Operation monitoring method and manufacturing device

Abstract

To provide a technique capable of evaluating a fast movement included in operations of a processing unit.SOLUTION: A specific operation of a processing unit is first imaged by an event base camera 70. Thus, event data E composed of information on only a pixel of which the luminance value is changed is acquired. Subsequently, an evaluation value based on the event data E is calculated. Operations of the processing unit are evaluated based on the calculated evaluation value thereafter. Information on a fast movement included in the operations of the processing unit is recorded in the event data E. Therefore, the fast movement can be evaluated based on the evaluation value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for monitoring the operation of a processing unit and a manufacturing apparatus equipped with the processing unit. [Background technology]

[0002] Reproducibility of operations is an important issue for industrial machinery and other devices. In particular, for devices that perform precise and fine processing on substrates, such as semiconductor manufacturing equipment, even slight differences in operation can significantly reduce product quality. For this reason, there is a demand for quantitative evaluation of even slight variations in the operations performed by the device.

[0003] Conventionally, there is known a technique of installing a camera in a device to monitor abnormalities in its operation. For example, Patent Document 1 describes a technique of capturing images of the substrate processing process with a camera and detecting the occurrence of an abnormality based on the obtained video. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-165607 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 uses a general frame-based camera. Therefore, the camera of Patent Document 1 captures a video composed of multiple frame images. Such a frame-based camera cannot capture extremely high-speed movements such as the flow of liquid. Therefore, the method of Patent Document 1 makes it difficult to evaluate high-speed movements included in the operation of a processing unit.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a technique that can evaluate high-speed movements included in the operation of a processing unit. [Means for solving the problem]

[0007] In order to solve the above problems, a first invention of the present application is a method for monitoring the operation of a processing unit, comprising: a) a step of capturing a specific operation of the processing unit with an event-based camera to obtain event data consisting of information only about pixels whose luminance values ​​have changed; b) a step of calculating an evaluation value based on the event data; and c) a step of evaluating the operation of the processing unit based on the evaluation value. In step a), the specific actions are photographed by the event-based camera in a plurality of the processing units to obtain a plurality of the event data; in step b), the evaluation value is calculated for each of the plurality of the event data; and in step c), the variation in the actions in the plurality of the processing units is evaluated based on the evaluation value.

[0009] The first part of this application 2 The invention is 1 The operation monitoring method of the present invention includes, after step a) and before step b), the steps of: x) calculating a feature value based on the information for each unit time for each of the plurality of event data; and y) aligning the timing of the plurality of event data based on the time-varying waveform of the feature value.

[0010] The first part of this application 3 The invention is 2 In the motion monitoring method of the present invention, the feature amount is the number of pixels whose luminance value changes within the unit time.

[0011] The first part of this application 4 The inventions are the first invention to the second invention. 3 In the motion monitoring method of any one of the above aspects, the evaluation value is the number of pixels in a predetermined evaluation region whose luminance value has changed during a predetermined counting time.

[0012] The first part of this application 5 The invention is 4 In the operation monitoring method of the invention, in step c), the operation of the processing unit is evaluated based on a histogram that tallies the number of pixels for each count time in which the brightness value changed among the multiple count times included in a predetermined inspection period.

[0013] The first part of this application 6 The invention is 4 Invention or 5 In the operation monitoring method of the present invention, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, and the evaluation region includes the surface of the substrate when the processing liquid is being supplied.

[0014] The first part of this application 7 The invention is 4 Invention or 5 In the operation monitoring method of the present invention, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, and the evaluation region includes a liquid column of the processing liquid that is ejected from a nozzle toward the substrate.

[0015] The first part of this application 8 The inventions are the first invention to the second invention. 3 In a motion monitoring method according to any one of the preceding inventions, the evaluation value is the number of pixel groups in a predetermined evaluation area whose brightness values ​​change during a predetermined inspection period and whose number of adjacent pixels is greater than or equal to a predetermined lower limit and less than or equal to a predetermined upper limit.

[0016] The first part of this application 9 The invention is 8 In the operation monitoring method of the present invention, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, and the evaluation region includes a peripheral edge portion of the substrate.

[0017] The first part of this application 10 The inventions are the first invention to the second invention. 3 An operation monitoring method according to any one of the preceding inventions, wherein the evaluation value is the number of pixels in a predetermined evaluation area whose brightness value has changed over a predetermined aggregation time, and in step c), the operation of the processing unit is evaluated based on the change in the evaluation value over time.

[0018] The first part of this application 11 The invention is 10In the operation monitoring method of the present invention, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, and the evaluation area includes the surface of the substrate during a drying process in which the processing liquid is shaken off while the substrate is being rotated.

[0019] The first part of this application 12 The invention comprises a processing unit that processes a processing object by performing a specific operation, an event-based camera that can output event data consisting of information only about pixels whose brightness values ​​have changed, and a computer communicably connected to the event-based camera, wherein the computer executes: a) a process of acquiring the event data by having the event-based camera capture the operation of the processing unit; b) a process of calculating an evaluation value based on the event data; and c) a process of evaluating the operation of the processing unit based on the evaluation value. In step a), the computer acquires a plurality of pieces of event data by photographing the specific actions in a plurality of the processing units with the event-based camera, calculates the evaluation value for each of the plurality of event data, and evaluates the variation in the actions in the plurality of the processing units based on the evaluation value in step c). [Effects of the Invention]

[0020] The first to third inventions of this application 12 According to the invention, a specific operation of a processing unit is captured by an event-based camera. An evaluation value is calculated based on the obtained event data. The event data records information about fast movements included in the operation of the processing unit. Therefore, the fast movements can be evaluated based on the evaluation value. This allows the variation in operation among multiple processing units to be evaluated.

