Substrate processing method, substrate processing monitoring method, storage medium, and substrate processing apparatus.

Abstract

To prevent problems from occurring during circuit board processing. [Solution] A substrate processing method according to one aspect of the present disclosure includes performing a predetermined process on a substrate, which includes rotating the substrate held by a holding unit, and repeatedly performing a monitoring process during the execution of the predetermined process. The monitoring process includes a first process of detecting the outer edge in an image obtained by imaging a range including the outer edge on the surface of the substrate, a second process of calculating the position of the outer edge in the image based on the detection result in the first process, and a third process of determining whether or not there is an abnormality in the holding of the substrate by the holding unit based on the calculation result in the second process.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing method, a method for monitoring substrate processing, a storage medium, and a substrate processing apparatus.

Background Art

[0002] Patent Document 1 discloses a substrate processing apparatus including a chamber, a substrate holding unit that holds a substrate in the chamber, a camera that images an imaging region including a monitoring target in the chamber and generates imaging image data, and a control unit that monitors the state of the monitoring target.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a substrate processing method, a method for monitoring substrate processing, a storage medium, and a substrate processing apparatus that can prevent the occurrence of troubles during substrate processing.

Means for Solving the Problems

[0005] A substrate processing method according to one aspect of the present disclosure includes performing a predetermined process including rotating a substrate held by a holding unit on the substrate, and repeatedly performing a monitoring process during the execution of the predetermined process. The monitoring process includes a first process of detecting an outer edge in an image obtained by imaging a range including the outer edge on the surface of the substrate, a second process of calculating the position of the outer edge in the image based on the detection result in the first process, and a third process of determining the presence or absence of an abnormality related to the holding of the substrate by the holding unit based on the calculation result in the second process.

Effects of the Invention

[0006] This disclosure provides a substrate processing method, a substrate processing monitoring method, a storage medium, and a substrate processing apparatus that can prevent the occurrence of problems during substrate processing. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic plan view showing an example of a substrate processing apparatus. [Figure 2] Figure 2 is a schematic front view showing an example of a substrate processing apparatus. [Figure 3] Figure 3 is a schematic diagram showing an example of a liquid processing apparatus. [Figure 4] Figure 4 is a schematic diagram showing an example of an image obtained by the imaging device. [Figure 5] Figure 5 is a block diagram showing an example of the functional configuration of a control device. [Figure 6] Figures 6(a) and 6(b) are schematic graphs illustrating an example of the time evolution of the outer edge position. [Figure 7] Figure 7 is a block diagram showing an example of the hardware configuration of a control device. [Figure 8] Figure 8 is a flowchart showing an example of the processing flow executed by the control device. [Figure 9] Figure 9(a) is a schematic diagram showing an example of an image obtained by the imaging device. Figure 9(b) is a schematic graph showing an example of the time change in the distance between the wafer and the cup. [Figure 10] Figure 10 is a schematic diagram showing an example of an image obtained by the imaging device. [Figure 11] Figure 11 is a schematic diagram showing an example of an image obtained by the imaging device. [Figure 12] Figures 12(a) and 12(b) are schematic diagrams showing examples of images obtained by the imaging device. [Modes for carrying out the invention]

[0008] Hereinafter, the wafer processing system as a substrate processing apparatus according to this embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0009] <Wafer Processing System> First, the configuration of the wafer processing system according to this embodiment will be described. Figures 1 and 2 are schematic plan view and front view, respectively, showing the general configuration of the wafer processing system 1. In this embodiment, the case in which the wafer processing system 1 is a photolithography processing system that performs resist film formation processing and development processing on a wafer W (substrate) will be described as an example.

[0010] As shown in Figure 1, the wafer processing system 1 includes a cassette station 2 for loading and unloading cassettes C containing multiple wafers W, and a processing station 3 equipped with multiple processing devices for performing predetermined processing on the wafers W. The wafer processing system 1 has a configuration in which the cassette station 2, the processing station 3, and an interface station 4 for transferring wafers W between the processing station 3 and an adjacent exposure device (not shown) on the opposite side are integrally connected. Although two processing stations 3 are installed between the cassette station 2 and the interface station 4 as shown in Figure 1, there may be one or three or more processing stations.

[0011] The cassette station 2 is equipped with multiple cassette mounting tables 21 and wafer transport devices 22 and 23. The cassette station 2 transports wafers W between the cassette C placed on the mounting table 21 and the processing station 3 using the wafer transport device 22 or 23. For this purpose, the wafer transport devices 22 and 23 are equipped with drive mechanisms that have movement paths in each direction, such as horizontal (X and Y directions), vertical (Z direction), and around the vertical axis (θ direction), as needed, and may also be equipped with drive mechanisms that have movement paths in all directions. At least one of the wafer transfer devices 22 and 23 can transfer the cassette C and the wafer W, and can also transfer the wafer W with the processing station 3. The wafer transfer operation with the processing station 3 means, for example, transferring the wafer W between the third block G3 having a transfer device accessible by the wafer transfer device 33 in the processing station 3 described later. The third block G3 may include a plurality of transfer devices (not shown) arranged in the vertical direction.

[0012] In addition, an inspection device (not shown) for inspecting the wafer W may be provided at a position accessible by either the wafer transfer device 22 or 23.

[0013] The processing station 3 is provided with a plurality of blocks, for example, three blocks G1, G2, and G4 of the first, second, and fourth. Also, as shown in FIG. 2, a plurality of layers 31 including the first and second blocks G1 and G2 are stacked in the vertical direction. For example, the first block G1 is provided on the front side of the processing station 3 (the negative X direction side in FIG. 1), and the second block G2 is provided on the back side of the processing station 3 (the positive X direction side in FIG. 1). The fourth block G4 is provided on the interface station 4 side of the processing station 3 (the positive Y direction side in FIG. 1) or at the connection portion with another adjacent processing station 3. The fourth block G4 may include a plurality of transfer devices arranged in the vertical direction. Also, the aforementioned third block G3 may be provided in the processing station 3.

[0014] A plurality of processing devices, for example, a patterning film forming device and a development processing device (both not shown) are arranged in the first block G1. As the patterning film forming device, for example, in addition to a resist film forming device, an antireflection film forming device can be included. For example, a plurality of processing devices are arranged side by side in the horizontal direction. The number, arrangement, and type of these processing devices can be arbitrarily selected.

[0015] In these patterning film forming apparatuses and development processing apparatuses, for example, a predetermined processing liquid is supplied onto the wafer W, or a predetermined gas is supplied. In this way, in the patterning film forming apparatus, formation of a resist film used as a mask when forming a pattern of the film on the lower layer side, formation of an antireflection film or the like for efficiently performing light irradiation processing such as exposure processing is performed. On the other hand, in the development processing apparatus, a part of the exposed resist film is removed to form the concavo-convex shape as the mask. As an example of the first block G1, a liquid processing apparatus U1 may be arranged. The liquid processing apparatus U1 (processing unit) is an apparatus that performs liquid processing using a processing liquid for film formation on the wafer W as a predetermined processing.

[0016] For example, in the second block G2, heat treatment apparatuses (not shown) that perform heat treatment such as heating and cooling of the wafer W are arranged side by side in the vertical and horizontal directions. Also, although not shown in the second block G2, a hydrophobization treatment apparatus that performs hydrophobization treatment to enhance the adhesion between the resist liquid and the wafer W, and a peripheral exposure apparatus that exposes the outer peripheral portion of the wafer W are arranged side by side in the vertical direction (Z direction in FIG. 2) and the horizontal direction. The number and arrangement of these heat treatment apparatuses, hydrophobization treatment apparatuses, and peripheral exposure apparatuses can also be arbitrarily selected.

[0017] As shown in FIG. 1, a wafer transfer region 32 is formed in the region sandwiched between the first block G1 and the second block G2 in plan view. In the wafer transfer region 32, for example, a wafer transfer apparatus 33 is arranged.

[0018] The wafer transfer device 33 has a transfer arm that can move, for example, in the Y direction, front-back direction, θ direction, and up-down direction. The wafer transfer device 33 moves within the wafer transfer area 32 and can transfer wafers W to predetermined devices in the surrounding first block G1, second block G2, third block G3, and fourth block G4. If there are multiple processing stations 3 as shown in Figure 1, the wafer transfer device 33 provided at the processing station 3 located on the interface station 4 side can transfer wafers W to predetermined devices in the fifth block G5, which will be described later, in addition to the first, second, and fourth blocks G1, G2, and G4.

[0019] Multiple wafer transfer devices 33 are arranged vertically, for example, as shown in Figure 2. One wafer transfer device 33 can transfer a wafer W to a predetermined device located at the height of multiple upper layers 31 of the stacked layers 31. Another wafer transfer device 33 can transfer the wafer W to a predetermined device located at the height of multiple layers 31 below those layers 31. Multiple wafer transfer areas 32 are provided to enable this type of wafer transfer W. The number of wafer transfer devices 33 and the number of layers 31 corresponding to one wafer transfer device 33 can be arbitrarily selected, such as providing one wafer transfer device 33 for each layer 31.

[0020] Furthermore, a shuttle transport device (not shown) may be provided in the wafer transport area 32 or in the first block G1 or the second block G2. The shuttle transport device transports the wafer W linearly between a space adjacent to one side of the processing station 3 and another space adjacent to the opposite side.

