Substrate processing method and substrate processing apparatus

Abstract

To provide a technique capable of performing monitoring processing for each of multiple monitoring targets on the basis of more appropriate image data.SOLUTION: A substrate processing method includes: a holding step of holding a substrate; a rotation step of rotating the substrate; a cup raising step of raising a processing cup surrounding the substrate; a supplying step of supplying fluid to the substrate inside the chamber for cleaning, removal of unwanted membranes, or etching; a drying step of drying the substrate supplied with fluid; a cup lowering step of lowering the processing cup surrounding the substrate; an imaging step of making a camera successively image the inside of the chamber and acquiring image data; a condition setting step of specifying a monitoring object from multiple monitoring object candidates in the chamber and changing an image condition on the basis of the monitoring object according to each step; and a monitoring step of performing monitoring processing on the monitoring object on the basis of the image data that has the image condition according to the monitoring object.SELECTED DRAWING: Figure 12

Description

[Technical Field]

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

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

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

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

[0005] However, in order to properly process a substrate, it is desirable to monitor more than just the processing liquid. However, the monitoring targets change depending on, for example, the progress of substrate processing. As a specific example, during a movement period in which the nozzle moves to a processing position above the substrate and stops, the nozzle stop position is monitored as a monitoring target. During the subsequent discharge period of the processing liquid, the discharge state of the processing liquid discharged from the nozzle is monitored as a monitoring target.

[0006] If image data for such various monitoring targets is acquired under common image conditions, it is not necessarily possible to acquire image data under image conditions suitable for all monitoring targets. For example, if image data is acquired with a wide field of view, high resolution, and a high frame rate, the amount of image data may become unnecessarily large depending on the monitoring target, which increases the processing load in the monitoring process unnecessarily.

[0007] Therefore, the present application has been made in consideration of the above-mentioned problems, and aims to provide a technology that can perform monitoring processing for each of a plurality of monitoring targets based on more appropriate image data. [Means for solving the problem]

[0008] A first aspect is a substrate processing method, comprising: a holding step of carrying a substrate into a chamber and holding the substrate; ,mosquito an imaging step in which a camera sequentially images the interior of the chamber to acquire image data; , Supervised a condition setting step of specifying a target to be monitored and changing image conditions based on the target to be monitored; before the supplying step of supplying a fluid to the substrate held inside the chamber, a monitoring step of performing a monitoring process on the monitoring target based on the image data having the image conditions according to the monitoring target. In the condition setting step, a resolution is set to a first resolution as the image condition; in the monitoring step, a monitoring process is performed on the monitoring target based on the image data having the first resolution before the supplying step; in the supplying step, a processing liquid as the fluid is supplied from a nozzle to the substrate; in the condition setting step, a resolution is set to a second resolution lower than the first resolution as the image condition corresponding to a discharge state of the processing liquid from the nozzle as the monitoring target; and in the monitoring step, a monitoring process is performed on the discharge state based on the image data having the second resolution in parallel with the supplying step. .

[0009] A second aspect is the substrate processing method according to the first aspect, wherein the image conditions include at least one of a resolution of the image data, a frame rate, and a size of a field of view captured in the image data.

[0010] A third aspect is a substrate processing method according to the second aspect, wherein in the condition setting step, the frame rate is set to a first frame rate as the image condition of the image data during a first period in which at least one of the shape and position of an object in the chamber is the monitored object, and the frame rate is set to a second frame rate higher than the first frame rate as the image condition of the image data during a second period in which the monitored object is a change in state over time of the processing liquid ejected as the fluid from a nozzle in the chamber.

[0011] A fourth aspect is a substrate processing method according to the third aspect, wherein in the condition setting step, the frame rate is set to the second frame rate as the image condition of the image data during a third period in which at least one of the shape and position of an object in the chamber and the change in state of the processing liquid over time are monitored.

[0012] A fifth aspect is a substrate processing method according to any one of the second to fourth aspects, wherein the resolution is set to a first resolution as the image condition of the image data during a first period in which at least one of the shape and position of an object in the chamber is the monitored object, and the resolution is set to a second resolution lower than the first resolution as the image condition of the image data during a second period in which the monitoring object is the change in state over time of the processing liquid ejected as the fluid from a nozzle in the chamber.

[0013] A sixth aspect is a substrate processing method according to the fifth aspect, wherein in the condition setting process, the resolution is set to the first resolution as the image condition of the image data during a third period in which at least one of the shape and position of the object in the chamber and the change in state of the processing liquid over time are monitored.

[0014] A seventh aspect is a substrate processing method according to the third or fourth aspect, wherein the monitored object, which includes at least one of the shape and position of the object, includes at least one of the shape and position of the substrate, at least one of the shape and position of the nozzle, and at least one of the shape and position of a processing cup that receives the fluid splashing from the periphery of the substrate.

[0015] An eighth aspect is a substrate processing method according to the third or fourth aspect, wherein the monitored objects, including changes in the state of the processing liquid over time, include the timing at which the processing liquid starts to be ejected, the timing at which the ejection stops, splashing of the processing liquid on the substrate, and dripping and flowing of the processing liquid from the nozzle.

[0016] A ninth aspect is a substrate processing method according to any one of the second to fourth aspects, wherein in the condition setting process, the frame rate is set to a first frame rate as the image condition for the image data in a fourth period in which the monitoring target is the presence or absence of a first abnormality occurring in the chamber during a first occurrence period, and the frame rate is set to a second frame rate higher than the first frame rate as the image condition for the image data in a fifth period in which the monitoring target is the presence or absence of a second abnormality occurring in the chamber during a second occurrence period that is shorter than the first occurrence period.

[0017] A tenth aspect is a substrate processing method according to any one of the first to fourth aspects, wherein the condition setting step includes a step of setting the image conditions as imaging conditions, and in the imaging step, the camera acquires the image data using the image conditions corresponding to the monitored object as imaging conditions.

[0018] An eleventh aspect is a substrate processing method according to any one of the first to fourth aspects, wherein in the imaging process, the camera acquires the image data under predetermined imaging conditions, and performs image processing on the image data acquired by the camera to acquire the image data having the image conditions corresponding to the monitored object.

[0019] A twelfth aspect is a substrate processing apparatus, comprising: a substrate holder that holds a substrate inside a chamber; ,before a camera that sequentially captures images of the interior of the chamber to acquire image data; a nozzle for supplying a fluid to the substrate held by the substrate holder; and a control unit that identifies a monitoring target, changes image conditions based on the monitoring target, and performs monitoring processing on the monitoring target based on the image data having the image conditions according to the monitoring target. The control unit sets a resolution to a first resolution as the image condition, and performs a monitoring process on the monitoring target based on the image data having the first resolution before supplying the fluid to the substrate, and sets a resolution to a second resolution lower than the first resolution as the image condition corresponding to a discharge state of the processing liquid from the nozzle as the monitoring target, and performs a monitoring process on the discharge state based on the image data having the second resolution in parallel with supplying the processing liquid as the fluid from the nozzle to the substrate. . [Effects of the Invention]

[0020] According to the first, second, seventh, eighth and twelfth aspects, the monitoring process for each of the multiple monitoring targets can be performed based on more appropriate image data.

[0021] According to the third aspect, when at least one of the position and shape of an object is to be monitored, the frame rate is set to a low first frame rate. This reduces the processing load. On the other hand, when the monitoring target is a change in the state of the processing liquid over time, the frame rate is set to a high second frame rate. This allows the change in the state of the processing liquid to be monitored with higher accuracy.

[0022] According to the fourth aspect, the frame rate is set to the high second frame rate, so that changes in the state of the processing liquid can be appropriately monitored.

[0023] According to the fifth aspect, during a second period in which the change in state of the processing liquid over time is the object to be monitored, the resolution is set to a lower second resolution. This reduces the processing load. On the other hand, during a first period in which at least one of the position and shape of the object is the object to be monitored, the resolution is set to a higher first resolution. This allows at least one of the position and shape of the object to be monitored with higher accuracy.

[0024] According to the sixth aspect, the resolution is set to the high first resolution, so that at least one of the shape and position of the object can be appropriately monitored.

[0025] According to the ninth aspect, for a first abnormality that occurs over a long period of time, the frame rate is set to a low first frame rate, so that the presence or absence of the first abnormality can be monitored with a low processing load. Also, for a second abnormality that occurs over a short period of time, the frame rate is set to a high second frame rate, so that the presence or absence of the second abnormality can be monitored.

[0026] According to the tenth aspect, the camera acquires image data under imaging conditions that correspond to the monitoring target, so that monitoring processing can be performed using image data that corresponds to the monitoring target.

[0027] According to the eleventh aspect, even if the camera cannot change the imaging conditions, it is possible to obtain image data having image conditions according to the monitoring target. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a diagram schematically illustrating an example of an overall configuration of a substrate processing apparatus. [Figure 2] FIG. 2 is a plan view schematically illustrating an example of the configuration of a processing unit. [Figure 3] FIG. 2 is a longitudinal sectional view schematically illustrating an example of the configuration of a processing unit. [Figure 4] FIG. 4 is a diagram schematically illustrating an example of a movement path of each nozzle. [Figure 5] FIG. 2 is a functional block diagram showing an example of the internal configuration of a control unit. [Figure 6] 10 is a flowchart illustrating an example of an operation of a processing unit. [Figure 7] 10 is a table showing an example of specific steps of a treatment liquid process. [Figure 8] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 9] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 10] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 11] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 12] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 13] 10 is a flowchart illustrating an example of an operation of a processing unit. [Figure 14] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 15] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 16] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 17] FIG. 2 is a diagram schematically illustrating an example of edge image data. [Figure 18] FIG. 2 is a diagram schematically illustrating an example of edge image data. [Figure 19] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 20] 10 is a graph schematically showing an example of the relationship between the position of the substrate and the rotation angle. [Figure 21] 10 is a table showing an example of monitoring targets and imaging conditions. [Figure 22] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 23] 10 is a graph schematically showing an example of a change in luminance value over time. [Figure 24] FIG. 2 is a longitudinal sectional view schematically illustrating an example of the configuration of a processing unit. [Figure 25] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 26] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 27] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 28] FIG. 10 is a diagram schematically illustrating an example of a difference image. [Figure 29] FIG. 2 is a longitudinal sectional view schematically illustrating an example of the configuration of a processing unit. [Figure 30] FIG. 2 is a diagram schematically illustrating an example of captured image data. [Figure 31] FIG. 10 is a diagram for explaining a field of view range. [Figure 32] 10 is a table showing an example of monitoring targets and imaging conditions. [Figure 33] FIG. 2 is a functional block diagram illustrating an example of an internal configuration of a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Unless otherwise specified, expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) not only express that positional relationship exactly, but also express 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. Expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) not only express a state in which there is strict quantitative equality, but also express a state in which there is a difference in which tolerance or equivalent functionality is obtained, unless otherwise specified. Expressions indicating shape (e.g., "rectangular shape" or "cylindrical shape") not only express the geometrically strict shape, but also express a shape with, for example, concaves and convexes or chamfers, within a range in which the same effect is obtained. The expressions "comprise," "include," "have," "includes," "includes," or "have" of one component are not exclusive expressions that exclude the presence of other components. The expression "at least one of A, B, and C" includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0033] <Overall configuration of substrate processing equipment> 1 is a schematic plan view for explaining an example of the internal layout of a substrate processing apparatus 100 according to the present embodiment. As shown in the example of FIG. 1, the substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W to be processed one by one.

[0034] The substrate processing apparatus 100 according to this embodiment performs a cleaning process on a substrate W, which is a circular, thin silicon substrate, using a chemical solution and a rinse liquid such as pure water, and then performs a drying process.

[0035] As the chemical liquid, for example, a mixed solution of ammonia and hydrogen peroxide (SC1), a mixed aqueous solution of hydrochloric acid and hydrogen peroxide (SC2), or a DHF liquid (dilute hydrofluoric acid) is used.

[0036] In the following description, chemical solutions, rinse solutions, organic solvents, etc. are collectively referred to as "processing solutions." Note that the term "processing solutions" includes not only chemical solutions used in cleaning processes, but also chemical solutions used to remove unnecessary films, and chemical solutions used 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 carrier may be a FOUP (Front Opening Unified Pod) that stores the substrate W in an enclosed space, a SMIF (Standard Mechanical Interface) pod, or an OC (Open Cassette) that exposes the substrate W to the outside air. The transfer robot transfers the substrate W between the carrier and the main transport robot 103.

[0039] The 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 having the same configuration.

[0040] Specifically, four towers, each including three processing units 1 stacked in the vertical direction, are arranged so as to surround the periphery of the main transport robot 103.

[0041] 1 schematically shows one of the three stacked processing units 1. The number of processing units 1 in the substrate processing apparatus 100 is not limited to 12 and may be changed as appropriate.

[0042] 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. 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.

[0043] One of the twelve processing units 1 mounted on the substrate processing apparatus 100 will be described below, but the other processing units 1 have the same configuration except that the nozzle arrangements are different.

[0044] <Processing unit> Next, the processing unit 1 will be described. One of the twelve processing units 1 mounted on the substrate processing apparatus 100 will be described below. FIG. 2 is a plan view of the processing unit 1. FIG. 3 is a vertical cross-sectional view of the processing unit 1.

[0045] The processing unit 1 includes, within a chamber 10, a spin chuck 20 which is an example of a substrate holder, a first nozzle 30, a second nozzle 60, a third nozzle 65, a fixed nozzle 80, a processing cup 40, and a camera 70.

[0046] The chamber 10 includes a sidewall 11 extending in the vertical direction, a ceiling wall 12 that closes the upper side of the space enclosed by the sidewall 11, and a floor wall 13 that closes the lower side. The space enclosed by the sidewall 11, the ceiling wall 12, and the floor wall 13 forms a processing space. In addition, a part of the sidewall 11 of the chamber 10 is provided with a loading / unloading entrance through which the main transport robot 103 loads and unloads the substrate W, and a shutter that opens and closes the loading / unloading entrance (both not shown).

[0047] A fan filter unit (FFU) 14 is attached to the ceiling wall 12 of the chamber 10 to further purify the air within the clean room in which the substrate processing apparatus 100 is installed and supply the purified air to the processing space within the chamber 10. The fan filter unit 14 includes a fan and a filter (e.g., a HEPA (High Efficiency Particulate Air) filter) for taking in air within the clean room and sending it into the chamber 10, and forms a downflow of purified air in the processing space within the chamber 10. A punched plate with a large number of blow-out holes may be provided directly below the ceiling wall 12 to uniformly distribute the purified air supplied from the fan filter unit 14.

[0048] The spin chuck 20 holds the substrate W in a horizontal position (a position in which the normal is aligned vertically). The spin chuck 20 includes a disk-shaped spin base 21 fixed in a horizontal position to the upper end of a rotation shaft 24 extending vertically. A spin motor 22 for rotating the rotation shaft 24 is provided below the spin base 21. The spin motor 22 rotates the spin base 21 in a horizontal plane via the rotation shaft 24. A cylindrical cover member 23 is provided to surround the periphery of the spin motor 22 and the rotation shaft 24.

[0049] The outer diameter of the disk-shaped spin base 21 is slightly larger than the diameter of the circular substrate W held by the spin chuck 20. Therefore, the spin base 21 has an upper surface 21a that faces the entire lower surface of the substrate W to be held.

[0050] A plurality of chuck pins 26 (four in this embodiment) are erected on the peripheral edge of the upper surface 21a of the spin base 21. The chuck pins 26 are arranged at equal intervals (at 90° intervals in the case of four chuck pins 26 as in this embodiment) along a circumference corresponding to the peripheral edge of the circular substrate W. Each chuck pin 26 is drivable between a holding position in contact with the peripheral edge of the substrate W and an open position spaced apart from the peripheral edge of the substrate W. The chuck pins 26 are driven in conjunction with each other by a link mechanism (not shown) housed in the spin base 21. The spin chuck 20 can hold the substrate W in a horizontal position close to the upper surface 21a above the spin base 21 by stopping the chuck pins 26 at their respective contact positions (see FIG. 3), and can release the substrate W by stopping the chuck pins 26 at their respective open positions.

