatment position. The guard for the chemical liquid is not particularly limited, but may be, for example, the outer guard 43. In this case, the guard lifting mechanism 55 stops the inner guard 41 and the middle guard 42 at their respective guard standby positions, and raises the outer guard 43 to the guard treatment position.

[0087] 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 arm drive motor moves the first nozzle 30 to the nozzle processing position, and the valve 35 opens to discharge 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. At this time, the chemical liquid acts on the upper surface of the substrate W, and processing according to the chemical liquid (e.g., cleaning processing) is performed on the substrate W. The chemical liquid splashed from the periphery of the substrate W is received by the inner circumferential surface of the guard part 40 (e.g., outer guard 43). When the chemical liquid processing has been sufficiently performed, the processing unit 1 stops supplying the chemical liquid.

[0088] Next, the processing unit 1 performs a rinse process on the substrate W. The guard lifting mechanism 55 adjusts the lifted state of the guard part 40 as necessary. That is, if the guard for the rinse liquid is different from the guard for the chemical liquid, the guard lifting mechanism 55 moves the guard corresponding to the rinse liquid among the guards 41 to 43 to the guard processing position. The guard for the rinse liquid is not particularly limited, but may be the inner guard 41. In this case, the guard lifting mechanism 55 lifts the guards 41 to 43 to their respective guard processing positions.

[0089] 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 rinse liquid) splashed from the periphery of the substrate W is received by the inner circumferential surface of the guard portion 40 (for example, the inner guard 41). When the rinsing process has been sufficiently performed, the processing unit 1 stops supplying the first rinse liquid.

[0090] If necessary, the processing unit 1 may supply a volatile second rinse liquid, such as highly volatile isopropyl alcohol, to the substrate W. If the guard for the second rinse liquid is different from the guard for the first rinse liquid described above, the guard lifting mechanism 55 may move the guard corresponding to the second rinse liquid among the guards 41 to 43 to the guard processing position. When the rinse process is completed, the first nozzle 30 moves to the nozzle standby position.

[0091] Next, the processing unit 1 performs a drying process on the substrate W (step S4: 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 has been sufficiently completed, the spin motor 22 stops the rotation of the substrate W.

[0092] Next, the guard lifting mechanism 55 lowers the guard portion 40 to the guard standby position (step S5: guard lowering step). That is, the guard lifting mechanism 55 lowers the guards 41 to 43 to their respective guard standby positions.

[0093] Next, the substrate holder 20 releases its hold on the substrate W, and the main transport robot 103 removes the processed substrate W from the processing unit 1 (step S6: hold release and unloading process). When the substrate W is unloaded, 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.

[0094] As described above, the substrate W is processed by the appropriate operation of various components in the processing unit 1. For example, the substrate holder 20 holds or releases the substrate W. The first nozzle 30 moves between the nozzle processing position and the nozzle standby position, and ejects the processing liquid toward the substrate W at the nozzle processing position. The guards 41 to 43 of the guard section 40 move to height positions according to each process.

[0095] <Monitoring process> If these components do not operate properly, the processing of the substrate W will be inappropriate. Therefore, in this embodiment, the processing unit 1 monitors at least one of the above components as a monitoring target, based on an image captured by the camera 70.

[0096] for example Delivery and Retention In the process (step S1), if the guard section 40 is not moved to the guard standby position, there is a possibility that the hand of the main transport robot 103 will collide with the guard section 40 when the substrate W is carried in. Delivery and Retention It is desirable to monitor the position of the guard 40 during the process.

[0097] For example, Delivery and Retention If the chuck pins 26 cannot move to the holding position after the substrate W is carried in during the process, the substrate holder 20 cannot properly hold the substrate W. Delivery and Retention It is also desirable to monitor the position of the chuck pins 26 of the substrate holder 20 after the substrate W is loaded for processing.

[0098] Furthermore, for example, if the first nozzle 30 cannot appropriately discharge the processing liquid in the liquid processing step (step S3), the processing of the substrate W may be excessive or insufficient. Therefore, it is also desirable to monitor the discharge state of the first nozzle 30 in the liquid processing step.

[0099] Furthermore, for example, if guard unit 40 cannot move appropriately to the guard processing position during a liquid processing step, the guard corresponding to the processing liquid will not be able to receive the processing liquid. Therefore, it is also desirable to monitor the position of guard unit 40 during the liquid processing step.

[0100] Furthermore, for example, if the guard section 40 does not move appropriately to the guard standby position in the guard lowering step (step S5), there is a possibility that the hand of the main transport robot 103 will collide with the guard section 40 in the subsequent holding release carry-out step (step S6). Therefore, it is also desirable to monitor the position of the guard section 40 in the guard lowering step.

[0101] 7 and 8 are diagrams schematically showing examples of captured images. In the captured image of FIG. 7, the substrate holding unit 20 holds the substrate W, and the guard unit 40 is stopped at the guard standby position. This captured image is obtained, for example, by the camera 70 capturing an image of the capture area during the loading and holding step (step S1) or the guard lowering step (step S5). In the captured image of FIG. 8, the substrate holding unit 20 holds the substrate W, only the outer guard 43 is stopped at the guard processing position, and the first nozzle 30 is stopped at the nozzle processing position. This captured image is obtained, for example, by the camera 70 capturing an image of the capture area during the liquid processing step.

[0102] The captured image in Fig. 7 includes the entire upper surface of the substrate W held by the substrate holder 20, and the captured image in Fig. 8 includes the entire upper periphery of the outer guard 43 positioned at the guard processing position. In other words, the camera 70 is installed so that the entire upper surface of the substrate W and the entire upper periphery of the outer guard 43 positioned at the guard processing position are included in the imaging area. Here, the camera 70 images the imaging area obliquely downward, and therefore the upper surface of the substrate W and the upper periphery of the outer guard 43, which are circular in plan view, have an elliptical shape in the captured image.

[0103] With such an imaging area, the captured image includes a plurality of chuck pins 26 as illustrated in Fig. 7, and also includes the first nozzle 30 positioned at the nozzle processing position as illustrated in Fig. 8. Although not shown, the captured image also includes the second nozzle 60 and the third nozzle 65 positioned at the nozzle processing position. This allows the monitoring processing unit 92 to monitor the states of the substrate holding unit 20, the first nozzle 30, the second nozzle 60, the third nozzle 65, and the guard unit 40 based on the captured image.

[0104] However, monitoring processor 92 does not need to constantly monitor all of these monitoring targets. For example, monitoring processor 92 only needs to monitor the discharge state of first nozzle 30 during the liquid processing step (step S3), and does not need to monitor during other steps.

[0105] Furthermore, when monitoring the states of these monitoring objects, the monitoring processor 92 does not need to use the entire area of ​​the captured image. That is, the monitoring processor 92 monitors the states of the monitoring objects based on a determination area that includes the monitoring objects. For example, the captured image in FIG. 7 shows a pin determination area R1 and a guard determination area R2. The pin determination area R1 is an area used to monitor the positions of the chuck pins 26 of the substrate holder 20. In the example of FIG. 7, the captured image includes four chuck pins 26, and therefore, four pin determination areas R1 are set in advance to correspond to the four chuck pins 26, respectively. Each pin determination area R1 is set to an area that includes at least a portion of the chuck pin 26 positioned at the holding position. In the example of FIG. 7, each pin determination area R1 is set to include a portion of the chuck pin 26 that abuts against the periphery of the substrate W.