[0021] Interface station 4 includes a fifth block G5 equipped with multiple transfer devices, and wafer transport devices 41 and 42. Interface station 4 transports wafers W between the fifth block G5, where wafers W are transferred by wafer transport device 33, and the exposure apparatus using wafer transport device 41 or 42. For this purpose, wafer transport devices 41 and 42 are each equipped with a drive mechanism having movement paths in various directions such as horizontal (X direction, Y direction), vertical (Z direction), and around the vertical axis (θ direction), as needed, and may also be equipped with a drive mechanism having movement paths in all directions. At least one of wafer transport devices 41 and 42 can support the wafer W and transport the wafer W between the transfer devices and the exposure apparatus in the fifth block G5.

[0022] A cleaning device for cleaning the surface of the wafer W, and the aforementioned peripheral exposure device, may be provided within the interface station 4 in a location accessible by either the wafer transport device 41 or 42.

[0023] The inspection device may be provided in the cassette station 2 as described above, but it may also be provided in the processing station 3 and the interface station 4 in a position accessible by any of the transport arms (33, 41, 42 in Figure 1 or Figure 2) located inside each of them.

[0024] The wafer processing system 1 described above is provided with a control device 100. The control device 100 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program that controls the processing of wafers W in the wafer processing system 1. The program storage unit also stores a program that controls the operation of the various processing devices and transport devices and other drive systems to realize wafer processing in the wafer processing system 1. The above program may have been recorded on a storage medium H readable by the computer and installed from the storage medium H to the control device 100. The storage medium H may include ROM, RAM, or a hard disk, but its structure and type are not limited, and it may be temporary or non-temporary. The control device 100 may include a part that stores, reads, and executes the program for realizing wafer processing and performs related communications, and the location of each part may be either inside or outside the wafer processing system 1. The control device 100 may be one or more circuits, and may be provided as a single unit or in parts.

[0025] <Operation of the wafer processing system> The wafer processing system 1 is configured as described above. Next, an example of wafer processing performed using the wafer processing system 1 configured as described above will be explained.

[0026] First, a cassette C containing multiple wafers W is brought into the cassette station 2 of the wafer processing system 1 and placed on the cassette tray 21. Next, each wafer W in the cassette C is sequentially removed by the wafer transport device 22 or 23 and transported to the transfer device of the third block G3.

[0027] The wafer W, transported to the transfer device in the third block G3, is supported by the wafer transfer device 33 and transported to a hydrophobic treatment device located in the second block G2, where a hydrophobic treatment is performed. Next, the wafer transfer device 33 transports the wafer to a resist film forming device (e.g., a liquid treatment device U1) where a resist film is formed on the wafer W. After that, it is transported to a heat treatment device for pre-baking before being transported to the transfer device in the fifth block G5. Note that if there are multiple processing stations 3 as shown in Figures 1 and 2, the wafer W is first placed in the transfer device in the fourth block G4 before being transported to the transfer device in the fifth block G5, and then transferred between the multiple wafer transfer devices 33. In addition, if necessary, the wafer W may be transported by the wafer transfer device 33 to a peripheral exposure device where the peripheral edge of the wafer is exposed.

[0028] The wafer W, transported to the transfer device of the fifth block G5, is then transported to the exposure device by wafer transport devices 41 and 42 and exposed in a predetermined pattern. The wafer W may be cleaned in a cleaning device before the exposure process.

[0029] The exposed wafer W is transported by wafer transport devices 41 and 42 to the transfer device for the fifth block G5. It is then transported by wafer transport device 33 to a heat treatment device for post-exposure baking.

[0030] The wafer W, which has been baked after exposure, is transported by the wafer transport device 33 to the developing device and developed. After development is complete, the wafer W is transported by the wafer transport device 33 to the heat treatment device and subjected to post-bake treatment.

[0031] Subsequently, the wafer W is transported by the wafer transport device 33 to the transfer device of the third block G3, and then transported by the wafer transport device 22 or 23 of the cassette station 2 to cassette C on a predetermined cassette mounting table 21. In this way, the series of photolithography processes is completed.

[0032] It should be noted that the wafer processing system in this disclosure is not limited to the configuration and operation described above. For example, in the above embodiment, the wafer processing system is directly connected to the exposure apparatus and the wafer W is transferred between the interface station 4 and the exposure apparatus, but the wafer processing system does not have to be directly connected to the exposure apparatus. In that case, for example, the wafer W is transported from the cassette station 2 to the processing station 3, the necessary processing is performed, and then it is transported back to the cassette station 2 for removal outside the system. Also, among the processing devices listed, those that are not necessary may not be provided in the wafer processing system, or processing may not be performed in those devices. The wafer processing system may also be a system that performs processing on a laminated substrate WL in which two or more unit substrates are bonded together. The wafer processing system may have a liquid processing device that performs liquid processing on the laminated substrate WL, and may have a heat processing device that performs heat processing on the laminated substrate WL.

[0033] (Specific examples of liquid processing equipment) Next, a specific example of the liquid processing apparatus U1 will be described with reference to Figure 3. The liquid processing apparatus U1 supplies a processing liquid for film formation (hereinafter referred to as "processing liquid L1") to the wafer W to be processed, and forms a film of processing liquid L1. In Figure 3, the film of processing liquid L1 is indicated by "F". In this disclosure, the film of processing liquid L1 formed by the liquid processing performed by the liquid processing apparatus U1, and the film of processing liquid L1 formed on the surface Wa during the liquid processing performed by the liquid processing apparatus U1 are collectively referred to as "film F".

[0034] The liquid treatment by the liquid treatment apparatus U1 includes rotating the wafer W held in the holding section. The liquid treatment by the liquid treatment apparatus U1 also includes supplying a treatment liquid L1 to the wafer W held in the holding section. The liquid treatment apparatus U1 rotates the wafer W for at least a portion of the liquid treatment execution period. For example, the liquid treatment apparatus U1 supplies the treatment liquid L1 to the surface Wa of the wafer W while rotating the wafer W, and after supplying the treatment liquid L1, rotates the wafer W to dry the coating F. As shown in Figure 3, the liquid treatment apparatus U1 includes, for example, a rotating holding section 50, a liquid supply section 60, and a cup 70.

[0035] The rotating holding unit 50 holds and rotates the wafer W. The rotating holding unit 50 includes a holding unit 52 and a rotation drive unit 54. The holding unit 52 holds (supports) the wafer W. For example, the holding unit 52 supports the center of the back surface Wb of the wafer W, which is placed horizontally with the surface Wa facing upward, and holds the wafer W by vacuum suction or the like. The rotation drive unit 54 is connected to the holding unit 52 via a shaft.

[0036] The rotary drive unit 54 is an actuator that includes a power source such as an electric motor, and rotates the holding unit 52 around a vertical axis Ax. As the holding unit 52 rotates due to the rotary drive unit 54, the wafer W held (supported) by the holding unit 52 rotates. The holding unit 52 holds the wafer W such that its center CP substantially coincides with the axis Ax.

[0037] The liquid processing apparatus U1 may have a plurality (for example, three) of lifting pins 58. The plurality of lifting pins 58 have the function of transferring the wafer W between the holding unit 52 and the wafer transfer device 33. The plurality of lifting pins 58 are arranged around the holding unit 52. The plurality of lifting pins 58 are connected to a lifting drive unit and are provided to be able to move up and down. For example, when transferring the wafer W to the wafer transfer device 33 after the liquid processing is completed, the plurality of lifting pins 58 rise, and the plurality of lifting pins 58 move the wafer W to above the holding unit 52 while the plurality of lifting pins 58 support the back surface of the wafer W.

[0038] The liquid supply unit 60 supplies a processing liquid L1 to the surface Wa of the wafer W. The processing liquid L1 is, for example, a solution (resist) for forming a resist film. The liquid supply unit 60 includes a nozzle 62, a supply source 64, a supply pipe 65, an on / off valve 66, and a nozzle drive unit 68.

[0039] The nozzle 62 is configured to discharge a processing liquid L1 onto the surface Wa of the wafer W held by the holding unit 52. The nozzle 62 is positioned, for example, above the wafer W (in one example, vertically above the center CP of the wafer W) and discharges the processing liquid L1 vertically downward. The supply source 64 is connected to the nozzle 62 via a supply pipe 65 and supplies the processing liquid L1 to the nozzle 62.

[0040] An on / off valve 66 is provided in the supply pipe 65 and switches the open / closed state of the flow path formed by the supply pipe 65. The nozzle drive unit 68 moves the nozzle 62 between an upper discharge position on the wafer W and a standby position different from the discharge position. The standby position is set, for example, outside the outer edge Ew of the wafer W. In addition to moving the nozzle 62 in the direction along the surface Wa of the wafer W, the nozzle drive unit 68 may also move the nozzle 62 in the vertical direction.

[0041] The cup 70 is positioned to surround the holding portion 52 and is a component that receives the processing liquid L1 after it has been supplied to the wafer W (surface Wa). The cup 70 forms a containment space with an open upper end. The holding portion 52 is located in this containment space, and the processing liquid L1 is supplied to the surface Wa of the wafer W while the wafer W is placed in the containment space. The cup 70 is configured to collect the processing liquid L1 that is scattered around from the wafer W as it is rotated by the rotating holding portion 50.