[0022] In particular, 2 According to the present invention, the timing of multiple event data can be aligned. This allows for accurate evaluation of variations in the operation of the processing units in steps b) and c). Furthermore, feature quantities for aligning the timing of multiple event data are calculated based on information contained in the event data. This eliminates the need to measure parameters for aligning the timing of event data separately from the event data. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 2 is a plan view of the substrate processing apparatus. [Figure 2] FIG. 2 is a vertical cross-sectional view of the processing unit. [Figure 3] FIG. 1 is a diagram conceptually illustrating how an event-based camera captures an image. [Figure 4] FIG. 2 is a block diagram showing connections between a control unit and each unit in a processing unit. [Figure 5] 10 is a flowchart showing a processing procedure for a substrate. [Figure 6] 10 is a flowchart showing the flow of operation monitoring. [Figure 7] FIG. 10 is a diagram showing an example of a frame image. [Figure 8] FIG. 10 is a diagram showing an example of an image of event data. [Figure 9] 10 is a graph showing an example of a waveform of a feature amount changing over time. [Figure 10] 10 is a flowchart showing a processing procedure for evaluating the state of the surface of a substrate when a processing liquid is supplied. [Figure 11] FIG. 10 is a diagram showing an example of a histogram. [Figure 12] 10 is a flowchart showing a processing procedure for evaluating the state of a liquid column when a processing liquid is supplied. [Figure 13] FIG. 10 is a diagram showing an example of a histogram. [Figure 14] 10 is a flowchart showing a processing procedure for evaluating the state of liquid splashing. [Figure 15] 10A and 10B are diagrams showing an example of detection of a pixel group corresponding to a liquid splash. [Figure 16] 10 is a flowchart showing a processing procedure for evaluating the state of the surface of a substrate during drying processing. [Figure 17] 10 is a graph showing an example of a waveform of a change in evaluation value over time. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0025] <1. Overall configuration of substrate processing equipment> 1 is a plan view of a substrate processing apparatus 100, which is an example of a manufacturing apparatus according to the present invention. The substrate processing apparatus 100 is an apparatus that supplies a processing liquid to the surface of a disk-shaped substrate W (silicon wafer) in a semiconductor wafer manufacturing process to process the surface of the substrate W. As shown in FIG. 1, the substrate processing apparatus 100 includes an indexer 101, a plurality of processing units 102, and a main transport robot 103.

[0026] The indexer 101 is a part for loading unprocessed substrates W from the outside and unloading processed substrates W to the outside. A plurality of carriers, each accommodating a plurality of substrates W, are arranged in the indexer 101. The indexer 101 also has a transfer robot (not shown). The transfer robot transfers substrates W between the carriers in the indexer 101 and the processing units 102 or the main transport robot 103.

[0027] The processing units 102 are so-called single-substrate processing units that process substrates W one by one. The multiple processing units 102 are arranged around the main transport robot 103. In this embodiment, four processing units 102 arranged around the main transport robot 103 are stacked in three tiers in the height direction. That is, the substrate processing apparatus 100 of this embodiment has a total of 12 processing units 102. The multiple substrates W are processed in parallel in each processing unit 102. However, the number of processing units 102 included in the substrate processing apparatus 100 is not limited to 12, and may be, for example, 1, 4, 8, 24, etc.

[0028] The main transport robot 103 is a mechanism for transporting substrates W between the indexer 101 and the plurality of processing units 102. The main transport robot 103 has, for example, a hand for holding the substrate W and an arm for moving the hand. The main transport robot 103 takes out the unprocessed substrate W from the indexer 101 and transports it to the processing unit 102. Furthermore, when the processing of the substrate W in the processing unit 102 is completed, the main transport robot 103 takes out the processed substrate W from the processing unit 102 and transports it to the indexer 101.

[0029] <2. Processing unit configuration> Next, a detailed description will be given of the configuration of the processing unit 102. The following describes one of the processing units 102 included in the substrate processing apparatus 100, but the other processing units 102 also have the same configuration.

[0030] Fig. 2 is a vertical cross-sectional view of the processing unit 102. As shown in Fig. 2, the processing unit 102 includes a chamber 10, a substrate holder 20, a rotation mechanism 30, a processing liquid supply unit 40, a processing liquid collector 50, a shield plate 60, an event-based camera 70, and a controller 80.

[0031] The chamber 10 is a housing that contains a processing space 11 for processing a substrate W. The chamber 10 has a sidewall 12 that surrounds the sides of the processing space 11, a top plate 13 that covers the upper part of the processing space 11, and a bottom plate 14 that covers the lower part of the processing space 11. A substrate holder 20, a rotation mechanism 30, a processing liquid supply unit 40, a processing liquid collector 50, a shielding plate 60, and an event-based camera 70 are housed inside the chamber 10. A loading / unloading port for loading and unloading the substrate W into and from the chamber 10, and a shutter for opening and closing the loading / unloading port are provided in part of the sidewall 12.

[0032] The substrate holding unit 20 is a mechanism that holds the substrate W horizontally (with its normal oriented vertically) inside the chamber 10. As shown in FIG. 2, the substrate holding unit 20 has a disk-shaped spin base 21 and a plurality of chuck pins 22. The plurality of chuck pins 22 are provided at equal angular intervals along the outer periphery of the upper surface of the spin base 21. The substrate W is held by the plurality of chuck pins 22 with its processing surface, on which a pattern is to be formed, facing upward. Each chuck pin 22 contacts the lower surface and outer periphery of the peripheral edge of the substrate W, and supports the substrate W at a position above the upper surface of the spin base 21 with a small gap therebetween.

[0033] A chuck pin switching mechanism 23 is provided inside the spin base 21 for switching the positions of the plurality of chuck pins 22. The chuck pin switching mechanism 23 switches the plurality of chuck pins 22 between a holding position where the chuck pins 22 hold the substrate W and a release position where the chuck pins 22 release the substrate W from the holding position.