[0106] The monitoring processing unit 92 monitors the position of the chuck pin 26 based on the pin determination area R1. For example, a reference image M1 for monitoring the position of the chuck pin 26 is stored in advance in the storage unit 94. The reference image M1 is an image in which the chuck pin 26 is positioned correctly in the holding position. The reference image M1 is generated in advance based on, for example, an image captured by the camera 70 when the chuck pin 26 is positioned correctly in the holding position and capturing an image of the imaging area. The reference image M1 is an image of the same area as the pin determination area R1. Here, since a plurality of pin determination areas R1 are provided, a plurality of reference images M1 corresponding to the plurality of pin determination areas R1 are set.

[0107] The monitoring processor 92 monitors the positions of the chuck pins 26 by comparing each pin determination area R1 with the corresponding reference image M1. As a specific example, the monitoring processor 92 calculates the similarity between the pin determination area R1 and the reference image M1. The similarity is not particularly limited, and may be any 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.

[0108] If the chuck pin 26 is located at the holding position, the similarity between the pin determination region R1 and the reference image M1 is high. Conversely, when the similarity is high, it can be considered that the chuck pin 26 is located at the holding position.

[0109] Therefore, when the similarity is equal to or greater than a predetermined pin threshold value, the monitoring processing unit 92 determines that the chuck pin 26 is normally positioned at the holding position, and when the similarity is less than the pin threshold value, the monitoring processing unit 92 determines that an abnormality has occurred with the chuck pin 26. The pin threshold value is set in advance, for example, by simulation or experiment, and is stored in the storage unit 94.

[0110] The guard determination area R2 is an area used to monitor the position of the guard unit 40. In the example of FIG. 7, two guard determination areas R2 are set. Each guard determination area R2 is set to an area that includes at least a portion of the outer guard 43 that is positioned at the guard standby position. In the example of FIG. 7, the guard determination area R2 is set to include a portion of the upper periphery of the outer guard 43.

[0111] The monitoring processing unit 92 monitors the position of the guard unit 40 based on the guard judgment area R2. For example, a reference image M2 for monitoring the position of the guard unit 40 is stored in advance in the storage unit 94. In the captured image of FIG. 7, the outer guard 43 is positioned at the guard standby position, so the reference image M2 is an image of the outer guard 43 normally positioned at the guard standby position. The reference image M2 is generated in advance, for example, based on a captured image generated by the camera 70 capturing an image of the captured area when the outer guard 43 is normally positioned at the guard standby position. The reference image M2 is an image of the same area as the guard judgment area R2. In the example of FIG. 7, multiple guard judgment areas R2 are provided, so multiple reference images M2 corresponding to the multiple guard judgment areas R2 are set.

[0112] The monitoring processing unit 92 monitors the position of the guard unit 40 by comparing each guard determination area R2 with the corresponding reference image M2. As a specific example, the monitoring processing unit 92 calculates the similarity between the guard determination area R2 and the reference image M2 for each guard determination area R2, and when both similarities are equal to or greater than a predetermined guard threshold, it determines that the guard unit 40 is normally positioned at the guard standby position, and when at least one of the both similarities is less than the guard threshold, it determines that an abnormality has occurred with the guard unit 40. The guard threshold is set in advance, for example, by simulation or experiment, and stored in the storage unit 94.

[0113] In the captured image of Fig. 8, only the outer guard 43 is located at the guard processing position. In this case, the guard determination region R2 is set to include at least a portion of the outer guard 43 located at the guard processing position. In the example of Fig. 8, two guard determination regions R2 are set to each include a portion of the upper periphery of the outer guard 43. An image in which only the outer guard 43 is located at the guard processing position is used as the reference image M2 corresponding to the guard determination region R2.

[0114] The monitoring processor 92 monitors the position of the outer guard 43 by comparing the guard determination area R2 with the reference image M2 in the same manner as described above.

[0115] The captured image in Fig. 8 also shows a discharge determination region R3. The discharge determination region R3 is a region used to monitor the discharge state of the processing liquid from the first nozzle 30. The discharge determination region R3 is set to a region that includes the liquid column of processing liquid from the first nozzle 30. In the example of Fig. 8, the discharge determination region R3 is set so that the upper end of the discharge determination region R3 is located below the lower end of the first nozzle 30 that is positioned at the nozzle processing position, and the lower end of the discharge determination region R3 is located above the landing position of the processing liquid on the upper surface of the substrate W. In addition, the lateral width of the discharge determination region R3 is set wider than the width of the liquid column of processing liquid.

[0116] The monitoring processing unit 92 monitors the discharge status of the first nozzle 30 based on the discharge determination region R3. Because the pixel values ​​within the discharge determination region R3 change depending on the discharge status of the first nozzle 30, the monitoring processing unit 92 can monitor the discharge status of the first nozzle 30 based on the pixel values ​​within the discharge determination region R3. As a specific example, the monitoring processing unit 92 calculates the sum of the pixel values ​​in the discharge determination region R3, and when this sum is within a predetermined range, it determines that treatment liquid is being discharged from the first nozzle 30, and when this sum is outside the predetermined range, it determines that treatment liquid is not being discharged from the first nozzle 30. The predetermined range is set in advance, for example, by simulation or experiment, and stored in the storage unit 94.

[0117] <Unnecessary reflected light> However, there are cases where the intensity of reflected light (including scattered light) from each object in the imaging area becomes significantly high. In such cases, high-brightness areas where pixel values ​​become very high are generated in the captured image. High-brightness areas may occur globally in the captured image, or locally. For example, when the intensity of the illumination light is high, the reflected light from the entire imaging area may be high. In this case, high-brightness areas occur globally in the captured image. Furthermore, depending on the angle of the reflective surface of each object in the imaging area, specularly reflected light from some objects may be incident on the light-receiving surface of camera 70. Since the intensity of specularly reflected light is high, in this case, high-brightness areas may occur locally in the captured image.

[0118] In the example of Figure 7, a localized high-brightness region HR1 is shown as a schematic ellipse. A notable example of high reflected light intensity is when pixel values ​​in the high-brightness region HR1 reach their maximum value, i.e., the pixel values ​​become saturated. When the intensity of reflected light becomes too high, the shape of an object in the high-brightness region HR1 may not be properly recognized. Therefore, if the reflected light from an object included in each determination region becomes too high, the visibility of the object may decrease, which may ultimately reduce monitoring accuracy.

[0119] For example, if the pin determination region R1 in the captured image in Fig. 7 includes a high-brightness region HR1 with high reflected light, the accuracy of monitoring the position of the chuck pin 26 may decrease. For this reason, it is desirable to reduce the brightness of the high-brightness region HR1 in the pin determination region R1 when monitoring the position of the chuck pin 26. In other words, it is desirable to reduce the reflected light from an object in the high-brightness region HR1.