[0051] The cover member 23 that covers the spin motor 22 has its lower end fixed to the floor wall 13 of the chamber 10 and its upper end reaching directly below the spin base 21. A flange-shaped member 25 is provided at the upper end of the cover member 23, which projects outward from the cover member 23 almost horizontally and then bends downward. With the spin chuck 20 holding the substrate W by gripping with multiple chuck pins 26, the spin motor 22 rotates the rotation shaft 24, thereby rotating the substrate W about a rotation axis CX that runs vertically through the center of the substrate W. The driving of the spin motor 22 is controlled by the control unit 9.

[0052] The first nozzle 30 is configured by attaching a discharge head 31 to the tip of a nozzle arm 32. The base end side of the nozzle arm 32 is fixedly connected to a nozzle base 33. The nozzle base 33 is rotatable about an axis along the vertical direction by a motor (not shown). As the nozzle base 33 rotates, the first nozzle 30 moves in an arc in the space above the spin chuck 20, as shown by arrow AR34 in FIG. 2.

[0053] Fig. 4 is a plan view that schematically shows an example of the movement path of the first nozzle 30. As illustrated in Fig. 4, the discharge head 31 of the first nozzle 30 moves in a circumferential direction around the nozzle base 33 as the nozzle base 33 rotates. The first nozzle 30 can stop at any appropriate position. In the example of Fig. 4, the first nozzle 30 can stop at each of a central position P31, a peripheral position P32, and a standby position P33.

[0054] The central position P31 is a position where the discharge head 31 vertically faces the center of the substrate W held by the spin chuck 20. The first nozzle 30 located at the central position P31 discharges the processing liquid onto the upper surface of the rotating substrate W, thereby supplying the processing liquid to the entire upper surface of the substrate W. This allows the entire upper surface of the substrate W to be processed.

[0055] The peripheral position P32 is a position where the discharge head 31 vertically faces the peripheral edge of the substrate W held by the spin chuck 20. When the first nozzle 30 is positioned at the peripheral position P32, it may discharge the processing liquid onto the upper surface of the rotating substrate W. This allows the processing liquid to be discharged only onto the peripheral edge of the upper surface of the substrate W, and enables only the peripheral edge of the substrate W to be processed (so-called bevel processing).

[0056] The first nozzle 30 can also eject the processing liquid onto the upper surface of the rotating substrate W while swinging between the central position P31 and the peripheral position P32. In this case as well, the entire upper surface of the substrate W can be processed.

[0057] On the other hand, the first nozzle 30 does not have to eject the treatment liquid at the peripheral position P32. For example, the peripheral position P32 may be an intermediate position where the first nozzle 30 waits temporarily when moving from the central position P31 to the waiting position P33.

[0058] The standby position P33 is a position where the discharge head 31 does not vertically face the substrate W held by the spin chuck 20. A standby pod that accommodates the discharge head 31 of the first nozzle 30 may be provided at the standby position P33.

[0059] 3, the first nozzle 30 is connected to a processing liquid supply source 36 via a supply pipe 34. A valve 35 is provided in the supply pipe 34. The valve 35 opens and closes the flow path of the supply pipe 34. When the valve 35 is opened, the processing liquid supply source 36 supplies the processing liquid to the first nozzle 30 through the supply pipe 34. Note that the first nozzle 30 may be configured to supply multiple types of processing liquid (including at least pure water).

[0060] Furthermore, in addition to the first nozzle 30, the processing unit 1 of this embodiment is also provided with a second nozzle 60 and a third nozzle 65. The second nozzle 60 and the third nozzle 65 of this embodiment have the same configuration as the first nozzle 30. That is, the second nozzle 60 is configured by attaching a discharge head 61 to the tip of a nozzle arm 62. The second nozzle 60 moves in an arc in the space above the spin chuck 20 as indicated by arrow AR64 by a nozzle base 63 connected to the base end of the nozzle arm 62. The relative positional relationships between a central position P61, a peripheral position P62, and a standby position P63, which are located on the movement path of the second nozzle 60, are the same as the relative positional relationships between the central position P31, the peripheral position P32, and the standby position P33, respectively.

[0061] Similarly, the third nozzle 65 is configured by attaching a discharge head 66 to the tip of a nozzle arm 67. The third nozzle 65 moves in an arc in the space above the spin chuck 20, as indicated by arrow AR69, using a nozzle base 68 connected to the base end of the nozzle arm 67. The third nozzle 65 moves in an arc between a processing position and a standby position outside the processing cup 40. The relative positional relationships between a central position P66, a peripheral position P67, and a standby position P68, which are located on the movement path of the third nozzle 65, are similar to the relative positional relationships between the central position P31, the peripheral position P32, and the standby position P33, respectively.

[0062] The third nozzle 65 may also be capable of moving up and down. For example, the third nozzle 65 is raised and lowered by a nozzle lifting mechanism (not shown) built into the nozzle base 68. In this case, the third nozzle 65 can also be stopped at an upper-center position P69 that is positioned vertically above the center position P66. Note that at least one of the first nozzle 30 and the second nozzle 60 may also be provided to be capable of moving up and down.

[0063] 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. Note that each of the second nozzle 60 and the third nozzle 65 may be configured to supply multiple types of processing liquid including at least pure water. Furthermore, at least one of the first nozzle 30, the second nozzle 60, and the third nozzle 65 may be a two-fluid nozzle that mixes a cleaning liquid such as pure water with a pressurized gas to generate droplets and sprays the mixed fluid of the droplets and the gas onto the substrate W. Furthermore, the number of nozzles provided in the processing unit 1 is not limited to three, and may be one or more.

[0064] 2 and 3, the processing unit 1 is also provided with a fixed nozzle 80. The fixed nozzle 80 is located above the spin chuck 20 and radially outward from the outer periphery of the spin chuck 20. As a more specific example, the fixed nozzle 80 is located vertically opposite a processing cup 40 (described later). The outlet of the fixed nozzle 80 faces the substrate W, and the opening axis thereof extends, for example, horizontally. The fixed nozzle 80 also ejects a processing liquid onto the upper surface of the substrate W held by the spin chuck 20. The processing liquid ejected from the fixed nozzle 80 lands, for example, at the center of the upper surface of the substrate W.

[0065] 3, the fixed nozzle 80 is connected to a processing liquid supply source 83 via a supply pipe 81. A valve 82 is provided in the supply pipe 81. The valve 82 opens and closes the flow path of the supply pipe 81. When the valve 82 is opened, the processing liquid supply source 83 supplies the processing liquid (e.g., pure water) to the fixed nozzle 80 through the supply pipe 81, and the processing liquid is discharged from the discharge port of the fixed nozzle 80.

[0066] The processing cup 40 surrounding the spin chuck 20 includes an inner cup 41, a middle cup 42, and an outer cup 43 that can be raised and lowered independently of one another. The inner cup 41 surrounds the periphery of the spin chuck 20 and has a shape that is substantially rotationally symmetrical with respect to the rotation axis CX that passes through the center of the substrate W held on the spin chuck 20. The inner cup 41 integrally includes a bottom portion 44 that is annular in plan view, a cylindrical inner wall portion 45 that rises upward from the inner peripheral edge of the bottom portion 44, a cylindrical outer wall portion 46 that rises upward from the outer peripheral edge of the bottom portion 44, a first guide portion 47 that rises from between the inner wall portion 45 and the outer wall portion 46 and extends obliquely upward toward the center (in the direction approaching the rotation axis CX of the substrate W held on the spin chuck 20) ​​while describing a smooth arc at its upper end, and a cylindrical middle wall portion 48 that rises upward from between the first guide portion 47 and the outer wall portion 46.

[0067] The inner wall portion 45 is formed to have a length such that when the inner cup 41 is in its most raised state, it can be accommodated with an appropriate gap between the cover member 23 and the flange-shaped member 25. The middle wall portion 48 is formed to have a length such that when the inner cup 41 and the inner cup 42 are in their closest proximity, it can be accommodated with an appropriate gap between a second guide portion 52 (described later) of the inner cup 42 and the processing liquid separation wall 53.

[0068] The first guide portion 47 has an upper end portion 47b that extends obliquely upward toward the center (toward the rotation axis CX of the substrate W) while describing a smooth arc. A waste groove 49 is formed between the inner wall portion 45 and the first guide portion 47 to collect and discard used processing liquid. A circular inner recovery groove 50 is formed between the first guide portion 47 and the middle wall portion 48 to collect and recover used processing liquid. A circular outer recovery groove 51 is formed between the middle wall portion 48 and the outer wall portion 46 to collect and recover a different type of processing liquid from the inner recovery groove 50.

[0069] A liquid exhaust mechanism (not shown) is connected to the waste groove 49 to discharge the processing liquid collected in the waste groove 49 and to forcibly exhaust the air inside the waste groove 49. For example, four liquid exhaust mechanisms are provided at equal intervals around the circumference of the waste groove 49. In addition, recovery mechanisms (both not shown) are connected to the inner recovery groove 50 and the outer recovery groove 51 to recover the processing liquid collected in the inner recovery groove 50 and the outer recovery groove 51 to recovery tanks provided outside the processing unit 1. The bottoms of the inner recovery groove 50 and the outer recovery groove 51 are inclined at a slight angle with respect to the horizontal, and the recovery mechanism is connected to the lowest point. This allows the processing liquid that has flowed into the inner recovery groove 50 and the outer recovery groove 51 to be smoothly recovered.

[0070] The intermediate cup 42 surrounds the periphery of the spin chuck 20 and has a shape that is substantially rotationally symmetrical with respect to the rotation axis CX that passes through the center of the substrate W held on the spin chuck 20. The intermediate cup 42 integrally includes a second guide portion 52 and a cylindrical processing liquid separation wall 53 connected to the second guide portion 52.

[0071] The second guide portion 52 is located outside the first guide portion 47 of the inner cup 41 and has a lower end portion 52a that is cylindrical and coaxial with the lower end portion of the first guide portion 47, an upper end portion 52b that extends obliquely upward toward the center (in the direction approaching the rotation axis CX of the substrate W) while drawing a smooth arc from the upper end of the lower end portion 52a, and a folded portion 52c that is formed by folding back the tip of the upper end portion 52b downward. When the inner cup 41 and the inner cup 42 are in the closest proximity, the lower end portion 52a is accommodated in the inner recovery groove 50 with an appropriate gap maintained between the first guide portion 47 and the middle wall portion 48. Furthermore, the upper end portion 52b is arranged to overlap the upper end portion 47b of the first guide portion 47 of the inner cup 41 in the vertical direction, and is in close proximity to the upper end portion 47b of the first guide portion 47 with an extremely small gap maintained when the inner cup 41 and the inner cup 42 are in the closest proximity. Furthermore, the folded portion 52c formed by folding the tip of the upper end portion 52b downward is of a length such that the folded portion 52c overlaps horizontally with the tip of the upper end portion 47b of the first guide portion 47 when the inner cup 41 and the middle cup 42 are in the closest position.

[0072] The upper end 52b of the second guide portion 52 is formed so that its thickness increases downward, and the processing liquid separation wall 53 has a cylindrical shape that extends downward from the outer peripheral edge of the lower end of the upper end 52b. The processing liquid separation wall 53 is accommodated in the outer recovery groove 51 with an appropriate gap maintained between the middle wall portion 48 and the outer cup 43 when the inner cup 41 and the middle cup 42 are in the closest position.

[0073] The outer cup 43 surrounds the periphery of the spin chuck 20 outside the second guide portion 52 of the inner cup 42 and has a shape that is approximately rotationally symmetrical with respect to the rotation axis CX that passes through the center of the substrate W held on the spin chuck 20. This outer cup 43 functions as a third guide portion. The outer cup 43 has a lower end portion 43a that is cylindrical and coaxial with the lower end portion 52a of the second guide portion 52, an upper end portion 43b that extends obliquely upward from the upper end of the lower end portion 43a toward the center (in the direction approaching the rotation axis CX of the substrate W) while drawing a smooth arc, and a folded portion 43c that is formed by folding back the tip of the upper end portion 43b downward.

[0074] When the inner cup 41 and the outer cup 43 are in the closest position, the lower end 43a is accommodated in the outer recovery groove 51 with an appropriate gap maintained between the processing liquid separation wall 53 of the inner cup 42 and the outer wall 46 of the inner cup 41. The upper end 43b is arranged to overlap the second guide portion 52 of the inner cup 42 in the vertical direction, and when the inner cup 42 and the outer cup 43 are in the closest position, it is in close proximity to the upper end 52b of the second guide portion 52 with a very small gap maintained. Furthermore, the fold portion 43c formed by folding the tip of the upper end 43b downward is formed so that when the inner cup 42 and the outer cup 43 are in the closest position, the fold portion 43c overlaps the fold portion 52c of the second guide portion 52 in the horizontal direction.

[0075] The inner cup 41, the middle cup 42, and the outer cup 43 can be raised and lowered independently of one another. That is, the inner cup 41, the middle cup 42, and the outer cup 43 are each provided with an individual cup lifting mechanism (not shown), which allows them to be raised and lowered separately and independently. As such cup lifting mechanisms, various known mechanisms such as a ball screw mechanism or an air cylinder can be used.

[0076] Partition plate 15 is provided around processing cup 40 to divide the inner space of chamber 10 into upper and lower sections. Partition plate 15 may be a single plate-like member surrounding processing cup 40, or may be a combination of multiple plate-like members joined together. Partition plate 15 may also have through-holes or notches that penetrate through it in the thickness direction. In this embodiment, through-holes are formed to pass support shafts that support nozzle base 33 of first nozzle 30, nozzle base 63 of second nozzle 60, and nozzle base 68 of third nozzle 65.

[0077] The outer peripheral edge of the partition plate 15 is connected to the side wall 11 of the chamber 10. In addition, the edge portion of the partition plate 15 surrounding the processing cup 40 is formed into a circular shape with a diameter larger than the outer diameter of the outer cup 43. Therefore, the partition plate 15 does not hinder the raising and lowering of the outer cup 43.

[0078] An exhaust duct 18 is provided in a portion of the side wall 11 of the chamber 10, near the floor wall 13. The exhaust duct 18 is connected to an exhaust mechanism (not shown). Of the clean air supplied from the fan filter unit 14 and flowing down through the chamber 10, the air that passes between the processing cup 40 and the partition plate 15 is discharged from the exhaust duct 18 to the outside of the apparatus.

[0079] The camera 70 is installed inside the chamber 10 above the partition plate 15. The camera 70 includes, for example, a CCD (Charge Coupled Device), which is a type of solid-state imaging element, and an optical system such as a lens. The camera 70 is provided to monitor various monitoring targets inside the chamber 10, which will be described later. Specific examples of the monitoring targets will be described in detail later. The camera 70 is positioned so that the various monitoring targets are included in the imaging field of view. The camera 70 captures the imaging field of view at each frame rate to obtain image data, and sequentially outputs the obtained image data to the control unit 9.

[0080] 3, an illumination unit 71 is provided in the chamber 10 at a position above the partition plate 15. If the chamber 10 is a darkroom, the control unit 9 may control the illumination unit 71 so that the illumination unit 71 emits light when the camera 70 captures an image.

[0081] The hardware configuration of the control unit 9 provided in the substrate processing apparatus 100 is the same as that of a general computer. That is, the control unit 9 is configured to include a processing unit such as a CPU that performs various arithmetic processing, a temporary storage medium such as a ROM (Read Only Memory) that is a read-only memory that stores a basic program, a random access memory (RAM) that is a readable and writable memory that stores various information, and a non-temporary storage medium such as a magnetic disk that stores control software or data. The CPU of the control unit 9 executes a predetermined processing program, whereby the control unit 9 controls each operating mechanism of the substrate processing apparatus 100, and processing in the substrate processing apparatus 100 progresses. Note that the control unit 9 may be realized by a dedicated hardware circuit that does not require software to realize its functions.