[0034] The rotation mechanism 30 is a mechanism for rotating the substrate holding part 20. The rotation mechanism 30 is housed inside a motor cover 31 provided below the spin base 21. As indicated by the dashed line in FIG. 2 , the rotation mechanism 30 has a spin motor 32 and a support shaft 33. The support shaft 33 extends vertically, with its lower end connected to the spin motor 32 and its upper end fixed to the center of the lower surface of the spin base 21. When the spin motor 32 is driven, the support shaft 33 rotates about its axis 330. Then, together with the support shaft 33, the substrate holding part 20 and the substrate W held by the substrate holding part 20 also rotate about the axis 330.

[0035] The processing liquid supply unit 40 is a mechanism that supplies a processing liquid to the upper surface of the substrate W held by the substrate holding unit 20. The processing liquid supply unit 40 has an upper surface nozzle 41 and a lower surface nozzle 42. As shown in FIGS. 1 and 2, the upper surface nozzle 41 has a nozzle arm 411, a nozzle head 412 provided at the tip of the nozzle arm 411, and a nozzle motor 413. The nozzle arm 411 rotates horizontally around the base end of the nozzle arm 411 by driving the nozzle motor 413. This allows the nozzle head 412 to move between a processing position (the position indicated by the two-dot chain line in FIG. 1) above the substrate W held by the substrate holding unit 20 and a retracted position (the position indicated by the solid line in FIG. 1) outside the processing liquid collection unit 50.

[0036] The nozzle head 412 is connected to a liquid supply unit (not shown) for supplying a processing liquid. Examples of processing liquids that can be used include an SPM cleaning liquid (a mixture of sulfuric acid and hydrogen peroxide), an SC-1 cleaning liquid (a mixture of ammonia water, hydrogen peroxide, and pure water), an SC-2 cleaning liquid (a mixture of hydrochloric acid, hydrogen peroxide, and pure water), a DHF cleaning liquid (dilute hydrofluoric acid), and pure water (deionized water). When the valve of the liquid supply unit is opened with the nozzle head 412 positioned at the processing position, the processing liquid supplied from the liquid supply unit is ejected from the nozzle head 412 toward the top surface of the substrate W held by the substrate holder 20.

[0037] The nozzle head 412 may be a so-called two-fluid nozzle that mixes the processing liquid with a pressurized gas to generate droplets and sprays the mixed fluid of the droplets and the gas onto the substrate W. Furthermore, one processing unit 102 may be provided with a plurality of upper surface nozzles 41.

[0038] The lower surface nozzle 42 is disposed inside a through-hole provided in the center of the spin base 21. The discharge port of the lower surface nozzle 42 faces the lower surface of the substrate W held by the substrate holding part 20. The lower surface nozzle 42 is also connected to a liquid supply part for supplying a processing liquid. When the processing liquid is supplied from the liquid supply part to the lower surface nozzle 42, the processing liquid is discharged from the lower surface nozzle 42 toward the lower surface of the substrate W.

[0039] The treatment liquid collecting unit 50 is a section that collects the treatment liquid after use. As shown in Fig. 2, the treatment liquid collecting unit 50 has an inner cup 51, a middle cup 52, and an outer cup 53. The inner cup 51, the middle cup 52, and the outer cup 53 can be moved up and down independently of each other by a lifting mechanism (not shown).

[0040] The inner cup 51 has an annular first guide plate 510 that surrounds the periphery of the substrate holding part 20. The inner cup 52 has an annular second guide plate 520 that is located outside and above the first guide plate 510. The outer cup 53 has an annular third guide plate 530 that is located outside and above the second guide plate 520. The bottom of the inner cup 51 extends to below the inner cup 52 and the outer cup 53. A first drainage groove 511, a second drainage groove 512, and a third drainage groove 513 are provided on the upper surface of the bottom, in that order from the inside.

[0041] The processing liquid ejected from the upper surface nozzle 41 and the lower surface nozzle 42 of the processing liquid supply unit 40 is supplied to the substrate W, and then scattered outward by centrifugal force caused by the rotation of the substrate W. The processing liquid scattered from the substrate W is then collected by any one of the first guide plate 510, the second guide plate 520, and the third guide plate 530. The processing liquid collected by the first guide plate 510 is discharged to the outside of the processing unit 102 through the first drainage groove 511. The processing liquid collected by the second guide plate 520 is discharged to the outside of the processing unit 102 through the second drainage groove 512. The processing liquid collected by the third guide plate 530 is discharged to the outside of the processing unit 102 through the third drainage groove 513.

[0042] As described above, the processing unit 102 has a plurality of discharge paths for the processing liquid. Therefore, the processing liquids supplied to the substrate W can be separated and recovered by type. Therefore, the recovered processing liquids can be disposed of or recycled separately according to the properties of each processing liquid.

[0043] The shielding plate 60 is a member for suppressing the diffusion of gas near the surface of the substrate W when performing certain processes such as drying. The shielding plate 60 has a disk-shaped outer shape and is arranged horizontally above the substrate holding unit 20. As shown in FIG. 2, the shielding plate 60 is connected to a lifting mechanism 61. When the lifting mechanism 61 is operated, the shielding plate 60 moves up and down between an upper position that is spaced above the upper surface of the substrate W held by the substrate holding unit 20, and a lower position that is closer to the upper surface of the substrate W than the upper position. The lifting mechanism 61 uses, for example, a mechanism that converts the rotational motion of a motor into linear motion using a ball screw.

[0044] Furthermore, a blowout port 62 for blowing out a drying gas (hereinafter referred to as "dry gas") is provided at the center of the lower surface of the shielding plate 60. The blowout port 62 is connected to an air supply unit (not shown) that supplies the dry gas. The dry gas may be, for example, heated nitrogen gas.