[0120] The same applies when both the guard determination region R2 and the discharge determination region R3 include high-brightness regions. That is, when the guard determination region R2 includes a high-brightness region, it is desirable to reduce the brightness of the high-brightness region within the guard determination region R2 when monitoring the position of the guard section 40. Similarly, when the discharge determination region R3 includes a high-brightness region, it is desirable to reduce the brightness of the discharge determination region R3 when monitoring the discharge state from the first nozzle 30. That is, it is desirable to reduce the reflected light from objects within the high-brightness region.

[0121] Alternatively, if the processing liquid adheres to each object within the imaging area, droplets of the processing liquid will be included in the captured image. For example, in the captured image of FIG. 8, when the first nozzle 30 is discharging the processing liquid, droplets of the processing liquid scatter from the periphery of the rotating substrate W. Some of this processing liquid is included in the guard determination area R2. If droplets are included in each determination area, the droplets may reduce monitoring accuracy. For example, if droplets are included in the guard determination area R2, even if the outer guard 43 is properly stopped at the guard processing position, the similarity between the guard determination area R2 and the reference image M2 decreases, and the monitoring processor 92 may erroneously detect an abnormality related to the guard unit 40. For this reason, it may be desirable to reduce the light reflected from droplets when monitoring the position of the guard unit 40.

[0122] As described above, it is desirable to reduce unwanted reflected light corresponding to each monitored object in the captured image. Unwanted reflected light includes, for example, high-intensity reflected light and reflected light from droplets, as described above.

[0123] <Polarization control unit> The polarization state of light reflected from each object in the imaging area depends on the material of the object. Therefore, the light reflected from the imaging area contains various polarization states depending on the object. The reflected light containing various polarization states passes through the polarizing filter 73 and enters the light receiving surface of the camera 70 (see also FIG. 3).

[0124] When reflected light passes through the polarizing filter 73, the intensity of the reflected light is reduced by a reduction rate that depends on the polarization state of the reflected light and the direction of the absorption axis of the polarizing filter 73. For example, reflected light whose polarization direction coincides with the absorption axis of the polarizing filter 73 is ideally absorbed by the polarizing filter 73 and disappears. In this case, the reduction rate is 100%. On the other hand, reflected light whose polarization direction is perpendicular to the absorption axis ideally passes through the polarizing filter 73 as is. In this case, the reduction rate is 0%.

[0125] The polarization states of the light reflected from each object are different from each other, so when the light reflected from each object passes through the polarizing filter 73, it is reduced by different reduction rates. In other words, the light reflected from each object passes through the polarizing filter 73 with different transmittances.

[0126] When the filter driver 74 rotates the polarizing filter 73 around the rotation axis Q2, the amount of reduction in the reflected light from each object changes according to the rotational position of the polarizing filter 73. Therefore, by adjusting the rotational position of the polarizing filter 73, the intensity of the reflected light from each object can be adjusted.

[0127] For example, when the filter driver 74 rotates the polarizing filter 73 to a rotational position θ1 that reduces unwanted reflected light from an object corresponding to the pin determination region R1, the polarizing filter 73 can reduce the unwanted reflected light. The rotational position θ1 may be, for example, a position where the polarization component along the absorption axis of the unwanted reflected light is maximized. When the camera 70 captures an image of the imaging region in this state, the brightness of the high-brightness region HR1 in the pin determination region R1 can be reduced, so that the chuck pin 26 is captured in the pin determination region R1 with high visibility (i.e., more clearly). In other words, the rotational position θ1 can be said to be a rotational position that can improve the visibility of the chuck pin 26 in the pin determination region R1. Because the visibility of the chuck pin 26 in the pin determination region R1 can be improved, the monitoring processor 92 can monitor the position of the chuck pin 26 with higher accuracy.

[0128] Furthermore, if the guard determination area R2 includes a high-brightness area, the filter driver 74 may rotate the polarizing filter 73 to a rotational position that reduces the reflected light corresponding to the guard determination area R2. This allows the polarizing filter 73 to reduce the reflected light. When the camera 70 captures an image of the imaging area in this state, the guard unit 40 appears in the guard determination area R2 in the captured image with high visibility. This allows the monitoring processor 92 to monitor the position of the guard unit 40 with high accuracy.

[0129] Alternatively, if the guard determination region R2 does not include a high-brightness region but does include droplets of processing liquid, the light reflected from the droplets may be reduced as unwanted reflected light. Specifically, the filter driver 74 rotates the polarizing filter 73 to a rotational position that reduces the light reflected from the droplets of processing liquid. This allows the polarizing filter 73 to reduce the reflected light. When the camera 70 captures the image of the imaging region in this state, the density of the image of the droplets of processing liquid in the guard determination region R2 of the captured image can be reduced. Because the processing liquid is transparent, reducing the light reflected from the droplets of processing liquid increases the density of the image of an object located behind the droplets in the imaging direction in the guard determination region R2 of the captured image. Therefore, the influence of the droplets can be suppressed when comparing the guard determination region R2 with the reference image M2, allowing the monitoring processor 92 to monitor the position of the guard unit 40 with higher accuracy.

[0130] Because the polarization state of light reflected from droplets of the processing liquid depends on the material of the processing liquid, the rotational position of polarizing filter 73 may be changed depending on the type of processing liquid during the chemical processing, first rinse processing, and second rinse processing in the liquid processing step. That is, when monitoring the position of guard member 40 during chemical processing, polarizing filter 73 is rotated to rotational position θ2 corresponding to the chemical liquid, when monitoring the position of guard member 40 during the first rinse processing, polarizing filter 73 is rotated to rotational position θ3 corresponding to the first rinse liquid, and when monitoring the position of guard member 40 during the second rinse processing, polarizing filter 73 is rotated to rotational position θ4 corresponding to the second rinse processing.

[0131] This allows the polarizing filter 73 to more appropriately reduce reflected light from the droplets in each process, making the image of the droplet in the guard determination region R2 thinner while making the image of an object located behind the droplet in the imaging direction darker. This allows the monitoring processing unit 92 to suppress the influence of the droplets and monitor the position of the guard unit 40 with greater accuracy.

[0132] <Specific monitoring process flow> 9 is a flowchart showing an example of the monitoring process. Delivery and Retention A case where the position of the chuck pin 26 is monitored in the process (step S1) will be described.

[0133] First, the filter driver 74 rotates the polarizing filter 73 to a rotational position corresponding to the chuck pin 26 that reduces unwanted reflected light (step S11: polarization adjustment step). Here, multiple rotational positions corresponding to multiple monitored objects and multiple monitoring timings are set in advance by simulation or experiment, and angle data indicating the rotational positions is stored in advance in the storage unit 94. Table 1 is a table that schematically shows an example of the angle data.

[0134] [Table 1]

[0135] In Table 1, a rotational position θ1 for reducing the brightness of the high-brightness region HR1 in the pin determination region R1 is preset as the rotational position when the object to be monitored is the chuck pin 26. Also, in Table 1, when the object to be monitored is the guard part 40, a rotational position is set according to the type of treatment in the liquid treatment step. Specifically, a rotational position θ2 for reducing the reflected light from droplets of the chemical liquid is preset as the rotational position when the chemical liquid treatment is performed. Similarly, rotational positions θ3 and θ4 for reducing the reflected light from droplets of the first rinse liquid and the second rinse liquid are preset as rotational positions corresponding to the first rinse liquid and the second rinse liquid, respectively.