[0042] The bottom of the cup 70 is provided with a drain port 71 and an exhaust port 72. The drain port 71 is an opening for discharging the processing liquid L1 collected by the cup 70 to the outside of the cup 70. The exhaust port 72 is an opening for discharging the gas inside the cup 70 to the outside of the cup 70. For example, gas generated when the processing liquid L1 is supplied to the wafer W is discharged from the exhaust port 72.

[0043] The cup 70 includes a circumferential wall 75 and an inclined wall 76. The circumferential wall 75 is formed in a cylindrical shape so as to extend along the circumferential direction about the axis Ax. The circumferential wall 75 is connected to the outer peripheral edge of the bottom of the cup 70 and extends along a direction parallel to the axis Ax. One end of the inclined wall 76 is connected to the upper end of the circumferential wall 75 and is inclined so as to extend toward the axis Ax from the point of connection with the upper end of the circumferential wall 75. The inclined wall 76 is formed in an annular shape.

[0044] When viewed from the axial direction in which the axis Ax extends (for example, from vertically above), the inner edge Ec of the cup 70 is located outside the outer edge Ew of the wafer W held in the holding portion 52. The inner edge Ec of the cup 70 corresponds, for example, to the inner edge of the inclined wall 76, and the outer edge Ew (periphery) of the wafer W corresponds, for example, to the periphery of the coating F formed on the surface Wa of the wafer W.

[0045] (Imaging device) The wafer processing system 1 includes an imaging device 90. The imaging device 90 acquires image data representing the processing status while a predetermined processing (e.g., liquid processing) is performed on the wafer W. The imaging device 90 may also acquire image data to record the processing status. The imaging device 90 is, for example, a camera that generates video data. The imaging device 90 is installed inside the housing of the liquid processing device U1.

[0046] The imaging device 90 is capable of imaging an imaging range that includes at least a portion of the outer edge Ew of the wafer W held in the holding unit 52. The imaging device 90 may be installed so as to be able to image the surface Wa of the wafer W held in the holding unit 52 from an oblique angle above. The field of view (imaging range) of the imaging device 90 may be set to include the entire surface Wa of the wafer W, or it may be set to include the center CP of the surface Wa and a portion of the outer edge Ew of the wafer W, without including the entire surface Wa of the wafer W. Figure 4 schematically illustrates an image MI (one frame in a video) obtained by the imaging device 90.

[0047] (Control device) The control device 100 controls one or more devices included in the wafer processing system 1. The control device 100 may also control the liquid processing device U1 so that liquid processing is performed on the wafer W to be processed. In addition to controlling devices such as the liquid processing device U1, the control device 100 (monitoring device) may also have a function to monitor the status of processing by the liquid processing device U1. Monitoring the status of processing means monitoring whether or not an abnormality has occurred in the processing to be monitored (for example, liquid processing by the liquid processing device U1).

[0048] The process monitored by the control device 100 may be a process (liquid treatment) that is continuously performed from the time the wafer W to be treated is placed in the holding unit 52 until the wafer W is removed from the holding unit 52. The process monitored by the control device 100 may include a process in which a plurality of lifting pins 58 raise and lower the wafer W, and a process in which the wafer W is transferred from the plurality of lifting pins 58 to the wafer transfer device 33 after the wafer W has been raised. The process monitored may include, for example, supplying a treatment liquid L1 to the surface Wa while rotating the wafer W with the rotating holding unit 50, and rotating the wafer W with the rotating holding unit 50 after stopping the supply of the treatment liquid L1. The contents of this disclosure will be explained below using the case in which the process monitored is liquid treatment by the liquid treatment device U1 as an example.

[0049] As shown in Figure 5, the control device 100 has a functional configuration (hereinafter referred to as "functional blocks") consisting of a processing condition holding unit 112, a processing control unit 114, and a monitoring processing execution unit 120. The processing performed by these functional blocks corresponds to the processing performed by the control device 100.

[0050] The processing condition holding unit 112 holds (stores) information indicating the conditions for liquid processing by the liquid processing apparatus U1. The liquid processing conditions held by the processing condition holding unit 112 include, for example, the rotation speed of the wafer W, the discharge flow rate of the processing liquid L1, the discharge time of the processing liquid L1, and the rotation time of the wafer W after the discharge of the processing liquid L1 stops. These conditions may be set in advance by an operator or the like.

[0051] The processing control unit 114 controls the rotating holding unit 50 and the liquid supply unit 60 included in the liquid processing apparatus U1 according to the liquid processing conditions held by the processing condition holding unit 112. For example, the processing control unit 114 controls the rotating holding unit 50 so that the wafer W rotates according to the set value of the rotation speed defined by the liquid processing conditions. Note that the set value of the rotation speed of the wafer W may be set to a different value for each process (unit processing) included in the liquid processing.

[0052] The monitoring process execution unit 120 repeatedly performs the following monitoring process while the liquid processing device U1 is performing liquid processing. The monitoring process includes a first process, a second process, and a third process. The first process is the process of detecting the outer edge Ew in the image MI obtained by imaging the area including the outer edge Ew on the surface Wa of the wafer W. The second process is the process of calculating the position of the outer edge Ew in the image MI based on the detection result in the first process. The third process is the process of determining whether or not there is an abnormality in the holding of the wafer W by the holding unit 52 based on the calculation result in the second process. The control device 100 may perform the above monitoring process at a predetermined monitoring cycle (for each monitoring cycle).

[0053] The monitoring processing execution unit 120 includes, as functional blocks, an image information acquisition unit 122, an edge detection unit 124, an outer edge position calculation unit 126, a calculation result storage unit 128, an anomaly determination unit 130, and an output unit 132. The processing performed by these functional blocks corresponds to the processing performed by the monitoring processing execution unit 120 (control device 100).

[0054] The image information acquisition unit 122 acquires image data from the imaging device 90 for performing monitoring processing. For example, while the liquid processing by the liquid processing device U1 is continuing, the image information acquisition unit 122 continues to acquire video data generated by imaging by the imaging device 90.

[0055] The edge detection unit 124 performs the first process described above for each monitoring cycle. The edge detection unit 124 detects edges corresponding to the outer edge Ew of the wafer W within the image MI included in the video data acquired by the image information acquisition unit 122. The image MI is different for each monitoring cycle, and the image MI used for a given monitoring cycle may be an image (still image) of a frame in the video data generated by the imaging device 90 for that monitoring cycle.

[0056] The edge detection unit 124 may extract a portion of the image MI and detect edges in that portion, as shown in Figure 4. In Figure 4, the portion of the region targeted for edge detection is indicated as "DR," and hereafter this region will be referred to as the "detection target region DR." The specific algorithm for detecting edges corresponding to the outer edge Ew of the wafer W is not limited to any particular algorithm, but the edge detection unit 124 may, for example, detect edges using the Canny method.

[0057] The edge detection unit 124 identifies the coordinates of pixels where an edge exists in the detection target area DR when detecting an edge corresponding to the outer edge Ew of the wafer W. The edge detection unit 124 identifies the coordinates of multiple points (multiple pixels) as the coordinates of pixels where an edge exists. The coordinates of each pixel are identified, for example, by the number of pixels from the respective reference positions in the horizontal and vertical directions on the image. In Figure 4, the horizontal direction on the image is indicated by an arrow labeled "x", and the vertical direction on the image is indicated by an arrow labeled "y".

[0058] The outer edge position calculation unit 126 performs the second process described above for each monitoring cycle. Based on the edge detection result by the edge detection unit 124, the outer edge position calculation unit 126 calculates the position of the outer edge Ew of the wafer W in the image MI. Calculating the position of the outer edge Ew of the wafer W in the detection target area DR is equivalent to calculating the position of the outer edge Ew of the wafer W in the image MI.

[0059] At the stage when the edge detection unit 124 detects an edge, multiple points are detected as edges. Therefore, the outer edge position calculation unit 126 calculates the position of the outer edge Ew of the wafer W from the coordinates of the multiple points detected by the edge detection unit 124. The outer edge position calculation unit 126 may calculate the position of the outer edge Ew of the wafer W by taking the average value (arithmetic mean) of the coordinates of the multiple points detected as edges by the edge detection unit 124. The outer edge position calculation unit 126 may also determine the position of the outer edge Ew of the wafer W by taking the arithmetic mean of the coordinates of all the multiple points detected as edges by the edge detection unit 124, or it may calculate the arithmetic mean of some of the coordinates (coordinates of multiple representative points) of all pixels detected as edges by the edge detection unit 124.

[0060] The outer edge position calculation unit 126 calculates the position of the outer edge Ew of the wafer W in at least one of the horizontal and vertical directions on the image. The outer edge position calculation unit 126 may calculate the position of the outer edge Ew of the wafer W for both the horizontal and vertical directions on the image. In this case, the outer edge position calculation unit 126 calculates the average value of the coordinates in the horizontal direction of the multiple points detected as edges, and calculates the average value of the coordinates in the vertical direction of the multiple points detected as edges. In addition to the position of the outer edge Ew in at least one of the horizontal and vertical directions on the image, the outer edge position calculation unit 126 may also calculate the Euclidean distance from a reference position in the image (straight-line distance between the reference position and the coordinates) as the position of the outer edge Ew of the wafer W.

