Position determination method and position determination device

Abstract

To provide a technique for determining a position of a substrate with a high degree of accuracy.SOLUTION: A position determination method has processes of setting an area including an edge of a substrate in a reference image as a reference area and detecting a pixel position of the edge of the substrate in the reference area as a reference pixel position, setting an area including the edge of the substrate in a comparison image as a comparison area and detecting a pixel position of the edge of the substrate in the comparison area as a comparison pixel position, and judging whether a difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold value.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a substrate position determination technology. Substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal displays, substrates for flat panel displays (FPDs) such as organic electroluminescence (EL) displays, substrates for optical discs, substrates for magnetic discs, substrates for magneto-optical discs, glass substrates for photomasks, ceramic substrates, substrates for field emission displays (i.e., FEDs), or substrates for solar cells. [Background technology]

[0002] In substrate processing, it is crucial that the substrate being processed is properly held in place.

[0003] For example, in Patent Document 1, the substrate is held by being adsorbed onto a stage. Also in Patent Document 1, the misalignment of the held substrate is detected based on the brightness information in the image obtained by the imaging unit. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2007-251143 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, the method described in Patent Document 1 may not have sufficient accuracy in determining the misalignment of the substrate.

[0006] The technology disclosed in this specification was developed in consideration of the problems described above, and is a technology for determining the misalignment of a substrate with high accuracy. [Means for solving the problem]

[0007] A first aspect of the position determination method disclosed in this specification includes the steps of: capturing an image of a substrate held in a reference position of a substrate holder and not rotating, and outputting the captured image as a reference image; setting a region in the reference image that includes the edge of the substrate as a reference region, and detecting the pixel position of the edge of the substrate in the reference region as a reference pixel position; capturing an image of a substrate placed in the substrate holder and not rotating, and outputting the captured image as a comparison image; and setting a region in the comparison image that includes the edge of the substrate as a comparison region The process includes setting the reference pixel position as a comparison pixel position, detecting the pixel position at the edge of the substrate in the comparison region as a comparison pixel position, and determining whether the difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold, wherein the step of detecting the reference pixel position includes calculating a reference score which is the value obtained by accumulating the difference between the brightness of the target pixel, which is the target pixel in the reference region, and the brightness of the adjacent pixel, which is the pixel adjacent to the target pixel in the radial direction of the substrate, with respect to pixels that are aligned with the target pixel in a direction orthogonal to the radial direction, and the radial direction in the reference region The position of the target pixel is determined along the line sequentially By repeatedly accumulating the difference between the brightness of the target pixel and the brightness of the adjacent pixel in the reference region while shifting the region, The step of determining the reference pixel position is the position of the target pixel corresponding to the largest of the calculated multiple reference scores, and the step of detecting the comparison pixel position is the difference between the brightness of the target pixel, which is the target pixel in the comparison region, and the brightness of the adjacent pixel, which is the pixel adjacent to the target pixel in the radial direction of the substrate. For each pixel in the aforementioned comparison region, the calculation is performed. A step of calculating a comparison score which is a value obtained by accumulating the values ​​of pixels adjacent to the target pixel in a direction perpendicular to the radial direction, and the radial direction in the comparison region The position of the target pixel is determined along the line sequentially By repeatedly accumulating the difference between the brightness of the target pixel and the brightness of the adjacent pixel in the comparison region while shifting the image, The process includes the step of setting the position of the target pixel corresponding to the largest of the calculated comparison scores as the comparison pixel position. [Effects of the Invention]

[0008] At least one of the technologies disclosed in this specification 1 According to an aspect, by integrating the luminance difference in a direction orthogonal to the radial direction of the substrate, the reference pixel position and the comparison pixel position can be detected with high accuracy. Therefore, based on the difference between the reference pixel position and the comparison pixel position, the misalignment of the substrate can be determined with high accuracy.

[0009] In addition, the objects, features, aspects, and advantages related to the technology disclosed in this specification will become clearer by the following detailed description and the accompanying drawings.

Brief Description of the Drawings

[0010] [Figure 1] It is a plan view schematically showing an example of the configuration of a substrate processing apparatus according to an embodiment. [Figure 2] It is a plan view of a processing unit according to an embodiment. [Figure 3] It is a cross-sectional view of a processing unit according to an embodiment. [Figure 4] It is a diagram conceptually showing an example of the function of a control unit. [Figure 5] It is a diagram schematically exemplifying the hardware configuration when actually operating the control unit shown as an example in FIG. 4. [Figure 6] It is a flowchart showing the operation of a substrate processing apparatus according to an embodiment. [Figure 7] It is a diagram showing an example of an image when imaging a spin chuck in a state where a substrate is properly held. [Figure 8] It is a schematic diagram of a reference region set in FIG. 7. [Figure 9] It is a schematic diagram of a reference region set in FIG. 7. [Figure 10] ]>It is a schematic diagram of a reference region set in FIG. 7. [Figure 11] It is a diagram showing an example of the distribution of the reference score in the reference region in the radial direction of the substrate. [Figure 12] It is a diagram showing an example of an image including a reference region. [Figure 13]This figure shows an example of the distribution of the reference score in the reference region along the radial direction of the substrate. [Figure 14] This figure shows an example of an image that includes a reference area. [Figure 15] This flowchart shows an example of the operation of a substrate processing apparatus according to an embodiment. [Figure 16] This figure shows an example of a whole image of the entire spin chuck, used to obtain a reference image of the first state. [Figure 17] This figure shows a spin chuck used to obtain the target image. [Figure 18] This figure shows an example of the distribution of matching coordinates. [Figure 19] This figure shows an example of the distribution of matching coordinates. [Figure 20] This figure shows an example of image extraction. [Figure 21] This figure shows an example of reference coordinates in a reference image. [Modes for carrying out the invention]

[0011] The embodiments will be described below with reference to the attached drawings. In the following embodiments, detailed features will be shown for the purpose of explaining the technology, but these are illustrative, and not all of them are necessarily essential features for the embodiments to be implementable.

[0012] Please note that the drawings are for illustrative purposes only, and for the sake of clarity, some components may be omitted or simplified as appropriate. Furthermore, the relative sizes and positions of components shown in different drawings are not necessarily accurately represented and may be modified as appropriate. In addition, hatching may be used in drawings other than cross-sectional views, such as plan views, to facilitate understanding of the embodiment.

[0013] Furthermore, in the following explanations, similar components will be denoted by the same symbols, and their names and functions will also be the same. Therefore, detailed explanations of them may be omitted to avoid redundancy.

[0014] Furthermore, in the descriptions contained in this specification, when a certain component is described as "equipped with," "includes," or "has," unless otherwise specified, it is not an exclusive expression that excludes the existence of other components.

[0015] Furthermore, even if ordinal numbers such as "first" or "second" are used in the descriptions contained herein, these terms are used for convenience to facilitate understanding of the embodiments, and the contents of the embodiments are not limited to the order that may result from these ordinal numbers.

[0016] Furthermore, in the descriptions contained herein, expressions indicating relative or absolute positional relationships, such as "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," include, unless otherwise specified, cases where the positional relationship is strictly defined, as well as cases where the angle or distance is displaced within a tolerance or a range in which equivalent functionality is obtained.

[0017] Furthermore, even if terms such as "top," "bottom," "left," "right," "side," "bottom," "front," or "back" are used in the descriptions of this specification to indicate a specific position or direction, these terms are used for convenience to facilitate understanding of the embodiments and are not related to the actual position or direction in which the embodiments are carried out.

[0018] <First Embodiment> The following describes a position determination device and a position determination method for determining the position of a substrate to be processed in a substrate processing apparatus according to this embodiment.

[0019] <About the configuration of the substrate processing unit> Figure 1 is a schematic plan view showing an example of the configuration of a substrate processing apparatus 100 according to this embodiment. The substrate processing apparatus 100 comprises a load port 601, an indexer robot 602, a center robot 603, a control unit 9, and at least one processing unit 1 (four processing units in Figure 1).

[0020] The substrates to be processed include, for example, semiconductor wafers, glass substrates for liquid crystal displays, substrates for flat panel displays (FPDs) such as organic electroluminescence (EL) displays, substrates for optical discs, substrates for magnetic discs, substrates for magneto-optical discs, glass substrates for photomasks, ceramic substrates, substrates for field emission displays (i.e., FEDs), or substrates for solar cells.

[0021] The substrate processing apparatus 100 according to this embodiment performs a cleaning treatment on a substrate W, which is a circular thin silicon substrate, using a chemical solution and a rinsing solution such as pure water, and then performs a drying treatment.

[0022] Examples of the above-mentioned chemical solutions include a mixture of ammonia and hydrogen peroxide (SC1), an aqueous solution of hydrochloric acid and hydrogen peroxide (SC2), or DHF solution (dilute hydrofluoric acid).

[0023] In the following explanation, chemical solutions and rinsing solutions will be collectively referred to as "processing solutions." Furthermore, "processing solutions" will include not only cleaning solutions, but also coating solutions such as photoresist solutions for film formation, chemical solutions for removing unwanted films, and chemical solutions for etching.

[0024] Processing unit 1 is a single-wafer device that can be used for substrate processing, and specifically, it is a device that performs a process to remove organic matter adhering to the substrate W. The organic matter adhering to the substrate W is, for example, a used resist film. This resist film is, for example, one that was used as an implantation mask for the ion implantation process.

[0025] The processing unit 1 may include a chamber 10. In this case, by controlling the atmosphere inside the chamber 10 with the control unit 9, the processing unit 1 can perform substrate processing in a desired atmosphere.