[0136] The polarization control unit 91 reads the angle data from the storage unit 94, identifies a rotation position according to the monitored object and monitoring timing, and outputs a control signal instructing that rotation position to the filter drive unit 74. Here, the polarization control unit 91 reads the rotation position θ1 from the angle data, and outputs a control signal to instruct rotation to the rotation position θ1 to the filter drive unit 74. The filter drive unit 74 rotates the polarization filter 73 to the rotation position θ1 based on the control signal.

[0137] Next, in a state where the illumination unit 71 irradiates the imaging area with illumination light, the camera 70 captures the imaging area to generate a captured image, and outputs the captured image to the control unit 9 (step S12: imaging step). Delivery and Retention This step is performed after the process control unit 93 outputs a control signal to the chuck driver to move the chuck pin 26 to the holding position. In the immediately preceding polarization adjustment step, the rotation position of the polarizing filter 73 is set to rotation position θ1, so that unnecessary reflected light from an object corresponding to the high-brightness region HR1 is reduced by the polarizing filter 73. Therefore, the brightness of the high-brightness region HR1 in the captured image is low, and the visibility of the chuck pin 26 in the pin determination region R1 is high.

[0138] Next, the monitoring processing unit 92 monitors the state of the monitoring object based on the captured image generated in the imaging process after the polarization adjustment process (step S13: monitoring process). For example, as described above, the monitoring processing unit 92 monitors the position of the chuck pin 26 based on a comparison between the pin determination region R1 of the captured image and the reference image M1. Specifically, when the similarity between the pin determination region R1 and the reference image M1 is equal to or greater than a pin threshold value, the monitoring processing unit 92 determines that the position of the chuck pin 26 is normal, and when the similarity is less than the pin threshold value, the monitoring processing unit 92 determines that an abnormality has occurred in the chuck pin 26.

[0139] When the monitoring processing unit 92 determines that an abnormality has occurred in the object to be monitored (here, the chuck pin 26), the control unit 9 may interrupt the processing of the substrate W, or may cause an alarm unit such as a display (not shown) to alarm the abnormality.

[0140] As described above, according to this embodiment, the polarizing filter 73 is provided, and the filter driver 74 rotates the polarizing filter 73 to a rotational position that reduces unwanted reflected light corresponding to the monitored object. This reduces unwanted reflected light incident on the light receiving surface of the camera 70, thereby reducing the influence of unwanted reflected light on the captured image. Therefore, the monitoring processor 92 can monitor the monitored object with higher accuracy based on the captured image.

[0141] Moreover, in the above-described specific example, the polarization control unit 91 reads the angle data from the storage unit 94 and instructs the rotation position defined by the angle data to the filter drive unit 74. The filter drive unit 74 rotates the polarization filter 73 to the rotation position based on the angle data. When a preset rotation position is used in this way, the rotation position can be determined by simpler processing.

[0142] In the above example, the angle data includes a rotational position θ1 that reduces unwanted reflected light in the pin determination region R1 and rotational positions θ2 to θ4 that reduce unwanted reflected light in the guard determination region R2. However, this is not necessarily limited to the pin determination region R1 and the guard determination region R2. The same applies to the discharge determination region R3. For example, if the polarizing filter 73 can reduce reflected light from the substrate W in the discharge determination region R3, a rotational position that effectively reduces unwanted reflected light from the substrate W may be set. In short, it is sufficient to set a first rotational position that reduces unwanted reflected light in the first determination region of the captured image used to monitor the first monitoring object as the monitored object, and a second rotational position that reduces unwanted reflected light in the second determination region of the captured image used to monitor the second monitoring object as the monitored object.

[0143] When monitoring the status of a first monitored object, the filter drive unit 74 rotates the polarizing filter 73 to a first rotation position, the camera 70 captures an image of the imaging area, and the monitoring processing unit 92 monitors the first monitored object based on the first determination area of ​​the captured image. Similarly, when monitoring the status of a second monitored object, the filter drive unit 74 rotates the polarizing filter 73 to a second rotation position, the camera 70 captures an image of the imaging area, and the monitoring processing unit 92 monitors the second monitored object based on the second determination area of ​​the captured image.

[0144] This allows the polarizing filter 73 to appropriately reduce unwanted reflected light within the determination area corresponding to the monitored object, depending on the monitored object. This allows the monitoring processing unit 92 to monitor the state of the monitored object based on the determination area in which unwanted reflected light has been reduced. This allows the monitoring processing unit 92 to monitor the state of the monitored object with higher accuracy.

[0145] Furthermore, in the above example, the angle data is set with rotational positions θ2 to θ4 according to the type of processing liquid in the guard determination region R2. This is because the type of processing liquid contained in the guard determination region R2 varies depending on the monitoring timing. However, such an object is not limited to the processing liquid. In short, if the object that causes unwanted reflected light changes depending on the monitoring timing, the rotational positions may be set as follows. That is, a first rotational position that reduces unwanted reflected light from a first object in the imaging region and a second rotational position that reduces unwanted reflected light from a second object different from the first object in the imaging region may be set.

[0146] When a first object is present in the imaging area (more specifically, an area corresponding to the determination area), the filter drive unit 74 rotates the polarizing filter 73 to a first rotation position, and the camera 70 captures the imaging area to generate a captured image, and the monitoring processing unit 92 monitors the state of the monitored object based on the captured image. Similarly, when a second object is present in the imaging area, the filter drive unit 74 rotates the polarizing filter 73 to a second rotation position, and the camera 70 captures the imaging area to generate a captured image, and the monitoring processing unit 92 monitors the state of the monitored object based on the captured image.

[0147] This allows the polarizing filter 73 to reduce unwanted reflected light corresponding to objects present in the imaging area. Therefore, the monitoring processing unit 92 can monitor the status of the monitored object based on the captured image in which the influence of unwanted reflected light is reduced. Therefore, the monitoring processing unit 92 can monitor the status of the monitored object with higher accuracy.

[0148] <How to determine the rotation position> In the above example, the polarization control unit 91 determines the rotation position based on preset angle data, but this is not necessarily limited to this. The polarization control unit 91 may also determine the rotation position of the polarizing filter 73 based on captured images. Specifically, the filter drive unit 74 sequentially changes the rotation position of the polarizing filter 73, while the camera 70 captures an image of the imaging area each time, thereby generating multiple captured images, and the polarization control unit 91 determines the rotation position of the polarizing filter 73 based on the multiple captured images. A more specific example will be described below.

[0149] 10 is a flowchart showing a specific example of the polarization adjustment process. First, polarization control unit 91 outputs a control signal to filter drive unit 74, causing filter drive unit 74 to rotate polarization filter 73 to rotational position θ[1] (step S21). Here, rotational position θ[n] (n=1, 2, . . . , N) is, for example, the rotational position when 360 degrees is divided into N.

[0150] Next, the camera 70 captures an image of the imaging area, generates a captured image, and outputs it to the control unit 9 (step S22). As a result, a captured image corresponding to the rotational position θ[1] is obtained.