[0045] When the processing liquid is supplied from the upper surface nozzle 41 to the substrate W, the shielding plate 60 is retracted to the upper position. When the drying process is performed on the substrate W after the supply of the processing liquid, the shielding plate 60 is lowered to the lower position by the lifting mechanism 61. Then, dry gas is blown from the blowing port 62 toward the upper surface of the substrate W. At this time, the shielding plate 60 prevents the gas from diffusing. As a result, the dry gas is efficiently supplied to the upper surface of the substrate W.

[0046] The event-based camera 70 is a device that captures images of specific operations within the chamber 10. The event-based camera 70 is installed, for example, at a position close to the inner surface of the side wall 12 of the chamber 10. FIG. 3 is a conceptual diagram showing how images are captured by the event-based camera 70. In this embodiment, a rectangular area including the substrate W supported by the spin base 21 and the nozzle head 412 is the image capture area A of the event-based camera 70. When an operation of discharging a processing liquid onto the surface of the substrate W from the nozzle head 412 is performed, or when an operation of drying the substrate W is performed, the event-based camera 70 captures the operation within the image capture area A.

[0047] A typical video camera (frame-based camera) outputs video data in which frame images containing information on the brightness values ​​of many pixels are arranged in chronological order. In contrast, an event-based camera 70 outputs event data E consisting of information only on pixels whose brightness values ​​have changed. The event data E is made up of multiple pieces of simple data e that are generated only when the brightness value changes. As shown in Figure 3, the simple data e consists of information on the coordinates x, y of the pixel whose brightness value has changed, the time t at which the brightness value changed, and the direction p of change in the brightness value. The direction p of change in the brightness value is "1" when the brightness changes in a brighter direction, and "0" when the brightness changes in a darker direction.

[0048] In this way, the event-based camera 70 outputs information only about pixels whose brightness values ​​have changed. Therefore, the amount of information in the event data E output from the event-based camera 70 is smaller than the amount of information in the video output from a frame-based camera. Therefore, when the event-based camera 70 is used, data acquisition and transfer can be performed faster than when a frame-based camera is used. Furthermore, the event-based camera 70 can acquire single data e at time intervals shorter than the time interval between frame images in a frame-based camera (for example, every few microseconds). Therefore, when the event-based camera 70 is used, it is possible to capture high-speed movement of the object being photographed.

[0049] The event-based camera 70 transmits the event data E obtained by photographing to the control unit 80.

[0050] The control unit 80 is a means for controlling the operation of each unit in the processing unit 102. Fig. 4 is a block diagram showing the electrical connection between the control unit 80 and each unit in the processing unit 102. As conceptually shown in Fig. 4, the control unit 80 is configured by a computer having a processor 81 such as a CPU, a memory 82 such as a RAM, and a storage unit 83 such as a hard disk drive.

[0051] An operation control program P1 and an operation monitoring program P2 are stored in the storage unit 83. The operation control program P1 is a computer program for controlling the operation of each part of the processing unit 102 in order to execute processing of the substrate W in the processing unit 102. The operation monitoring program P2 is a computer program for monitoring and evaluating specific operations in the processing unit 102 based on event data E obtained from the event-based camera 70.

[0052] 4, the control unit 80 is communicatively connected to the chuck pin switching mechanism 23, spin motor 32, nozzle motor 413, valves of the processing liquid supply unit 40, the lifting mechanism of the processing liquid collector 50, the lifting mechanism 61 of the shielding plate 60, and the event-based camera 70, either wired or wirelessly. The control unit 80 is also electrically connected to a display unit 84, such as a liquid crystal display. The control unit 80 controls the operation of each of the above-mentioned units based on an operation control program P1 and an operation monitoring program P2 stored in a storage unit 83. This causes the processing of steps S1 to S5, S11 to S15, S21 to S25, S31 to S35, S41 to S46, and S51 to S55, which will be described later, to proceed.

[0053] <3. Operation of the substrate processing apparatus> Next, a description will be given of the processing of the substrate W in the processing unit 102. Fig. 5 is a flowchart showing the processing procedure for the substrate W.

[0054] When a substrate W is processed in the processing unit 102, first, the main transport robot 103 loads the substrate W to be processed into the chamber 10 (step S1). The substrate W loaded into the chamber 10 is held horizontally by the multiple chuck pins 22 of the substrate holder 20. Thereafter, the spin motor 32 of the rotation mechanism 30 is driven to start rotation of the substrate W (step S2). Specifically, the support shaft 33, the spin base 21, the multiple chuck pins 22, and the substrate W held by the chuck pins 22 rotate around the axis 330 of the support shaft 33.

[0055] Next, the processing liquid is supplied from the processing liquid supply unit 40 (step S3). In step S3, the nozzle motor 413 is driven to move the nozzle head 412 to a processing position facing the upper surface of the substrate W. Then, the processing liquid is discharged from the nozzle head 412 arranged at the processing position. Parameters such as the discharge speed and discharge time of the processing liquid are set in advance in the memory unit 83 in the control unit 80. The control unit 80 executes the discharge operation of the processing liquid from the upper surface nozzle 41 in accordance with the settings.

[0056] In step S3, the upper surface nozzle 41 may be swung horizontally at the processing position while the processing liquid is being discharged from the upper surface nozzle 41. Furthermore, the processing liquid may be discharged from the lower surface nozzle 42 as necessary.

[0057] During the processing liquid supply process of step S3, the shielding plate 60 is positioned at an upper position above the upper surface nozzle 41. When the supply of the processing liquid to the substrate W is completed and the upper surface nozzle 41 is positioned at the retracted position, the control unit 80 operates the lifting mechanism 61 to move the shielding plate 60 from the upper position to the lower position. Then, the rotation speed of the spin motor 32 is increased to speed up the rotation of the substrate W, and drying gas is blown toward the substrate W from the blowing port 62 provided on the lower surface of the shielding plate 60. This dries the surface of the substrate W (step S4).