[0026] The control unit 9 can control the operation of each component in the substrate processing apparatus 100. The control unit 9 can also determine the position of the held substrate. Carrier C is a container for housing substrate W. Load port 601 is a container holding mechanism that holds multiple carriers C. Indexer robot 602 can transport substrate W between load port 601 and substrate mounting section 604. Center robot 603 can transport substrate W between substrate mounting section 604 and processing unit 1.

[0027] With the above configuration, the indexer robot 602, the substrate mounting unit 604, and the center robot 603 function as transport mechanisms that transport the substrate W between their respective processing units 1 and the load port 601.

[0028] The unprocessed substrate W is removed from the carrier C by the indexer robot 602. The unprocessed substrate W is then transferred to the center robot 603 via the substrate mounting unit 604.

[0029] The central robot 603 loads the unprocessed substrate W into the processing unit 1. The processing unit 1 then processes the substrate W.

[0030] The processed substrate W in processing unit 1 is removed from processing unit 1 by the center robot 603. The processed substrate W is then transferred to the indexer robot 602 via the substrate mounting unit 604, after passing through other processing units 1 as needed. The indexer robot 602 loads the processed substrate W into the carrier C. The processing of the substrate W is then completed.

[0031] Figure 2 is a plan view of the processing unit 1 according to this embodiment. Figure 3 is a cross-sectional view of the processing unit 1 according to this embodiment.

[0032] Figure 2 shows the state in which the substrate W is not held in the spin chuck 20, and Figure 3 shows the state in which the substrate W is held in the spin chuck 20.

[0033] The processing unit 1 includes, within the chamber 10, a spin chuck 20 for holding the substrate W in a horizontal position (i.e., a position where the normal to the upper surface of the substrate W is aligned with the vertical direction), three nozzles 30, nozzle 60, and nozzle 65 for supplying processing liquid to the upper surface of the substrate W held by the spin chuck 20, a processing cup 40 surrounding the spin chuck 20, and a camera 70 for imaging the spin chuck 20 and the substrate W held by the spin chuck 20.

[0034] Furthermore, a partition plate 15 is provided around the processing cup 40 inside the chamber 10, dividing the inner space of the chamber 10 vertically.

[0035] The chamber 10 comprises side walls 11 that are aligned vertically and surround the chamber on all four sides, a ceiling wall 12 that closes off the upper side of the side walls 11, and a floor wall 13 that closes off the lower side of the side walls 11. The space enclosed by the side walls 11, the ceiling wall 12, and the floor wall 13 becomes the processing space for the substrate W.

[0036] Furthermore, a portion of the side wall 11 of the chamber 10 is provided with an entrance / exit for the center robot 603 to load and unload the substrate W into and out of the chamber 10, and a shutter for opening and closing the entrance / exit (neither of which are shown in the figure).

[0037] A fan filter unit (FFU) 14 is mounted on the ceiling wall 12 of the chamber 10 to further purify the air in the cleanroom where the substrate processing device 100 is installed and supply it to the processing space within the chamber 10. The FFU 14 is equipped with a fan and a filter (for example, a high-efficiency particulate air filter (HEPA) filter) to take in air from the cleanroom and send it into the chamber 10.

[0038] The FFU 14 creates a downflow of clean air in the processing space within the chamber 10. To uniformly distribute the clean air supplied from the FFU 14, a perforated plate with numerous outlet holes may be provided directly below the ceiling wall 12.

[0039] The spin chuck 20 comprises a spin base 21, a spin motor 22, a cover member 23, and a rotating shaft 24. The spin base 21 has a disc shape and is fixed in a horizontal position to the upper end of the rotating shaft 24, which extends vertically. The spin motor 22 is located below the spin base 21 and rotates the rotating shaft 24. The spin motor 22 rotates the spin base 21 in the horizontal plane via the rotating shaft 24. The cover member 23 has a cylindrical shape that surrounds the spin motor 22 and the rotating shaft 24.

[0040] The outer diameter of the disc-shaped spin base 21 is slightly larger than the diameter of the circular substrate W held by the spin chuck 20. The spin base 21 has a holding surface 21a that faces the entire lower surface of the substrate W to be held.

[0041] Multiple chuck pins 26 (four in this embodiment) are provided on the periphery of the holding surface 21a of the spin base 21. The multiple chuck pins 26 are arranged at equal intervals along the circumference corresponding to the outer diameter of the outer circle of the circular substrate W. In this embodiment, four chuck pins 26 are provided at 90° intervals.

[0042] Multiple chuck pins 26 are driven in conjunction by a link mechanism (not shown) housed within the spin base 21. The spin chuck 20 holds the substrate W in a horizontal position above the spin base 21, close to the holding surface 21a, by bringing each of the multiple chuck pins 26 into contact with the outer edge of the substrate W and gripping the substrate W (see Figure 3). The spin chuck 20 also releases gripping the substrate W by moving each of the multiple chuck pins 26 away from the outer edge of the substrate W.

[0043] At least one of the multiple chuck pins 26 is configured to be held at the outer edge of the substrate W by a magnet or spring, and can maintain an open state, where it is separated from the outer edge of the substrate W, and a closed state, where it is in contact with the outer edge of the substrate W. The driving of the chuck pin 26 is controlled by the control unit 9.

[0044] Furthermore, if only some of the multiple chuck pins 26 are driven to grip the substrate W, the other chuck pins 26 may be support pins that support the lower surface of the substrate W.

[0045] The cover member 23 that covers the spin motor 22 has its lower end fixed to the floor wall 13 of the chamber 10, and its upper end reaches directly below the spin base 21. At the upper end of the cover member 23, a flange-shaped member 25 is provided that extends outward almost horizontally from the cover member 23 and then bends downward.

[0046] With the spin chuck 20 holding the substrate W by gripping with multiple chuck pins 26, the spin motor 22 rotates the rotation axis 24, thereby rotating the substrate W around the rotation axis CX, which is aligned vertically and passes through the center of the substrate W. The drive of the spin motor 22 is controlled by the control unit 9.

[0047] The nozzle 30 is constructed by attaching a discharge head 31 to the tip of a nozzle arm 32. The base end of the nozzle arm 32 is fixedly connected to a nozzle base 33. The nozzle base 33 is rotatable around an axis aligned with the vertical direction by a motor 332 (nozzle moving part) provided on the nozzle base 33.

[0048] As the nozzle base 33 rotates, the nozzle 30 moves in an arc along the horizontal direction between a position above the spin chuck 20 and a standby position outside the processing cup 40, as shown by arrow AR34 in Figure 2. The rotation of the nozzle base 33 causes the nozzle 30 to swing above the holding surface 21a of the spin base 21.

[0049] In this embodiment, the processing unit 1 is provided with two additional nozzles, 60 and 65, in addition to the nozzle 30 described above. The nozzles 60 and 65 in this embodiment have the same configuration as the nozzle 30 described above.

[0050] In other words, the nozzle 60 is configured by attaching a discharge head to the tip of a nozzle arm 62, and moves in an arc between a processing position above the spin chuck 20 and a standby position outside the processing cup 40, as indicated by arrow AR64, by a nozzle base 63 connected to the base end of the nozzle arm 62.

[0051] Similarly, the nozzle 65 is configured with a discharge head attached to the tip of a nozzle arm 67 and moves in an arc between a processing position above the spin chuck 20 and a standby position outside the processing cup 40, as indicated by arrow AR69, by a nozzle base 68 connected to the base end of the nozzle arm 67.

[0052] Nozzles 60 and 65 are configured to be supplied with multiple types of processing liquids, each containing at least pure water, and the processing liquids are discharged onto the upper surface of the substrate W held by the spin chuck 20 at the processing position.

[0053] A bottom surface treatment liquid nozzle 28 is provided along the vertical direction, inserted through the inside of the rotating shaft 24. The upper end opening of the bottom surface treatment liquid nozzle 28 is formed at a position opposite the center of the lower surface of the substrate W held by the spin chuck 20. Multiple types of treatment liquids are supplied to the bottom surface treatment liquid nozzle 28. The treatment liquid discharged from the bottom surface treatment liquid nozzle 28 lands on the lower surface of the substrate W held by the spin chuck 20.

[0054] The operation of nozzles 30, 60, 65, and the bottom treatment liquid nozzle 28 is controlled by the control unit 9.

[0055] The processing cup 40 surrounding the spin chuck 20 comprises an inner cup 41, a middle cup 42, and an outer cup 43 that can move up and down independently of each other. The inner cup 41 surrounds the spin chuck 20 and has a shape that is substantially rotationally symmetric with respect to the axis of rotation CX passing through the center of the substrate W held by the spin chuck 20. This inner cup 41 integrally comprises an annular bottom portion 44 in plan view, a cylindrical inner wall portion 45 rising upward from the inner periphery of the bottom portion 44, a cylindrical outer wall portion 46 rising upward from the outer periphery of the bottom portion 44, a first guide portion 47 rising from between the inner wall portion 45 and the outer wall portion 46, with its upper end drawing a smooth arc and extending diagonally upward toward the center (in the direction approaching the axis of rotation CX of the substrate W held by the spin chuck 20), and a cylindrical middle wall portion 48 rising upward from between the first guide portion 47 and the outer wall portion 46.

[0056] The inner wall portion 45 is formed to a length such that, when the inner cup 41 is in its highest position, it is housed between the cover member 23 and the flange-shaped member 25 while maintaining an appropriate gap. The middle wall portion 48 is formed to a length such that, when the inner cup 41 and the middle cup 42 are in their closest proximity, it is housed between the second guide portion 52 of the middle cup 42 (described later) and the processing liquid separation wall 53 while maintaining an appropriate gap.