[0151] Next, the polarization control unit 91 calculates an index related to the intensity of unwanted reflected light based on the captured image (step S23). The index is, for example, contrast. Explaining this based on the example of FIG. 7, if the high-brightness region HR1 is included in the entire pin determination region R1, the contrast of the pin determination region R1 will be low. As the brightness of the high-brightness region HR1 decreases, the objects in the pin determination region R1 become clearer, and the contrast will be high. Conversely, when the contrast is high, the brightness of the high-brightness region HR1 is low and the objects in the pin determination region R1 are clear, and when the contrast is low, the brightness of the high-brightness region HR1 is high and the visibility of the objects is low. In other words, the contrast can be said to indicate the intensity of unwanted reflected light. Therefore, the polarization control unit 91 calculates the contrast of the pin determination region R1 as the index.

[0152] Furthermore, if the entire pin determination region R1 includes the high-brightness region HR1, the higher the brightness of the high-brightness region HR1, the lower the visibility of objects, resulting in a smaller number of contours in the pin determination region R1. As the brightness of the high-brightness region HR1 decreases, objects in the pin determination region R1 become clearer, resulting in a larger number of contours. Conversely, a large number of contours indicates low brightness in the high-brightness region HR1 and clear objects in the pin determination region R1, while a small number of contours indicates high brightness in the high-brightness region HR1 and low object visibility. In other words, the number of contours indicates the intensity of unwanted reflected light. Therefore, the polarization control unit 91 may calculate the number of contours in the pin determination region R1 as an index. Specifically, the polarization control unit 91 performs edge detection processing, such as the Canny method, on the pin determination region R1 to generate an edge image, then performs contour tracking on the edge image to label the contours, and calculates the number of labeled contours as the number of contours.

[0153] Next, the polarization control unit 91 determines whether the calculated index is equal to or greater than a predetermined threshold value (step S24). The threshold value is set in advance by, for example, simulation or experiment, and is stored in the storage unit 94 in advance.

[0154] If the index is less than the threshold value, the influence of unwanted reflected light is still large in the pin determination region R1 of the captured image, so in step S21, the polarization control unit 91 causes the filter drive unit 74 to rotate the polarizing filter 73 to rotational position θ[2]. Rotational position θ[2] is, for example, a position rotated by a predetermined angle from rotational position θ[1]. Then, the polarization control unit 91 again executes steps S22 to S24 in this order.

[0155] By repeating steps S21 to S23, the rotational position of polarizing filter 73 is rotated sequentially by a predetermined angle, and captured images corresponding to each rotational position θ[n] are obtained, and indices for each captured image can be calculated. In other words, indices can be calculated for each rotational position θ[n].

[0156] When the index of the captured image is less than a predetermined threshold value, the influence of unnecessary reflected light in the pin determination area R1 of the captured image has been sufficiently reduced, and therefore the polarization control unit 91 determines the rotational position of the polarizing filter 73 to be the rotational position determined in the latest step S21 (step S25).

[0157] As described above, according to the above-described operation, polarization control unit 91 sequentially rotates polarizing filter 73 and determines the rotational position of polarizing filter 73 based on the index of the captured image corresponding to each rotational position θ[n]. This eliminates the need for the operator to determine the rotational position of polarizing filter 73 in advance, thereby reducing the burden on the operator.

[0158] 10, the rotational position of the polarization filter 73 is determined when the index becomes equal to or greater than a threshold value, but this is not necessarily limited to this. Alternatively, the indexes corresponding to all rotational positions θ[1], . . . ,θ[N] may be calculated first, and the rotational position may be determined by comparing these indexes. For example, the polarization control unit 91 may determine the rotational position so that the index becomes the highest.

[0159] <Lighting Department> Fig. 11 is a diagram schematically illustrating the configuration of another embodiment of the processing unit 1. Hereinafter, the processing unit 1 in Fig. 11 will be referred to as processing unit 1A. The processing unit 1A is different from the processing unit 1 in the configuration of the illumination unit 71.

[0160] In the processing unit 1A, the illumination unit 71 is provided at a position closer to the rotation axis CX than the illumination unit 71 of the processing unit 1. In the example of Fig. 3, the radial position of the illumination unit 71 of the processing unit 1 is outside the outermost periphery of the guard unit 40, whereas in the example of Fig. 11, the radial position of the illumination unit 71 of the processing unit 1A is inside the outermost periphery of the guard unit 40. In this processing unit 1A, the camera 70 is provided radially outside the illumination unit 71 with respect to the imaging area.

[0161] 11, the illumination section 71 of the processing unit 1A includes a plurality of unit illumination sections 711. Each unit illumination section 711 has a light source such as a light-emitting diode. As illustrated in FIG. 11, the plurality of unit illumination sections 711 may be located radially outward from the fan filter unit 14. This makes it less likely that the illumination section 71 will disturb the airflow from the fan filter unit 14. The plurality of unit illumination sections 711 may be arranged side by side in the circumferential direction around the rotation axis CX. The plurality of unit illumination sections 711 may also be arranged at equal intervals in the circumferential direction.

[0162] In the processing unit 1A, it is possible to increase the angle formed by the imaginary line L1 connecting each unit illumination section 711 and the monitored object and the imaginary line L2 connecting the camera 70 and the monitored object.

[0163] It is known that the polarization state of reflected light that enters polarizing filter 73 from an object also depends on the position of the light source. For example, when the angle formed by the imaginary line connecting the light source and the object (imaginary line L1 in FIG. 11) and the imaginary line connecting the object and camera 70 (imaginary line L2 in FIG. 11) approaches 90 degrees, the polarization state of the reflected light (including scattered light) approaches linear polarization, thereby increasing the effect of polarizing filter 73 in reducing reflected light.

[0164] According to the processing unit 1A, the angle between the virtual lines L1 and L2 can be made closer to 90 degrees, so that the effect of the polarizing filter 73 in reducing unwanted reflected light can be enhanced.

[0165] An example of the monitoring process in the processing unit 1A is similar to the flowchart in Fig. 9. In this case, the illumination section 71 may emit illumination light from all of the plurality of unit illumination sections 711.

[0166] <Unit lighting section> On the other hand, when monitoring a monitoring target, the control unit 9 may irradiate illumination light to a unit illumination unit 711 corresponding to the monitoring target among the plurality of unit illumination units 711. More specifically, the control unit 9 may irradiate illumination light to a unit illumination unit 711 among the plurality of unit illumination units 711 that has a greater effect of reducing reflected light.

[0167] 12 is a functional block diagram schematically illustrating an example of the internal configuration of the control unit 9 of the processing unit 1A according to another embodiment. The control unit 9 further includes an illumination control unit 95. The illumination control unit 95 can control the multiple unit illumination units 711 independently of each other. As will be described later, the illumination control unit 95 switches the unit illumination units 711 on and off depending on the monitored object. In other words, the unit illumination unit 711 that emits illumination light among the multiple unit illumination units 711 is changed depending on the monitored object.

[0168] 13 is a flowchart showing an example of monitoring processing according to another embodiment. First, the lighting control unit 95 causes the unit lighting units 711 corresponding to the monitored object to emit illumination light (step S31: lighting step). Here, the unit lighting units 711 corresponding to the monitored object are set in advance by simulation or experiment, and lighting data indicating the unit lighting units 711 are stored in advance in the storage unit 94. Table 2 is a table that schematically shows an example of the lighting data.