[0058] When the drying process of the substrate W is completed, the spin motor 32 is stopped to stop the rotation of the substrate W. Then, the substrate W is released from the chuck pins 22. Thereafter, the main transport robot 103 removes the processed substrate W from the substrate holder 20 and transports it outside the chamber 10 (step S5).

[0059] Each processing unit 102 repeatedly performs the above-described processing of steps S1 to S5 on a plurality of substrates W that are transported in sequence.

[0060] <4. About behavior monitoring> Next, an operation monitoring function of the substrate processing apparatus 100 will be described. The operation monitoring function is a function for monitoring specific operations performed in the plurality of processing units 102 and detecting variations (in-machine differences) in the operations among the processing units 102. In the following description, the operation to be monitored is the supplying operation of the processing liquid in step S3 or the drying operation in step S4 described above. However, the operation to be monitored may be an operation other than the supplying operation of the processing liquid and the drying operation.

[0061] 6 is a flowchart showing the flow of operation monitoring. The substrate processing apparatus 100 first executes a specific operation in each of the processing units 102. Then, the event-based camera 70 of each processing unit 102 captures an image of the operation (step S11). This acquires a plurality of event data E. Here, the specific operation may be performed on a substrate W as a product, or may be performed on a dummy substrate for adjustment when adjusting the processing unit 102. The event-based camera 70 of each processing unit 102 transmits the acquired event data E to the control unit 80. The control unit 80 stores the plurality of event data E transmitted from the event-based camera 70 in the memory unit 83.

[0062] Fig. 7 is a diagram showing an example of a frame image F obtained when a photographing area A in the processing unit 102 is photographed with a normal frame-based camera. Fig. 8 is a diagram showing an example of an image of event data E obtained by photographing the same photographing area A with the event-based camera 70. In Fig. 8, pixels containing single data e of the event data E are indicated by black dots.

[0063] In a normal frame image F, a brightness value is defined for every pixel. Therefore, in a normal frame image F, even parts with no movement are displayed as an image, as shown in Figure 7. In contrast, event data E is made up of information only about pixels whose brightness values ​​have changed. Therefore, in event data E, as shown in Figure 8, simple data e exists only in parts with movement, and simple data e does not exist in parts with no movement.

[0064] Next, the control unit 80 calculates a feature amount based on the information of the single data e for each unit time for each of the multiple event data E (step S12). In step S12, the control unit 80 tallies the number of single data e for each unit time for each event data E. The unit time is a time longer than the interval at which the event-based camera 70 acquires the single data e, and may be, for example, about 5 seconds. The control unit 80 determines the number of single data e present in the event data E per unit time as the feature amount. In other words, the control unit 80 determines the number of pixels whose luminance value has changed per unit time as the feature amount. However, other numerical values ​​calculated based on the event data E may also be used as the feature amount.

[0065] When feature amounts are calculated for each unit time for a plurality of event data E, a time-varying waveform WF of the feature amounts is obtained for each event data E. Fig. 9 is a graph showing an example of the time-varying waveform WF of the feature amounts of two event data E. In the graph of Fig. 9, the horizontal axis represents time, and the vertical axis represents the feature amounts.

[0066] The control unit 80 aligns the timing of the plurality of event data E by comparing the time-varying waveforms WF of the feature quantities of the plurality of event data E (step S13). Specifically, the control unit 80 calculates a cross-correlation function between the time-varying waveform WF of one reference event data E and the time-varying waveforms WF of the other event data E. The control unit 80 then calculates the time offset at which the cross-correlation function has a maximum value. Thereafter, the control unit 80 shifts the time of the other event data E so as to eliminate the time offset. This aligns the timing of actions in the plurality of event data E with the reference event data E. That is, the same actions are performed at the same time in the plurality of event data E.

[0067] Once the timing of the plurality of event data E is aligned, the control unit 80 then calculates an evaluation value for each of the plurality of event data E (step S14). Then, the control unit 80 evaluates the specific operation of the processing unit 102 based on the calculated evaluation value (step S15). The evaluation value may be calculated based on the event data E. The control unit 80 calculates the evaluation value using a preset calculation method according to the event to be evaluated in the specific operation of the processing unit 102.

[0068] The processing of steps S14 to S15 will be described in more detail below for four examples in which the events to be evaluated are different.

[0069] <4-1. Evaluating the state of the substrate surface when processing liquid is supplied> When the processing liquid is supplied from the upper nozzle 41 to the surface of the substrate W, a high-speed flow of the processing liquid is formed on the surface of the substrate W. The following describes how to evaluate the state of the surface of the substrate W at this time. Figure 10 is a flowchart showing a processing procedure for evaluating the state of the surface of the substrate W when the processing liquid is being supplied.

[0070] 10, the control unit 80 first designates an evaluation area (step S21). The evaluation area is designated, for example, based on information input by a user to the control unit 80. Here, an area of ​​the imaging area A that includes the surface of the substrate W when the processing liquid is supplied is designated as the evaluation area.

[0071] Next, the control unit 80 specifies the tallying time (step S22). The tallying time is specified, for example, based on information input by the user to the control unit 80. The tallying time is a time longer than the interval at which the single data e is acquired by the event-based camera 70. When evaluating the state of the surface of the substrate W during the supply of the processing liquid, the tallying time may be set to, for example, 1 second.