[0082] 5 is a functional block diagram showing an example of the internal configuration of the control unit 9. The control unit 9 includes a monitoring processing unit 91, a condition setting unit 92, and a processing control unit 93.

[0083] The process control unit 93 controls each component within the chamber 10. Specifically, the process control unit 93 controls the spin motor 22, various valves such as valves 35 and 82, the motors and nozzle lifting mechanisms of the nozzle bases 33, 63, and 68, the cup lifting mechanism, and the fan filter unit 14. 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. An example of a specific flow of processing the substrate W will be described in detail later.

[0084] The monitoring processing unit 91 performs monitoring processing based on the captured image data acquired by the camera 70 capturing an image of the inside of the chamber 10. This allows the monitoring processing unit 91 to monitor various monitoring targets inside the chamber 10. Specific examples of the monitoring processing will be described in detail later.

[0085] The condition setting unit 92 identifies a monitoring target to be monitored and changes the imaging conditions of the camera 70 according to the monitoring target. The condition setting unit 92 then notifies the camera 70 of the imaging conditions. The imaging conditions include, for example, at least one of resolution, frame rate, and field of view. The camera 70 acquires captured image data under the imaging conditions notified by the condition setting unit 92 and outputs the captured image data to the control unit 9. A specific example of imaging conditions according to the monitoring target will be described in detail later.

[0086] <An example of substrate processing flow> <Overall flow> 6 is a flowchart showing an example of the flow of substrate processing. First, the main transport robot 103 loads an unprocessed substrate W into the processing unit 1 (step S1: loading step). Next, the spin chuck 20 holds the substrate W in a horizontal position (step S2: holding step). Specifically, the plurality of chuck pins 26 move to their respective abutment positions, thereby holding the substrate W.

[0087] Next, the spin motor 22 starts rotating the substrate W (step S3: rotation step). Specifically, the spin motor 22 rotates the spin chuck 20, thereby rotating the substrate W held by the spin chuck 20. Next, the cup lifting mechanism lifts the processing cup 40 (step S4: cup lifting step). As a result, the processing cup 40 stops at the upper position.

[0088] Next, processing liquid is sequentially supplied to the substrate W (step S5: processing liquid step). Note that in this processing liquid step (step S5), the cup lifting mechanism switches the cup to be lifted appropriately depending on the type of processing liquid to be supplied to the substrate W, but since this point is different from the essence of this embodiment, a description thereof will be omitted below.

[0089] FIG. 7 is a table showing an example of a specific procedure for the processing liquid process (step S5). In the example of FIG. 7, the processing liquid process is defined by steps ST1 to ST12. The table shows the required time for each step, the flow rate (discharge flow rate) of the processing liquid discharged from the first nozzle 30, the second nozzle 60, the third nozzle 65, and the fixed nozzle 80, and the positions of the first nozzle 30, the second nozzle 60, and the third nozzle 65. The example of FIG. 7 also shows examples of monitoring processes and imaging conditions that can be performed in each step, which will be described in detail later.

[0090] 7, in step ST1, the discharge flow rates of the processing liquid from the first nozzle 30, the second nozzle 60, the third nozzle 65, and the fixed nozzle 80 are zero over the required time t1, and the first nozzle 30, the second nozzle 60, and the third nozzle 65 are stopped at their respective standby positions P33, P63, and P68. The required time t1 may be zero, for example. In this case, step ST1 simply represents the initial state.

[0091] In the next step ST2, the nozzle base 33 moves the first nozzle 30 from the standby position P33 to the central position P31 in a required time t2, which is, for example, about several seconds.

[0092] In the next step ST3, the first nozzle 30 ejects the processing liquid onto the upper surface of the substrate W at a flow rate F30 for a required time t3. 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 of the substrate W, and splashes off from the periphery of the substrate W. The processing liquid that splashes off from the periphery of the substrate W is received and collected in the processing cup 40. The required time t3 is, for example, several tens of seconds, and the flow rate F30 is, for example, several thousand cc / min. This step ST3 allows the substrate W to be processed in accordance with the processing liquid.

[0093] In the next step ST4, for required time t4, the fixed nozzle 80 discharges a processing liquid (e.g., a rinse liquid) at a flow rate F80, while the nozzle base 33 moves the first nozzle 30 from the central position P31 to the peripheral position P32. The processing liquid from the fixed nozzle 80 lands in the center of the upper surface of the substrate W, spreads over the upper surface of the substrate W due to centrifugal force, and splashes from the peripheral edge of the substrate W. The processing liquid splashed from the peripheral edge of the substrate W is received and collected in the processing cup 40. The required time t4 is, for example, several tens of seconds, and the flow rate F80 is, for example, several thousand cc / min.

[0094] In the next step ST5, the fixed nozzle 80 continues to discharge the processing liquid (e.g., rinse liquid) at a flow rate F80, while the nozzle base 33 moves the first nozzle 30 from the peripheral position P32 to the standby position P33 for a required time t5. The required time t5 is, for example, about several seconds.

[0095] In the next step ST6, the fixed nozzle 80 continues to discharge the processing liquid (e.g., rinse liquid) at a flow rate F80, while the nozzle base 63 moves the second nozzle 60 from the standby position P63 to the peripheral position P62 for a required time t6. The required time t6 is, for example, about several seconds.

[0096] The fixed nozzle 80 discharges the processing liquid from step ST4 to step ST6. When the processing liquid discharged from the fixed nozzle 80 is a rinse liquid, the processing liquid remaining on the upper surface of the substrate W at the end of step ST3 can be replaced with the rinse liquid.

[0097] In the next step ST7, at required time t7, the nozzle base 63 moves the second nozzle 60 from the peripheral position P62 to the central position P61, and the second nozzle 60 ejects the processing liquid at a flow rate F60 onto the upper surface of the substrate W. The required time t7 is, for example, about several tens of seconds, and the flow rate F60 is, for example, about several thousand cc / min. The upper surface of the substrate W can be processed by this step ST7.

[0098] In the next step ST8, the nozzle base 63 moves the second nozzle 60 from the central position P61 to the standby position P63 in a required time t8, which is, for example, about several seconds.

[0099] In the next step ST9, the nozzle base 68 moves the third nozzle 65 from the standby position P68 to the upper-center position P69 in a required time t9, which is, for example, about several seconds.

[0100] In the next step ST10, the third nozzle 65 ejects the processing liquid onto the upper surface of the substrate W at a flow rate F65 for a required time t10. The required time t10 is, for example, several tens of seconds, and the flow rate F65 is, for example, several thousand cc / min. If the processing liquid ejected by the third nozzle 65 is a rinse liquid, the processing liquid remaining on the upper surface of the substrate W at the end of step ST7 can be replaced with the rinse liquid.

[0101] In the next step ST11, the nozzle base 63 lowers the third nozzle 65 from the upper central position P69 to the central position P65 in a required time t11. The required time t11 is, for example, about several tens of seconds.

[0102] In the next step ST12, the nozzle base 63 moves the third nozzle 65 from the central position P65 to the standby position P68 in a required time t12. The required time t12 is, for example, about several seconds.

[0103] 6, after the treatment liquid step (step S5) is completed, the treatment unit 1 dries the substrate W (step S6: drying step). For example, the spin motor 22 increases the rotation speed of the substrate W to dry the substrate W (so-called spin drying).

[0104] Next, the cup lifting mechanism lowers the processing cup 40 (step S7: cup lowering step).

[0105] Next, the spin motor 22 stops rotating the spin chuck 20 and the substrate W, and the spin chuck 20 releases its hold on the substrate W (step S8: release step). Specifically, the plurality of chuck pins 26 move to their respective release positions, thereby releasing the hold.

[0106] Next, the main transport robot 103 unloads the processed substrate W from the processing unit 1 (step S9: unloading step).

[0107] In this manner, the substrate W is processed.

[0108] <Monitoring> The monitoring processor 91 monitors the inside of the chamber 10 using the camera 70 and determines whether the processing of the substrate W is proceeding appropriately. As will be understood from the following explanation, the objects monitored by the monitoring processor 91 change sequentially depending on the progress of the processing. Examples of objects monitored inside the chamber 10 will be explained below.

[0109] <Target of monitoring> <Nozzle position> In the above-described treatment liquid step (see FIG. 7), the first nozzle 30, the second nozzle 60, and the third nozzle 65 move appropriately. For example, the first nozzle 30 moves from the standby position P33 to the central position P31 in step ST2. At this time, the first nozzle 30 may stop at a position shifted from the central position P31 due to a motor abnormality of the nozzle base 33 or the like. In this case, the processing in step ST3 may end inappropriately.

[0110] Therefore, the position of the nozzle may be used as a monitoring target during the process (period) in which the nozzle moves. In the example of Figure 7, the process of performing position monitoring processing to monitor the nozzle position is schematically shown by diagonal hatching. A specific example of the position monitoring processing will be described below.

[0111] Fig. 8 is a diagram schematically illustrating an example of captured image data acquired in a step of performing a position monitoring process. Fig. 8 shows an example of captured image data acquired in step ST2. The captured image data in Fig. 8 includes the discharge head 31 of the first nozzle 30 stopped at the central position P31. That is, Fig. 8 shows captured image data acquired after the first nozzle 30 moves from the standby position P33 to the central position P31 in step ST2. In addition to the first nozzle 30, this captured image data also includes the processing cup 40 positioned at the upper position, the substrate W positioned in the opening of the processing cup 40, and the fixed nozzle 80.

[0112] The monitoring processing unit 91 analyzes the captured image data acquired in step ST2 to detect the position of the first nozzle 30. For example, the monitoring processing unit 91 identifies the position of the first nozzle 30 in the captured image data by pattern matching the captured image data with reference image data RI1 including the first nozzle 30 (specifically, the ejection head 31) that has been stored in advance in a storage medium. Note that in the example of Fig. 8, the reference image data RI1 is shown schematically by a virtual line superimposed on the captured image data.

[0113] Next, the monitoring processing unit 91 determines whether the detected position of the first nozzle 30 is appropriate. For example, the monitoring processing unit 91 determines whether the difference between the position of the first nozzle 30 and a preset central position P31 is equal to or less than a predetermined nozzle position tolerance. When the difference is equal to or less than the nozzle position tolerance, the monitoring processing unit 91 determines that the first nozzle 30 is positioned at the central position P31. On the other hand, when the difference is greater than the nozzle position tolerance, the monitoring processing unit 91 determines that the first nozzle 30 is not positioned at the central position P31. In other words, the monitoring processing unit 91 determines that a nozzle position abnormality has occurred.

[0114] When an abnormality occurs, the monitoring processing unit 91 may cause a notifying unit (e.g., a display or a speaker, not shown) to notify the abnormality. Also, the control unit 9 may stop the operation of the processing unit 1 to interrupt the processing of the substrate W. This point is similar to the various monitoring processes described below, so a repeated explanation will be avoided below.

[0115] Meanwhile, the first nozzle 30 moves from the standby position P33 to the central position P31 in step ST2. The monitoring processor 91 does not need to determine whether the position of the first nozzle 30 is appropriate while it is moving. Therefore, the monitoring processor 91 may determine that the first nozzle 30 has stopped when the position of the first nozzle 30 in multiple consecutive frames of captured image data becomes constant. The monitoring processor 91 may then determine whether the difference between the position of the first nozzle 30 after it has stopped and the central position P31 is equal to or less than the nozzle position tolerance. In other words, the monitoring processor 91 may determine whether the position of the first nozzle 30 is appropriate after the position of the first nozzle 30 has stabilized.

[0116] In the example of Fig. 7, in step ST3, following step ST2, the first nozzle 30 stops at the central position P31. If the position of the first nozzle 30 does not change in this way between the successive steps ST2 and ST3, the monitoring processing unit 91 does not need to perform the position monitoring process in step ST3. In the example of Fig. 7, the monitoring processing unit 91 does not perform the position monitoring process in step ST3. This makes it possible to reduce the execution of unnecessary position monitoring processes, and to reduce the processing load on the monitoring processing unit 91.

[0117] 7, in step ST4, the first nozzle 30 moves from the central position P31 to the peripheral position P32. Therefore, the monitoring processing unit 91 may also perform position monitoring processing in step ST4. Specifically, the monitoring processing unit 91 may detect the position of the first nozzle 30 after it has stopped based on the captured image data, and determine whether the first nozzle 30 is appropriately stopped at the peripheral position P32. This determination of whether it is appropriate can also be made in the same manner as described above.

[0118] 7, the first nozzle 30 moves from the peripheral position P32 to the standby position P33 in step ST5. However, in the example of FIG. 7, the monitoring processor 91 does not perform position monitoring processing in step ST5. In other words, the monitoring processor 91 does not monitor the position of the first nozzle 30 with respect to the standby position P33. This is because even if the first nozzle 30 stops at a position shifted from the standby position P33, this has little effect on the processing of the substrate W. Of course, the monitoring processor 91 may also perform position monitoring processing with respect to the standby position P33.

[0119] The monitoring processing unit 91 may also perform position monitoring processing on the second nozzle 60 and the third nozzle 65 at least in the steps in which their positions change. In the example of Fig. 7, the second nozzle 60 moves in steps ST6 and ST7, so the monitoring processing unit 91 performs position monitoring processing to monitor the position of the second nozzle 60 in steps ST6 and ST7. Furthermore, in the example of Fig. 7, the third nozzle 65 moves in steps ST9 and ST11, so the monitoring processing unit 91 performs position monitoring processing to monitor the position of the third nozzle 65 in steps ST9 and ST11.

[0120] 7, the monitoring processing unit 91 does not perform the position monitoring process in step ST8 in which the second nozzle 60 moves to the standby position P63, and in step ST12 in which the third nozzle 65 moves to the standby position P68. Of course, the position monitoring process may also be performed in these steps.

[0121] <Processing liquid> In the above-described processing liquid step (see FIG. 7), the first nozzle 30, the second nozzle 60, the third nozzle 65, and the fixed nozzle 80 appropriately discharge the processing liquid. For example, the first nozzle 30 discharges the processing liquid onto the upper surface of the substrate W during the required time t3 of step ST3. At this time, the first nozzle 30 appropriately discharges the processing liquid, thereby enabling the substrate W to be processed.

[0122] Therefore, the state of the treatment liquid may be monitored during the process of discharging the treatment liquid from each nozzle. In the example of Figure 7, the process of performing treatment liquid monitoring processing related to the treatment liquid is schematically shown by sandy hatching. A specific example of the treatment liquid monitoring processing will be described below.

[0123] <Discharge time> For example, if the discharge time during which the first nozzle 30 actually discharges the processing liquid in step ST3 deviates from the specified time, the processing of step ST3 may end inappropriately. Specifically, if the discharge time is too short, the substrate W will be insufficiently processed, and if the discharge time is too long, the substrate W will be overprocessed.

[0124] Therefore, the ejection start timing and ejection stop timing of the treatment liquid, and in turn the ejection time, may be adopted as the monitoring targets in the process of ejecting the treatment liquid from each nozzle. A specific example of the ejection time monitoring process for monitoring the ejection time of the treatment liquid will be described below.

[0125] Fig. 9 is a diagram schematically illustrating an example of captured image data acquired in a step of performing a discharge time monitoring process. Fig. 9 illustrates an example of captured image data acquired in step ST3. The captured image data in Fig. 9 includes the first nozzle 30 discharging the treatment liquid. In other words, Fig. 9 illustrates captured image data acquired after the first nozzle 30 starts discharging the treatment liquid in step ST3.

[0126] Before the first nozzles 30 start discharging the treatment liquid in step ST3, the camera 70 sequentially acquires captured image data (e.g., FIG. 8) that includes the first nozzles 30 that are not discharging the treatment liquid. Once the treatment liquid starts to be discharged from the first nozzles 30, the camera 70 sequentially acquires captured image data (e.g., FIG. 9) that includes the first nozzles 30 that have discharged the treatment liquid. Therefore, if it is possible to identify whether the first nozzles 30 are discharging the treatment liquid for each piece of sequentially acquired captured image data, it is possible to identify the timing at which the first nozzles 30 start discharging the treatment liquid based on the identification result.