[0169] [Table 2]

[0170] In Table 2, when the monitored object is a chuck pin 26, a unit illumination unit 711 is set for each chuck pin 26. Specifically, unit illumination units 711a to 711d are set in advance corresponding to chuck pins 26a to 26d of the chuck pins 26, respectively. Also, in Table 2, when the monitored object is the guard unit 40, unit illumination unit 711e is set among the unit illumination units 711. Note that if the position of the guard determination region R2 differs between the guard standby position and the guard processing position, a unit illumination unit 711 corresponding to each position may be set.

[0171] The unit lighting units 711 may be set in advance as follows: That is, for example, the unit lighting units 711 corresponding to the monitored object may be set so that the angle formed by the virtual line connecting the unit lighting units 711 and the monitored object and the virtual line connecting the monitored object and the camera 70 is close to 90 degrees.

[0172] Alternatively, the worker may visually check the captured images and set the unit illumination units 711 in advance. More specifically, the worker may visually check multiple captured images obtained by rotating the polarizing filter 73 around the rotation axis Q2 in each illumination mode while sequentially changing the unit illumination units 711 that emit illumination light, and set rotational positions of the unit illumination units 711 and polarizing filters 73 that are appropriate for monitoring the monitored object. In other words, the worker may visually check the actual captured images and set, via a user interface (not shown), rotational positions of the unit illumination units 711 and polarizing filters 73 that can appropriately reduce unnecessary reflected light.

[0173] In the example of Table 2, one unit illumination unit 711 is set corresponding to the monitored object, but multiple unit illumination units 711 may be set.

[0174] The lighting control unit 95 reads the angle data from the storage unit 94 and outputs a control signal to the unit lighting unit 711 corresponding to the monitored object. The unit lighting unit 711 emits illumination light based on the control signal. The illumination light is emitted onto the imaging area.

[0175] Next, the polarization control unit 91 outputs a control signal to the filter driving unit 74, causing the filter driving unit 74 to rotate the polarizing filter 73 (step S32: polarization adjustment step). For example, the polarization control unit 91 reads angle data from the storage unit 94, and outputs a control signal to instruct the filter driving unit 74 to rotate to the rotation position included in the angle data. The filter driving unit 74 rotates the polarizing filter 73 to that rotation position based on the control signal.

[0176] 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 S33: imaging step). In this imaging step, the unit illumination units 711, which can effectively reduce unwanted reflected light, irradiate illumination light, and the rotation position of the polarizing filter 73 is set to a position where unwanted reflected light can be reduced, so that a captured image that is less affected by unwanted reflected light can be obtained.

[0177] Next, the monitoring processing unit 92 monitors the state of the monitoring object based on the captured image (step S34: monitoring step). The monitoring step is the same as the monitoring step in step S13.

[0178] According to the above-described operation, the unit illumination unit 711 that is arranged at a position where the effect of reducing unwanted reflected light is greatest among the multiple unit illumination units 711 emits illumination light. This makes it possible to further reduce the influence of unwanted reflected light on the captured image, and the monitoring processing unit 92 can monitor the state of the monitored object with higher accuracy.

[0179] <Second embodiment> 14 is a diagram schematically illustrating an example of the configuration of a substrate processing apparatus 100A according to the second embodiment. The substrate processing apparatus 100A is a batch-type processing apparatus that processes a plurality of substrates W collectively. The substrate processing apparatus 100A includes a processing unit 1B. Although not shown, the substrate processing apparatus 100A also includes various components such as a load port that loads and unloads a carrier that stores a plurality of substrates W, and a substrate transport unit (not shown) that transports the plurality of substrates W between the load port and the processing unit 1B. The substrate processing apparatus 100A may also include a plurality of processing units 1B.

[0180] The processing unit 1B includes a processing tank 15B, a lifter 20B, a liquid supply section 30B, a liquid drainage section 40B, a camera 70B, an illumination section 71B, a polarizing filter 73B, and a filter drive section 74B.

[0181] In the example of Fig. 14, a chamber 10B is also provided. In the example of Fig. 14, the chamber 10B has a box-like shape that opens vertically upward. An openable and closable lid may be provided at the upper end of the chamber 10B.

[0182] The processing tank 15B is provided in the chamber 10B and has a box-like shape that opens vertically upward. The processing tank 15B stores the processing liquid.

[0183] The liquid supply unit 30B supplies the processing liquid to the processing tank 15B. In the example of FIG. 14, the liquid supply unit 30B includes a nozzle 31B, a liquid supply pipe 32B, and a valve 33B. The nozzle 31B is provided at the lower side of the processing tank 15B. The downstream end of the liquid supply pipe 32B is connected to the nozzle 31B, and the upstream end of the liquid supply pipe 32B is connected to a processing liquid supply source 34B. The processing liquid supply source 34B has a tank (not shown) that stores the processing liquid.

[0184] Valve 33B is provided in liquid supply pipe 32B. When valve 33B is opened, the processing liquid is supplied from processing liquid supply source 34B through liquid supply pipe 32B to nozzle 31B and discharged from the discharge port of nozzle 31B into processing tank 15B. When valve 33B is closed, the supply of the processing liquid to processing tank 15B ends.

[0185] The lifter 20B (corresponding to a substrate holding section) holds a substrate W and raises and lowers the held substrate W. The lifter 20B can hold multiple substrates W. For example, the lifter 20B holds multiple substrates W in a state where the multiple substrates W are arranged at intervals in the thickness direction. In the example of FIG. 14, the lifter 20B includes a connecting plate 21B and multiple support members 22B. The connecting plate 21B is disposed in an orientation where its thickness direction is aligned horizontally. The multiple support members 22B have elongated shapes extending along the thickness direction of the connecting plate 21B, and one end of each support member 22B is connected to the connecting plate 21B. Each support member 22B has multiple grooves (not shown) into which the multiple substrates W are respectively inserted. When the substrates W are inserted into the grooves of the support member 22B, the support member 22B supports the substrates W in an upright orientation.

[0186] The lifter 20B has a lifting mechanism (not shown) that raises and lowers the plurality of substrates W between a processing position inside the processing tank 15B and a raised position vertically above the processing tank 15B. The lifting mechanism has, for example, a ball screw mechanism and a motor, and raises and lowers the connecting plate 21B. This also raises and lowers the plurality of substrates W supported by the support member 22B. The lifter 20B lowers the plurality of substrates W to the processing position, allowing the plurality of substrates W to be immersed in the processing solution.

[0187] At the lifting position, the lifter 20B transfers the plurality of substrates W to and from a substrate transport unit (not shown). As a specific example, the substrate transport unit transports the plurality of unprocessed substrates W from the load port to the lifting position, and at the lifting position, hands the plurality of substrates W to the lifter 20B. The lifter 20B lowers the plurality of substrates W to the processing position, whereby the plurality of substrates W are immersed in a processing liquid, and processing according to the processing liquid is performed on the plurality of substrates W. When the lifter 20B raises the plurality of processed substrates W to the lifting position, the substrate transport unit receives the plurality of substrates W from the lifter 20B and transports them to the next processing unit 1B or the load port.