[0072] Next, the control unit 80 counts the number of pixels whose luminance value has changed in the specified evaluation area for each specified aggregation time. Specifically, the control unit 80 counts, among the multiple single data e included in the event data E, the number of single data e that have coordinate information x, y included in the specified evaluation area and time information t that matches the specified aggregation time. However, multiple single data e with the same coordinate information x, y are counted as one. In other words, even if the luminance value of the same pixel changes multiple times within one aggregation time, it is counted as one. Then, the control unit 80 sets the number of aggregated single data e (i.e., the number of pixels whose luminance value has changed) as the evaluation value (step S23).

[0073] Next, the control unit 80 creates a histogram H1 of the evaluation values ​​(step S24). FIG. 11 is a diagram showing an example of the histogram H1 created for two processing units 102. In the example of FIG. 11, the test period for creating the histogram H1 is set to 5 seconds. The horizontal axis of the histogram H1 indicates the number of counting periods in which the luminance value changed, out of the five counting periods included in the test period. The vertical axis of the histogram H1 indicates the number of pixels.

[0074] That is, histogram H1 in FIG. 11 shows, among the multiple pixels belonging to the evaluation area, the number of pixels whose luminance value changed zero times in the total time period during the 5-second inspection period, the number of pixels whose luminance value changed once in the total time period, the number of pixels whose luminance value changed twice in the total time period, the number of pixels whose luminance value changed three times in the total time period, the number of pixels whose luminance value changed four times in the total time period, and the number of pixels whose luminance value changed five times in the total time period.

[0075] By creating such a histogram H1, the tendency of changes in the luminance values ​​of a large number of pixels belonging to the evaluation area can be statistically represented in a single graph. The control unit 80 evaluates the operation of the processing unit 102 based on the created histogram H1 (step S25).

[0076] In step S25, the control unit 80 compares the histograms H1 created for each processing unit 102. Then, it determines whether the difference between the histogram H1 of the reference processing unit 102 and the histograms H1 of the other processing units 102 is within a preset tolerance range. If the difference between the histograms H1 is outside the tolerance range, the control unit 80 determines that there is a large variation in operation (in-machine difference) between those processing units 102. Thereafter, the control unit 80 displays the evaluation result on the display unit 84.

[0077] <4-2. Evaluating the state of the liquid column when supplying processing liquid> When the processing liquid is supplied from the upper nozzle 41 to the surface of the substrate W, a liquid column L of the processing liquid discharged from the nozzle head 412 is formed between the nozzle head 412 and the substrate W, as shown in Fig. 8. The following describes a case where the state of this liquid column L, such as fluctuations, is evaluated. Fig. 12 is a flowchart showing a processing procedure for evaluating the state of the liquid column L when the processing liquid is supplied.

[0078] 12, the control unit 80 first designates an evaluation area (step S31). The evaluation area is designated, for example, based on information input by a user to the control unit 80. Here, an area of ​​the imaging area A that includes the liquid column L of the processing liquid discharged from the upper surface nozzle 41 toward the substrate W is designated as the evaluation area.

[0079] Next, the control unit 80 specifies the tallying time (step S32). The tallying time is specified, for example, based on information input by the user to the control unit 80. The tallying time is a time longer than the interval at which the single data e is acquired by the event-based camera 70. When evaluating the state of the liquid column L during the supply of the processing liquid, the tallying time may be set to, for example, 1 second.

[0080] Next, the control unit 80 counts the number of pixels whose luminance value has changed in the specified evaluation area for each specified aggregation time. Specifically, the control unit 80 counts, among the multiple single data e included in the event data E, the number of single data e that have coordinate information x, y included in the specified evaluation area and time information t that matches the specified aggregation time. However, multiple single data e with the same coordinate information x, y are counted as one. In other words, even if the luminance value of the same pixel changes multiple times within one aggregation time, it is counted as one. Then, the control unit 80 sets the number of aggregated single data e (i.e., the number of pixels whose luminance value has changed) as the evaluation value (step S33).

[0081] Next, the control unit 80 creates a histogram H2 of the evaluation values ​​(step S34). FIG. 13 is a diagram showing an example of the histogram H2 created for two processing units 102. In the example of FIG. 13, the test period for creating the histogram H2 is set to 10 seconds. The horizontal axis of the histogram H2 indicates the number of counting periods in which the luminance value changed out of the 10 counting periods included in the test period. The vertical axis of the histogram H1 indicates the number of pixels.

[0082] That is, histogram H2 in FIG. 13 shows, among the multiple pixels belonging to the evaluation area, the number of pixels whose luminance value changed zero times in the total time period, the number of pixels whose luminance value changed one time in the total time period, the number of pixels whose luminance value changed two times in the total time period, the number of pixels whose luminance value changed three times in the total time period, the number of pixels whose luminance value changed four times in the total time period, the number of pixels whose luminance value changed five times in the total time period, the number of pixels whose luminance value changed six times in the total time period, the number of pixels whose luminance value changed seven times in the total time period, the number of pixels whose luminance value changed eight times in the total time period, the number of pixels whose luminance value changed nine times in the total time period, and the number of pixels whose luminance value changed ten times in the total time period.

[0083] By creating such a histogram H2, the tendency of changes in the luminance values ​​of a large number of pixels belonging to the evaluation area can be statistically represented in a single graph. The control unit 80 evaluates the operation of the processing unit 102 based on the created histogram H2 (step S35).

[0084] In step S35, the control unit 80 compares the histograms H2 created for each processing unit 102. Then, it determines whether the difference between the histogram H2 of the reference processing unit 102 and the histograms H2 of the other processing units 102 is within a preset tolerance range. If the difference between the histograms H2 is outside the tolerance range, the control unit 80 determines that there is a large variation in operation (in-machine difference) between those processing units 102. Thereafter, the control unit 80 displays the evaluation result on the display unit 84.