[0057] The first guide portion 47 has an upper end portion 47b that extends diagonally upward toward the center (towards the rotation axis CX of the substrate W) while drawing a smooth arc. The space between the inner wall portion 45 and the first guide portion 47 is a waste groove 49 for collecting and disposing of used processing liquid. The space between the first guide portion 47 and the middle wall portion 48 is an annular inner recovery groove 50 for collecting and recovering used processing liquid. Furthermore, the space between the middle wall portion 48 and the outer wall portion 46 is an annular outer recovery groove 51 for collecting and recovering processing liquid of a different type from that in the inner recovery groove 50.

[0058] The inner cup 42 surrounds the spin chuck 20 and has a shape that is substantially rotationally symmetric with respect to the rotation axis CX passing through the center of the substrate W held by the spin chuck 20. The inner cup 42 has a second guide portion 52 and a cylindrical processing liquid separation wall 53 connected to the second guide portion 52.

[0059] The second guide portion 52 is located outside the first guide portion 47 of the inner cup 41 and has a lower end portion 52a that is coaxially cylindrical with respect to the lower end of the first guide portion 47, an upper end portion 52b that extends diagonally upward toward the center (towards the rotation axis CX of the substrate W) in a smooth arc from the upper end of the lower end portion 52a, and a folded portion 52c formed by folding the tip of the upper end portion 52b downward. The lower end portion 52a is housed in the inner recovery groove 50 while maintaining an appropriate gap between the first guide portion 47 and the inner wall portion 48 when the inner cup 41 and the middle cup 42 are in their closest proximity. The upper end portion 52b is provided so as to overlap the upper end portion 47b of the first guide portion 47 of the inner cup 41 in the vertical direction, and is close to the upper end portion 47b of the first guide portion 47 while maintaining a very small gap when the inner cup 41 and the middle cup 42 are in their closest proximity. The folded portion 52c is positioned so that when the inner cup 41 and the middle cup 42 are in their closest proximity, the folded portion 52c horizontally overlaps with the tip of the upper end portion 47b of the first guide portion 47.

[0060] The upper end portion 52b of the second guide portion 52 is formed such that its thickness increases towards the bottom. The processing liquid separation wall 53 has a cylindrical shape and is provided so as to extend downward from the lower outer peripheral edge of the upper end portion 52b. The processing liquid separation wall 53 is housed in the outer recovery groove 51 with the inner cup 41 and the middle cup 42 in the closest possible position, while maintaining an appropriate gap between the middle wall portion 48 and the outer cup 43.

[0061] The outer cup 43 has a shape that is substantially rotationally symmetric with respect to the rotation axis CX passing through the center of the substrate W held by the spin chuck 20. The outer cup 43 surrounds the spin chuck 20 outside the second guide portion 52 of the inner cup 42. This outer cup 43 functions as a third guide portion. The outer cup 43 has a lower end portion 43a that is coaxially cylindrical with the lower end portion 52a of the second guide portion 52, an upper end portion 43b that extends diagonally upward toward the center (towards the rotation axis CX of the substrate W) in a smooth arc from the upper end of the lower end portion 43a, and a folded portion 43c formed by folding the tip of the upper end portion 43b downward.

[0062] The lower end portion 43a is housed in the outer recovery groove 51 while maintaining an appropriate gap between the liquid separation wall 53 of the middle cup 42 and the outer wall portion 46 of the middle cup 41, when the inner cup 41 and the outer cup 43 are in their closest proximity. The upper end portion 43b is provided so as to overlap the second guide portion 52 of the middle cup 42 in the vertical direction, and is in close proximity to the upper end portion 52b of the second guide portion 52 while maintaining a very small gap, when the middle cup 42 and the outer cup 43 are in their closest proximity. When the middle cup 42 and the outer cup 43 are in their closest proximity, the folded portion 43c overlaps the folded portion 52c of the second guide portion 52 in the horizontal direction.

[0063] The operation of the processing cup 40 is controlled by the control unit 9.

[0064] The partition plate 15 is provided to divide the inner space of the chamber 10 vertically around the processing cup 40.

[0065] The outer edge of the partition plate 15 is connected to the side wall 11 of the chamber 10. In addition, the outer edge of the partition plate 15 surrounding the processing cup 40 is formed to be circular in shape with a diameter larger than the outer diameter of the outer cup 43.

[0066] Furthermore, an exhaust duct 18 is provided, which is part of the side wall 11 of the chamber 10 and near the floor wall 13. The exhaust duct 18 is connected to an exhaust mechanism (not shown). Of the clean air supplied from the FFU 14 and flowing down inside the chamber 10, the air that passes between the processing cup 40 and the partition plate 15 is discharged outside the device through the exhaust duct 18.

[0067] Figure 4 is a conceptual diagram illustrating an example of the functions of the control unit 9. As shown in the example in Figure 4, the control unit 9 comprises an analysis unit 91 and a drive control unit 93. The control unit 9 also functions as a position determination device, along with a spin chuck 20 for holding the substrate W and a camera 70 for imaging the substrate W in its held state.

[0068] The analysis unit 91 determines that the substrate W is properly held in the spin chuck 20. The specific operation of the analysis unit 91 will be described later.

[0069] The drive control unit 93 controls the drive of the drive unit 190, which includes the chuck pin 26, spin motor 22, nozzle 30, nozzle 60, nozzle 65, bottom processing liquid nozzle 28, and processing cup 40 in the processing unit 1. Here, the drive unit 190 for the chuck pin 26 includes a motor (not shown) for moving a magnet or switching between biasing and debuffing a spring.

[0070] Figure 5 is a schematic diagram illustrating the hardware configuration when the control unit 9, which is exemplified in Figure 4, is actually put into operation.

[0071] Figure 5 shows the hardware configuration for realizing the analysis unit 91 and drive control unit 93 in Figure 4, which includes a processing circuit 1102A that performs calculations and a memory device 1103 that can store information.

[0072] The processing circuit 1102A is, for example, a CPU. The storage device 1103 is, for example, a memory (storage medium) such as a hard disk drive (i.e., HDD), RAM, ROM, or flash memory.

[0073] <About the operation of the substrate processing unit> The normal processing of a substrate W in the substrate processing apparatus 100 includes, in order, the steps of: the center robot 603 receiving the substrate W to be processed from the indexer robot 602 and transporting it to each processing unit 1; the processing unit 1 performing substrate processing on the substrate W; and the center robot 603 transporting the processed substrate W from the processing unit 1 and returning it to the indexer robot 602.

[0074] Next, with reference to Figure 6, the procedures for the cleaning and drying processes, which are typical substrate processing steps for a substrate W in each processing unit 1, will be described. Figure 6 is a flowchart showing the operation of the substrate processing apparatus 100 according to this embodiment. The following operations are mainly performed by the control unit 9.

[0075] First, a chemical solution is supplied to the surface of the substrate W to perform a predetermined chemical treatment (Step ST01). Then, pure water is supplied to perform a pure water rinse treatment (Step ST02).

[0076] Furthermore, the substrate W is rotated at high speed to shake off the pure water, thereby drying the substrate W (step ST03).

[0077] When the processing unit 1 performs substrate processing, the spin chuck 20 holds the substrate W, and the processing cup 40 moves up and down.

[0078] When the processing unit 1 performs chemical treatment, for example, only the outer cup 43 rises, and an opening is formed between the upper end 43b of the outer cup 43 and the upper end 52b of the second guide portion 52 of the inner cup 42, surrounding the substrate W held by the spin chuck 20. In this state, the substrate W rotates together with the spin chuck 20, and chemical treatment is supplied to the upper and lower surfaces of the substrate W from the nozzle 30 and the lower surface treatment liquid nozzle 28. The supplied chemical treatment flows along the upper and lower surfaces of the substrate W due to the centrifugal force caused by the rotation of the substrate W, and eventually splashes laterally from the outer edge of the substrate W. This allows the chemical treatment of the substrate W to proceed. The chemical treatment splashed from the outer edge of the rotating substrate W is caught by the upper end 43b of the outer cup 43, flows down along the inner surface of the outer cup 43, and is collected in the outer recovery groove 51.

[0079] When the processing unit 1 performs a pure water rinsing treatment, for example, the inner cup 41, the middle cup 42, and the outer cup 43 all rise, and the substrate W held in the spin chuck 20 is surrounded by the first guide portion 47 of the inner cup 41. In this state, the substrate W rotates together with the spin chuck 20, and pure water is supplied to the top and bottom surfaces of the substrate W from the nozzle 30 and the bottom surface treatment liquid nozzle 28. The supplied pure water flows along the top and bottom surfaces of the substrate W due to the centrifugal force caused by the rotation of the substrate W, and eventually splashes laterally from the outer edge of the substrate W. This allows the pure water rinsing treatment of the substrate W to proceed. The pure water splashed from the outer edge of the rotating substrate W flows down the inner wall of the first guide portion 47 and is discharged from the waste groove 49. Furthermore, if pure water is to be recovered via a separate route from the chemical solution, the inner cup 42 and the outer cup 43 may be raised to form an opening between the upper end 52b of the second guide portion 52 of the inner cup 42 and the upper end 47b of the first guide portion 47 of the inner cup 41, surrounding the substrate W held by the spin chuck 20.

[0080] When the processing unit 1 performs the shake-off drying process, the inner cup 41, middle cup 42, and outer cup 43 all descend, and the upper end 47b of the first guide portion 47 of the inner cup 41, the upper end 52b of the second guide portion 52 of the middle cup 42, and the upper end 43b of the outer cup 43 are all positioned below the substrate W held by the spin chuck 20. In this state, the substrate W is rotated at high speed together with the spin chuck 20, and the water droplets adhering to the substrate W are shaken off by centrifugal force, and the drying process is performed.