[0188] The drainage section 40B discharges the treatment liquid from the treatment tank 15B to the outside. The drainage section 40B includes a drainage pipe 41B and a valve 42B. The upstream end of the drainage pipe 41B is connected to, for example, the bottom of the treatment tank 15B, and the downstream end of the drainage pipe 41B is connected to the outside. The valve 42B is provided on the drainage pipe 41B. When the valve 42B is opened, the treatment liquid is supplied from the treatment tank 15B to the outside through the drainage pipe 41B. When the valve 42B is closed, the discharge of the treatment liquid ends.

[0189] Camera 70B is provided vertically above treatment tank 15B and captures an image of an imaging area including the interior (specifically, the bottom) of treatment tank 15B. Camera 70B has the same configuration as camera 70. In the example of FIG. 14, camera 70B is provided above chamber 10B. In the example of FIG. 14, camera 70B is provided directly above treatment tank 15B, and camera 70B is provided so that its imaging direction is vertically downward. Note that the imaging direction of camera 70B is not limited to vertically downward, and may be inclined relative to the vertical direction. In other words, the imaging direction of camera 70B may be diagonally downward.

[0190] Illumination unit 71B is provided vertically above treatment tank 15B and irradiates the imaging area of ​​camera 70B with illumination light. In the example of Fig. 14, the illumination direction of illumination unit 71B is diagonally downward. Illumination unit 71B has the same configuration as illumination unit 71.

[0191] Polarizing filter 73B is provided between camera 70B and the imaging area. Polarizing filter 73B is similar to polarizing filter 73.

[0192] The filter driver 74B rotates the polarizing filter 73B around a rotation axis Q3 that is aligned with the optical axis of the polarizing filter 73B. This causes the absorption axis of the polarizing filter 73B to rotate around the rotation axis Q3. In the example of FIG. 14, the rotation axis Q3 is also aligned with the imaging direction of the camera 70B. The configuration of the filter driver 74B is similar to that of the filter driver 74.

[0193] The control unit 9 is the same as that in the first embodiment. That is, the control unit 9 includes a polarization control unit 91, a monitoring processing unit 92, and a processing control unit 93. The polarization control unit 91 is connected to a filter driving unit 74B The monitoring processing unit 92 controls the camera. 70B The state of the object to be monitored is monitored based on the captured image from the processing control unit 93. The processing control unit 93 controls the processing unit 1B and the substrate transport unit to cause the substrate processing apparatus 100A to perform processing on the substrate W.

[0194] In this processing unit 1B, the control unit 9 can monitor various components within the chamber 10B as monitoring targets based on images captured by the camera 70B. As a specific example, the monitoring targets include the bottom of the processing tank 15B. Fragments of the substrate W may remain on the bottom of the processing tank 15B. That is, if any of the substrates W held by the lifter 20B is chipped (i.e., cracked), the fragments will fall to the bottom of the processing tank 15B.

[0195] Here, the lifter 20B lifts the substrate W from the processing tank 15B and delivers the substrate W to a substrate transport unit (not shown), after which the camera 70B captures an image of the imaging area. Based on the captured image, the control unit 9 determines whether or not there are any fragments of the substrate W at the bottom of the processing tank 15B.

[0196] 15 is a diagram schematically illustrating an example of a captured image. The captured image in FIG. 15 includes the interior of the processing tank 15B, and includes the fragments Wa1 of the substrate W.

[0197] In the case where the processing liquid is stored in the processing tank 15B, the visibility of the bottom of the processing tank 15B is actually low in the captured image. This is because the illumination light is reflected by the surface of the processing liquid stored in the processing tank 15B. In the example of FIG. 15, a high-brightness region HR2 reflected by the surface of the processing liquid is schematically shown by a dashed line. In the example of FIG. 15, the fragment Wa1 is included in the high-brightness region HR2, so the fragment Wa1 is actually low in visibility and is obscured.

[0198] On the other hand, even when the processing tank 15B is empty and no processing liquid is stored therein, a high-brightness area may be formed in the captured image due to reflection from the interior of the processing tank 15B. In such a high-brightness area, the fragments Wa1 are difficult to see, and the fragments Wa1 are obscured.

[0199] Therefore, the polarization control unit 91 is a filter driving unit. 74B and outputs a control signal to the polarizing filter. 73B The polarization state of the light reflected from the liquid surface in the stored state differs from the polarization state of the light reflected from the inside of the treatment tank 15B in the empty state, so the polarization control unit 91 controls the filter driving unit 92 at a rotation position according to each state. 74B For example, a rotation position corresponding to the state of the treatment tank 15B is set in advance, and angle data indicating the rotation position is stored in the storage unit 94 in advance.

[0200] An example of the monitoring process for the bottom of the processing tank 15B is the same as that shown in the flowchart of Fig. 9. That is, in the polarization adjustment process (step S11), 74B Polarizing filters based on unwanted reflected light 73B Rotate the polarizing filter 73B As a specific example, a rotation position corresponding to the state of the treatment tank 15B is set in advance by simulation or experiment, and angle data indicating the rotation position is stored in advance in the storage unit 94. Table 3 is a table that schematically shows an example of the angle data.

[0201] [Table 3]

[0202] In Table 3, a rotational position θ10 that reduces unwanted reflected light from the surface of the processing liquid is preset as the rotational position when the processing liquid is stored in the processing tank 15B. Also, in Table 3, a rotational position θ11 that reduces unwanted reflected light from inside the processing tank 15B is preset as the rotational position when the processing tank 15B is empty.

[0203] The polarization control unit 91 reads out the angle data from the storage unit 94. When the processing liquid is stored in the processing tank 15B, the polarization control unit 91 identifies the rotation position θ10 according to the storage state from the angle data, and outputs a control signal to the filter driving unit 92 to instruct the rotation to the rotation position θ10. 74B On the other hand, when the processing tank 15B is empty, the polarization control unit 91 determines the rotation position θ11 corresponding to the empty state from the angle data, and outputs a control signal to the filter driving unit 92 to instruct the rotation to the rotation position θ11. 74B The filter driver outputs 74B The polarizing filter is controlled based on the control signal. 73B Rotate.

[0204] The polarization control unit 91 does not necessarily need to determine the rotation position based on the angle data in the storage unit 94, but may determine the rotation position of the polarization filter 73 based on a plurality of captured images when the polarization filter 73 is rotated sequentially, as in the first embodiment. 73B The rotational position of the

[0205] Next, in the imaging step (step S12), the camera 70B captures an image of the imaging area to generate a captured image, and outputs the captured image to the control unit 9.

[0206] Next, in the monitoring step (step S13), the monitoring processor 92 determines the presence or absence of fragments Wa1 of the substrate W inside the processing tank 15B based on the captured image. As a specific example, a reference image M4 for monitoring the processing tank 15B is stored in advance in the storage unit 94. The reference image M4 is an image including the processing tank 15B in a state where no fragments Wa1 remain, for example, an image when the processing tank 15B is empty. The reference image M4 is, for example, an image including the processing tank 15B in a state where no fragments Wa1 remain, captured by the camera. 70B is generated in advance based on a captured image generated by capturing an image of the imaging area. The reference image M4 is an image of the same area as the captured image.