[0085] <4-3. Evaluating liquid splashing caused by a chuck pin> When the processing liquid is supplied to the surface of the substrate W while the substrate W is being rotated, the processing liquid splashes from the peripheral edge of the substrate W. At this time, larger splashes of the processing liquid may occur near the chuck pins 22 than in other areas. The following describes how to evaluate the state of this splash. Fig. 14 is a flowchart showing a processing procedure for evaluating the state of splash.

[0086] 14, the control unit 80 first designates an evaluation area (step S41). The evaluation area is designated, for example, based on information input by a user to the control unit 80. Here, an area of ​​the imaging area A that includes the peripheral portion of the substrate W held by the substrate holding unit 20 is designated as the evaluation area.

[0087] Next, the control unit 80 specifies an inspection period (step S42). The inspection period is specified, for example, based on information input to the control unit 80 by the user. The inspection period is a time longer than the interval at which the event-based camera 70 acquires the single data e. When evaluating the state of splashing, the inspection period may be set to, for example, 0.1 seconds.

[0088] Next, the control unit 80 identifies pixels in the specified evaluation region whose luminance value has changed during the specified inspection period (step S43). Specifically, the control unit 80 identifies, from among the plurality of single data e included in the event data E, a single data e having coordinate information x, y included in the specified evaluation region and time information t that matches the specified inspection period.

[0089] FIG. 15 is a diagram showing an example of pixels (hereinafter referred to as "detected pixels P") whose luminance values ​​changed during the inspection period in the evaluation area. The control unit 80 extracts pixel groups PG from the plurality of detected pixels P, where the number of adjacent pixels is equal to or greater than a predetermined lower limit and equal to or less than a predetermined upper limit. This allows the area corresponding to the liquid splash to be detected as pixel groups PG (step S44). In FIG. 15, the detected pixel groups PG are indicated by dashed circles.

[0090] 15, a large number of detection pixels P are arranged linearly in a portion corresponding to the peripheral edge of the substrate W. However, since an upper limit is set on the number of adjacent detection pixels P, this portion is not detected as a liquid splash.

[0091] The control unit 80 counts the number of pixel groups PG detected as liquid splashes in the evaluation area (step S45). The control unit 80 then sets the counted number of pixel groups PG as an evaluation value. Thereafter, the control unit 80 evaluates the operation of the processing unit 102 based on the evaluation value (step S46).

[0092] In step S46, the control unit 80 compares the number of pixel groups PG counted for each processing unit 102. Then, it determines whether the difference between the number of pixel groups PG in the reference processing unit 102 and the number of pixel groups PG in the other processing units 102 is within a preset tolerance range. If the difference in the number of pixel groups PG is outside the tolerance range, the control unit 80 determines that there is a large variation in operation (in-machine difference) between those processing units 102. The control unit 80 then displays the evaluation result on the display unit 84.

[0093] <4-4. When evaluating drying time> In step S4 described above, the substrate W is rotated at high speed to spin off the processing liquid, thereby drying the surface of the substrate W. At this time, the thickness of the liquid film of the processing liquid on the surface of the substrate W gradually decreases, causing a change in the optical interference fringes. Below, a case where the state of the surface of the substrate W during such a drying process is evaluated will be described. Figure 16 is a flowchart showing the processing procedure for evaluating the state of the surface of the substrate W during the drying process.

[0094] 16, the control unit 80 first designates an evaluation area (step S51). The evaluation area is designated, for example, based on information input by a user to the control unit 80. Here, within the imaging area A, an area including the surface of the substrate W during the drying process is designated as the evaluation area.

[0095] Next, the control unit 80 specifies the tallying time (step S52). The tallying time is specified, for example, based on information input by the user to the control unit 80. The tallying time is a time longer than the interval at which the single data e is acquired by the event-based camera 70. When evaluating the surface condition of the substrate W during the drying process, the tallying time may be set to, for example, 0.1 seconds.

[0096] Next, the control unit 80 counts the number of pixels whose luminance value has changed in the specified evaluation area for each specified aggregation time. Specifically, the control unit 80 counts, among the multiple single data e included in the event data E, the number of single data e that have coordinate information x, y included in the specified evaluation area and time information t that matches the specified aggregation time. However, multiple single data e with the same coordinate information x, y are counted as one. In other words, even if the luminance value of the same pixel changes multiple times within one aggregation time, it is counted as one. Then, the control unit 80 sets the number of aggregated single data e (i.e., the number of pixels whose luminance value has changed) as the evaluation value (step S53).

[0097] Next, the control unit 80 creates a time-varying waveform VW of the evaluation value (step S54). Fig. 17 is a graph showing the time-varying waveforms VW created for the two processing units 102. The horizontal axis of the graph in Fig. 17 represents time. The vertical axis of the graph in Fig. 17 represents the number of pixels. In other words, the graph in Fig. 17 shows the change over time in the number of pixels whose luminance value has changed among the multiple pixels belonging to the evaluation area.

[0098] The control unit 80 evaluates the operation of the processing units 102 based on the created time-varying waveform VW of the evaluation value (step S55). In step S55, the control unit 80 measures the time (hereinafter referred to as the "drying time T") from the time when the evaluation value starts to increase to the time when the evaluation value stops decreasing in the time-varying waveform VW. The control unit 80 then compares the measured drying times T for each processing unit 102. The control unit 80 determines whether the difference between the drying time T of the reference processing unit 102 and the drying times T of the other processing units 102 is within a preset tolerance range. If the difference in the drying time T is outside the tolerance range, the control unit 80 determines that there is a large variation in operation (inter-instrument difference) between those processing units 102. The control unit 80 then displays the evaluation result on the display unit 84.