[0127] Therefore, the monitoring processing unit 91 determines for each captured image data whether the first nozzle 30 is ejecting treatment liquid. In the examples of Figures 8 and 9, a discharge determination region R1 is set in the captured image data. The discharge determination region R1 includes an area extending in the discharge direction from the tip of the first nozzle 30 (i.e., the tip of the ejection head 31). The discharge determination region R1 has, for example, a rectangular shape extending in the discharge direction (downward in this case) from the tip of the first nozzle 30.

[0128] 8 and 9, the pixel values ​​in the discharge determination region R1 differ when the first nozzle 30 is discharging the treatment liquid and when the first nozzle 30 is not discharging the treatment liquid. For example, the sum of the pixel values ​​in the discharge determination region R1 when the first nozzle 30 is discharging the treatment liquid is greater than the sum of the pixel values ​​in the discharge determination region R1 when the first nozzle 30 is not discharging the treatment liquid.

[0129] Therefore, the monitoring processor 91 determines whether the first nozzle 30 is discharging the treatment liquid for each captured image data acquired in step ST3 based on the pixel values ​​in the discharge determination region R1. As a specific example, the monitoring processor 91 determines whether the sum of the pixel values ​​in the discharge determination region R1 is equal to or greater than a predetermined discharge reference value, and determines that the first nozzle 30 is discharging the treatment liquid when the sum is equal to or greater than the discharge reference value. Furthermore, the monitoring processor 91 determines that the first nozzle 30 is not discharging the treatment liquid when the sum is less than the discharge reference value.

[0130] Note that the method for determining whether or not the treatment liquid is being discharged based on the pixel values ​​in the discharge determination region R1 is not limited to this, and various other methods can be used. For example, the variance of the pixel values ​​in the discharge determination region R1 when the first nozzle 30 is discharging the treatment liquid is larger than the variance when the first nozzle 30 is not discharging the treatment liquid. Therefore, the monitoring processing unit 91 may calculate this variance and determine whether or not the treatment liquid is being discharged based on the size of the variance. It is also possible to use standard deviation instead of variance.

[0131] The monitoring processing unit 91 determines the start timing based on, for example, the timing of acquiring captured image data when the first nozzle 30 is not ejecting processing liquid and the timing of acquiring captured image data when the first nozzle 30 is ejecting processing liquid.

[0132] Similarly, the monitoring processor 91 can also identify the end timing at which the first nozzle 30 stops discharging the processing liquid.

[0133] The monitoring processing unit 91 then calculates the difference between the discharge stop timing and the discharge start timing as the discharge time. Next, the monitoring processing unit 91 determines whether the discharge time is appropriate. For example, the monitoring processing unit 91 determines whether the difference between the discharge time and the specified time is equal to or less than a predetermined time tolerance. When the difference is equal to or less than the time tolerance, the monitoring processing unit 91 determines that the discharge time is appropriate. On the other hand, when the difference is greater than the time tolerance, the monitoring processing unit 91 determines that the discharge time is inappropriate. In other words, the monitoring processing unit 91 determines that an abnormality in the discharge time has occurred.

[0134] Furthermore, in the above-described processing liquid step (see FIG. 7), the second nozzle 60 and the third nozzle 65 also discharge the processing liquid, so that the discharge time monitoring process may be performed in each process of discharging the processing liquid. The discharge time monitoring process for the second nozzle 60 and the third nozzle 65 is the same as that for the first nozzle 30.

[0135] The fixed nozzle 80 discharges the treatment liquid from step ST4 to step ST6. In the example of Fig. 7, the monitoring processing unit 91 performs treatment liquid monitoring processing in step ST4, but this treatment liquid monitoring processing includes a liquid splash monitoring processing, which will be described later, and does not include a discharge time monitoring processing for the fixed nozzle 80. Also, in the example of Fig. 7, the monitoring processing unit 91 does not perform treatment liquid monitoring processing in steps ST5 and ST6. However, this is not a limitation, and the monitoring processing unit 91 may perform a discharge time monitoring processing for the fixed nozzle 80 from step ST4 to step ST6.

[0136] Fig. 10 is a diagram schematically illustrating an example of captured image data acquired in steps ST4 to ST6. The captured image data in Fig. 10 includes the fixed nozzle 80 discharging the treatment liquid. In other words, Fig. 10 illustrates captured image data acquired after the fixed nozzle 80 has discharged the treatment liquid.

[0137] 8 to 10, a discharge determination region R11 is set to determine whether or not the treatment liquid is being discharged from the fixed nozzle 80. Because the fixed nozzle 80 discharges the treatment liquid horizontally, the discharge determination region R11 has, for example, a rectangular shape extending laterally from the tip of the fixed nozzle 80. The discharge time monitoring process using the discharge determination region R11 is similar to the discharge time monitoring process using the discharge determination region R1.

[0138] <Liquid splash> In step ST3, the first nozzle 30 may eject the processing liquid onto the upper surface of the substrate W at a flow rate greater than the flow rate F30, for example, due to various factors, which may cause the processing liquid to splash (so-called liquid splash) on the upper surface of the substrate W. If such liquid splash occurs, the processing unit 1 cannot process the substrate W appropriately.

[0139] Therefore, the presence or absence of splashing of the processing liquid may be monitored during the process in which each nozzle ejects the processing liquid. A specific example of a splash monitoring process for monitoring the presence or absence of splashing will be described below.

[0140] Fig. 11 is a diagram schematically illustrating an example of captured image data acquired in step ST3. In the captured image data of Fig. 11, liquid splashing occurs. As illustrated in Fig. 11, the processing liquid flowing down from the first nozzle 30 splashes off the upper surface of the substrate W, causing the processing liquid to splash in a crown shape surrounding the landing position.

[0141] 8 to 11, a liquid splash determination region R2 is set in the captured image data. The liquid splash determination region R2 may be set to an area that includes a portion of the processing liquid splashing from the upper surface of the substrate W. Because the processing liquid splashes around the landing position, the liquid splash determination region R2 may be set, for example, adjacent to the discharge determination region R1. In the illustrated example, the liquid splash determination region R2 is separated from the discharge determination region R1 and is located, for example, to the left of the discharge determination region R1. In the illustrated example, the liquid splash determination region R2 has a rectangular shape.

[0142] The pixel values ​​in the splash determination region R2 differ when no splash occurs (e.g., FIG. 9) and when splash occurs (e.g., FIG. 11). For example, when light hits the processing liquid that has splashed from the upper surface of the substrate W, the light is diffusely reflected, and therefore the sum of the pixel values ​​in the splash determination region R2 when splash occurs is greater than the sum of the pixel values ​​in the splash determination region R2 when no splash occurs.

[0143] Therefore, the monitoring processor 91 determines whether or not a splash has occurred for each piece of captured image data acquired in step ST3, based on the pixel values ​​within the splash determination region R2. As a specific example, the monitoring processor 91 determines whether or not the sum of the pixel values ​​within the splash determination region R2 is equal to or greater than a predetermined splash reference value, and determines that no splash has occurred when the sum is less than the splash reference value. On the other hand, the monitoring processor 91 determines that a splash has occurred when the sum is equal to or greater than the splash reference value. In other words, the monitoring processor 91 determines that a splash abnormality has occurred.

[0144] Note that the method for determining the presence or absence of splashing based on the pixel values ​​within the splash detection region R2 is not limited to this, and various other methods can be used. For example, when light hits the processing liquid that has splashed from the upper surface of the substrate W, the light is diffusely reflected, so the variance of the pixel values ​​within the splash detection region R2 when splashing occurs is larger than the variance when splashing does not occur. Therefore, the monitoring processing unit 91 may calculate the variance and determine the presence or absence of splashing based on the size of the variance. Note that it is also possible to use a standard deviation instead of the variance.

[0145] Since the second nozzle 60, the third nozzle 65, and the fixed nozzle 80 also discharge the treatment liquid, the monitoring processor 91 performs a liquid splash monitoring process during the process in which each nozzle discharges the treatment liquid. Note that since the fixed nozzle 80 discharges the treatment liquid in a horizontal direction from its tip, liquid splashes tend to occur on the opposite side of the fixed nozzle 80 from the liquid landing position. In the example of Fig. 11, the liquid splash detection region R2 is located on the opposite side of the fixed nozzle 80 from the liquid landing position, and therefore can also be used to detect liquid splashes associated with the discharge of treatment liquid from the fixed nozzle 80.

[0146] In the example of FIG. 7, the liquid splash monitoring process is performed on the fixed nozzle 80 in step ST4, but the liquid splash monitoring process may also be performed in steps ST5 and ST6.

[0147] <Drop> When the first nozzle 30, the second nozzle 60, and the third nozzle 65 stop discharging the processing liquid, droplets of the processing liquid may fall from each discharge port (so-called dripping). If such droplets fall onto the upper surface of the substrate W, problems may occur.

[0148] Therefore, the presence or absence of dripping may be monitored during the process in which each nozzle ejects the treatment liquid. A specific example of dripping monitoring processing for monitoring the presence or absence of dripping will be described below.

[0149] Fig. 12 is a diagram schematically illustrating an example of captured image data acquired in step ST3. Fig. 12 illustrates captured image data acquired immediately after the first nozzle 30 stops discharging the treatment liquid, and in the example of Fig. 12, dripping has occurred.

[0150] 8, 9, and 12, the pixel values ​​in the discharge determination region R1 differ when the first nozzle 30 is not discharging the treatment liquid (FIG. 8), when the first nozzle 30 is discharging the treatment liquid (FIG. 9), and when dripping occurs (FIG. 12). For example, the sum of the pixel values ​​in the discharge determination region R1 when dripping occurs is smaller than the sum of the pixel values ​​in the discharge determination region R1 when the first nozzle 30 is discharging the treatment liquid, and is larger than the sum of the pixel values ​​in the discharge determination region R1 when the first nozzle 30 is not discharging the treatment liquid.

[0151] Therefore, the monitoring processing unit 91 determines whether or not dripping has occurred for each captured image data acquired in step ST3 based on the pixel values ​​of the discharge determination region R1. As a specific example, the monitoring processing unit 91 may determine that the first nozzle 30 is discharging treatment liquid when the sum of the pixel values ​​in the discharge determination region R1 is equal to or greater than a predetermined first reference value, determine that a dripping abnormality has occurred when the sum of the pixel values ​​in the discharge determination region R1 is less than the first reference value and equal to or greater than a predetermined second reference value, and determine that the first nozzle 30 is not discharging treatment liquid when the sum of the pixel values ​​in the discharge determination region R1 is less than the second reference value.

[0152] Note that the method for determining whether or not there is dripping based on pixel values ​​within the discharge determination region R1 is not limited to this, and various other methods can be used. For example, the presence or absence of dripping may be determined based on the variance or standard deviation within the discharge determination region R1.

[0153] <Outflow> Even though the process control unit 93 outputs a close signal to each valve, an abnormality in the valve may cause each valve to open slightly. In this case, the discharge of the process liquid cannot be stopped appropriately, and the process liquid continues to flow out of the nozzle (so-called outflow). In this case, the process liquid continues to be discharged onto the upper surface of the substrate W, which may cause processing problems.

[0154] Therefore, the presence or absence of outflow may be adopted as a monitoring target in the process in which each nozzle ejects the treatment liquid. A specific example of outflow monitoring processing for monitoring the presence or absence of outflow will be described below.

[0155] As described above, an outflow is an abnormality in which processing liquid is discharged from a nozzle while a close signal is being output to a valve. Because the valve is controlled by the processing control unit 93, the monitoring processing unit 91 can recognize whether a close signal is being output to the valve. Furthermore, the monitoring processing unit 91 can determine whether processing liquid is being discharged from the nozzle based on the captured image data, as described in the discharge time monitoring process.

[0156] For example, when the monitoring processor 91 determines that the first nozzle 30 is discharging the processing liquid even though the processing controller 93 is outputting a close signal to the valve 35, the monitoring processor 91 determines that an outflow abnormality has occurred in the first nozzle 30. The same applies to the second nozzle 60 and the third nozzle 65.

[0157] <Imaging conditions> As described above, the object to be monitored changes depending on each step that defines the treatment liquid process (step S5). In FIG. 7, for example, the object to be monitored is the position of the first nozzle 30 during the execution of step ST2, and the change in the state (shape) of the treatment liquid discharged from the first nozzle 30 during the execution of step ST3 (e.g., discharge start, discharge stop, splashing, dripping, and outflow). In other words, during the execution of step ST2, the change in the state of the treatment liquid is not monitored, but the position of the nozzle is, whereas during the execution of step ST3, the position of the nozzle is not monitored, but the discharge state of the treatment liquid is,. Also, as during the execution of step ST7, both the position of the nozzle and the change in the state of the treatment liquid may be monitored.

[0158] In this embodiment, the condition setting unit 92 sets the imaging conditions according to the monitoring target in each execution period. As a specific example, the imaging conditions in an execution period in which the nozzle position is the monitoring target (e.g., process ST2) and the imaging conditions in an execution period in which the state change of the processing liquid is the monitoring target (e.g., process ST3) will be described below, and then the imaging conditions in an execution period in which both the nozzle position and the state change of the processing liquid are the monitoring targets (e.g., process ST7) will be described.

[0159] <Nozzle position monitoring process> The higher the resolution of the captured image data, the more precisely and clearly the shape of each nozzle is captured in the captured image data. Therefore, if the camera 70 acquires captured image data for position monitoring processing at high resolution, the monitoring processing unit 91 can detect the position of the nozzle with higher accuracy based on the captured image data.

[0160] Therefore, the condition setting unit 92 sets the resolution to a high resolution as an imaging condition when the camera 70 acquires captured image data for the position monitoring process. Specifically, the condition setting unit 92 sets the resolution to a higher resolution as an imaging condition in steps ST2, ST4, ST6, ST7, ST9, and ST11 (see also FIG. 7).

[0161] On the other hand, even if the frame rate of the captured image data is low, problems are unlikely to occur in the position monitoring process. In other words, because the position monitoring process monitors the stop position of the nozzle, a low frame rate does not cause problems in the position monitoring process. Furthermore, even if changes in the nozzle position over time are monitored, the frame rate can be low if there is no great need to detect the nozzle position at short time intervals.

[0162] However, when the processing liquid monitoring process is performed, it is better to have a high frame rate, as will be described in detail later.

[0163] Therefore, the condition setting unit 92 sets the resolution to a high resolution and the frame rate to a low frame rate as the imaging conditions during the execution periods of steps ST2, ST6, ST9, and ST11. In other words, the condition setting unit 92 sets the resolution to a high resolution and the frame rate to a low frame rate as the imaging conditions for captured image data that is not used in the processing liquid monitoring process but is used in the position monitoring process. In other words, the condition setting unit 92 sets the resolution to a high resolution and the frame rate to a low frame rate as the imaging conditions during the period when the nozzle position is monitored and not when a change in the state of the processing liquid is monitored.

[0164] The condition setting unit 92 notifies the camera 70 of the set imaging conditions. The camera 70 acquires captured image data in accordance with the received imaging conditions. That is, the camera 70 acquires captured image data at high resolution and a low frame rate in steps ST2, ST6, ST9, and ST11.

[0165] The resolution can be changed, for example, by the binning function of the camera 70. The binning function is a function that changes the number of light receiving elements of the camera 70 that are read out as one pixel. For example, consider a case where the light receiving surface of the camera 70 is composed of Nx (e.g., 2448) vertical pixels by Ny (e.g., 2048) horizontal pixels. The camera 70 reads out data from each light receiving element as one pixel, thereby obtaining captured image data having Nx vertical pixels by Ny horizontal pixels. Alternatively, the camera 70 reads out data from a total of four light receiving elements, for example, two vertical pixels by two horizontal pixels, as one pixel, thereby obtaining captured image data having Nx / 2 (e.g., 1224) vertical pixels by Ny / 2 horizontal pixels (e.g., 1024) horizontal pixels. Since the field of view of the captured image data does not change, the resolution of the captured image data can be reduced.