[0081] <Regarding the determination of the substrate's holding position> The operation for determining whether the substrate W is properly held in the spin chuck 20 will be described below. This determination operation is performed in the control unit 9 prior to substrate processing.

[0082] First, the analysis unit 91 of the control unit 9 sets a reference region and a comparison region in multiple images captured by the camera 70. Furthermore, it sets the pixel positions corresponding to the edges of the substrate W in the reference region as reference pixel positions and the pixel positions corresponding to the edges of the substrate W in the comparison region as comparison pixel positions.

[0083] The analysis unit 91 of the control unit 9 determines that the substrate W is properly held in the spin chuck 20 if the difference (difference in pixel position) between the reference pixel position and the comparison pixel position does not exceed a predetermined threshold. On the other hand, if the difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold, the analysis unit 91 of the control unit 9 determines that the substrate W is not properly held and issues a predetermined warning (such as an alarm display).

[0084] <Regarding the setting of the reference area> Figure 7 shows an example of an image captured by the camera 70 of the spin chuck 20 while it is properly holding the substrate W. As shown in the example in Figure 7, the substrate W is positioned in a reference position opposite the spin base 21 of the spin chuck 20, and its peripheral edge is gripped by a plurality of chuck pins 26.

[0085] The analysis unit 91 in the control unit 9 sets the regions including the edges of the substrate W in the reference image, which is the image shown above, i.e., the reference image showing the substrate W being held in a reference position without rotation, as reference region 320, reference region 321, reference region 322, reference region 323, and reference region 304. Each of these reference regions is set at the edges of the substrate W in a properly held state.

[0086] Here, it is desirable to set the reference region to an area within the region including the edge of the substrate W where the change in brightness is relatively small. This is because, when calculating the brightness difference described later, changes in brightness at areas other than the edge of the substrate W may reduce the detection accuracy of the edge of the substrate W. Changes in brightness at areas other than the edge of the substrate W are affected, for example, by the presence or absence of structures placed around the substrate W.

[0087] Next, the analysis unit 91 in the control unit 9 calculates the brightness of each pixel in the reference region, and further calculates the brightness difference (brightness difference) between each pixel and adjacent pixels. Here, the direction in which pixels are adjacent to each other is along the radial direction of the substrate W.

[0088] Figure 8 is a schematic diagram of the reference region 320 set in Figure 7. The X and Y axes in Figure 8 indicate the direction in which the pixels are arranged. As shown in the example in Figure 8, the direction 311 of adjacent pixels is along the radial direction of the substrate W (corresponding to the X-axis direction in Figure 8).

[0089] Here, the brightness difference described above is calculated only when the brightness of pixels located radially outside the substrate W (i.e., pixels located on the negative X-axis side in Figure 8) is high, and may not be calculated (or set to 0) when the brightness of pixels located radially outside the substrate W is low. Doing so makes it easier to distinguish between an image showing the substrate W, where the brightness is relatively low, and an image showing the surrounding area around the substrate W, where the brightness is relatively high.

[0090] Then, the analysis unit 91 in the control unit 9 adds up the brightness differences calculated as described above for each pixel in a direction perpendicular to the radial direction of the substrate W (corresponding to the Y-axis direction in Figure 8). By adding up the brightness differences in a direction perpendicular to the radial direction of the substrate W, the difference between the brightness difference of the pixel row where the edge of the substrate W is located and the brightness differences of other pixel rows becomes more pronounced, thus improving the detection accuracy of the edge of the substrate W. The value of the brightness difference thus added up in the reference region is used as the reference score.

[0091] Here, in reference regions set at an angle in the image, such as reference region 322 or reference region 323 in Figure 7, the radial direction of the substrate W may not coincide with the direction of adjacent pixels in the image. In such cases, the pixels may be remapped so that the radial direction of the substrate W coincides with the direction of adjacent pixels. The same remapping may be done in the comparison region described later.

[0092] Figures 9 and 10 are schematic diagrams of the reference region 323 set in Figure 7. The X and Y axes in Figures 9 and 10 indicate the direction in which the pixels are arranged.

[0093] The direction in which the pixels of the reference region 323 set in Figure 7 are arranged (the X-axis and Y-axis directions in Figure 9) does not coincide with the direction 311 in which pixels are adjacent to each other. Therefore, the image corresponding to the reference region 323 is rotated so that the direction 311 and the direction in which the pixels are arranged (the X-axis or Y-axis direction in Figure 9) coincide, and then the pixels are mapped again in the X-axis and Y-axis directions. By changing the arrangement of pixels in the image in this way, the brightness difference between adjacent pixels and their sum can be easily calculated.

[0094] <Regarding the detection of the reference pixel position> Next, the analysis unit 91 in the control unit 9 compares the respective reference scores calculated as described above in the radial direction of the substrate W.

[0095] Figure 11 shows an example of the distribution of reference scores in the reference region 323 along the radial direction of the substrate W. In Figure 11, the left vertical axis represents the magnitude of the score, and the horizontal axis represents the pixel position in the radial direction of the substrate W (smaller values ​​indicate an inner position in the radial direction).

[0096] Figure 12 is an example of an image that includes the reference region 323. Figure 12 shows the direction 311 in which images of the reference region 323 are adjacent to each other.

[0097] The reference score 409 in Figure 11 represents the distribution of values ​​(scores) obtained by summing the brightness differences between adjacent pixels (pairs of the target pixel and its adjacent pixels) in the reference region 323 in a direction orthogonal to direction 311. The peak score 401 of the reference score 409 in Figure 11 corresponds to pixel position 501 in Figure 12. Similarly, the peak score 402 of the reference score 409 in Figure 11 corresponds to pixel position 502 in Figure 12.

[0098] In Figure 12, the low-luminance image visible between pixel positions 501 and 502 in the reference region 323 corresponds to the shadow of the substrate W. The shadow of the substrate W is inevitably displayed in the image depending on the imaging direction of the camera 70, but it can be difficult to clearly identify the edge of the substrate W in the image where the shadow of the substrate W is displayed. Therefore, to ensure high reproducibility, the region containing the shadow of the substrate W can be designated as the edge of the substrate W.

[0099] Therefore, in order to accurately detect the boundary between the low-luminance region representing the substrate W including the shadow and the high-luminance region other than the substrate W (i.e., the boundary formed by the shadow of the substrate W), the distribution coefficient based on the luminance distribution of pixels in the reference region 323 is multiplied by the value of the reference score 409. In Figure 11, the distribution coefficient 600 of pixels in the reference region 323 is shown superimposed. The distribution coefficient 600 is shown as the ratio of the luminance heights shown on the right vertical axis. The distribution coefficient 600 is obtained by normalizing the average luminance of pixels located radially outside the substrate W compared to the target pixel and expressing it as a ratio.

[0100] The corrected reference score 410 is obtained by multiplying the reference score of 409 by the distribution coefficient of 600. In the corrected reference score 410, peak 412, which corresponds to pixel position 502 in Figure 12, has a higher score than peak 411, which corresponds to pixel position 501. Therefore, pixel position 502 in the reference region 323 can be detected as the pixel position at the edge of the substrate W (reference pixel position).

[0101] The distribution coefficient 600 mentioned above is shown as a ratio to the average value of the brightness of each pixel in the reference region 323. However, the distribution coefficient 600 can be any value that reflects the brightness distribution in the reference region 323. For example, it could be the average brightness of all pixels located radially inward from the target pixel, or it could be replaced with the variance or standard deviation of the brightness distribution in the reference region 323.

[0102] Alternatively, the edge of the substrate W that does not include shadows may be considered the edge of the substrate W. In other words, if the edge of the substrate W can be clearly identified, the pixel position 501 in Figure 12 may be detected as the pixel position (reference pixel position) of the edge of the substrate W.

[0103] Furthermore, while the above-mentioned reference pixel position corresponds to the position of the single pixel with the highest reference score (or corrected reference score), to improve the accuracy of the reference pixel position, for example, an approximation curve can be generated using the scores of the pixels adjacent to the highest-scoring pixel (or even further adjacent surrounding pixels), and the position of the vertex of this approximation curve can be used as the reference pixel position (spline interpolation). This process can improve the positional accuracy of the reference pixel position. The same applies to the comparison pixel position described later.

[0104] Figure 13 shows an example of the distribution of reference scores in the reference region 322 along the radial direction of the substrate W. In Figure 13, the left vertical axis represents the magnitude of the score, and the horizontal axis represents the pixel position in the radial direction of the substrate W (smaller values ​​indicate an inner position in the radial direction).

[0105] Figure 14 is an example of an image that includes the reference region 322. Figure 14 shows the direction 311 in which images of the reference region 322 are adjacent to each other.

[0106] The reference score 409A in Figure 13 represents the distribution of the sum of the brightness differences between adjacent pixels in direction 311 within the reference region 322, in a direction orthogonal to direction 311. The peak score 403 of the reference score 409A in Figure 13 corresponds to pixel position 503 in Figure 14.

[0107] Here, as in Figure 11, the distribution coefficient based on the luminance distribution of pixels in the reference region 322 is multiplied by the value of the reference score 409A. In Figure 13, the distribution coefficient 600A of pixels in the reference region 322 is shown overlaid. The distribution coefficient 600A is represented by the ratio of the luminance heights shown on the right vertical axis.

[0108] The corrected reference score 410A is obtained by multiplying the reference score 409A by the distribution coefficient 600A. In the corrected reference score 410A, peak 413, which corresponds to pixel position 504 in Figure 14, has the highest score. Pixel position 504 corresponds to a position radially inward of the reference region 322 and is not appropriate as a pixel position at the edge of the substrate W.