[0061] The calculation result storage unit 128 stores the calculation results (calculation results in the second process) from the outer edge position calculation unit 126 at each monitoring cycle. By storing the calculation results at each monitoring cycle, the calculation result storage unit 128 obtains waveform information representing the time change of the result of calculating the position of the outer edge Ew of the wafer W (hereinafter simply referred to as "outer edge position").

[0062] The abnormality determination unit 130 executes the third process described above at each monitoring cycle. At each monitoring cycle, the abnormality determination unit 130 determines whether or not there is an abnormality in the holding of the wafer W by the holding unit 52 during liquid processing, based on the calculation result of the outer edge position by the outer edge position calculation unit 126. The monitoring cycle may be set to a time shorter than the time it takes for the wafer W to rotate once during liquid processing by the liquid processing apparatus U1.

[0063] Here, referring to Figures 6(a) and 6(b), we will explain why processing anomalies can be detected from the calculation results of the outer edge position of wafer W. Figure 6(a) shows the time change of the calculation results of the position of the outer edge Ew of wafer W in the lateral direction (x direction), and Figure 6(b) shows the time change of the calculation results of the position of the outer edge Ew of wafer W in the vertical direction (y direction). The rotation angle of wafer W included in the image MI differs for each monitoring cycle. In Figures 6(a) and 6(b), the horizontal axis of the graph is labeled "frame number" and represents the number of frames in the video data, but it effectively represents time. Focusing on the detection target area DR, a different rotation angle of wafer W means that a part (range) of the outer edge Ew of wafer W included in the detection target area DR is different.

[0064] Assuming that the outer edge Ew of the wafer W is an ideal circle and that the center CP of the wafer W perfectly coincides with the axis Ax representing the rotation center by the rotating holding unit 50, the outer edge position in the detection target area DR does not change even if the rotation angle of the wafer W is different. On the other hand, the wafer W has some degree of warping, and the center CP of the wafer W when held by the holding unit 52 does not exactly coincide with the axis Ax. Therefore, the outer edge position in the detection target area DR changes with each monitoring cycle.

[0065] As the wafer W rotates, the position of the outer edge in the detection area DR changes periodically, as shown in Figures 6(a) and 6(b). Periodic changes in the outer edge position caused by the warping of the wafer W or the displacement (eccentricity) of the center CP relative to the axis Ax do not pose a major problem if the degree is small. However, if the degree of periodic change in the outer edge position is large from the initial stage of processing, or increases during processing, there is a possibility that some abnormality is occurring in the holding of the wafer W. If processing continues in the state of such an abnormality, the holding of the wafer W will be released, and trouble may occur. Specific examples of such trouble during processing include damage to the wafer W itself, and contamination of the processing liquid within the equipment due to such damage, or even without damage, due to the release of holding.

[0066] From the above, it can be concluded that abnormalities related to the holding of the wafer W by the holding unit 52 can be detected by monitoring the magnitude (amplitude) of the outer edge position of the wafer W, or the time change of the outer edge position of the wafer W. Hereinafter, abnormalities related to the holding of the wafer W by the holding unit 52 will be simply referred to as "abnormalities." Note that detecting abnormalities includes not only detecting the abnormal state itself, but also detecting signs of an abnormal state. The abnormality determination unit 130 determines whether or not there is an abnormality by determining whether the calculation result of the outer edge position in the second processing in that cycle, or the result of accumulating the calculation results of the outer edge position up to that cycle, satisfies certain conditions for each monitoring cycle.

[0067] The abnormality detection unit 130 determines whether an abnormality exists, for example, based on a comparison between the outer edge position calculated in the second process and a predetermined threshold. For example, the abnormality detection unit 130 determines that an abnormality has occurred if, for each monitoring cycle, the calculated value of the outer edge position in the second process during that cycle exceeds the first threshold, or falls below a second threshold that is smaller than the first threshold. The first and second thresholds may be determined by prior experiments or the like. By detecting an abnormality, the abnormality detection unit 130 helps to prevent problems such as damage to the wafer W.

[0068] In the second process, if the outer edge position is calculated in both the horizontal and vertical directions of the image, the abnormality determination unit 130 may determine whether or not there is an abnormality based on the calculation result of the corresponding outer edge position in both the horizontal and vertical directions. The abnormality determination unit 130 may determine that an abnormality has occurred if the conditions for determining an abnormality are met in at least one of the horizontal and vertical directions.

[0069] In Figure 6(a), the outer edge position (calculated value) in the lateral direction is indicated by "p(x)", the first threshold is indicated by "Th1(x)", and the second threshold is indicated by "Th2(x)". The time corresponding to the current monitoring cycle is indicated by "t1". The abnormality determination unit 130 may determine that an abnormality has occurred if the outer edge position p(x) at time t1 is greater than the first threshold Th1(x) or less than the second threshold Th2(x). The abnormality determination unit 130 may determine that no abnormality has occurred if the outer edge position p(x) at time t1 is less than or equal to the first threshold Th1(x) and greater than or equal to the second threshold Th2(x).

[0070] In Figure 6(b), the outer edge position (calculated value) in the vertical direction is indicated by "p(y)", the first threshold is indicated by "Th1(y)", and the second threshold is indicated by "Th2(y)". The abnormality determination unit 130 may determine that an abnormality has occurred if the outer edge position p(y) at time t1 is greater than the first threshold Th1(y) or less than the second threshold Th2(y). The abnormality determination unit 130 may determine that no abnormality has occurred if the outer edge position p(y) at time t1 is less than or equal to the first threshold Th1(y) and greater than or equal to the second threshold Th2(y).

[0071] The first threshold Th1(x) and the first threshold Th1(y) may be set to the same value or to different values. The second threshold Th2(x) and the second threshold Th2(y) may be set to the same value or to different values. When the abnormality determination unit 130 determines that an abnormality has occurred, it is equivalent to the abnormality determination unit 130 detecting an abnormality.

[0072] The output unit 132 outputs a signal indicating that an abnormality has been detected (hereinafter referred to as the "abnormality signal") when the abnormality detection unit 130 determines that an abnormality has occurred. The output unit 132 outputs the abnormality signal while the liquid processing is continuing when the abnormality detection unit 130 determines that an abnormality has occurred. The output unit 132 may also output the abnormality signal to the processing control unit 114.

[0073] If the processing control unit 114 receives an abnormal signal, it may control the rotating holding unit 50 to reduce the speed at which it rotates the wafer W held in the holding unit 52 while the liquid processing under monitoring is being performed. Alternatively, if the processing control unit 114 receives an abnormal signal, it may control the rotating holding unit 50 to stop the rotation of the wafer W held in the holding unit 52. In addition to the processing control unit 114, the output unit 132 may notify operators of the detection of an abnormality by outputting an abnormal signal to an output device connected to the control device 100.

[0074] Figure 7 is a block diagram illustrating the hardware configuration of the control device 100. As shown in Figure 7, the control device 100 has a circuit 151. The circuit 151 includes a processor 152, a memory 153, a storage 154, a timer 155, and an input / output port 156.

[0075] The storage 154 consists of one or more non-volatile memory devices, such as flash memory or a hard disk. The storage 154 stores a program that causes the wafer processing system 1 (apparatus) to execute the substrate processing method described later. The memory 153 consists of one or more volatile memory devices, such as random access memory. The memory 153 temporarily stores the program loaded from the storage 154.

[0076] The processor 152 is composed of one or more computing devices such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The processor 152 executes the program loaded into the memory 153. The calculation results from the processor 152 are temporarily stored in the memory 153. The timer 155 measures the elapsed time by counting clock pulses. The input / output port 156 performs input and output of electrical signals to and from the rotation holding unit 50, the liquid supply unit 60, and the imaging device 90, etc., in response to requests from the processor 152.

[0077] <Substrate Processing Method> Next, a substrate processing method performed in the wafer processing system 1 will be described. This substrate processing method includes a processing step and a monitoring step (a method for monitoring substrate processing). The processing step is a step of applying liquid processing to the wafer W, which is held in the holding unit 52, including rotating the wafer W. The monitoring step is a step of repeatedly performing the monitoring process described above while the processing step is being executed.

[0078] Figure 8 shows an example of a processing flow executed by the control device 100. While the processing flow is being executed, imaging by the imaging device 90 continues. The control device 100 first executes step S11 with the liquid processing by the liquid processing device U1 having started. In step S11, for example, the monitoring processing execution unit 120 waits until a preset monitoring start timing is reached. The monitoring start timing may be set to coincide with the start timing of the process in the liquid processing in which the supply of the processing liquid L1 is stopped and rotation is performed to dry the coating F.

[0079] Next, the control device 100 executes step S12. In step S12, for example, the monitoring processing execution unit 120 waits until the monitoring period, which represents the period during which it performs the monitoring process, is reached. The monitoring period may be set so that the monitoring process is executed each time a still image of one frame is obtained, or it may be set so that the monitoring process is executed each time a still image of multiple frames is obtained.

[0080] Next, the control device 100 executes steps S13 and S14. In step S13, for example, the edge detection unit 124 extracts the detection target area DR from the image MI. The range of the detection target area DR may be set in advance by an operator or the like. In step S14, for example, the edge detection unit 124 detects the edge corresponding to the outer edge Ew in the detection target area DR. In one example, the edge detection unit 124 detects the edge using the Canny method.