[0166] The frame rate can be changed, for example, by changing the period during which the shutter (electronic shutter or mechanical shutter) of the camera 70 is opened. A high frame rate is, for example, 100 fps, and a low frame rate is, for example, 30 fps.

[0167] In each of steps ST2, ST6, ST9, and ST11, the camera 70 acquires images at a high resolution and a low frame rate, and the monitoring processing unit 91 performs position monitoring processing based on the captured image data at a high resolution and a low frame rate. Because the high-resolution captured image data is used, the monitoring processing unit 91 can detect the nozzle position with high accuracy. On the other hand, because the low-frame-rate captured image data is used, the processing load on the monitoring processing unit 91 can be reduced. This reduces power consumption.

[0168] <Processing liquid monitoring process> The higher the frame rate of the captured image data, the shorter the time intervals at which the camera 70 can acquire captured image data. Therefore, the multiple captured image data can more easily capture changes in the state of the treatment liquid being ejected from each nozzle. For example, the higher the frame rate, the more easily it is possible to capture changes from a state in which the treatment liquid is not being ejected to a state in which the treatment liquid is being ejected. Therefore, the higher the frame rate, the more accurately the monitoring processing unit 91 can monitor the timing at which the ejection of the treatment liquid starts. The same applies to the timing at which the ejection of the treatment liquid stops. Ultimately, the monitoring processing unit 91 can calculate the processing time with higher accuracy.

[0169] Furthermore, the higher the frame rate, the shorter the time interval at which image data is acquired, so that even a phenomenon that occurs for a short period of time can be captured in the image data. For example, even if a momentary splash occurs due to a momentary increase in the discharge flow rate of the processing liquid caused by a flow rate fluctuation, if the frame rate is high, the camera 70 can acquire image data that includes the splash.

[0170] Furthermore, dripping occurs when the discharge of the processing liquid is stopped, and the period of occurrence is not very long. Furthermore, the period of occurrence of outflow may also be short depending on the degree of the valve abnormality. If the frame rate is high, even if dripping or outflow occurs momentarily, the camera 70 can acquire captured image data including the dripping or outflow.

[0171] Therefore, the condition setting unit 92 sets the frame rate to a high frame rate as an imaging condition in steps ST3, ST4, ST7, and ST10. In other words, the condition setting unit 92 sets the frame rate to a high frame rate as an imaging condition when the camera 70 acquires captured image data for the treatment liquid monitoring process.

[0172] On the other hand, changes in the state of the processing liquid can also be detected from captured image data acquired at low resolution. Therefore, the condition setting unit 92 sets the resolution to low and the frame rate to high as the imaging conditions for steps ST3 and ST10. In other words, the condition setting unit 92 sets the resolution to low and the frame rate to high as the imaging conditions for captured image data that is not used for the position monitoring process but is used for the processing liquid monitoring process. In other words, the condition setting unit 92 sets the resolution to low and the frame rate to high as the imaging conditions for a period in which the nozzle position is not monitored but a change in the state of the processing liquid is monitored.

[0173] The condition setting unit 92 notifies the camera 70 of the set imaging conditions. The camera 70 acquires captured image data according to the received imaging conditions. Therefore, the monitoring processing unit 91 performs processing liquid monitoring processing based on the captured image data acquired at low resolution and high frame rate in each of steps ST3 and ST10. In this way, since the captured image data at a high frame rate is used, the monitoring processing unit 91 can monitor the ejection start timing, ejection stop timing, liquid splashing, dripping, and outflow with higher accuracy. Furthermore, since the captured image data at low resolution is used, the processing load of the monitoring processing unit 91 can be reduced. Therefore, power consumption can be reduced.

[0174] <Concurrent execution of position monitoring process and processing liquid monitoring process> The condition setting unit 92 sets the resolution to a high resolution and the frame rate to a high frame rate as the imaging conditions for steps ST4 and ST7. In other words, the condition setting unit 92 sets the resolution to a high resolution and the frame rate to a high frame rate as the imaging conditions for the captured image data used in both the position monitoring process and the processing liquid monitoring process. In other words, the condition setting unit 92 sets the resolution to a high resolution and the frame rate to a low frame rate as the imaging conditions for the period in which both the nozzle position and the change in the state of the processing liquid are monitored.

[0175] The condition setting unit 92 notifies the camera 70 of the set imaging conditions. The camera 70 acquires captured image data according to the received imaging conditions. Therefore, the monitoring processing unit 91 performs both the position monitoring process and the processing liquid monitoring process based on the captured image data acquired at high resolution and a high frame rate in each of steps ST4 and ST7. This allows the position monitoring process and the processing liquid monitoring process to be performed with higher accuracy.

[0176] <Recipe information> The control unit 9 receives recipe information indicating a substrate processing procedure (including each process and various conditions for each process) from, for example, an upstream device or an operator. The process control unit 93 controls the processing unit 1 based on the recipe information, thereby performing processing on the substrate W. The recipe information may include, for example, information on "process," "time," "discharge flow rate," and "position" shown in FIG. 7. In this case, the condition setting unit 92 identifies a monitoring target in each process based on the recipe information, sets imaging conditions as described above according to the monitoring target, and notifies the camera 70 of the imaging conditions.

[0177] As a specific example, the condition setting unit 92 identifies a process in which the nozzle is moving based on "position" information included in the recipe information, and adopts the nozzle position as the monitoring target for that process. The condition setting unit 92 also identifies a process in which the nozzle is discharging the processing liquid based on "discharge flow rate" information included in the recipe information, and adopts a change in the state of the processing liquid as the monitoring target for that process. Then, as described above, the condition setting unit 92 sets the imaging conditions for the execution period of each process according to the monitoring target for that process.

[0178] It should be noted that the condition setting unit 92 does not necessarily need to identify the monitoring target in each process based on recipe information. Information specifying the processing procedure and the monitoring target may be input to the control unit 9 by an upstream device or an operator. In this way, the condition setting unit 92 can identify the monitoring target in each process by reading the information, and can set imaging conditions according to the monitoring target.

[0179] <Overall flow of monitoring process> 13 is a flowchart showing an example of the overall flow of the above-mentioned monitoring process. The condition setting unit 92 identifies a monitoring target for each process from multiple monitoring target candidates based on the processing procedure (e.g., recipe information, etc.), and sets imaging conditions for each process based on the identified monitoring target (step S11: condition setting process). The monitoring target candidates here refer to monitoring targets before they are identified, and include, for example, the nozzle position, the timing at which the discharge of the processing liquid starts and stops, splashing, dripping, and outflow.

[0180] The camera 70 sequentially acquires captured image data based on the imaging conditions set by the condition setting unit 92 (step S12: imaging step). As a result, the camera 70 acquires captured image data under imaging conditions according to the monitoring target in each step.

[0181] The monitoring processing unit 91 performs monitoring processing on the monitoring target in each step based on captured image data captured under imaging conditions according to the monitoring target (step S13: monitoring step).

[0182] The imaging step and the monitoring step are preferably performed in parallel with the processing of the substrate W. This allows the monitoring process to be performed during processing of the substrate W. In the condition setting step, imaging conditions for all steps may be set in advance before processing of the substrate W, or imaging conditions for each step may be set sequentially as the processing of the substrate W progresses.

[0183] <Effects of the embodiment> As described above, the condition setting unit 92 sets the imaging conditions according to the monitoring target and notifies the imaging conditions to the camera 70. The camera 70 acquires captured image data under the notified imaging conditions, and can therefore acquire captured image data under the imaging conditions according to the monitoring target.

[0184] For example, during the execution of a process in which the nozzle position is monitored and not the change in the state of the processing liquid, the camera 70 acquires captured image data at a high resolution and a low frame rate. Therefore, the monitoring processing unit 91 performs position monitoring processing based on the captured image data at a high resolution and a low frame rate. This allows the nozzle position to be monitored with high accuracy based on the captured image data at a high resolution, while reducing the processing load by using a low frame rate.

[0185] Furthermore, for example, during a process in which the nozzle position is not the object of monitoring but the change in the state of the processing liquid is the object of monitoring, the camera 70 acquires captured image data at a low resolution and a high frame rate. Therefore, the monitoring processing unit 91 performs the processing liquid monitoring process based on the captured image data at a low resolution and a high frame rate. This allows the processing load to be reduced by using low resolution while still monitoring the change in the state of the processing liquid with high accuracy based on the captured image data at a high frame rate.

[0186] Furthermore, during the execution of a process in which both the nozzle position and the change in the state of the processing liquid are monitored, the camera 70 captures image data at a high resolution and a high frame rate, allowing the monitoring processing unit 91 to perform the position monitoring process and the processing liquid monitoring process with high accuracy.

[0187] <Other examples of monitoring targets> The monitoring target is not limited to the above specific example, and various other monitoring targets can be used within the chamber 10. In short, the condition setting unit 92 may change the imaging conditions sequentially in response to changes in the monitoring target, regardless of the type of monitoring target. Other specific examples of monitoring targets will be described below.

[0188] <Retention abnormalities and board shape abnormalities> In the holding step (step S2), the spin chuck 20 holds the substrate W. At this time, the spin chuck 20 may not be able to hold the substrate W in an appropriate position. For example, while the spin chuck 20 holds the substrate W, the contact position between one of the chuck pins 26 and the periphery of the substrate W may shift vertically. In this case, the substrate W is held in an inclined position. If the amount of shift becomes large, the substrate W may even climb onto the chuck pins 26. Hereinafter, an abnormality in which the spin chuck 20 is unable to hold the substrate W in a horizontal position will be referred to as a holding abnormality. When such a holding abnormality occurs, the substrate W cannot be processed appropriately.

[0189] Furthermore, abnormalities may occur in the shape of the substrate W. For example, if a crack occurs at the periphery of the substrate W, a step occurs at the cracked portion of the periphery of the substrate W, and the periphery of the substrate W does not have a circular shape. Furthermore, if a chip occurs in part of the periphery of the substrate W, the periphery of the substrate W also does not have a circular shape. In such cases, the spin chuck 20 is also likely to be unable to hold the substrate W in a horizontal position. Hereinafter, abnormalities such as cracks in the substrate W will be referred to as shape abnormalities. If such shape abnormalities occur, the substrate W cannot be processed appropriately.

[0190] Therefore, the presence or absence of holding abnormalities and abnormalities in the shape of the substrate may be adopted as the monitoring targets. An example of a substrate monitoring process for monitoring the presence or absence of holding abnormalities and abnormalities in the shape of the substrate will be described below.

[0191] 14 to 16 are diagrams schematically illustrating an example of captured image data acquired during the rotation process. FIGS. 14 to 16 show captured image data acquired before the processing cup 40 is raised. That is, FIGS. 14 to 16 show captured image data from the start of the rotation process (step S3) to the cup raising process (step S4). FIG. 14 illustrates a state in which the spin chuck 20 holds the substrate W in a horizontal position, FIG. 15 illustrates a state in which the spin chuck 20 holds the substrate W in an inclined position, and FIG. 16 illustrates a state in which a crack has occurred in the substrate W. Although the chuck pins 26 holding the substrate W may be included in the captured image data, they are omitted from FIGS. 14 to 16 to avoid complication.

[0192] When the spin chuck 20 holds the substrate W in a horizontal position and the substrate W is rotated, ideally, the peripheral (outline) shape of the substrate W is always constant. In the illustrated example, the camera 70 captures an image of the substrate W from an oblique angle, so the peripheral shape of the substrate W in the captured image data has an elliptical shape. Ideally, the peripheral shape of the substrate W is always constant in multiple captured image data acquired sequentially while the substrate W is rotating. However, in reality, the position of the peripheral edge of the substrate W fluctuates slightly while the substrate W is rotating.

[0193] On the other hand, when the spin chuck 20 holds the substrate W in an inclined position, the rotation axis CX of the spin chuck 20 is not perpendicular to the substrate W. Therefore, when the spin chuck 20 rotates the substrate W, the peripheral shape of the substrate W varies relatively greatly among the multiple captured image data. In other words, the peripheral shape of the substrate W fluctuates significantly. In the example of Figure 15, the peripheral shape of the substrate W acquired at different times is schematically shown by virtual lines.

[0194] Furthermore, if a crack occurs on the periphery of the substrate W, the shape of the periphery of the substrate W will deviate from an elliptical shape. In the example of Fig. 16, a step occurs on the periphery of the substrate W due to the crack. In this case, when the spin chuck 20 rotates the substrate W, the position of the periphery of the substrate W will also differ relatively greatly among the multiple captured image data. In other words, the periphery of the substrate W will fluctuate significantly.

[0195] Therefore, the monitoring processor 91 obtains the difference in the peripheral shape of the substrate W between the plurality of pieces of image data sequentially acquired by the camera 70, and determines whether the difference is equal to or smaller than a predetermined substrate tolerance. When the difference is equal to or smaller than the substrate tolerance, the monitoring processor 91 determines that the spin chuck 20 is holding the substrate W normally in a horizontal position, and when the difference is larger than the substrate tolerance, it determines that a holding abnormality or an abnormal substrate shape has occurred.

[0196] It should be noted that the monitoring processing unit 91 does not need to compare the entire peripheral shape of the substrate W between the captured image data, and it is sufficient to compare, for example, the shape of a portion of the front side or a portion of the back side of the peripheral edge of the substrate W between the captured image data. In the examples of Figures 14 to 16, a substrate determination region R3 is set in the captured image data. In the examples of Figures 14 to 16, the substrate determination region R3 is a region that includes a portion of the front side of the peripheral edge of the substrate W, and has a shape that extends along the peripheral edge of the substrate W.

[0197] The monitoring processor 91, for example, extracts the substrate determination region R3 from the captured image data and calculates the difference between the substrate determination regions R3 of the two captured image data to obtain a difference image. Specifically, the monitoring processor 91 subtracts pixel values ​​of pixels at the same position within the substrate determination region R3 to obtain a difference image. This subtraction cancels out pixel values ​​within the same first region within the substrate determination region R3, and emphasizes pixel values ​​within different second regions. In other words, the absolute value of the pixel values ​​of the pixels within the second region becomes larger than the absolute value of the pixel values ​​of the pixels within the first region. Therefore, in the difference image, the region sandwiched between the peripheries of the substrate W within the two substrate determination regions R3 (hereinafter referred to as the peripheral difference) is emphasized.

[0198] Next, the monitoring processor 91 performs edge extraction processing, such as the Canny method, on the difference image to obtain an edge image. FIGS. 17 and 18 are diagrams schematically illustrating examples of edge images. FIG. 17 illustrates an edge image obtained when the spin chuck 20 holds a normal substrate W in a horizontal position, while FIG. 18 illustrates an edge image obtained when the spin chuck 20 holds a normal substrate W in an inclined position. In the examples of FIGS. 17 and 18, an edge 201 corresponds to the peripheral difference. As can be seen from FIGS. 17 and 18, although the edge image includes multiple edges, the longest edge 201 extending in an arc corresponds to the peripheral difference.

[0199] 17 and 18, the circumferential length of the edge 201 when the substrate W is normally held in a horizontal position is longer than the circumferential length of the edge 201 when the substrate W is held abnormally. This is thought to be because the vertical fluctuation of the periphery of the substrate W is large when the substrate W is held abnormally, causing the position of the periphery of the substrate W to fluctuate vertically over a wider circumferential range. When a crack occurs in the substrate W, the vertical fluctuation of the periphery of the substrate W is also large, so the circumferential length of the edge 201 is longer.

[0200] Therefore, the monitoring processor 91 calculates the circumferential length of the edge 201 from the edge image, determines whether the calculated length is equal to or less than a predetermined substrate reference value, and determines that the spin chuck 20 is holding a normal substrate W in a horizontal position when the calculated length is equal to or less than the substrate reference value. On the other hand, the monitoring processor 91 determines that a holding abnormality or an abnormal substrate shape has occurred when the calculated length is longer than the substrate reference value.