[0109] The cause of the above-mentioned malfunction is thought to be high brightness in the area where the substrate W is shown. As shown in the example in Figure 14, when the brightness increases due to the reflection of images of other structures on the surface of the substrate W, if we try to detect the pixel position at the edge of the substrate W using the correction reference score 410A calculated by multiplying by the distribution coefficient 600A, the high brightness in the area where the substrate W is shown increases the correction reference score in that area, hindering the proper detection of the pixel position at the edge of the substrate W.

[0110] Therefore, the edge of the substrate W can be detected as the reference pixel position using a correction reference score only when the luminance on the radially inner side of the substrate W within the reference area is lower than the luminance on the radially outer side of the substrate W. In this way, even if an unintended change in luminance occurs in an image showing a substrate W with relatively low luminance, it is possible to suppress the detection of the reference pixel position based on that change.

[0111] For example, the boundary line 700 shown in Figure 14 is a line that divides the reference area 322 in half in the radial direction of the substrate W. The average brightness of pixels inside the boundary line 700 in the radial direction of the substrate W is compared with the average brightness of pixels outside the boundary line 700 in the radial direction of the substrate W. Only when the average brightness of pixels inside the boundary line 700 is lower (or the average brightness of pixels outside the radial direction of the substrate W is higher) is the edge of the substrate W detected as the reference pixel position using a correction reference score.

[0112] While the boundary line 700 used for comparing average brightness is not limited to a line dividing the reference area 322 in half, considering that the reference area is set such that the pixel positions corresponding to the edges of the substrate W are near the center of the reference area, using boundary line 700 to divide the reference area in half makes it easy to distinguish between areas with low average brightness (for example, the area where the substrate W is shown) and areas with high average brightness (for example, the surrounding area surrounding the substrate W). Therefore, it becomes easier to determine whether the brightness on the radially inner side of the substrate W within the reference area is higher or lower than the brightness on the radially outer side of the substrate W.

[0113] <Regarding the settings for the comparison term> The comparison region is set in the same way as the reference region. Specifically, the substrate W held in the spin chuck 20 is imaged using the camera 70 or another imaging device, and the analysis unit 91 in the control unit 9 sets a comparison region in the obtained image that is the same range as when the reference region is set. Here, the substrate W in the image in which the comparison region is set differs from the substrate W in the image in which the reference region is set, and it is unclear whether or not it is properly held in the spin chuck 20. The comparison image (the image compared to the reference image), which is the image in which the comparison region is set, that is, the image showing the substrate W that will be processed, is assumed to show the substrate W that will be processed.

[0114] Next, the analysis unit 91 in the control unit 9 calculates the brightness of each pixel in the comparison area, and further calculates the brightness difference (brightness difference) between each pixel and its adjacent pixels. Here, the direction in which pixels are adjacent to each other is along the radial direction of the substrate W.

[0115] Then, the analysis unit 91 in the control unit 9 sums up the brightness differences calculated as described above for each pixel in a direction perpendicular to the radial direction of the substrate W. The summed brightness difference value in the comparison region is used as the comparison score.

[0116] <Regarding the detection of the comparison pixel position> Next, the analysis unit 91 in the control unit 9 compares the respective comparison scores calculated as described above in the radial direction of the substrate W.

[0117] Then, the pixel position corresponding to the peak with the highest comparison score is detected as the comparison pixel position. Here, if the luminance on the radially inner side of the substrate W within the comparison region is lower than the luminance on the radially outer side of the substrate W, the comparison pixel position can be detected using the corrected comparison score. In this way, even if an unintended change in luminance occurs in an image showing a substrate W with relatively low luminance, it is possible to suppress the detection of the comparison pixel position based on that change.

[0118] Here, the corrected comparison score is obtained by multiplying the comparison score value by the distribution coefficient value, which is based on the brightness distribution of pixels in the comparison area.

[0119] <Regarding the determination of the holding position> Next, the analysis unit 91 of the control unit 9 determines that the substrate W is properly held in the spin chuck 20 if the difference (difference in pixel position) between the reference pixel position and the corresponding comparison pixel position does not exceed a predetermined threshold. Here, the reference pixel position and the corresponding comparison pixel position refer to the reference pixel position detected in the reference region and the comparison pixel position detected in the comparison region, respectively, when the reference region and the corresponding comparison region are specified.

[0120] In this process, by also referring to the results of the positional displacement in the comparison region located diagonally across the substrate W, the direction of the overall positional displacement of the substrate W can be detected.

[0121] For example, if the displacement in the comparison region corresponding to the reference region 320 is radially inward of the substrate W, and the displacement in the comparison region corresponding to the reference region 322 is radially outward of the substrate W, then the substrate W as a whole is held shifted towards the side where the reference region 322 is set. Similarly, if the displacement in the comparison region corresponding to the reference region 321 is radially inward of the substrate W, and the displacement in the comparison region corresponding to the reference region 323 is radially outward of the substrate W, then the substrate W as a whole is held shifted towards the side where the reference region 323 is set.

[0122] <Second Embodiment> A position determination device and a position determination method for determining the position of a substrate to be processed in a substrate processing apparatus according to this embodiment will be described. In the following description, components similar to those described in the embodiments described above will be denoted by the same reference numerals, and their detailed descriptions will be omitted as appropriate.

[0123] <About the configuration of the substrate processing unit> The configuration of the substrate processing apparatus is the same as that shown in Figures 1 to 5.

[0124] <About the operation of the substrate processing unit> In this embodiment, in addition to determining the holding position of the substrate W, the analysis unit 91 performs matching processing using the image of the chuck pin captured by the camera 70 and calculates matching coordinates. Then, the analysis unit 91 detects the open / closed state of the chuck pin 26 based on the matching coordinates.

[0125] As described above, the analysis unit 91 operates in such a way that it can determine whether the substrate W is properly held while considering the open / closed state of the chuck pins 26 in the spin chuck 20 that holds the substrate W. Therefore, the holding state of the substrate W can be accurately determined.

[0126] Figure 15 is a flowchart showing an example of the operation of a substrate processing apparatus according to this embodiment. The operation shown in Figure 15 is performed by the control unit 9.

[0127] First, in step ST11, it is determined whether the control information transmitted from the drive control unit 93 instructs the chuck pin 26 to be in a closed state. If the control information instructs the chuck pin 26 to be in a closed state, the process proceeds to step ST12. On the other hand, if the control information does not instruct the chuck pin 26 to be in a closed state, step ST11 is repeated.

[0128] Next, in step ST12, the analysis unit 91 determines whether the substrate W is riding on the chuck pins 26 based on the matching coordinates described later. If the substrate W is riding on the chuck pins 26, the process proceeds to step ST13. On the other hand, if the substrate W is not riding on the chuck pins 26, the process proceeds to step ST14.

[0129] In step ST13, the drive control unit 93 issues a predetermined warning (such as displaying an alarm or prompting the user to reposition the substrate W) if the substrate W is not being held properly (i.e., the substrate W is not positioned correctly by the chuck pins 26, or one of the chuck pins is not gripping the substrate W).

[0130] In step ST14, the analysis unit 91 determines whether the chuck pin 26 is in the closed position based on the matching coordinates described later. If the chuck pin 26 is in the closed position, the process proceeds to step ST15. On the other hand, if the chuck pin 26 is not in the closed position, the process proceeds to step ST16.

[0131] In step ST15, the analysis unit 91 determines the holding position of the substrate W as shown in the first embodiment and determines whether the difference between the reference pixel position and the corresponding comparison pixel position exceeds a predetermined threshold. If it exceeds the threshold, the process proceeds to step ST13. On the other hand, if it does not exceed the threshold, the process proceeds to step ST17 and displays a predetermined indication that the substrate W is being held properly.

[0132] In step ST16, the analysis unit 91 determines the holding position of the substrate W as shown in the first embodiment and determines whether the difference between the reference pixel position and the corresponding comparison pixel position exceeds a predetermined threshold. If it exceeds the threshold, the process proceeds to step ST13. On the other hand, if it does not exceed the threshold, the process proceeds to step ST18, where a predetermined display is made indicating that the substrate W is in place and that the chuck pins 26 are in an open state different from the control information.

[0133] <Regarding the detection of the open / closed state of the chuck pin> The following describes the detection of the open / closed state of the chuck pin 26 (state detection) performed by the control unit 9, which is one of the operations described above.

[0134] The drive of the chuck pin 26 is controlled by the drive control unit 93 of the control unit 9. However, due to malfunctions of the chuck pin 26 itself or malfunctions of the substrate W gripped by the chuck pin 26 (for example, if the position where the substrate W is placed is different from the predetermined position), the chuck pin 26 may not operate as intended by the drive control unit 93 (as indicated by the control information transmitted from the drive control unit 93). Therefore, by detecting the open / closed state of the chuck pin 26, it is possible to confirm whether the chuck pin 26 is operating as instructed by the drive control unit 93. Furthermore, depending on the result of this confirmation, the placement of the substrate W can be corrected or the drive control unit 93 can be instructed to output a control signal again.

[0135] In this embodiment, multiple images representing the chuck pin 26 are prepared, and matching coordinates are calculated by performing a matching process (specifically, a pattern matching process) between them. Here, matching coordinates are coordinates that indicate the relative positional relationship between images when the matching score between the images is highest.

[0136] In this embodiment, first, three types of reference images are prepared according to the open / closed state of the chuck pin 26. Specifically, reference images are prepared showing the chuck pin 26 in the following states: the state in which the chuck pin 26 is completely closed without gripping the substrate W (first state), the state in which the chuck pin 26 is gripping the substrate W (second state), and the state in which the chuck pin 26 is open (third state).