[0081] Next, the control device 100 executes step S15. In step S15, for example, the outer edge position calculation unit 126 calculates the position of the outer edge Ew in the detection target area DR (outer edge position) from the coordinates of the multiple points detected as edges in step S14. Each pixel detected as an edge has horizontal and vertical coordinates. In one example, the outer edge position calculation unit 126 calculates the outer edge position in the horizontal direction by finding the average value of the horizontal coordinates of the multiple points detected as edges. The outer edge position calculation unit 126 also calculates the outer edge position in the vertical direction by finding the average value of the vertical coordinates of the multiple points detected as edges.

[0082] Next, the control device 100 executes step S16. In step S16, for example, the abnormality determination unit 130 determines whether the outer edge position calculated in step S15 is within the normal range. Whether it is within the normal range is determined, for example, by comparing the outer edge position with the first threshold and second threshold described above. In one example, the abnormality determination unit 130 determines that an abnormality has occurred if the outer edge position calculated in step S15 falls outside the normal range in at least one of the horizontal and vertical directions on the image. The abnormality determination unit 130 determines that no abnormality has occurred if the outer edge position calculated in step S15 is within the normal range in both the horizontal and vertical directions on the image.

[0083] In step S16, if it is determined that the outer edge position calculated in step S15 is outside the normal range (step S16: NO), the control device 100 proceeds to step S21. In step S21, for example, the output unit 132 outputs the abnormal signal to the processing control unit 114, and the processing control unit 114 controls the rotation holding unit 50 to stop the rotation of the wafer W. As a result, the liquid processing being monitored is interrupted.

[0084] After step S21 is performed, the control device 100 performs step S22. In step S22, for example, the output unit 132 outputs an abnormality signal to the output device connected to the control device 100 to notify that an abnormality has occurred.

[0085] On the other hand, if in step S16 it is determined that the outer edge position calculated in step S15 falls within the normal range (step S16: YES), the control device 100 proceeds to step S17. In step S17, for example, the monitoring processing execution unit 120 determines whether or not it is a preset monitoring end timing. The monitoring end timing may be set to coincide with the end timing of the process in which the supply of the processing liquid L1 is stopped and the film F is rotated to dry it.

[0086] If it is determined in step S17 that it is not time to end monitoring (step S17: NO), the control device 100 returns to step S12, and the control device 100 executes the series of processes including steps S12 to S16 again. On the other hand, if it is determined in step S17 that it is time to end monitoring (step S17: YES), the processing flow ends.

[0087] In the above processing flow, a series of processes including steps S12 to S15 are repeatedly executed until the monitoring ends. If the calculated value of the outer edge position falls outside the normal range while this series of processes is being repeatedly executed, the process is interrupted. This prevents the liquid treatment (for example, rotation to dry the coating F) from continuing while there is a possibility of an abnormality in the holding by the holding unit 52. The control device 100 may also execute the above processing flow for subsequent wafers W. That is, the control device 100 may execute the above processing flow each time liquid treatment is performed by the liquid treatment apparatus U1 for each of the multiple wafers W.

[0088] <Variation> The processing flow illustrated in Figure 8 is an example and can be modified as appropriate. In the above processing flow, the control device 100 may execute one step and the next step in parallel, or execute each step in a different order than the example described above. The control device 100 may substitute any of the steps, or in addition to the above processing flow, execute processing with content different from the example described above. Separately from the above processing flow, the control device 100 may monitor or record the processing status in liquid processing using the image MI itself, without focusing solely on the detection target area DR.

[0089] In determining whether an abnormality has occurred in step S16, not only the outer edge position calculated in the current monitoring cycle, but also the outer edge position calculated in previous monitoring cycles may be considered. For example, the abnormality determination unit 130 may determine whether the average value of the calculated outer edge position over multiple monitoring cycles, including the current monitoring cycle, is within the normal range.

[0090] The abnormality determination unit 130 may determine that an abnormality has occurred if, in multiple monitoring cycles including the current monitoring cycle (for example, two or more consecutive monitoring cycles), the calculated value of the outer edge position in each cycle is not within the normal range.

[0091] The method for determining whether or not an abnormality has occurred is not limited to comparing the calculated value of the outer edge position with a threshold value. The abnormality determination unit 130 may also determine the presence or absence of an abnormality based on the waveform information (time change of the outer edge position) stored in the calculation result storage unit 128. As described above, the outer edge position on the image changes periodically with the rotation of the wafer W. Therefore, unless an abnormality occurs, the periodic change in the outer edge position on the image is considered to depend on the rotation speed of the wafer W.

[0092] In one example, the anomaly detection unit 130 calculates the frequency in the waveform information representing the time change of the outer edge position obtained up to the time of execution of the third process. As shown in Figure 6(a), the anomaly detection unit 130 may calculate the interval T between adjacent peaks in the waveform information and determine the frequency from that interval T. Alternatively, the anomaly detection unit 130 may convert the waveform information into a frequency spectrum using a Fourier transform or the like, and then calculate the frequency with the largest component from that frequency spectrum.

[0093] After calculating the frequency, the abnormality determination unit 130 may determine whether or not there is an abnormality based on the comparison result between the frequency calculated from the waveform information and a reference frequency corresponding to the set value of the rotation speed of the wafer W when performing liquid processing. When the rotation speed of the wafer W is set to "N (rpm)", the reference frequency is obtained by dividing N by 60. The abnormality determination unit 130 may determine that an abnormality has occurred if the frequency calculated from the waveform information falls outside the range obtained by adding a predetermined tolerance to the reference frequency.

[0094] Determining an anomaly based on a comparison between the frequency calculated from waveform information and a reference frequency also includes determining an anomaly based on a comparison between the period calculated from the waveform information and a reference period corresponding to the set value of the rotation speed. Even when determining the presence or absence of an anomaly using the frequency calculated from the waveform information in this way, the waveform information includes the outer edge position calculated in the second process, so the presence or absence of an anomaly is determined based on the calculation results in the second process.

[0095] The abnormality determination unit 130 may determine the presence or absence of an abnormality based on the waveform information stored in the calculation result storage unit 128 and a determination model pre-constructed by machine learning. The above determination model is a model constructed by machine learning to output a determination result of the presence or absence of an abnormality in response to input information representing the time change in the position of the outer edge Ew. If the processing conditions are the same, even if the individual wafers W are different, the periodic change in the position of the outer edge on the image is expected to show a similar trend as long as no abnormality occurs. For example, the above determination model is constructed to capture cases where the waveform information to be evaluated shows a different trend from the periodic change in the position of the outer edge when it is normal (classifying it as abnormal).

[0096] The monitoring processing execution unit 120 may include a model construction unit as a functional block for constructing a judgment model. In one example, the model construction unit constructs a judgment model by performing machine learning using an autoencoder based on normal data obtained by accumulating waveform information obtained when no abnormalities occur. An autoencoder is a type of neural network, and the intermediate layers of the judgment model are constructed to output output information that has the same value as the input information for the input information.

[0097] If the waveform information of the object to be evaluated, whose abnormality status is unknown, tends to be similar to the normal data provided during training, the output from the judgment model will be similar to the waveform information of the object to be evaluated. When the waveform information of the object to be evaluated is input to a judgment model based on an autoencoder, if no abnormality occurs, output information with a small error from the input information is obtained. On the other hand, if an abnormality occurs, output information with a large error from the input information is obtained. The abnormality determination unit 130 may use a judgment model constructed by machine learning using an autoencoder to determine the presence or absence of an abnormality according to the magnitude of the difference between the input information and the output information.

[0098] The time range of waveform information obtained up to the monitoring period (the timing at which monitoring is performed) differs depending on the monitoring period. Therefore, the model construction unit may construct multiple judgment models according to the timing at which monitoring is performed. The model construction unit does not necessarily need to construct a different judgment model for each monitoring period; it may construct judgment models for a certain range of time axes. Even when determining the presence or absence of an anomaly using such a judgment model, the waveform information to be evaluated input to the judgment model includes the outer edge position calculated in the second process, so the presence or absence of an anomaly is determined based on the calculation result in the second process.

[0099] In the above monitoring process, in addition to the position of the outer edge Ew of the wafer W (outer edge position), the position of the inner edge Ec of the cup 70 may be used to determine whether or not there is an abnormality. As shown in Figure 9(a), the edge detection unit 124 may detect the edge corresponding to the inner edge Ec in addition to the edge corresponding to the outer edge Ew in the first process. The outer edge position calculation unit 126 may calculate the position of the inner edge Ec of the cup 70 in addition to the outer edge position in the second process. The outer edge position calculation unit 126 may calculate the position of the inner edge Ec of the cup 70 in the second process using the same calculation method as for calculating the outer edge position.

[0100] The anomaly detection unit 130 may determine whether an anomaly exists based on the distance d between the outer edge position and the inner edge position Ec calculated in the second process. Figure 9(b) schematically shows a graph representing the time change of distance d. The anomaly detection unit 130 may determine that an anomaly has occurred if the distance d is greater than the first threshold Th1(d) or less than the second threshold Th2(d). Instead of comparing the distance d with the threshold, the anomaly detection unit 130 may determine whether an anomaly exists based on a comparison between the frequency obtained from waveform information representing the time change of distance d and the above-mentioned reference frequency. The anomaly detection unit 130 may also determine whether an anomaly exists based on waveform information representing the time change of distance d (waveform information at the time of evaluation) and a determination model pre-constructed by machine learning. Even when determining the presence or absence of an anomaly using distance d in this way, the outer edge position calculated in the second process is used to determine the distance d, so the presence or absence of an anomaly is determined based on the calculation result in the second process.