[0201] As described above, in the substrate monitoring process for monitoring the presence or absence of holding abnormalities and substrate shape abnormalities, it is necessary to detect the position of the peripheral edge of the substrate W. Therefore, it is desirable that the condition setting unit 92 set the resolution to high resolution as the imaging condition for the captured image data used in the substrate monitoring process. In other words, the condition setting unit 92 sets the resolution to high resolution as the imaging condition for the rotation period of the substrate W before the processing cup 40 is raised. This enables the monitoring processing unit 91 to detect holding abnormalities or substrate shape abnormalities with higher accuracy.

[0202] On the other hand, in the substrate monitoring process, although a differential image between a plurality of captured image data is acquired, holding abnormalities or abnormalities in the shape of the substrate can be detected without increasing the frame rate. Therefore, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition for the captured image data used in the substrate monitoring process. In other words, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition for the rotation period of the substrate W before the processing cup 40 is raised. This reduces the processing load on the monitoring processing unit 91.

[0203] In addition, when a shape abnormality occurs in the substrate, fluctuations increase at the periphery of the substrate W, so there is a possibility that the shape abnormality of the substrate can be detected even if the resolution is set to low. Therefore, when monitoring for shape abnormalities of the substrate but not for holding abnormalities, the condition setting unit 92 may set the resolution to low.

[0204] Furthermore, the presence or absence of holding abnormalities or abnormal substrate shape does not necessarily need to be monitored during the period in which the substrate is rotating before the processing cup 40 is raised. As long as the camera 70 can capture an image of the peripheral edge of the rotating substrate W, it is possible to monitor for holding abnormalities or abnormal substrate shape.

[0205] <Eccentricity abnormality> In the holding step (step S2), when the spin chuck 20 holds the substrate W, the substrate W may be misaligned with respect to the spin chuck 20 in a plan view. If the center of the substrate W is misaligned from the rotation axis CX of the spin chuck 20 by more than a predetermined eccentricity tolerance, the substrate W will not rotate properly in the rotation step (step S3). Hereinafter, an abnormality in which the center of the substrate W is misaligned from the rotation axis CX by more than the eccentricity tolerance will be referred to as an eccentricity abnormality. If such an eccentricity abnormality occurs, the substrate W may not be able to be processed properly.

[0206] Therefore, the object to be monitored may be the eccentricity abnormality of the substrate W. A specific example of the eccentricity monitoring process for monitoring the presence or absence of the eccentricity abnormality of the substrate W will be described below.

[0207] FIG. 19 is a diagram schematically illustrating an example of captured image data acquired during the rotation process. FIG. 19 shows captured image data acquired before the processing cup 40 is raised. That is, FIG. 19 shows captured image data from the start of the rotation process (step S3) to the cup raising process (step S4). FIG. 19 illustrates a state in which an eccentricity abnormality has occurred. When the substrate W is eccentric, the position of the periphery of the substrate W varies depending on the rotation position of the substrate W. For example, in the captured image data, the periphery of the substrate W has an elliptical shape, and the point P1 where the major axis intersects with the periphery of the substrate W varies laterally depending on the rotation position of the substrate W. In the example of FIG. 19, the substrate W acquired at different times is schematically illustrated by virtual lines.

[0208] Fig. 20 is a graph showing an example of the relationship between point P1 and the rotation angle θ of the substrate W. As shown in Fig. 20, point P1 fluctuates sinusoidally with the rotation angle θ as a variable. The horizontal position of point P1 in Fig. 20 is shown to be larger the further to the right in Fig. 19. The rotation angle θ1 at which point P1 is largest indicates the eccentricity direction of the substrate W, and the amplitude A1 of point P1 indicates the amount of eccentricity between the substrate W and the rotation axis CX.

[0209] First, the monitoring processing unit 91 detects the position of point P1 in each of the multiple captured image data. For example, the monitoring processing unit 91 may perform edge extraction processing on each captured image data to obtain an edge image, identify an elliptical edge having an elliptical shape from the edge image, and identify the rightmost point of the elliptical edge as point P1. Alternatively, the monitoring processing unit 91 may calculate an elliptical approximation line that is closest to the elliptical edge using, for example, the least squares method, and calculate the intersection of the major axis of the elliptical approximation line and the elliptical approximation line as point P1.

[0210] Next, the monitoring processing unit 91 calculates a sine wave VL1 of point P1 by performing curve interpolation processing such as spline interpolation processing on the rotation angle θ of the substrate W at each acquisition timing when the camera 70 acquires the captured image data and on point P1 in each captured image data. Next, the monitoring processing unit 91 calculates the amplitude A1 (amount of eccentricity) and the rotation angle θ1 (direction of eccentricity) based on the sine wave VL1.

[0211] The monitoring processor 91 determines whether the amount of eccentricity is equal to or less than the eccentricity tolerance, and if it determines that the amount of eccentricity is equal to or less than the eccentricity tolerance, it determines that no eccentricity abnormality has occurred.On the other hand, if the amount of eccentricity is greater than the eccentricity tolerance, the monitoring processor 91 determines that an eccentricity abnormality has occurred.

[0212] In such eccentricity monitoring processing, the higher the resolution of the captured image data, the more accurately the position of point P1 can be detected. Therefore, the condition setting unit 92 sets the resolution to a high resolution as the imaging condition for the captured image data used in the eccentricity monitoring processing. In other words, the condition setting unit 92 sets the resolution to a high resolution as the imaging condition for the rotation period of the substrate W before the processing cup 40 is raised. This allows the monitoring processing unit 91 to detect eccentricity abnormalities with higher accuracy.

[0213] On the other hand, in the eccentricity monitoring process, it is sufficient that there are multiple plot points for point P1 during one rotation of the substrate W, and the frame rate does not necessarily have to be high. Furthermore, even when the number of plot points is increased, there is no need to increase the frame rate as long as the rotation speed of the substrate W is reduced. Therefore, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition for the captured image data used in the eccentricity monitoring process. In other words, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition for the rotation period of the substrate W before the processing cup 40 is raised. This can reduce the processing load on the monitoring processing unit 91.

[0214] <Loading position of substrate W> In the loading step (step S1), the main transport robot 103 loads the substrate W into the processing unit 1. For example, the main transport robot 103 first moves the substrate W to the space above the spin chuck 20. Next, the main transport robot 103 lowers the substrate W to transfer the substrate W to the spin chuck 20. If the transfer position (loading position) is misaligned in a plan view, this may cause an eccentricity abnormality in the substrate W. Hereinafter, a load abnormality will be referred to as a load abnormality when the load position is misaligned beyond a predetermined load tolerance.

[0215] Therefore, the monitoring target may be the presence or absence of abnormalities in the loading of the substrate W. A specific example of the loading monitoring process for monitoring the presence or absence of abnormalities in the loading position of the substrate W will be described below.

[0216] The camera 70 sequentially acquires captured images during the loading process. The monitoring processor 91 detects the position of the center of the substrate W as the loading position based on the captured image data. For example, as described above, the monitoring processor 91 may acquire an edge image from the captured image data, identify an elliptical edge from the edge image, and calculate an elliptical approximation line from the elliptical edge. The monitoring processor 91 calculates the center of this elliptical approximation line as the position of the center of the substrate W. For example, the monitoring processor 91 may determine that the substrate W has been transferred to the spin chuck 20 when the position of the center of the substrate W becomes consistent across multiple captured image data sets, and identify the position of the center of the substrate W as the loading position. The monitoring processor 91 determines whether the difference between the loaded position and a predetermined reference loaded position is equal to or less than a predetermined load tolerance. If the difference is equal to or less than the load tolerance, the monitoring processor 91 determines that a load abnormality has not occurred. On the other hand, if the difference is greater than the load tolerance, the monitoring processor 91 determines that a load abnormality has occurred.

[0217] The higher the resolution of the captured image data, the more accurately the monitoring processor 91 can detect the position of the center of the substrate W. Therefore, the condition setting unit 92 sets the resolution to a high resolution as the imaging condition for the captured image data used in the loading monitoring process. In other words, the condition setting unit 92 sets the resolution to a high resolution as the imaging condition during the execution period of the loading process. This allows the monitoring processor 91 to detect loading abnormalities with higher accuracy.

[0218] On the other hand, the carry-in monitoring process does not require a high frame rate. Therefore, the condition setting unit 92 may set the frame rate as the imaging condition for the captured image data used in the carry-in monitoring process to a low frame rate. In other words, the condition setting unit 92 may set the frame rate as the imaging condition during the execution period of the carry-in process to a low frame rate. This can reduce the processing load on the monitoring processing unit 91.

[0219] <Processing cup abnormality> In the cup lifting step (step S4), the processing cup 40 may not be lifted properly, for example, due to an abnormality in the cup lifting mechanism. That is, the processing cup 40 may stop in a position displaced from its predetermined upper position. In this case, it may not be possible to properly collect the processing liquid that splashes from the periphery of the substrate W. Hereinafter, an abnormality in which the processing cup 40 is displaced from the predetermined cup reference position by more than a predetermined cup tolerance will be referred to as a cup position abnormality.

[0220] Furthermore, the processing cup 40 may have a shape abnormality. For example, the processing cup 40 may be deformed. If the processing cup 40 has a shape abnormality like this, there is a possibility that the processing liquid may not be collected properly. Hereinafter, the shape abnormality of the processing cup 40 will be referred to as a cup shape abnormality.

[0221] Therefore, the presence or absence of abnormal cup position and cup shape may be adopted as the monitoring target. A specific example of the cup monitoring process for monitoring the presence or absence of abnormal cup position and cup shape will be described below.

[0222] The camera 70 acquires captured image data during the cup lifting process (step S4). The monitoring processor 91 detects the position of the processing cup 40 based on the captured image data. For example, the monitoring processor 91 detects the position of the processing cup 40 by pattern matching the captured image data with reference image data obtained by capturing an image of a normal processing cup 40.

[0223] Since the processing cup 40 moves in the cup lifting step (step S4), the monitoring processor 91 determines whether the position of the processing cup 40 is appropriate after the processing cup 40 stops. More specifically, when the position of the processing cup 40 falls within a predetermined range in the multiple captured image data, the monitoring processor 91 determines that the processing cup 40 has stopped and determines whether the position of the processing cup 40 is appropriate. For example, the monitoring processor 91 determines whether the difference between the position of the processing cup 40 and the cup reference position is equal to or less than a predetermined cup position tolerance, and if the difference is equal to or less than the cup position tolerance, it determines that no cup position abnormality has occurred. On the other hand, if the difference is greater than the cup position tolerance, the monitoring processor 91 determines that a cup position abnormality has occurred.

[0224] Next, cup shape abnormalities will be described. When a cup shape abnormality occurs, the difference between the region of the captured image data that includes the processing cup 40 and the reference image data that includes a normal processing cup 40 stopped at a normal position becomes large. Therefore, for example, the monitoring processor 91 calculates the difference between the reference image data and the captured image data to obtain a difference image. Next, the monitoring processor 91 performs binarization processing on the difference image to obtain a binarized image. In the binarized image, the absolute values ​​of the pixel values ​​in the portions where the captured image data and the reference image data differ become large. For example, the monitoring processor 91 calculates the area of ​​the portion with a large pixel value and determines whether the area is equal to or smaller than a predetermined cup shape tolerance. If the area is equal to or smaller than the cup shape tolerance, the monitoring processor 91 determines that a cup shape abnormality does not occur in the processing cup 40. If the area is greater than the cup shape tolerance, the monitoring processor 91 determines that a cup shape abnormality occurs in the processing cup 40.

[0225] The higher the resolution of the captured image data, the more accurately the position of the processing cup 40 and the above-mentioned differences can be detected. Therefore, the condition setting unit 92 sets the resolution to a high resolution as the imaging condition for the captured image data used in the processing cup monitoring process. In other words, the condition setting unit 92 sets the resolution to a high resolution as the imaging condition during the execution period of the cup lifting process. This allows the monitoring processing unit 91 to monitor the presence or absence of cup position abnormalities and cup shape abnormalities with high accuracy.

[0226] On the other hand, a high frame rate is not necessarily required for monitoring the processing cup 40. Therefore, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition for the captured image data used in the processing cup monitoring process. In other words, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition during the execution period of the cup lifting step. This can reduce the processing load on the monitoring processing unit 91.

[0227] The cup monitoring process may be performed not only in the cup lifting step (step S4) but also in the cup lowering step (step S7).

[0228] Furthermore, not only the position but also the shape of the processing cup 40 is monitored. Not only the position but also the shape of the nozzle may be monitored. In other words, the monitoring processing unit 91 may monitor whether there is any abnormality in the shape of the nozzle.

[0229] <Imaging conditions for monitoring position and shape and changes over time> 21 is a table showing imaging conditions according to the above-mentioned monitoring targets. As illustrated in FIG. 21, the resolution is set to high resolution for captured image data used in monitoring processes related to nozzle position and shape abnormalities, substrate holding abnormalities, shape abnormalities, loading abnormalities and eccentricity abnormalities, and processing cup position and shape abnormalities. In other words, when the position or shape of an object in chamber 10 is the monitoring target, condition setting unit 92 sets the resolution to high resolution.

[0230] This allows the monitoring processing unit 91 to monitor the position or shape of the object with high accuracy. On the other hand, the condition setting unit 92 may set the frame rate to a low frame rate when the position or shape of an object in the chamber 10 is the target of monitoring. In this case, the processing load on the monitoring processing unit 91 can be reduced.

[0231] In contrast, the frame rate is set to a high frame rate for captured image data used in processing liquid monitoring processing related to the start and stop of discharge of the processing liquid from the nozzle, splashing, dripping, outflow, etc. of the processing liquid. In other words, when the monitoring target is a change in the state of the processing liquid in the chamber 10 over time, the condition setting unit 92 sets the frame rate to a high frame rate. This allows the monitoring processing unit 91 to monitor the change in the state of the processing liquid over time with high accuracy. On the other hand, when the monitoring target is a change in the state of the processing liquid in the chamber 10 over time, the condition setting unit 92 may set the resolution to a low resolution. In this case, the processing load on the monitoring processing unit 91 can be reduced.

[0232] However, for captured image data used for both the monitoring process for the position or shape of the object and the monitoring process for the change in the state of the processing liquid over time, the resolution is set to high resolution and the frame rate is set to high frame rate, which enables the monitoring processing unit 91 to monitor the position or shape of the object and the change in the state of the processing liquid over time with high accuracy.

[0233] <More examples of what is being monitored> <Etching endpoint> For example, when the first nozzle 30 discharges an etching liquid as the processing liquid in step ST3, the etching target on the upper surface of the substrate W is etched by the processing liquid. Specifically, as time passes from the start of discharge of the processing liquid, the etching target is removed, and eventually the underlying layer located directly below the etching target is exposed. If this etching processing time (discharge time of the processing liquid) deviates from the specified time, the etching will be insufficient or excessive.

[0234] When the etching target on the top surface of the substrate W is removed, the base layer is exposed, and this change appears in the captured image data. That is, since the light reflectance of the etching target and the base layer differs, the pixel value of the pixel corresponding to the substrate W in the captured image data differs between the state in which the etching target is exposed and the state in which the base layer is exposed. Therefore, the timing at which the removal of the etching target from the substrate W is substantially completed (etching end point) can be detected from the change in the pixel value over time.

[0235] Therefore, an etching endpoint may be adopted as the monitoring target. A specific example of an etching monitoring process for monitoring the etching endpoint will be described below.

[0236] Fig. 22 shows an example of captured image data acquired in step ST3. The captured image data in Fig. 22 includes the first nozzle 30 discharging the etching liquid. In other words, Fig. 22 shows captured image data acquired after the first nozzle 30 starts discharging the etching liquid.