[0099] 4-5. Effects of the operation monitoring method according to this embodiment As described above, in the substrate processing apparatus 100, the event-based camera 70 captures images of specific operations of the processing units 102. Then, an evaluation value is calculated based on the obtained event data E. Information on high-speed movements included in the operations of the processing units 102 is recorded in the event data E. Therefore, the high-speed movements can be evaluated based on the evaluation value.

[0100] Furthermore, in the operation monitoring method of this embodiment, before calculating the evaluation value in step S14, processing is performed in steps S12 and S13 to align the timing of the multiple event data E. In this way, in step S14, the evaluation value can be calculated based on the multiple event data E whose operation timings are aligned. As a result, in step S15, the variation in the operations of the multiple processing units 102 can be evaluated with higher accuracy.

[0101] Furthermore, in the operation monitoring method of this embodiment, feature amounts for aligning the timing of multiple pieces of event data E are calculated based on information included in the event data E. That is, the event data E for evaluating the operation of the processing unit 102 is also used for timing alignment. In this way, there is no need to measure parameters for aligning the timing of the event data E separately from the event data E. Therefore, it is possible to reduce the amount of measurement processing required for operation monitoring.

[0102] <5. Variations> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

[0103] In the above embodiment, a specific action is captured in multiple processing units 102, and the variation in the action is evaluated between the processing units 102. However, a repeated action may be captured multiple times in one processing unit 102, and the variation in the action in one processing unit 102 may be evaluated based on the obtained event data E.

[0104] In the above embodiment, an example has been described in which the operation of the processing unit 102 that supplies a processing liquid to the surface of the substrate W is evaluated. However, the processing unit to be evaluated may be a unit that performs other processing on the substrate W. Furthermore, the object to be processed may be an object other than the substrate W. The operation monitoring method of the present invention can be widely applied to apparatuses that perform processing involving movement.

[0105] However, in an apparatus that supplies a processing liquid to a substrate W for precision electronic components such as a semiconductor wafer, it is necessary to extremely precisely manage the reproducibility of operations in a plurality of processing units. For this reason, it is particularly significant to apply the operation monitoring method of the present invention to an apparatus that supplies a processing liquid to the substrate W. [Explanation of symbols]

[0106] 10 Chambers 20 Board holding part 30 Rotation mechanism 40 Processing liquid supply unit 50 Treatment liquid collection section 60 Breaker 70 Event-based Cameras 80 Control Unit 100 Substrate processing apparatus 102 Processing Unit P1 Motion Control Program P2 behavior monitoring program W substrate A. Shooting area E Event Data e Single Data H1 Histogram H2 Histogram P detection pixel PG pixel group T drying time WF feature value time-varying waveform Waveform of VW evaluation value over time

Claims

1. A method for monitoring the operation of a processing unit, comprising: a) capturing a specific operation of the processing unit with an event-based camera to acquire event data consisting of information on only pixels whose luminance values ​​have changed; b) calculating an evaluation value based on the event data; c) evaluating the operation of the processing unit based on the evaluation value; and In the step a), the specific actions are captured by the event-based camera in the plurality of processing units to acquire the plurality of event data; In the step b), the evaluation value is calculated for each of the plurality of event data; In the step c), the variation in the operations of the plurality of processing units is evaluated based on the evaluation value.

2. An operation monitoring method according to claim 1, After step a) and before step b), x) calculating a feature amount based on the information for each unit time for each of the plurality of event data; y) aligning the timing of the plurality of event data based on the time-varying waveform of the feature amount; A motion monitoring method comprising:

3. An operation monitoring method according to claim 2, The feature is the number of pixels whose luminance value changes in the unit time.

4. 4. The operation monitoring method according to claim 1, further comprising: The operation monitoring method, wherein the evaluation value is the number of pixels in a predetermined evaluation region whose luminance value has changed during a predetermined counting period.

5. An operation monitoring method according to claim 4, In the step c), the operation of the processing unit is evaluated based on a histogram that tallies the number of pixels for each count time during which the luminance value has changed among the plurality of count times included in a predetermined inspection period.

6. An operation monitoring method according to claim 4 or claim 5, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, The evaluation region includes the surface of the substrate when the processing liquid is supplied.

7. An operation monitoring method according to claim 4 or claim 5, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, The evaluation region includes a liquid column of the processing liquid ejected from a nozzle toward the substrate.

8. 4. The operation monitoring method according to claim 1, further comprising: An operation monitoring method, wherein the evaluation value is the number of pixel groups in a predetermined evaluation area whose brightness values ​​change during a predetermined inspection period and whose number of adjacent pixels is greater than a predetermined lower limit value and less than a predetermined upper limit value.

9. An operation monitoring method according to claim 8, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, The evaluation region includes a periphery of the substrate.

10. 4. The operation monitoring method according to claim 1, further comprising: the evaluation value is the number of pixels whose luminance value has changed in a predetermined calculation time in a predetermined evaluation region, In the step c), the operation of the processing unit is evaluated based on a change in the evaluation value over time.

11. The operation monitoring method according to claim 10, the processing unit is a unit that supplies a processing liquid to a surface of a substrate, The operation monitoring method, wherein the evaluation region includes the surface of the substrate during a drying process in which the processing liquid is shaken off while the substrate is being rotated.

12. a processing unit that processes a processing object by performing a specific operation; an event-based camera capable of outputting event data consisting of information on only pixels whose brightness values ​​have changed; a computer communicatively connected to the event-based camera; Equipped with The computer a) acquiring the event data by having the event-based camera capture the operation of the processing unit; b) calculating an evaluation value based on the event data; c) evaluating the operation of the processing unit based on the evaluation value; Run The computer In the step a), the specific actions are captured by the event-based camera in the plurality of processing units to acquire the plurality of event data; In the step b), the evaluation value is calculated for each of the plurality of event data; In the step c), the manufacturing apparatus evaluates the variations in the operations of the plurality of processing units based on the evaluation values.

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