[0101] If an abnormal signal is output from the output unit 132, the processing control unit 114 may control the rotation holding unit 50 to reduce the rotation speed of the wafer W instead of stopping the rotation of the wafer W. If the rotation speed of the wafer W is reduced, the processing control unit 114 may continue processing by the liquid processing apparatus U1 with the rotation speed reduced.

[0102] The processing to be monitored by the control device 100 (monitoring processing execution unit 120) is not limited to liquid processing by the liquid processing device U1. The processing to be monitored can be any processing that involves the rotation of the wafer W. The processing to be monitored may be, for example, processing by a developing device. The monitoring processing execution unit 120 does not have to be included in the control device 100. In this case, a monitoring device consisting of a separate computer from the control device 100 may include the monitoring processing execution unit 120. This monitoring device may be connected to the control device 100 in a communicative manner.

[0103] When comparing the relative magnitudes of two numbers within a computer, either the "greater than or equal to" and "greater than" criteria can be used, as can either the "less than or equal to" and "less than" criteria. The choice of such criteria does not change the technical significance of the process of comparing the relative magnitudes of two numbers.

[0104] Here, with reference to Figures 10, 11, 12(a), and 12(b), we will illustrate the monitoring process performed by the control device 100 during processing of a laminated substrate WL obtained by bonding two or more unit substrates together. As illustrated in Figure 10, the laminated substrate WL (substrate) is formed, for example, by bonding a unit substrate W1 and a unit substrate W2 together. Figure 10 schematically illustrates the image MI obtained by the imaging device 90 during the execution of processing (a predetermined process) on the laminated substrate WL.

[0105] The outer diameters of unit substrate W1 and unit substrate W2 may coincide. Unit substrate W1 and unit substrate W2 may be bonded together such that their centers coincide and one main surface faces the other. The coincidence of outer diameters and centers includes not only cases where they coincide perfectly, but also cases where they substantially coincide, allowing for errors such as manufacturing tolerances. Unit substrate W1 and unit substrate W2 may be bonded together without adhesive by fusion bonding or anode bonding, or they may be bonded together with adhesive.

[0106] Liquid treatment of the laminated substrate WL may be performed using a liquid treatment apparatus U1 having a configuration similar to that illustrated in Figure 3. Liquid treatment of the laminated substrate WL may include filling the gap between the unit substrate W1 and the unit substrate W2 at the periphery of the laminated substrate WL with treatment liquid. The rotating holding part 50 of the liquid treatment apparatus U1 may hold the laminated substrate WL so that the unit substrate W1 is positioned above the unit substrate W2, and rotate the laminated substrate WL. In Figure 10, "Wa" represents the surface of the unit substrate W1, and the surface of the unit substrate W1 can also be said to be the surface of the laminated substrate WL. "Ew" represents the outer edge of the surface Wa of the laminated substrate (the surface Wa of the unit substrate W1).

[0107] The imaging device 90 may be positioned so as to be able to image the surface Wa of the laminated substrate WL held by the holding unit 52 from an oblique angle above. In a plan view, the imaging device 90 does not have to overlap the laminated substrate WL held by the holding unit 52. In a plan view, the direction in which the line segment connecting the imaging device 90 and the rotation center of the holding unit 52 extends is defined as the "depth direction". In the depth direction, the direction (orientation) approaching the imaging device 90 is defined as "forward" or "front side", and the direction (orientation) moving away from the imaging device 90 is defined as "back" or "back side". As illustrated in Figure 10, the field of view (imaging range) of the imaging device 90 may be set to include at least a part of the outer edge Ew located in front of the center CP of the laminated substrate WL held by the holding unit 52, and at least a part of the outer edge Ew located behind it.

[0108] In Figure 10, "rL" represents a line extending laterally (horizontal direction on the image: x-axis direction) within the image MI that includes the center CP of the laminated substrate WL, and this is referred to as the "reference line rL". A detection target area DR, which represents a portion of the area to be detected, may be set above the reference line rL within the image MI. In the image MI, the area above the reference line rL corresponds to the area behind the center CP of the laminated substrate WL held by the holding part 52 in the depth direction. In the image MI, above the reference line rL, only the outer edge of the upper unit substrate W1 may be observed, while below the reference line rL, the outer edges (outer surfaces) of unit substrates W1 and W2 may be observed.

[0109] Two or more detection target areas DR are set, and the edge detection unit 124 may detect edges in each of the two or more detection target areas DR in the first processing. For example, as two or more detection target areas DR, detection target area DR1 and detection target area DR2 are set above the reference line rL in the image MI. In the lateral direction on the image, one part of detection target area DR1 overlaps with the position of the center CP, while the entirety of detection target area DR2 does not overlap with the position of the center CP.

[0110] In the second process, the outer edge position calculation unit 126 may calculate the position of the outer edge Ew in the vertical direction (y-axis direction) on the image from the edge detected in the detection target area DR1. In the second process, the outer edge position calculation unit 126 may also calculate the position of the outer edge Ew in the horizontal direction (x-axis direction) on the image from the edge detected in the detection target area DR2. In the detection target area DR1, fluctuations in the position of the outer edge Ew in the vertical direction are more easily observed compared to the detection target area DR2. In the detection target area DR2, fluctuations in the position of the outer edge Ew in the horizontal direction are more easily observed compared to the detection target area DR1.

[0111] Unlike the example shown in Figure 10, as shown in Figure 11, the two detection target regions DR may be set above and below the reference line rL in the image MI, respectively. Detection target region DR1 is set above the reference line rL in the image MI, and detection target region DR3 is set below the reference line rL in the image MI. Detection target region DR3 may be set to include the outer edge of the lowest unit substrate in the laminated substrate WL (unit substrate W2 in the example of Figure 11), but not to include the outer edges of other unit substrates. This allows edge detection to be performed without changing the position of detection target region DR3, even if the number of unit substrates included in the laminated substrate WL changes. Focusing on the monitoring process using detection target region DR3, in the first process, the outer edge on the back surface (bottom surface) of unit substrate W2 may be detected as an edge, rather than the surface Wa of the laminated substrate WL (surface Wa of unit substrate W1).

[0112] The monitoring process, including the first, second, and third processes, may be performed during periods when the laminated substrate WL is not rotating. For example, the control device 100 may perform the monitoring process during the period when the laminated substrate WL is being moved upward by the multiple lifting pins 58, and at least one of the periods after the laminated substrate WL has been moved upward. The control device 100 may repeat the monitoring process after the laminated substrate WL has been moved upward, or it may perform the monitoring process only once.

[0113] Figures 12(a) and 12(b) schematically illustrate image MIs used when monitoring is performed after the laminated substrate WL has been moved upward by the multiple lifting pins 58. The image MI exemplified in Figure 12(a) is an image obtained by capturing the state of the laminated substrate WL before movement (while it is held by the holding part 52). The image MI exemplified in Figure 12(b) is an image obtained by capturing the state of the laminated substrate WL after it has been raised by the multiple lifting pins 58 and is supported by the multiple lifting pins 58.

[0114] The edge detection unit 124 may detect an edge in the detection target area DR4, which is an example of the detection target area DR. The detection target area DR4 may be set to include a part of the outer edge of the laminated substrate WL when it has been raised by a plurality of lifting pins 58. The detection target area DR4 may or may not include a part of the outer edge of the laminated substrate WL before it has been raised. In the second process, the outer edge position calculation unit 126 may calculate the position of the outer edge Ew in the vertical direction (y-axis direction) on the image from the edge detected in the detection target area DR4.

[0115] In the third process, the abnormality determination unit 130 may determine whether there is an abnormality regarding the rise of the laminated substrate WL based on the result of comparing the calculated value of the position of the outer edge Ew in the vertical direction on the image with a normal range obtained by adding a tolerance to a predetermined normal position. The predetermined normal position and tolerance (i.e., the above normal range) may be determined by prior experiments. The abnormality determination unit 130 may determine that there is an abnormality if the calculated value of the position of the outer edge Ew falls outside the normal range, and determine that there is a normal (not abnormal) condition if the calculated value of the position of the outer edge Ew falls within the normal range.

[0116] In one of the various examples described above, at least some of the matters described in the other examples may be combined. For example, multiple types of anomaly detection methods (comparison of outer edge position and threshold, comparison of frequencies, use of a detection model, and use of distance to the cup) may be combined.

[0117] <Summary of this disclosure> This disclosure includes the configurations described in [1] to

[22] below, and the configurations described in Appendix 1 to Appendix 3. Each of the configurations described in Appendix 1 to Appendix 3 may be combined with any of the configurations described in [1] to

[22] .