[0237] 22, multiple etching determination regions R4 are set in the captured image data. In the example of Fig. 22, three etching determination regions R4 are arranged side by side from the center toward the periphery of the substrate W. That is, the three etching determination regions R4 are set at different positions in the radial direction of the substrate W.

[0238] As etching progresses, the pixel values ​​in the etching judgment region R4 gradually change over time, and once etching in the etching judgment region R4 is complete, the change in pixel values ​​over time becomes smaller. Figure 23 is a graph showing an example of the change in luminance value over time in one etching judgment region R4. Here, the luminance value in the etching judgment region R4 is determined by the sum or average of the pixel values ​​in the etching judgment region R4.

[0239] As shown in Fig. 23, the brightness value initially remains almost constant over time. In the example of Fig. 23, after time T1 when the discharge of the etching liquid starts, the brightness value decreases over time, and after time T2, the brightness value remains constant over time again. This is because the etching target is gradually removed during the period from time T1 to time T2, so the brightness value changes in accordance with the removal of the etching target, whereas the etching target is completely removed at time T2.

[0240] Therefore, the monitoring processor 91 calculates, for example, the sum or average of pixel values ​​within the etching determination region R4 as a brightness value, and calculates a derivative value, which is the amount of change in the brightness value per unit time. The monitoring processor 91 then detects the time when the derivative value falls below a predetermined derivative reference value as time T1, and the time when the derivative value exceeds the derivative reference value as time T2. Time T2 is the etching endpoint in the etching determination region R4.

[0241] The etching end point of each etching decision region R4 may be different from one another. For example, when the first nozzle 30 discharges the etching liquid to the central portion of the substrate W, the etching end point may be faster in the etching decision region R4 closer to the center.

[0242] Furthermore, when the first nozzle 30 discharges the etching liquid while swinging between the central position P31 and the peripheral position P32, each etching endpoint may change depending on the change in the moving speed of the first nozzle 30 and the flow rate of the etching liquid at each position on the swing path. For example, the etching endpoint of the central etching determination region R4 among the three etching determination regions R4 may be the fastest.

[0243] When the monitoring processor 91 detects the etching end points in all of the etching determination regions R4, the process controller 93 may close the valve 35 to terminate the discharge of the etching liquid from the first nozzle 30. This reduces the possibility of insufficient etching occurring in all of the etching determination regions R4.

[0244] In such an etching monitoring process, the brightness value, which is the sum or average within the etching determination region R4, does not depend much on the resolution. Therefore, the condition setting unit 92 may set the resolution to a low resolution as an imaging condition for the captured image data used in the etching monitoring process. In other words, the condition setting unit 92 may set the resolution to a low resolution as an imaging condition during the execution period of step ST3. This reduces the processing load on the monitoring processing unit 91.

[0245] Furthermore, since the etching progress speed is not particularly high, a high frame rate is not required. Therefore, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition for the captured image data used in the etching monitoring process. In other words, the condition setting unit 92 may set the frame rate to a low frame rate as an imaging condition during the execution period of step ST3. This reduces the processing load on the monitoring processing unit 91.

[0246] When a change in the state of the processing liquid is also adopted as a monitoring target in step ST3, the condition setting unit 92 sets the frame rate to a low frame rate as an imaging condition in step ST3.

[0247] <Dry abnormality> 24 is a diagram schematically illustrating an example of the configuration of a processing unit 1A, which is another example of the processing unit 1. The processing unit 1A has the same configuration as the processing unit 1, except for the presence or absence of a heating unit 29.

[0248] The heating unit 29 is a heating means for heating the substrate W. The heating unit 29 includes a disk-shaped hot plate 291 and a heater 292 serving as a heat source. The hot plate 291 is disposed between the upper surface 21a of the spin base 21 and the lower surface of the substrate W held by the chuck pins 26. The heater 292 is embedded inside the hot plate 291. The heater 292 uses, for example, an electric heating wire such as a nichrome wire that generates heat when electricity is applied. When electricity is applied to the heater 292, the hot plate 291 is heated to a temperature higher than the ambient temperature.

[0249] In the processing unit 1A, the third nozzle 65 not only discharges the processing liquid (e.g., a rinse liquid) but also an inert gas. The inert gas is a gas that has low reactivity with the substrate W, and includes, for example, a rare gas such as argon gas or nitrogen. For example, the discharge head of the third nozzle 65 is provided with a first internal flow path and a first discharge port for the processing liquid, and a second internal flow path and a second discharge port for the gas, and the first internal flow path is connected to a processing liquid supply source through a first supply pipe, and the second internal flow path is connected to a gas supply source through a second supply pipe. A first valve is provided on the first supply pipe, and a second valve is provided on the second supply pipe.

[0250] The flow of substrate processing by this processing unit 1A is the same as that shown in FIG. 6, but the drying process (step S6) differs from the specific example described above. An example of the drying process in the processing unit 1A will be described below. Note that the camera 70 acquires captured image data during the drying process. FIGS. 25 to 27 are diagrams schematically showing examples of captured image data acquired during the drying process. These captured image data will also be referred to below.

[0251] First, the third nozzle 65 moves from the standby position P68 to the central position P65. Next, the third nozzle 65 supplies, for example, a rinse liquid that is more volatile than pure water to the upper surface of the rotating substrate W. The rinse liquid is, for example, IPA (isopropyl alcohol). As a result, the rinse liquid spreads over the entire upper surface of the substrate W, and the processing liquid remaining on the upper surface of the substrate W is replaced with the rinse liquid.

[0252] Next, the spin motor 22 stops rotating the substrate W, and the third nozzle 65 stops spraying the rinse liquid. As a result, the rinse liquid on the upper surface of the substrate W comes to rest. That is, a liquid film LF1 of the rinse liquid is formed on the upper surface of the substrate W (see FIG. 25). Next, the heater 292 of the heating unit 29 is energized. This causes the temperature of the heating unit 29 to rise, and the substrate W is heated by the heat of the heating unit 29. As a result, the lower portion of the liquid film LF1 of the rinse liquid that is in contact with the upper surface of the substrate W is also heated. Then, this lower portion of the liquid film LF1 is vaporized. As a result, an IPA vapor layer is formed between the upper surface of the substrate W and the liquid film LF1. That is, the liquid film LF1 is in a state of floating above the upper surface of the substrate W.

[0253] Next, the third nozzle 65 ejects an inert gas. The inert gas is ejected toward the center of the liquid film LF1. As the inert gas is sprayed onto the liquid film LF1, the liquid film LF1 moves radially outward and flows outward from the peripheral edge of the substrate W. As a result, a circular opening is formed in the center of the liquid film LF1 in plan view (see FIG. 26). Since no processing liquid such as a rinse liquid is present in this opening, this opening is a dry region DR1. The liquid film LF1 is pressed by the inert gas and gradually moves radially outward and flows off from the peripheral edge of the substrate W, so that the dry region DR1 expands isotropically over time. In other words, the dry region DR1 expands while maintaining its circular shape in plan view. In the example of FIG. 26, the dry region DR1 in captured image data acquired at different times is schematically shown by virtual lines.

[0254] When the liquid film LF1 on the upper surface of the substrate W is removed, the third nozzle 65 stops ejecting the inert gas and moves to the standby position P68. The power supply to the heater 292 of the heating unit 29 is also stopped.

[0255] In the drying process described above, it is difficult to stably form and expand the dried regions DR1 as intended. That is, when a large number of substrates W are processed sequentially, the position, shape, or number of the dried regions DR1 may not be as intended during the drying process of some of the substrates W.

[0256] For example, the substrate W is heated to form a vapor layer of the rinse liquid between the upper surface of the substrate W and the liquid film LF1. At this time, fine bubbles may be generated in the liquid film LF1, which may cause an opening DR2 to form in part of the liquid film LF1 (see FIG. 27). If an opening DR2 forms in part of the liquid film LF1 before the inert gas is sprayed, the vapor of the rinse liquid between the upper surface of the substrate W and the liquid film LF1 will leak through the opening DR2. This makes it impossible to maintain the vapor layer, and the drying process cannot be performed properly.

[0257] In addition, the drying region DR1 is gradually expanded by blowing inert gas as described above. At this time, the shape of the drying region DR1 may be distorted or multiple drying regions DR1 may be generated. In this case, the drying process cannot be performed properly.

[0258] In the following, such abnormalities relating to the openings will be collectively referred to as dry abnormalities. Here, dry abnormalities will be adopted as the monitoring target. A specific example of the dry monitoring process for monitoring the presence or absence of dry abnormalities will be described below.

[0259] First, monitoring of abnormal drying that occurs before the inert gas is discharged (FIG. 27) will be described. FIG. 25 shows a state in which a liquid film LF1 of the rinse liquid is properly formed on the upper surface of the substrate W, and FIG. 27 shows a state in which an unintended opening DR2 is formed in the liquid film LF1 of the rinse liquid.

[0260] The monitoring processor 91 calculates the difference between the reference image data (e.g., FIG. 27) obtained by capturing an image of a normal state and the captured image data to obtain a difference image. If an opening DR2 is formed, the absolute value of the pixel value of the portion corresponding to the opening DR2 in the difference image will be high. If the area of ​​the portion is large, it can be said that an opening DR2 has been formed. Therefore, the monitoring processor 91 determines whether the area of ​​the portion with the high absolute value of the pixel value is equal to or less than a predetermined dryness tolerance value, and if the area is equal to or less than the dryness tolerance value, it determines that a dryness abnormality has not occurred. On the other hand, if the area is larger than the dryness tolerance value, the monitoring processor 91 determines that a dryness abnormality has occurred.

[0261] Next, an example of monitoring for abnormal drying that occurs after the inert gas is discharged will be described. The monitoring processing unit 91 calculates the difference between two captured image data sets acquired sequentially after the inert gas is discharged to obtain differential image data. FIG. 28 is a diagram schematically showing an example of differential image data. This differential image data includes a closed curve C corresponding to the peripheral edge of the dried region DR1. If the dried region DR1 expands while maintaining its circular shape, the closed curve C will form an elliptical shape. If the shape of the dried region DR1 is distorted, the closed curve C will be distorted from its elliptical shape.

[0262] To detect this distortion, circularity R is introduced. Circularity R is an index that indicates how close closed curve C is to a perfect circle. Circularity R is expressed by the following formula using the length L of closed curve C and the area S of closed curve C.

[0263] R=2πS / L 2 ···(1) The circularity R of the closed curve C when it has an elliptical shape is higher than the circularity R when it is distorted from an elliptical shape. Therefore, the monitoring processing unit 91 determines whether the circularity R of the closed curve C is equal to or greater than a predetermined dryness reference value, and determines that no drying abnormality has occurred when the circularity R is equal to or greater than the dryness reference value. On the other hand, the monitoring processing unit 91 determines that a drying abnormality has occurred when the circularity R is less than the dryness reference value.

[0264] In the dryness monitoring process, there is no need to know the exact shape of the dry region DR1 or the exact location and shape of the opening DR2, so the resolution of the captured image data may be low. Also, since the period during which the above-mentioned dryness abnormality occurs is not particularly short, the frame rate may also be low.

[0265] Therefore, the condition setting unit 92 may set the resolution of the captured image data used in the drying monitoring process to a low resolution and the frame rate to a low frame rate. In other words, the condition setting unit 92 may set the resolution to a low resolution and the frame rate to a low frame rate as the imaging conditions during the execution period of the drying process. This allows the monitoring processing unit 91 to monitor for drying abnormalities with a low processing load.

[0266] <Hume Anomaly> 29 is a diagram schematically illustrating an example of the configuration of a processing unit 1B, which is another example of the processing unit 1. The processing unit 1B has the same configuration as the processing unit 1, except for the presence or absence of a blocking plate 85.

[0267] The shielding plate 85 is a member for suppressing diffusion of gas near the upper surface of the substrate W. The shielding plate 85 has a disk-shaped outer shape and is arranged horizontally above the spin chuck 20. The shielding plate 85 is connected to a shielding plate lifting mechanism 86. When the shielding plate lifting mechanism 86 is operated, the shielding plate 85 moves up and down between an upper position that is spaced above the upper surface of the substrate W held by the spin chuck 20 and a lower position that is closer to the upper surface of the substrate W than the upper position. The shielding plate lifting mechanism 86 uses, for example, a mechanism that converts the rotational motion of a motor into linear motion using a ball screw.

[0268] Furthermore, a blowout port 87 for blowing out an inert gas such as nitrogen gas is provided in the center of the lower surface of the blocking plate 85. The blowout port 87 is connected to an air supply unit (not shown) that supplies drying gas to be blown onto the substrate W in the drying step.

[0269] When the processing liquid is supplied to the substrate W from each of the first nozzle 30, the second nozzle 60, and the third nozzle 65, the shielding plate 85 is retracted to the upper position. After the processing liquid process (step S4) using the processing liquid is completed, when the drying process (step S6) of the substrate W is performed, the shielding plate 85 is lowered to the lower position by the shielding plate lifting mechanism 86. Then, a drying gas (e.g., heated nitrogen gas) is blown from the blowing port 87 toward the upper surface of the substrate W. At this time, the shielding plate 85 prevents the gas from diffusing. As a result, the drying gas is efficiently supplied to the upper surface of the substrate W.

[0270] In processing unit 1B, first nozzle 30 is connected to sulfuric acid supply source 36a and hydrogen peroxide solution supply source 36b via supply pipe 34. Supply pipe 34 includes, for example, a junction supply pipe 341, a first supply pipe 342a, and a second supply pipe 342b. The downstream end of junction supply pipe 341 is connected to first nozzle 30, and the upstream end of junction supply pipe 341 is connected to the downstream end of first supply pipe 342a and the downstream end of second supply pipe 342b. The upstream end of first supply pipe 342a is connected to sulfuric acid supply source 36a, and the upstream end of second supply pipe 342b is connected to hydrogen peroxide solution supply source 36b. A first valve 35a is provided to first supply pipe 342a, and a second valve 35b is provided to second supply pipe 342b.

[0271] When the first valve 35a and the second valve 35b are opened with the first nozzle 30 moved to the central position P31, the sulfuric acid supplied from the sulfuric acid supply source 36a to the first supply pipe 342a and the hydrogen peroxide solution supplied from the hydrogen peroxide solution supply source 36b to the second supply pipe 342b join together at the joining supply pipe 341 to form the SPM liquid. The SPM liquid is then ejected from the first nozzle 30 toward the upper surface of the substrate W held by the spin chuck 20.

[0272] <Substrate processing flow> The flow of substrate processing by this processing unit 1B is the same as that shown in FIG. 6, but in the processing liquid step (step S5), the first nozzle 30 discharges a mixed liquid of sulfuric acid and hydrogen peroxide (SPM liquid) as the processing liquid. Specifically, the processing control unit 93 opens the first valve 35a and the second valve 35b, thereby supplying sulfuric acid and hydrogen peroxide to the first nozzle 30, and the first nozzle 30 discharges the mixed liquid toward the substrate W. The temperature of the SPM liquid is set to, for example, 150°C to 200°C. This makes it possible to remove, for example, a resist formed on the upper surface of the substrate W.

[0273] When the resist has been sufficiently removed, first valve 35a is closed to stop the supply of sulfuric acid. As hydrogen peroxide solution is supplied, it pushes out the sulfuric acid inside junction supply pipe 341 and first nozzle 30 (pushing-out process). This reduces the possibility of sulfuric acid unintentionally dropping from first nozzle 30 in subsequent processes.

[0274] During this pushing-out process, the supply of sulfuric acid is stopped, so the proportion of hydrogen peroxide solution above the upper surface of the substrate W increases. As a result, a large amount of hydrogen peroxide solution reacts with sulfuric acid, which may generate an atmosphere consisting of numerous fine particles called fumes. If the amount of fumes generated is normal, their diffusion is suppressed by the downflow within the chamber 10. However, if the amount of fumes generated becomes excessive and the fumes adhere to, for example, the shield plate 85, the adhered fumes will eventually solidify and become particles. These particles may then fly off the shield plate 85 again and adhere to the surface of the substrate W as foreign matter. Hereinafter, an abnormality in which fumes diffuse to a higher position will be referred to as a fume abnormality.