[0137] Figure 16 shows an example of an overall image of the entire spin chuck 20 to obtain a reference image of the first state. As shown in the example in Figure 16, the image captured by the camera 70 or the like includes multiple chuck pins 26 (each chuck pin is also referred to as chuck pin 26a, chuck pin 26b, chuck pin 26c, and chuck pin 26d).

[0138] From the images described above, a reference image 201 is extracted for detecting the open / closed state of the chuck pin 26. Specifically, for at least one of the multiple chuck pins 26, the reference image 201 is set to include at least a portion of the chuck pin 26 (for example, the upper end of the chuck pin 26 that is displaced as the chuck pin 26 opens and closes).

[0139] In this embodiment, three types of reference images 201 are provided for each of the multiple chuck pins 26 according to the open / closed state described above. However, it is sufficient to have at least one type of reference image 201 for at least one chuck pin 26.

[0140] Furthermore, the reference image 201 may be extracted from an image obtained by actually imaging the chuck pin 26 with the camera 70, or it may be extracted from an image obtained by another method.

[0141] Furthermore, the image for obtaining the reference image 201 of the second state is not limited to the case where the chuck pin 26 is actually holding the substrate W, but may also be achieved by disabling the magnet or spring that enables the chuck pin 26 to hold the substrate W, thereby showing the chuck pin 26 in the image with the same degree of opening and closing as when it is holding the substrate W.

[0142] Furthermore, the range of the reference image 201 in the second state should not include the substrate W. If the range of the reference image 201 does not include any parts other than the chuck pin 26, the accuracy will be improved by the matching described later.

[0143] Next, the camera 70 is used to capture an image of the spin chuck 20, including the chuck pin 26. Then, a target image is prepared, which is used for pattern matching processing with the reference image.

[0144] Figure 17 shows a spin chuck 20 for obtaining a target image. As shown in the example in Figure 17, the overall image captured by the camera 70 or the like includes multiple chuck pins 26.

[0145] From the image described above, a target image 202 is extracted for pattern matching with the reference image 201. Specifically, for at least one of the multiple chuck pins 26, the range including at least a portion of the chuck pin 26 is set as the target image 202.

[0146] Here, the range of the reference image 201 can be made to correspond to a portion of the target image 202. That is, the range of the target image 202 can be set to be wider than the range of the reference image 201. By setting the range of the target image 202 in this way, the reference image 201 can be sequentially shifted within the range of the target image 202, and pattern matching processing can be performed to search for the matching coordinates that are calculated when the matching score is highest.

[0147] Specifically, first, the coordinates of a predetermined pixel in the reference image 201 of the first state of the chuck pin 26 are set to reference coordinates (X basis_pos1 ,Y basis_pos1 ) and similarly, the coordinates of a predetermined pixel in the reference image 201 of the second state of the chuck pin 26 are set to the reference coordinate (X basis_pos2 ,Y basis_pos2 ) and the coordinates of a predetermined pixel in the reference image 201 of the third state of the chuck pin 26 are set to the reference coordinate (X basis_pos3 ,Y basis_pos3 Figure 21 shows an example of reference coordinates in reference image 201. As shown in the example in Figure 21, the reference coordinates can be the lower left corner (origin Z) of the corresponding reference image. Note that the reference coordinates may be any location within the reference image (for example, the upper right corner of the reference image, or the center of the reference image).

[0148] The reference image 201, along with the target image 202, is shown in the coordinate system of the overall image of the chuck pin 26 and is located within the coordinate system of the target image 202.

[0149] Next, assuming that the control unit 9 recognizes the current open / closed state of the chuck pin 26 as the first state, pattern matching is performed between the target image 202 and the reference image 201. Then, the coordinates of the origin Z of the reference image 201 when the matching score is the highest are searched. When the matching score is the highest, for example, when using SSD (Sum of Squared Difference), which is one of the methods for indicating the similarity between images, R SSD corresponds to the minimum value of the sum of the squared differences of the pixel values indicating the similarity. In addition, methods for indicating the similarity between images in pattern matching include, but are not limited to, SAD (Sum of Absolute Difference) or NCC (Normalized Cross-Correlation).

[0150] Here, when the highest matching score is within a predetermined threshold (for example, the minimum value of the R SSD value is smaller than the threshold), the coordinates of the origin Z of the reference image 201 when the matching score is the highest are calculated as the matching coordinates (X target , Y target ). The matching coordinates are calculated in the coordinate system of the target image 202.

[0151] On the other hand, when the highest matching score is not within the predetermined threshold (for example, the minimum value of the R SSD value is larger than the threshold), it is assumed that the matching fails and the matching coordinates are not calculated. As a result, since the open / closed state of the chuck pin 26 can be detected based on the matching coordinates when the matching score is high, the detection accuracy of the open / closed state of the chuck pin 26 is improved. Note that the matching coordinates may be calculated regardless of whether the matching score is within the threshold.

[0152] Next, the analysis unit 91 detects the open / closed state of the chuck pin 26 based on the matching coordinates. Specifically, the reference coordinates (X basis_pos1 , Ybasis_pos1 ) and the matching coordinates (X) obtained as described above. target ,Y target If the similarity between the two coordinates is within a predetermined threshold, the control unit 9 considers its recognition that the chuck pin 26 is in the first state to be correct (i.e., it detects that the open / closed state of the chuck pin 26 is in the first state). The similarity here is determined, for example, by calculating the Euclidean distance between the two coordinates and determining whether that value is within the threshold mentioned above.

[0153] On the other hand, if the similarity is not within a predetermined threshold, the control unit 9 considers its recognition that the chuck pin 26 is in the first state to be incorrect, and then determines the reference coordinate (X) of the second state. basis_pos2 ,Y basis_pos2 ) and the matching coordinates (X target ,Y target The similarity between (X) and the reference coordinates of the second state is calculated. basis_pos2 ,Y basis_pos2 If the similarity between ) and is not within a predetermined threshold, further, the reference coordinate (X) of the third state basis_pos3 ,Y basis_pos3 ) and the matching coordinates (X target ,Y target The similarity between the two is calculated. This method allows for accurate detection of the open / closed state of the chuck pin 26.

[0154] Figures 18 and 19 show examples of matching coordinate distributions. Figure 18 shows the distribution of matching coordinates for chuck pin 26b in Figures 16 and 17. Figure 19 shows the distribution of matching coordinates for chuck pin 26d in Figures 16 and 17. In Figures 18 and 19, the vertical axis shows an example of the Y coordinate (numerical value is an example) of the coordinate system provided in the target image, and the horizontal axis shows an example of the X coordinate (numerical value is an example) of the coordinate system provided in the target image.

[0155] Figures 18 and 19 show the results of pattern matching processing performed with multiple target images, each using a second state of a different chuck pin 26 as a reference image. In Figures 18 and 19, ranges 301, 302, and 303 represent predetermined ranges centered on the reference coordinates of the first, second, and third states, respectively. Range 301 contains the matching coordinates when the chuck pin 26 in the target image 202 represents the first state (range 301 corresponds to the threshold range used when calculating the similarity of the first state). Range 302 contains the matching coordinates when the chuck pin 26 in the target image 202 represents the second state (range 302 corresponds to the threshold range used when calculating the similarity of the second state). Furthermore, range 303 contains the matching coordinates when the chuck pin 26 in the target image 202 represents the third state (range 303 corresponds to the threshold range used when calculating the similarity of the third state).

[0156] As shown in Figures 18 and 19, the range in which the matching coordinates are located is clearly divided depending on the open / closed state of the chuck pin 26 in the target image 202 (i.e., the first state, the second state, and the third state). In other words, the open / closed state of the chuck pin 26 in the target image 202 can be clearly distinguished by the matching coordinates (this is also true for chuck pins other than chuck pins 26b and chuck pin 26d shown in Figures 18 and 19). Therefore, the analysis unit 91 can detect the open / closed state of the chuck pin 26 by determining which range the calculated matching coordinates belong to.

[0157] Here, if the matching coordinates are not included in any of ranges 301, 302, and 303, the analysis unit 91 does not detect the open / closed state of the chuck pin 26. As a result, the open / closed state of the chuck pin 26 can be detected based on matching coordinates that are included in the appropriate range, thus improving the accuracy of detecting the open / closed state of the chuck pin 26. Note that if the chuck pin 26 is not in any of the first, second, or third states, that is, if the substrate W is riding on the chuck pin 26 (corresponding to step ST12), or if the substrate W is placed but the chuck pin 26 is unable to grip the substrate W and is in an empty gripping state, the matching coordinates will be located at coordinates not included in any of ranges 301, 302, and 303.

[0158] In the example above, the second state of the chuck pin 26 was used as the reference image. However, even if other states (i.e., the first or third state) are used as the reference image, the range in which the matching coordinates are located is clearly divided according to the open / closed state of the chuck pin 26 in the target image 202 (i.e., the first, second, and third states). Therefore, as in the example above, the open / closed state of the chuck pin 26 in the target image 202 can be detected according to the matching coordinates.

[0159] Furthermore, the ranges 301, 302, and 303, which include the matching coordinates, may have their size or position changed based on the average value of the calculated matching coordinates. However, if the change in the size or position of the range exceeds a predetermined threshold, it may be possible that the chuck pin 26 is not being driven properly due to aging or other reasons, and warnings may be issued as needed.

[0160] <Regarding the detection of the presence or absence of a circuit board> Ranges 301, 302, and 303 shown in Figures 18 and 19 correspond to matching coordinates representing different open / closed states of the chuck pin 26 (a state in which the chuck pin 26 is completely closed without gripping the substrate W, a state in which the chuck pin 26 is gripping the substrate W, and a state in which the chuck pin 26 is open regardless of the presence or absence of the substrate W). Of the three open / closed states described above, if the chuck pin 26 is gripping the substrate W, the state in which the chuck pin 26 is completely closed without gripping the substrate W is excluded, and if the chuck pin 26 is not gripping the substrate W, the state in which the chuck pin 26 is gripping the substrate W is excluded. Therefore, the range in which the matching coordinates may be included is limited depending on whether or not the chuck pin 26 is gripping the substrate W.