[0118] [1] A substrate processing method comprising: performing a predetermined process on a substrate (W,WL) that is held by a holding unit (52), including rotating the substrate (W,WL); and repeatedly performing a monitoring process while the predetermined process is being executed, wherein the monitoring process includes: a first process of detecting the outer edge (Ew) in an image (MI) obtained by imaging an area including the outer edge (Ew) on the surface (Wa) of the substrate (W,WL); a second process of calculating the position of the outer edge (Ew) in the image (MI) based on the detection result in the first process; and a third process of determining whether or not there is an abnormality in the holding of the substrate (W,WL) by the holding unit (52) based on the calculation result in the second process. As described above, if the position of the outer edge (Ew) in the image (MI) fluctuates significantly over time, it can be determined that some kind of abnormality has occurred in the holding of the substrate (W,WL) by the holding unit (52). In the above substrate processing method, the determination of whether or not there is an abnormality based on the position of the outer edge (Ew) is performed repeatedly during the execution of the process, so that an abnormality in the holding of the substrate (W,WL) can be detected during the process. This makes it possible to avoid continuing the process in the state of an abnormality that could potentially cause damage to the substrate (W,WL). Therefore, it is possible to prevent the occurrence of troubles during substrate processing (for example, damage to the substrate (W,WL)).

[0119] [2] The substrate processing method according to [1] above, wherein the substrate (WL) to be processed in the above predetermined processing is a laminated substrate (WL) in which two or more unit substrates (W1, W2) are bonded to each other. The weight of a multilayer substrate (WL) is greater than that of a substrate composed of a single unit substrate. Therefore, even if the degree of misalignment between the rotation center during processing and the center (CP) of the multilayer substrate (WL) is small, abnormalities related to holding may occur. For this reason, it is even more beneficial to perform the above monitoring process while a predetermined process is being performed on the multilayer substrate (WL).

[0120] [3] The substrate processing method described in [2] above, wherein the image (MI) is obtained by imaging with an imaging device (90) positioned diagonally above the laminated substrate (WL), and in the first processing, a portion of the image (MI) (DR, DR1, DR2) is extracted, the outer edge (Ew) is detected in the portion of the image (MI) (DR, DR1, DR2), and the portion of the image (MI) (DR, DR1, DR2) is set to be above a lateral reference line (rL) that includes the center (CP) of the laminated substrate (WL). The outer edge (Ew) observed above the reference line (rL) in the image (MI) is the boundary between the surface (Wa) of the laminated substrate (WL) and the area outside the laminated substrate (WL). On the other hand, the outer edge (Ew) observed below the reference line (rL) in the image (MI) is the boundary between the surface (Wa) and the edge (circumferential surface) of the laminated substrate (WL). Therefore, the contrast of the outer edge (edge) portion in the image is greater above the reference line (rL) than below it. This allows for highly accurate calculation of the position of the outer edge (Ew) on the laminated substrate (WL).

[0121] [4] The substrate processing method according to any one of [1] to [3] above, further comprising, when the above abnormality is detected in the monitoring process, reducing the speed at which the substrate (W, WL) held in the holding part (52) is rotated, or stopping the rotation of the substrate (W, WL) held in the holding part (52) during the execution of the predetermined process. In this case, it is possible to more reliably avoid the process continuing even when an abnormality has occurred.

[0122] [5] The substrate processing method according to [1] or [2] above, wherein in the first processing, a portion of the image (MI) is extracted (DR), and the outer edge (Ew) is detected in the portion of the image (DR). While there may be cases where images (MI) are acquired for purposes other than monitoring, the range of images required for other purposes may not match the range of images required for monitoring. The method described above utilizes a portion of the area (DR) to perform monitoring, thus enabling compatibility between monitoring and image acquisition for other purposes.

[0123] [6] In the third process, the presence or absence of the above abnormality is determined based on the result of comparing the position of the outer edge (Ew) calculated in the second process with predetermined thresholds (Th1, Th2), the substrate processing method according to any one of [1] to [5] above. If the position of the outer edge (Ew) fluctuates significantly, it is assumed that there is an abnormality in the holding of the substrate (W,WL). The above method allows for the detection of abnormalities in the holding of the substrate (W,WL) through a simple process of comparing the outer edge position with a threshold value.

[0124] [7] A substrate processing method according to any one of [1] to [6] above, the third process comprising: calculating the frequency in waveform information representing the time change of the position of the outer edge (Ew) obtained up to the time of execution of the third process; and determining whether or not there is an abnormality based on the result of comparing the frequency calculated from the waveform information with a reference frequency corresponding to the set value of the rotation speed of the substrate (W, WL) when executing the predetermined process. In this case, it is possible to detect anomalies that cannot be determined solely by the magnitude of the fluctuation in the outer edge position.

[0125] [8] A substrate processing method according to any one of [1] to [7] above, wherein in the third process, the presence or absence of the above abnormality is determined based on a determination model that has been built in advance by machine learning to output a determination result of the presence or absence of the above abnormality in response to input of information representing the time change in the position of the outer edge (Ew), and waveform information representing the time change in the position of the outer edge (Ew) obtained up to the time of execution of the third process. In this case, it is possible to detect anomalies that cannot be determined solely by the magnitude of the fluctuation in the outer edge position.

[0126] [9] The substrate processing method according to any one of [1] to [8] above, wherein the predetermined processing is a liquid processing method that includes supplying a processing liquid (L1) to a substrate (W,WL) held in a holding part (52), the holding part (52) is surrounded by a cup (70) that receives the processing liquid (L1) after it has been supplied to the substrate (W,WL), in the second processing the position of the outer edge (Ew) and the position of the inner edge (Ec) of the cup (70) are calculated, and in the third processing the presence or absence of the above abnormality is determined based on the distance (d) between the position of the outer edge (Ew) and the position of the inner edge (Ec) calculated in the second processing. In this case, it is possible to detect anomalies that cannot be determined solely by the magnitude of the fluctuation in the outer edge position.

[0127]

[10] A substrate processing method according to any one of [1] to [9] above, wherein in the second process, the position of the outer edge (Ew) is calculated by taking the average value of the coordinates of multiple points detected as the outer edge (Ew) in the first process. In images (MI), the boundary between the substrate (W,WL) and other regions is not always clear, and noise may be present in the detection result of the outer edge (Ew) in the first processing. Even if noise is present, the influence on the calculated value of the outer edge position can be reduced by calculating the average value. This allows for accurate detection of anomalies based on the outer edge position.

[0128]

[11] A substrate processing method according to any one of [1] to

[10] above, wherein in the second process, the position of the outer edge (Ew) is calculated in the horizontal and vertical directions of the image (MI), and in the third process, the presence or absence of the above abnormality is determined based on the calculation result of the position of the outer edge (Ew) in the horizontal and vertical directions, and if the conditions for determining the above abnormality are met in at least one of the horizontal and vertical directions, it is determined that the above abnormality has occurred. If the calculation result for the outer edge position in either the horizontal or vertical direction indicates an abnormality, it is determined to be an abnormality, thus allowing for more reliable detection of the occurrence of an abnormality.

[0129]

[12] A method for monitoring substrate processing, which includes repeatedly performing a monitoring process while a predetermined process is being performed on a substrate (W,WL) that is held by a holding unit (52), the monitoring process comprising: a first process of detecting the outer edge (Ew) in an image (MI) obtained by imaging an area including the outer edge (Ew) on the surface (Wa) of the substrate (W,WL); a second process of calculating the position of the outer edge (Ew) in the image (MI) based on the detection result in the first process; and a third process of determining whether or not there is an abnormality in the holding of the substrate (W,WL) by the holding unit (52) based on the calculation result in the second process. This substrate processing monitoring method, like the substrate processing method described above, can prevent problems from occurring during substrate processing.

[0130]

[13] The monitoring method according to

[12] , further comprising, when an abnormality is detected in the monitoring process, reducing the speed at which the substrate (W,WL) held by the holding unit (52) rotates, or stopping the rotation of the substrate (W,WL) held by the holding unit (52) during the execution of the predetermined process. In this case, it is possible to more reliably avoid the process continuing even when an abnormality has occurred.

[0131]

[14] The monitoring method described in

[12] or

[13] above, wherein in the first processing, a portion of the image (MI) is extracted (DR), and the outer edge (Ew) is detected in the portion of the image (DR). While there may be cases where images (MI) are acquired for purposes other than monitoring, the range of images required for other purposes may not match the range of images required for monitoring. The method described above utilizes a portion of the area (DR) to perform monitoring, thus enabling compatibility between monitoring and image acquisition for other purposes.

[0132]

[15] In the third process, the presence or absence of the above abnormality is determined based on the result of comparing the position of the outer edge (Ew) calculated in the second process with predetermined thresholds (Th1, Th2), as described in any one of

[12] to

[14] above. If the position of the outer edge (Ew) fluctuates significantly, it is assumed that there is an abnormality in the holding of the substrate (W,WL). The above method allows for the detection of abnormalities in the holding of the substrate (W,WL) through a simple process of comparing the outer edge position with a threshold value.

[0133]

[16] The monitoring method according to any one of

[12] to

[15] above, wherein the third process includes calculating the frequency in waveform information representing the time change of the position of the outer edge (Ew) obtained up to the time of execution of the third process, and determining whether or not there is an abnormality based on the result of comparing the frequency calculated from the waveform information with a reference frequency corresponding to the set value of the rotation speed of the substrate (W,WL) when the predetermined process is executed. In this case, it is possible to detect anomalies that cannot be determined solely by the magnitude of the fluctuation in the outer edge position.

[0134]

[17] In the third process, the presence or absence of the above-mentioned abnormality is determined based on a determination model pre-built by machine learning to output a determination result of the presence or absence of the above-mentioned abnormality in response to input of information representing the time change in the position of the outer edge (Ew), and waveform information representing the time change in the position of the outer edge (Ew) obtained up to the time of execution of the third process, as described in any one of

[12] to

[16] above. In this case, it is possible to detect anomalies that cannot be determined solely by the magnitude of the fluctuation in the outer edge position.