[0275] Therefore, a fume abnormality may be adopted as a monitoring target. A specific example of a fume monitoring process for monitoring the presence or absence of a fume abnormality will be described below.

[0276] Fig. 30 is a diagram schematically showing an example of captured image data acquired during the extrusion process. The captured image data in Fig. 30 contains fumes. In the example of Fig. 30, the fumes have spread to the vicinity of the underside of the shielding plate 85. In other words, Fig. 30 shows a state in which a fume abnormality has occurred.

[0277] 30, a fume determination region R5 is set in the captured image data. The fume determination region R5 is a region above the substrate W, and is a region that fumes do not reach in a normal push-out process. The pixel values ​​within the fume determination region R5 differ depending on whether fumes are present or not.

[0278] Therefore, the monitoring processor 91 determines whether a fume abnormality has occurred based on the pixel values ​​in the fume determination region R5. For example, the monitoring processor 91 calculates the difference between the image data acquired before the fume generation and the image data acquired during the extrusion process to obtain a difference image. Next, the monitoring processor 91 calculates the average value of the pixel values ​​in the fume determination region R5 of the difference image. If fumes are present in the fume determination region R5, this average value will be large.

[0279] Therefore, the monitoring processing unit 91 determines whether the average value is equal to or greater than a predetermined first fume standard value, and if so, sets the average value as the integration target value. Next, the monitoring processing unit 91 calculates the excess value of the average value over the first fume standard value (= integration target value - first fume standard value), and calculates an integration value by sequentially integrating the excess values ​​for each captured image data. Next, the monitoring processing unit 91 determines whether the integration value is equal to or greater than a predetermined second fume standard value, and if the integration value is equal to or greater than the second fume standard value, determines that a fume abnormality has occurred.

[0280] In such fume monitoring processing, there is no great need to know the exact location of the fume generation area, so the resolution of the captured image data may be low. Also, since the period during which fume abnormalities occur is not particularly short, the frame rate may also be low.

[0281] Therefore, the condition setting unit 92 may set the resolution to a low resolution and the frame rate to a low frame rate as the resolution conditions for the captured image data used in the fume monitoring process. In other words, the condition setting unit 92 may set the resolution to a low resolution and the frame rate to a low frame rate as the imaging conditions during the execution period of the push-out process. This allows the monitoring processing unit 91 to monitor fume abnormalities with a low processing load.

[0282] <Crystallization in chamber 10> For example, volatile components of the processing liquid may adhere to the components inside the chamber 10, causing crystallization of the components inside the chamber 10. Hereinafter, such abnormalities will be referred to as crystal abnormalities.

[0283] Therefore, crystal abnormalities may be adopted as a monitoring target. A specific example of crystal monitoring processing for monitoring the presence or absence of crystal abnormalities will be described below.

[0284] The crystal monitoring process is performed, for example, when no substrates W have been loaded into the processing unit 1 and each component within the processing unit 1 is stopped at its initial position. In other words, the crystal monitoring process is performed in a standby state where no processing is being performed on a substrate W. Furthermore, this crystal monitoring process does not need to be performed for each processing of a substrate W, but is performed, for example, whenever the number of processed substrates W reaches a predetermined number or more, or when a predetermined period of time has elapsed since the previous crystal monitoring process.

[0285] The monitoring processing unit 91 may determine whether or not there is a crystal abnormality by comparing reference image data acquired by capturing an image of the inside of a normal chamber 10 in a standby state with the captured image data acquired by the camera 70. For example, a crystal determination region to be subjected to crystallization may be set in advance, and it may be determined that a crystal abnormality has occurred when the sum of pixel values ​​in the difference image between the reference image and the captured image data in the crystal determination region is large.

[0286] Since there is not much need to accurately detect the position and shape of crystal abnormalities, high resolution is not necessary. Furthermore, since crystal abnormalities continue to occur once they occur, a high frame rate is also not necessary. Therefore, the condition setting unit 92 may set the resolution to a low resolution and the frame rate to a low frame rate as imaging conditions for the captured image data used in the crystal monitoring process. In other words, the condition setting unit 92 may set the resolution to a low resolution and the frame rate to a low frame rate as imaging conditions during a standby period when the processing unit 1 is stopped. This allows the monitoring processing unit 91 to monitor for the presence or absence of crystal abnormalities with a low processing load.

[0287] <Duration of abnormality occurrence and frame rate> As described above, the condition setting unit 92 sets the frame rate to a low frame rate during the execution period of a process that monitors for first abnormalities (e.g., drying abnormalities, fume abnormalities, and crystal abnormalities) that occur in a first occurrence period. On the other hand, the condition setting unit 92 sets the frame rate to a high frame rate during the execution period of a process that monitors for second abnormalities (e.g., liquid splashing, dripping, and overflow) that may occur in a second occurrence period that is shorter than the first occurrence period.

[0288] As a result, for a first abnormality that occurs over a long period of time, the frame rate is set to the low first frame rate, thereby reducing the processing load on the monitoring processing unit 91. Furthermore, for a second abnormality that occurs over a short period of time, the frame rate is set to the high second frame rate, thereby enabling the monitoring processing unit 91 to appropriately monitor for the presence or absence of the second abnormality.

[0289] <Cleaning the inside of chamber 10> The processing unit 1 may be provided with a chamber nozzle (not shown) for cleaning the inside of the chamber 10. This chamber nozzle discharges a cleaning liquid (e.g., pure water) into the chamber 10 to clean various components inside the chamber 10 (chamber cleaning process). This chamber cleaning process is performed when no substrate W has been loaded into the processing unit 1. In other words, the chamber cleaning process is performed in a standby state where no processing is being performed on the substrate W. For example, the processing control unit 93 may perform the chamber cleaning process by discharging a cleaning liquid from the chamber nozzle every time a substrate W is loaded, or may perform the chamber cleaning process every time the number of processed substrates W reaches a predetermined number or more, or may perform the chamber cleaning process when a predetermined period of time has elapsed since the previous chamber cleaning process.

[0290] The object of monitoring may be abnormal discharge of the cleaning liquid discharged from the tip of the chamber nozzle. A specific example of the chamber cleaning monitoring process will be described below.

[0291] The camera 70 sequentially acquires captured image data during the chamber cleaning process. The captured image data includes the tip of the chamber nozzle. A discharge determination area is also set in the captured image data, including an area extending from the tip of the chamber nozzle in the discharge direction. The monitoring processing unit 91 determines whether or not a discharge abnormality has occurred based on pixel values ​​within the discharge determination area of ​​the captured image data. For example, a discharge abnormality may be determined by comparing the determination discharge area of ​​the reference image data when the processing liquid is normally discharged with the determination discharge area of ​​the captured image data.

[0292] Such discharge abnormalities do not directly affect the processing of the substrate W, and therefore do not require high resolution and a high frame rate. Therefore, the condition setting unit 92 may set the resolution to a low resolution and the frame rate to a low frame rate as the imaging conditions for the captured image data used in this chamber cleaning monitoring process. In other words, the condition setting unit 92 may set the resolution to a low resolution and the frame rate to a low frame rate as the imaging conditions during the execution of the chamber cleaning process. This allows the monitoring processing unit 91 to monitor for the presence or absence of discharge abnormalities with a low processing load.

[0293] <Other examples of imaging conditions> In the above example, resolution and frame rate are used as examples of imaging conditions. However, this is not necessarily limited to these. For example, the size of the field of view captured in the captured image data may be used as an imaging condition. For example, camera 70 can capture images of the interior of chamber 10 in field of view V1 (see FIG. 2) and can also capture images of the interior of chamber 10 in field of view V2. Field of view V1 is wider than field of view V2. The field of view angle of field of view V1 in a plan view is, for example, 120 degrees, and the field of view angle of field of view V2 is, for example, 60 degrees.

[0294] The image data acquired within the field of view V2 includes the entire opening of the processing cup 40, but only the vicinity of the opening. The image data acquired within the field of view V1 includes the entire opening of the processing cup 40 and an area further away from the opening.

[0295] Fig. 31 is a diagram schematically illustrating an example of captured image data having different field of view ranges. In the example of Fig. 31, captured image data obtained by cutting out a predetermined area as field of view range V2 from captured image data acquired in a wide field of view range V1 corresponds to captured image data acquired in field of view range V2. Therefore, the amount of data of captured image data in field of view range V2 is smaller than the amount of data of captured image data in field of view range V1.

[0296] The camera 70 can adjust the field of view by, for example, cropping a portion of the image data read from all of the light receiving elements. Alternatively, the camera 70 may read data from only the light receiving elements within a region designated as the field of view. This also allows the camera 70 to change the field of view.

[0297] Incidentally, in all of the above-mentioned monitoring processes for the monitoring target, it is not necessary to use the captured image data acquired in the widest field of view range V1. For example, in the position monitoring process for monitoring the nozzle positions, it is sufficient that the tip of each nozzle is included in the captured image data, and field of view range V2 is sufficient.

[0298] Therefore, the condition setting unit 92 may set the field of view range depending on the monitoring target. Fig. 32 is a table showing an example of monitoring targets and imaging conditions. In the example of Fig. 32, the resolution for shape abnormalities of the substrate W may be set to either high resolution or low resolution. In the above example, the algorithms for monitoring shape abnormalities and holding abnormalities of the substrate W are the same, so when holding abnormalities are also to be monitored, it is advisable to set the resolution to high resolution.

[0299] Furthermore, the condition setting unit 92 may adopt the imaging condition with the higher data volume as the imaging condition during a period in which monitoring processes for multiple monitoring targets are performed in parallel. For example, when both a monitoring process requiring a large field of view and a monitoring process not requiring a large field of view are performed in parallel, the condition setting unit 92 sets the field of view to a large field of view as the imaging condition for that process. For example, in an extrusion process in which sulfuric acid is extruded from the first nozzle 30 using hydrogen peroxide water, it is possible to perform monitoring processes for both fume abnormalities and the discharge state of the treatment liquid. In this case, the condition setting unit 92 sets the imaging conditions for the extrusion process to a large field of view, a low resolution, and a high frame rate.

[0300] <Image conditions> In the above example, the condition setting unit 92 set the imaging conditions of the camera 70. However, this is not necessarily limited to this. For example, the camera 70 may acquire captured image data under predetermined imaging conditions. The predetermined imaging conditions may, for example, be a wide field of view, a high resolution, and a high frame rate. The control unit 9 may change the image conditions of the captured image data by performing image processing on the captured image data received from the camera 70. The image conditions here are the same as the imaging conditions. However, the image conditions are not directly used to control the camera 70. The image conditions are, for example, the field of view, resolution, and frame rate of the captured image data.

[0301] 33 is a functional block diagram schematically showing an example of the internal configuration of the control unit 9. The control unit 9 includes a monitoring processing unit 91, a condition setting unit 92, a process control unit 93, and a preprocessing unit 94.

[0302] The pre-processing unit 94 changes the image conditions of the captured image data received from the camera 70. For example, the pre-processing unit 94 acquires captured image data having a small field of view V2 by cutting out a partial area of ​​the captured image data. The pre-processing unit 94 also acquires captured image data having a low resolution by, for example, averaging the pixel values ​​of adjacent nx vertical by ny horizontal pixels in the captured image data to combine them into one pixel. The pre-processing unit 94 also acquires captured image data having a low frame rate by, for example, deleting at least one frame of captured image data from every other frame of captured image data acquired sequentially.

[0303] As described above, the condition setting unit 92 identifies a monitoring target from among the monitoring target candidates in the chamber 10, and sets image conditions according to the monitoring target.

[0304] The preprocessing unit 94 performs the above-described processing on the captured image data so that the image conditions of the captured image data received from the camera 70 match the image conditions set by the condition setting unit 92 .

[0305] The monitoring processing unit 91 executes monitoring processing for the monitoring target based on the captured image data processed by the pre-processing unit 94 .

[0306] This also allows the monitoring processing unit 91 to monitor the monitoring target based on captured image data having image conditions that correspond to the monitoring target. Therefore, even with a camera 70 whose imaging conditions cannot be changed, the monitoring processing unit 91 can monitor the monitoring target based on captured image data having image conditions that correspond to the monitoring target. This allows the monitoring target to be monitored with high accuracy, as described above. Furthermore, the processing load on the monitoring processing unit 91 can also be reduced appropriately.

[0307] As described above, the substrate processing method and the substrate processing apparatus 100 have been described in detail. However, the above description is merely an example in all respects, and the substrate processing apparatus is not limited thereto. 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.

[0308] For example, although the above example employs the field of view, resolution, and frame rate as image conditions, this is not necessarily limited to these. For example, the image conditions such as the exposure time and white balance of the camera 70 may be changed depending on the monitoring target.

[0309] In the above example, the condition setting unit 92 changes the image conditions in a binary manner. For example, the condition setting unit 92 sets the resolution to either high resolution or low resolution depending on the monitoring target. However, the condition setting unit 92 may change the image conditions (e.g., resolution) more finely depending on the monitoring target. [Explanation of symbols]

[0310] 1 Processing Unit 10 chambers 20 Spin Chuck 30 nozzles (first nozzle) 40 Processing Cups 60 nozzle (second nozzle) 65 nozzle (third nozzle) 80 nozzle (fixed nozzle) 9 Control Unit 70 Camera 100 Substrate processing apparatus W substrate

Claims

1. A substrate processing method, comprising: a holding step of carrying a substrate into a chamber and holding the substrate; a supplying step of supplying a processing liquid from a nozzle onto the substrate held inside the chamber; an imaging step in which a camera sequentially images the interior of the chamber to acquire image data; a condition setting step of specifying a monitoring target, setting a resolution to a first resolution as an image condition before the supplying step, and setting the resolution to a second resolution lower than the first resolution as an image condition when the monitoring target includes a discharge state of the treatment liquid discharged from the nozzle but does not include a position of the nozzle; a monitoring step of performing a monitoring process on the monitoring target based on the image data having the first resolution before the supplying step, and performing a monitoring process on the ejection state based on the image data having the second resolution in parallel with the supplying step; A substrate processing method comprising:

2. 2. The substrate processing method according to claim 1, The substrate processing method, wherein the image conditions further include at least one of a frame rate of the image data and a size of a field of view captured in the image data.

3. 3. The substrate processing method according to claim 2, In the condition setting step, setting the frame rate to a first frame rate as the image condition when the monitoring target is the presence or absence of a first abnormality occurring in the chamber during a first occurrence period; a substrate processing method, wherein the frame rate is set to a second frame rate higher than the first frame rate as the image condition when the monitoring target is the presence or absence of a second abnormality occurring in the chamber during a second occurrence period shorter than the first occurrence period.

4. 3. The substrate processing method according to claim 1, further comprising: the condition setting step includes a step of setting the image conditions as imaging conditions, In the imaging step, the camera acquires the image data using the image conditions according to the monitoring target as imaging conditions.

5. 3. The substrate processing method according to claim 1, further comprising: A substrate processing method in which, in the imaging process, the camera acquires the image data under predetermined imaging conditions, and performs image processing on the image data acquired by the camera to acquire the image data having the image conditions corresponding to the monitored object.

6. A substrate processing apparatus, a substrate holder that holds a substrate inside the chamber; a camera that sequentially captures images of the interior of the chamber to acquire image data; a nozzle for supplying a processing liquid to the substrate held by the substrate holder; Control unit and Equipped with The control unit setting a resolution to a first resolution as an image condition before supplying the processing liquid to the substrate; performing a monitoring process on a monitoring target based on the image data having the first resolution before supplying the processing liquid to the substrate; setting a resolution to a second resolution lower than the first resolution as the image condition when the monitoring target includes a discharge state of the treatment liquid from the nozzle but does not include a position of the nozzle; The substrate processing apparatus performs a monitoring process for the discharge state based on the image data having the second resolution in parallel with the supply of the processing liquid from the nozzle to the substrate.

Images