[0161] Therefore, for example, the analysis unit 91 performs image analysis (for example, brightness analysis at a position corresponding to the center of the spin base 21) on an image showing the spin chuck 20 as shown in Figure 17, and detects whether or not the chuck pins 26 are gripping the substrate W. This allows the open / closed state of the chuck pins 26 to be detected not only when the matching coordinates are limited to one of the ranges 301, 302, and 303, but also within a limited range (coordinate range) depending on whether or not the chuck pins 26 are gripping the substrate W. As a result, detection of the open / closed state of the chuck pins 26 based on matching coordinates not included in the appropriate range is suppressed, thus improving the detection accuracy of the open / closed state of the chuck pins 26.

[0162] <Regarding the extraction range of the target image> If structures other than the chuck pin 26 (for example, the substrate W, or water droplets adhering to the periphery of the spin chuck 20) ​​are included within the range of the target image 202, the matching accuracy may decrease.

[0163] Therefore, when extracting the target image 202, by setting the extraction range to have a longitudinal direction along the outer edge 400 of the substrate W, it is possible to avoid including structures other than the chuck pin 26 in the image (at least reduce the range in which structures other than the chuck pin 26 are included in the image) and suppress mismatching.

[0164] Figure 20 shows an example of target image extraction. As shown in the example in Figure 20, the extraction range is set so that the target image 202A has a longitudinal direction along the outer edge 400 of the substrate W. Therefore, it is possible to avoid including structures other than the chuck pin 26 in the target image 202A.

[0165] Although the extraction range of the target image 202 was described above, the extraction range of the reference image 201A can also be set to have a longitudinal direction along the outer edge 400 of the substrate W.

[0166] <Regarding the effects resulting from the multiple embodiments described above> Next, examples of the effects produced by the multiple embodiments described above will be shown. In the following description, the effects will be described based on the specific configurations illustrated in the multiple embodiments described above, but they may be replaced with other specific configurations illustrated in this specification to the extent that similar effects are produced. That is, for convenience, in the following, only one of the corresponding specific configurations may be described as representative, but the specific configuration described as representative may be replaced with other corresponding specific configurations.

[0167] Furthermore, such substitutions may be made across multiple embodiments. That is, the configurations exemplified in different embodiments may be combined to produce similar effects.

[0168] According to the embodiment described above, in the position determination method, a substrate W held at a reference position in the substrate holding unit (spin chuck 20) ​​and not rotating is imaged, and the imaged image is output as a reference image. Then, the region in the reference image that includes the edge of the substrate W is set as a reference region 320 (or reference regions 321, 322, and 323), and the pixel position of the edge of the substrate W in the reference region is detected as a reference pixel position. On the other hand, a substrate W placed in the spin chuck 20 and not rotating is imaged, and the imaged image is output as a comparison image. Then, the region in the comparison image that includes the edge of the substrate W is set as a comparison region, and the pixel position of the edge of the substrate W in the comparison region is detected as a comparison pixel position. Then, it is determined whether the difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold. Here, the step of detecting the reference pixel position includes the steps of: calculating a reference score, which is the value obtained by accumulating the difference between the brightness of the target pixel in the reference region and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate W, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction; and setting the position of the target pixel corresponding to the maximum reference score among a plurality of reference scores sequentially calculated in the radial direction of the reference region as the reference pixel position. Furthermore, the step of detecting the comparison pixel position includes the steps of: calculating a comparison score, which is the value obtained by accumulating the difference between the brightness of the target pixel in the comparison region and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate W, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction; and setting the position of the target pixel corresponding to the maximum comparison score among a plurality of comparison scores sequentially calculated in the radial direction of the comparison region as the comparison pixel position.

[0169] With this configuration, the brightness difference is accumulated in a direction perpendicular to the radial direction of the substrate W to calculate a score, and the reference pixel position and comparison pixel position can be detected with high accuracy using this score. Therefore, the positional misalignment of the edge of the substrate W can be determined with high accuracy based on the difference between the reference pixel position and the comparison pixel position.

[0170] Unless otherwise specified, the order in which each process is performed can be changed.

[0171] Furthermore, the same effect can be achieved even if other configurations exemplified in this specification are appropriately added to the above configuration, that is, if other configurations in this specification that are not mentioned as the above configuration are appropriately added.

[0172] Furthermore, according to the embodiments described above, the difference between the brightness of the target pixel and the brightness of the adjacent pixel is calculated only when the brightness of the pixel located radially outward from the target pixel and the adjacent pixel is higher. With such a configuration, it becomes easier to distinguish between an image showing the substrate W where the brightness is relatively low and an image showing the surrounding area surrounding the substrate W where the brightness is relatively high.

[0173] Furthermore, according to the embodiments described above, the corrected reference score is obtained by multiplying the reference score by a distribution coefficient based on the luminance distribution in the reference region. The reference pixel position is the position of the target pixel corresponding to the corrected reference score that is maximum in the reference region. With this configuration, the corrected reference score can be calculated using a distribution coefficient that reflects the luminance distribution in the reference region, thereby improving the detection accuracy of the reference pixel position.

[0174] Furthermore, according to the embodiments described above, the reference pixel position corresponds to the position of the target pixel that has the maximum correction reference score in the reference region only when the average brightness in the inner range of the reference region is lower than the average brightness in the radially outer range of the reference region. With such a configuration, even if an unintended brightness change occurs in an image showing a substrate W with relatively low brightness, it is possible to suppress the detection of the reference pixel position based on that change.

[0175] Furthermore, according to the embodiments described above, the corrected comparison score is obtained by multiplying the comparison score by a distribution coefficient based on the luminance distribution in the comparison region. The comparison pixel position is the position of the target pixel corresponding to the corrected comparison score that is maximum in the comparison region. With this configuration, the corrected comparison score can be calculated using a distribution coefficient that reflects the luminance distribution in the comparison region, thereby improving the detection accuracy of the comparison pixel position.

[0176] Furthermore, according to the embodiments described above, the comparison pixel position corresponds to the position of the target pixel that yields the maximum correction comparison score in the comparison region only when the average brightness in the inner range of the comparison region is lower than the average brightness in the radially outer range of the comparison region. With such a configuration, even if an unintended brightness change occurs in an image showing a substrate W with relatively low brightness, it is possible to suppress the detection of the comparison pixel position based on that change.

[0177] Furthermore, according to the embodiments described above, the distribution coefficient is the average brightness of pixels located radially outside the target pixel. With such a configuration, the brightness distribution of pixels in the reference region can be reflected in the reference score, or the brightness distribution of pixels in the comparison region can be reflected in the comparison score, thereby improving the detection accuracy of the reference pixel position or the comparison pixel position.

[0178] Furthermore, according to the embodiments described above, the pixels in the reference region and the comparison region are remapped so that they are arranged along the radial direction. With this configuration, even if the pixel arrangement direction in the image does not match the radial direction of the substrate W, the brightness difference between adjacent pixels and its sum can be easily calculated by remapping and changing the pixel arrangement.

[0179] According to the embodiment described above, the position determination device comprises a substrate holding unit for holding the substrate W, an imaging unit, and an analysis unit 91. Here, the substrate holding unit corresponds to, for example, a spin chuck 20. The imaging unit corresponds to, for example, a camera 70. The camera 70 images the substrate W on the spin chuck 20. The analysis unit 91 analyzes the image captured by the camera 70 to detect the pixel positions at the edges of the substrate W. Here, the image of the substrate W held at a reference position on the spin chuck 20 and not rotating, as captured by the camera 70, is defined as the reference image. Furthermore, in the reference region 320 (or reference region 321, reference region 322, reference region 323), which is the region including the edges of the substrate W in the reference image, the pixel positions at the edges of the substrate W are defined as the reference pixel positions. Furthermore, the image of the substrate W placed on the spin chuck 20 and not rotating, as captured by the camera 70 (an image to be compared with the reference image), is defined as the comparison image. Furthermore, in the comparison region, which is the area including the edge of the substrate W in the comparison image, the pixel position at the edge of the substrate W is defined as the comparison pixel position. The analysis unit 91 then detects the reference pixel position and the comparison pixel position, and determines whether the difference between the reference pixel position and the comparison pixel position exceeds a threshold. Here, the analysis unit 91 calculates a reference score, which is the value obtained by accumulating the difference between the brightness of the target pixel in the reference region and the brightness of the adjacent pixels adjacent to the target pixel in the radial direction of the substrate W, with respect to pixels that are aligned with the target pixel in a direction perpendicular to the radial direction. The analysis unit 91 then detects the position of the target pixel corresponding to the largest reference score among the multiple reference scores sequentially calculated in the radial direction of the reference region as the reference pixel position. The analysis unit 91 also calculates a comparison score, which is the value obtained by accumulating the difference between the brightness of the target pixel in the comparison region and the brightness of the adjacent pixels adjacent to the target pixel in the radial direction of the substrate W, with respect to pixels that are aligned with the target pixel in a direction perpendicular to the radial direction. The analysis unit 91 then detects the position of the target pixel corresponding to the largest comparison score among the multiple comparison scores sequentially calculated in the radial direction within the comparison region, and uses this position as the comparison pixel position.

[0180] With this configuration, the brightness difference is accumulated in a direction perpendicular to the radial direction of the substrate W to calculate a score, and the reference pixel position and comparison pixel position can be detected with high accuracy using this score. Therefore, the positional misalignment of the edge of the substrate W can be determined with high accuracy based on the difference between the reference pixel position and the comparison pixel position.