[0135]

[18] The monitoring method according to any one of

[12] to

[17] above, wherein the predetermined process is a liquid process that includes supplying a processing liquid (L1) to a substrate (W,WL) held in a holding part (52), the holding part (52) is surrounded by a cup (70) that receives the processing liquid (L1) after it has been supplied to the substrate (W,WL), in the second process the position of the inner edge (Ec) of the cup (70) is calculated in addition to the position of the outer edge (Ew), and in the third process the presence or absence of the above abnormality is determined based on the distance (d) between the position of the outer edge (Ew) and the position of the inner edge (Ec) calculated in the second process. In this case, it is possible to detect anomalies that cannot be determined solely by the magnitude of the fluctuation in the outer edge position.

[0136]

[19] In the second process, the position of the outer edge (Ew) is calculated by taking the average value of the coordinates of multiple points detected as the outer edge (Ew) in the first process, the monitoring method described in any one of

[12] to

[18] above. In images (MI), the boundary between the substrate (W,WL) and other regions is not always clear, and noise may be present in the detection result of the outer edge (Ew) in the first processing. Even if noise is present, the influence on the calculated value of the outer edge position can be reduced by calculating the average value. This allows for accurate detection of anomalies based on the outer edge position.

[0137]

[20] The monitoring method according to any one of

[12] to

[19] above, wherein in the second process, the position of the outer edge (Ew) is calculated in the horizontal and vertical directions of the image (MI), and in the third process, the presence or absence of the above abnormality is determined based on the calculation result of the position of the outer edge (Ew) in the horizontal and vertical directions, and if the conditions for determining the above abnormality are met in at least one of the horizontal and vertical directions, it is determined that the above abnormality has occurred. If the calculation result for the outer edge position in either the horizontal or vertical direction indicates an abnormality, it is determined to be an abnormality, thus allowing for more reliable detection of the occurrence of an abnormality.

[0138]

[21] A computer-readable storage medium storing a program for causing the device to execute the substrate processing method described in any one of [1] to

[11] above, or the monitoring method described in any one of

[12] to

[20] above. This storage medium, like the circuit board processing method described above, can prevent problems from occurring during circuit board processing.

[0139]

[22] A substrate processing apparatus (1) comprising: a processing unit (U1) that performs a predetermined process on a substrate (W,WL) including rotating the substrate (W,WL) held by a holding unit (52); and a monitoring processing execution unit (120) that repeatedly performs a monitoring process while the predetermined process is being executed, wherein the monitoring process includes: a first process of detecting the outer edge (Ew) in an image (MI) obtained by imaging a range including the outer edge (Ew) on the surface (Wa) of the substrate (W,WL); a second process of calculating the position of the outer edge (Ew) in the image (MI) based on the detection result in the first process; and a third process of determining whether or not there is an abnormality in the holding of the substrate (W,WL) by the holding unit (52) based on the calculation result in the second process. This substrate processing apparatus (1), like the substrate processing method described above, can prevent the occurrence of problems during substrate processing.

[0140] A substrate processing method and a substrate processing apparatus for performing said substrate processing, comprising: applying a predetermined process to a laminated substrate (WL) in which unit substrates (W1, W2) of the same magnitude as described in Appendix 1.2 are bonded together; and repeatedly performing a monitoring process during the execution of the predetermined process, wherein the monitoring process includes: a first process of detecting the outer edge in an image (MI) obtained by imaging a range including the outer edge of the laminated substrate (WL); a second process of calculating the position of the outer edge in the image (MI) based on the detection result in the first process; and a third process of determining whether or not there is an abnormality in the predetermined process based on the calculation result in the second process.

[0141] Appendix 2.2 The laminated substrate (WL) formed by bonding unit substrates (W1, W2) of the same magnitude to each other is subjected to a predetermined process, and during the execution of the predetermined process, a first process is performed to detect the outer edge in an image (MI) obtained by imaging a range including the outer edge of the laminated substrate (WL), a second process is performed to calculate the position of the outer edge in the image (MI) based on the detection result in the first process, and a third process is performed to determine whether or not there is an abnormality in the predetermined process based on the calculation result in the second process. The predetermined process includes moving the laminated substrate (WL) upward and supporting the laminated substrate (WL) in the upward-moved state.

[0142] Appendix 3. The substrate processing method and substrate processing apparatus according to Appendix 1 or 2, wherein in the first processing step, the outer edge (Ew) of the surface (Wa) of the laminated substrate (WL) is detected. [Explanation of symbols]

[0143] 1...Wafer processing system, W...Wafer, WL...Laminated substrate, W1, W2...Unit substrate, Wa...Surface, Ew...Outer edge, U1...Liquid processing device, L1...Processing liquid, 52...Holding unit, 70...Cup, Ec...Inner edge, 90...Imaging device, 100...Control device, 120...Monitoring processing execution unit, MI...Image, DR, DR1, DR2, DR3, DR4...Detection target area.

Claims

1. A predetermined process is performed on the substrate, which includes rotating the substrate held in the holding part. This includes repeatedly executing a monitoring process during the execution of the predetermined process, The aforementioned monitoring process is: A first process of detecting the outer edge in an image obtained by imaging a range including the outer edge of the surface of the substrate, A second process is performed to calculate the position of the outer edge within the image based on the detection results in the first process, A third process, which determines whether or not there is an abnormality in the holding of the substrate by the holding unit, based on the calculation results in the second process, is included. Substrate processing method.

2. The substrate to be processed in the predetermined process is a laminated substrate in which two or more unit substrates are bonded together. The substrate processing method according to claim 1.

3. The above image was obtained by imaging with an imaging device positioned diagonally above the laminated substrate. In the first process, a portion of the image is extracted, and the outer edge is detected in that portion of the image. The aforementioned portion of the region is set above a lateral reference line that includes the center of the laminated substrate within the image. The substrate processing method according to claim 2.

4. If the monitoring process detects the abnormality, the process further includes reducing the rotation speed of the substrate held in the holding unit, or stopping the rotation of the substrate held in the holding unit, during the execution of the predetermined process. The substrate processing method according to claim 1.

5. In the first process, a portion of the image is extracted, and the outer edge is detected within that portion. The substrate processing method according to claim 1.

6. In the third process, the presence or absence of the abnormality is determined based on the comparison result between the position of the outer edge calculated in the second process and a predetermined threshold. The substrate processing method according to claim 1.

7. The third process described above is: Calculate the frequency in the waveform information representing the time change of the position of the outer edge obtained up to the time of execution of the third process, This includes determining whether or not there is an abnormality based on the result of comparing the frequency calculated from the waveform information with a reference frequency corresponding to the set value of the rotation speed of the substrate when executing the predetermined process, The substrate processing method according to claim 1.

8. In the third process, the presence or absence of the abnormality is determined based on a determination model pre-built by machine learning to output a determination result of whether or not the abnormality is present in response to input of information representing the time change in the position of the outer edge, and waveform information representing the time change in the position of the outer edge obtained up to the time of execution of the third process. The substrate processing method according to claim 1.

9. The predetermined process is a liquid treatment that includes supplying a treatment liquid to the substrate held in the holding part, The holding portion is surrounded by a cup that receives the processing liquid after it has been supplied to the substrate. In the second process described above, in addition to the position of the outer edge, the position of the inner edge of the cup is calculated. In the third process, the presence or absence of the abnormality is determined based on the distance between the position of the outer edge and the position of the inner edge calculated in the second process. The substrate processing method according to claim 1.

10. In the second process, the position of the outer edge is calculated by determining the average value of the coordinates of the multiple points detected as the outer edge in the first process. A substrate processing method according to any one of claims 1 to 9.

11. In the second process, the position of the outer edge is calculated in the horizontal and vertical directions of the image, In the third process described above, In both the horizontal and vertical directions, the presence or absence of the abnormality is determined based on the calculation result of the position of the outer edge. If the conditions for determining an abnormality are met in at least one of the lateral and vertical directions, it is determined that an abnormality has occurred. A substrate processing method according to any one of claims 1 to 9.

12. The process includes repeatedly performing a monitoring process while a predetermined process, which includes rotating the substrate held in the holding part, is being performed on the substrate, The aforementioned monitoring process is: A first process of detecting the outer edge in an image obtained by imaging a range including the outer edge of the surface of the substrate, A second process is performed to calculate the position of the outer edge within the image based on the detection results in the first process, A third process, which determines whether or not there is an abnormality in the holding of the substrate by the holding unit, based on the calculation results in the second process, is included. A method for monitoring substrate processing.

13. A computer-readable storage medium storing a program for causing an apparatus to execute the substrate processing method described in any one of claims 1 to 9.

14. A processing unit that performs a predetermined process on the substrate, including rotating the substrate held in the holding unit, The system includes a monitoring process execution unit that repeatedly performs monitoring processes during the execution of the predetermined process, The aforementioned monitoring process is: A first process of detecting the outer edge in an image obtained by imaging a range including the outer edge of the surface of the substrate, A second process is performed to calculate the position of the outer edge within the image based on the detection results in the first process, A third process, which determines whether or not there is an abnormality in the holding of the substrate by the holding unit, based on the calculation results in the second process, is included. Circuit board processing equipment.

Images