[0207] The monitoring processor 92 monitors the internal state of the processing tank 15B by comparing the captured image with the reference image M4. For example, the monitoring processor 92 first calculates the similarity between the captured image and the reference image M4. If the similarity between the captured image and the reference image M4 is high, it is considered that no fragments Wa1 of the substrate W remain.

[0208] Therefore, the monitoring processor 92 compares the similarity with a fragment threshold value to determine whether or not fragments Wa1 remain on the substrate W. The fragment threshold value is set in advance, for example, by simulation or experiment, and is stored in the memory unit 94. The monitoring processor 92 determines that no fragments Wa1 remain when the similarity is equal to or greater than the fragment threshold value, and determines that no fragments Wa1 remain when the similarity is less than the fragment threshold value.

[0209] As described above, in the polarization adjustment process, the polarizing filter 73B The polarizing filter stops at a rotation position according to the state of the processing tank 15B. 73B The polarizing filter stops at a rotation position corresponding to the unwanted reflected light from each object in the imaging area. 73B When the processing liquid is stored in the processing tank 15B, the polarizing filter stops at a rotation position θ10 corresponding to the unwanted reflected light from the surface of the processing liquid, and when the processing liquid is not stored, the polarizing filter stops at a rotation position θ10 corresponding to the unwanted reflected light from the inside of the processing tank 15B. 73B can appropriately reduce unwanted reflected light depending on each state.

[0210] Therefore, the influence of unwanted reflected light in the captured image can be reduced, and the interior of the treatment tank 15B can be made clearer. Therefore, the monitoring processor 92 can monitor the interior of the treatment tank 15B with higher accuracy. More specifically, since the influence of unwanted reflected light on the similarity between the captured image and the reference image M4 can be reduced, the influence of unwanted reflected light is also small when comparing the similarity with the fragment threshold value. Therefore, the monitoring processor 92 can determine the presence or absence of fragment Wa1 with high accuracy.

[0211] As in the first embodiment, the illumination unit 71B may include a plurality of unit illumination units 711, and the control unit 9 may include an illumination control unit 95.

[0212] Furthermore, in the above example, the monitoring processor 92 determines whether or not there are any fragments Wa1 of the substrate W in the processing bath 15B, but it may also determine whether or not there is any abnormality in the processing bath 15B.

[0213] As described above, the substrate processing apparatus 100, 100A and the monitoring method have been described in detail. However, the above description is merely an example 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. [Explanation of symbols]

[0214] 10,10B Chamber 100,100A substrate processing equipment 20 Board holding part 20B Board holding part (lifter) 26 zipper pin 30 nozzles (first nozzle) 60 nozzle (second nozzle) 68 Nozzle (3rd Nozzle) 41 Guard (inner guard) 42 Guard (Medium Guard) 43 Guard (Outer Guard) 70,70B camera 71,71B Lighting section 711, 711a~711e Unit lighting section 73,73B Polarizing Filter 74,74B Filter drive unit 9 Control Unit 94 Memory section S11 Polarization adjustment process (step) S12 Imaging process (step) S13 Monitoring process (step) W substrate

Claims

1. A chamber; a substrate holder for holding a substrate; an illumination unit that irradiates an imaging area including a monitoring target in the chamber with illumination light; a polarizing filter that transmits light from the imaging region in accordance with the polarization state of the light; a filter driving unit that rotates the polarizing filter to a rotation position corresponding to the monitored object, thereby reducing unnecessary reflected light corresponding to the monitored object with the polarizing filter; a camera that captures an image of the imaging area through the polarizing filter and generates captured image data; a control unit that controls the filter driving unit and monitors the monitoring target based on the captured image data generated by the camera; Equipped with The control unit determines the rotational position of the polarizing filter based on a plurality of captured image data generated by the camera capturing images of the imaging area while the filter drive unit sequentially rotates the polarizing filter.

2. The substrate processing apparatus according to claim 1 , The control unit determines the rotation position based on contrast of the plurality of pieces of captured image data or the number of contour lines in the plurality of pieces of captured image data.

3. A chamber, a substrate holder for holding a substrate; an illumination unit that irradiates an imaging area including a monitoring target in the chamber with illumination light; a polarizing filter that transmits light from the imaging region in accordance with the polarization state of the light; a filter driving unit that rotates the polarizing filter to a rotation position corresponding to the monitored object, thereby reducing unnecessary reflected light corresponding to the monitored object with the polarizing filter; a camera that captures an image of the imaging area through the polarizing filter and generates captured image data; a control unit that controls the filter driving unit and monitors the monitoring target based on the captured image data generated by the camera; Equipped with The illumination unit includes a plurality of unit illumination units, and one of the plurality of unit illumination units that emits the illumination light is switched according to the object to be monitored so as to enhance the effect of reducing the unnecessary reflected light by the polarizing filter.

4. 4. The substrate processing apparatus according to claim 3, a storage unit that stores in advance angle data indicating a rotational position of the polarizing filter corresponding to the monitored object; The filter driving unit rotates the polarizing filter to the rotation position corresponding to the object to be monitored based on the angle data.

5. 5. The substrate processing apparatus according to claim 1, the filter driving unit rotates the polarizing filter to a first rotation position that reduces the unnecessary reflected light within a first determination area of ​​the captured image data used for monitoring a first monitoring object as the monitoring object; the control unit monitors the first monitored object based on the first determination area of ​​the captured image data when the polarizing filter is positioned at the first rotation position; the filter driving unit rotates the polarizing filter to a second rotation position that reduces the unnecessary reflected light within a second determination area of ​​the captured image data used for monitoring a second monitored object as the monitored object; The control unit monitors the second monitored object based on the second determination area of ​​the captured image data when the polarizing filter is positioned at the second rotation position.

6. 5. The substrate processing apparatus according to claim 1, the filter driving unit, when a first object is present within the imaging area, rotates the polarizing filter to a first rotation position that reduces the unnecessary reflected light from the first object; the control unit monitors the monitored object based on the captured image data when the polarizing filter is located at the first rotation position and the first object is present in the imaging area; the filter driving unit, when a second object is present within the imaging area, rotates the polarizing filter to a second rotation position that reduces the unnecessary reflected light from the second object; The control unit monitors the object to be monitored based on the captured image data when the polarizing filter is positioned at the second rotation position and the second object is present in the imaging area.

7. 7. The substrate processing apparatus according to claim 1, the illumination unit is provided vertically above the imaging area, The substrate processing apparatus, wherein the camera is provided outside the illumination unit with respect to the imaging area in a plan view, and captures an image of the imaging area obliquely downward.

8. a polarization adjustment step in which a polarizing filter is provided between an imaging area including a monitoring object in a chamber that accommodates a substrate holder that holds a substrate and a camera, the polarizing filter transmitting light from the imaging area in accordance with the polarization state of the light is rotated to reduce unnecessary reflected light corresponding to the monitoring object with the polarizing filter; an imaging step of imaging the imaging area through the polarizing filter with the camera while an illumination unit irradiates the imaging area with illumination light, and generating captured image data; a monitoring step of monitoring the monitoring target based on the captured image data generated by the camera; Equipped with In the polarization adjustment step, the polarization filter is rotated sequentially, and the rotation position of the polarization filter is determined based on a plurality of captured image data generated by the camera capturing images of the imaging area.

Images