[0181] Furthermore, the same effect can be achieved even if other configurations exemplified in this specification are appropriately added to the above configuration, that is, if other configurations in this specification that are not mentioned as above configurations are appropriately added.

[0182] <Modifications of the multiple embodiments described above> In the embodiments described above, the brightness of pixels was added together to calculate a reference score or comparison score. However, instead of the brightness of pixels, for example, the average values ​​of the RGB elements in a single pixel may be added together. Furthermore, adjacent pixels, which are pixels adjacent to the target pixel, are not limited to the single pixel next to the target pixel, but may include one or two more adjacent pixels.

[0183] Furthermore, in the various embodiments described above, the material, dimensions, shape, relative arrangement, or implementation conditions of each component may also be described, but these are merely examples in all aspects and are not limiting.

[0184] Accordingly, countless variations and equivalents not shown are envisioned within the scope of the art disclosed herein. These include, for example, modifications, additions, or omissions of at least one component, as well as the extraction of at least one component from at least one embodiment and its combination with a component from another embodiment.

[0185] Furthermore, in at least one embodiment described above, if a material name or the like is mentioned without further specification, it is assumed that the material includes other additives, such as an alloy, unless otherwise specified, to avoid any inconsistencies.

[0186] Furthermore, each component described in the embodiments described above can be envisioned as software or firmware, or as corresponding hardware. As software, it may be referred to as, for example, a "part," and as hardware, it may be referred to as, for example, a "processing circuit." [Explanation of symbols]

[0187] 91 Analysis Department 201 Reference Image 201A Reference Image 304 Reference area 320 Reference area 321 Reference area 322 Reference area 323 Reference area 409 benchmark score 409A Reference Score 410 Corrected Criteria Score 410A Correction Reference Score 501 pixel position 502 pixel position 503 pixel position 504 pixel position 600 Distribution coefficient 600A Distribution Coefficient

Claims

1. The process involves capturing an image of a substrate that is held in a reference position in the substrate holder and is not rotating, and outputting the captured image as a reference image. The steps include setting a region in the reference image that includes the edge of the substrate as a reference region, and detecting the pixel position of the edge of the substrate in the reference region as a reference pixel position, The process involves taking an image of the substrate, which is placed in the substrate holding section and is not rotating, and outputting the captured image as a comparison image. The steps include setting the region in the comparison image that includes the edge of the substrate as a comparison region, and detecting the pixel position of the edge of the substrate in the comparison region as a comparison pixel position, The system includes a step of determining whether the difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold, The step of detecting the reference pixel position is, A step of calculating a reference score, which is the value obtained by accumulating the difference between the brightness of a target pixel in the reference region and the brightness of adjacent pixels adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction. The process includes the step of setting the position of the target pixel corresponding to the largest reference score among a plurality of reference scores calculated by sequentially shifting the position of the target pixel along the radial direction in the reference region and repeatedly accumulating the difference between the brightness of the target pixel and the brightness of the adjacent pixels in the reference region, as the reference pixel position. The step of detecting the comparison pixel position is, The process of calculating a comparison score, which is the sum of the values ​​obtained by calculating the difference between the brightness of the target pixel in the comparison region and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate for each pixel in the comparison region, and by integrating the values ​​obtained by integrating the values ​​obtained by pixels adjacent to the target pixel in a direction perpendicular to the radial direction, The process includes the step of setting the position of the target pixel corresponding to the largest comparison score among a plurality of comparison scores calculated by sequentially shifting the position of the target pixel along the radial direction in the comparison region and repeatedly accumulating the difference between the brightness of the target pixel and the brightness of the adjacent pixel in the comparison region, as the comparison pixel position. Location determination method.

2. The position determination method is as described in claim 1, The difference between the brightness of the target pixel and the brightness of the adjacent pixel is calculated only when the brightness of the pixel located on the outer side of the substrate in the radial direction is higher than that of the target pixel and the adjacent pixel. Location determination method.

3. A step of imaging a substrate that is held in a reference position of the substrate holder and is not rotating, and outputting the image as a reference image, The steps include setting a region in the reference image that includes the edge of the substrate as a reference region, and detecting the pixel position of the edge of the substrate in the reference region as a reference pixel position, The process involves taking an image of the substrate, which is placed in the substrate holding section and is not rotating, and outputting the captured image as a comparison image. The steps include setting the region in the comparison image that includes the edge of the substrate as a comparison region, and detecting the pixel position of the edge of the substrate in the comparison region as a comparison pixel position, The system includes a step of determining whether the difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold, The step of detecting the reference pixel position is, A step of calculating a reference score, which is the value obtained by accumulating the difference between the brightness of a target pixel in the reference region and the brightness of adjacent pixels adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction. The process includes setting the position of the target pixel corresponding to the largest reference score among a plurality of reference scores sequentially calculated in the radial direction within the reference region as the reference pixel position. The step of detecting the comparison pixel position is, The process of calculating a comparison score, which is the sum of the values ​​obtained by calculating the difference between the brightness of the target pixel in the comparison region and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate for each pixel in the comparison region, and by integrating the values ​​obtained by integrating the values ​​obtained by pixels adjacent to the target pixel in a direction perpendicular to the radial direction, The process includes setting the position of the target pixel corresponding to the largest of the multiple comparison scores sequentially calculated in the radial direction within the comparison region as the comparison pixel position. The corrected reference score is obtained by multiplying the aforementioned reference score by a distribution coefficient based on the luminance distribution in the aforementioned reference region. The reference pixel position is the position of the target pixel corresponding to the correction reference score that is maximized in the reference region. Location determination method.

4. The position determination method is as described in claim 3, The reference pixel position becomes the position of the target pixel corresponding to the correction reference score that is maximum in the reference region only when the average brightness in the inner range of the reference region is lower than the average brightness in the radially outer range of the reference region. Location determination method.

5. A step of imaging a substrate that is held in a reference position of the substrate holder and is not rotating, and outputting the image as a reference image, The steps include setting a region in the reference image that includes the edge of the substrate as a reference region, and detecting the pixel position of the edge of the substrate in the reference region as a reference pixel position, The process involves taking an image of the substrate, which is placed in the substrate holding section and is not rotating, and outputting the captured image as a comparison image. The steps include setting the region in the comparison image that includes the edge of the substrate as a comparison region, and detecting the pixel position of the edge of the substrate in the comparison region as a comparison pixel position, The system includes a step of determining whether the difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold, The step of detecting the reference pixel position is, A step of calculating a reference score, which is the value obtained by accumulating the difference between the brightness of a target pixel in the reference region and the brightness of adjacent pixels adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction. The process includes setting the position of the target pixel corresponding to the largest reference score among a plurality of reference scores sequentially calculated in the radial direction within the reference region as the reference pixel position. The step of detecting the comparison pixel position is, The process of calculating a comparison score, which is the sum of the values ​​obtained by calculating the difference between the brightness of the target pixel in the comparison region and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate for each pixel in the comparison region, and by integrating the values ​​obtained by integrating the values ​​obtained by pixels adjacent to the target pixel in a direction perpendicular to the radial direction, The process includes setting the position of the target pixel corresponding to the largest of the multiple comparison scores sequentially calculated in the radial direction within the comparison region as the comparison pixel position. The corrected comparison score is obtained by multiplying the aforementioned comparison score by a distribution coefficient based on the luminance distribution in the comparison region. The comparison pixel position is the position of the target pixel corresponding to the correction comparison score that is maximized in the comparison region. Location determination method.

6. The position determination method is as described in claim 5, The position of the comparison pixel corresponds to the position of the target pixel that yields the maximum correction comparison score in the comparison region only when the average brightness in the inner range of the comparison region is lower than the average brightness in the outer range of the radial direction of the comparison region. Location determination method.

7. The position determination method is as described in claim 3, The distribution coefficient is the average brightness of pixels located radially outside the target pixel. Location determination method.

8. A step of imaging a substrate that is held in a reference position of the substrate holder and is not rotating, and outputting the image as a reference image, The steps include setting a region in the reference image that includes the edge of the substrate as a reference region, and detecting the pixel position of the edge of the substrate in the reference region as a reference pixel position, The process involves taking an image of the substrate, which is placed in the substrate holding section and is not rotating, and outputting the captured image as a comparison image. The steps include setting the region in the comparison image that includes the edge of the substrate as a comparison region, and detecting the pixel position of the edge of the substrate in the comparison region as a comparison pixel position, The system includes a step of determining whether the difference between the reference pixel position and the comparison pixel position exceeds a predetermined threshold, The step of detecting the reference pixel position is, A step of calculating a reference score, which is the value obtained by accumulating the difference between the brightness of a target pixel in the reference region and the brightness of adjacent pixels adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction. The process includes setting the position of the target pixel corresponding to the largest reference score among a plurality of reference scores sequentially calculated in the radial direction within the reference region as the reference pixel position. The step of detecting the comparison pixel position is, The process of calculating a comparison score, which is the sum of the values ​​obtained by calculating the difference between the brightness of the target pixel in the comparison region and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate for each pixel in the comparison region, and by integrating the values ​​obtained by integrating the values ​​obtained by pixels adjacent to the target pixel in a direction perpendicular to the radial direction, The process includes setting the position of the target pixel corresponding to the largest of the multiple comparison scores sequentially calculated in the radial direction within the comparison region as the comparison pixel position. The pixels in the reference region and the comparison region are remapped so that they are arranged along the radial direction. Location determination method.

9. A substrate holding section that holds the substrate, The substrate holding section includes an imaging unit for imaging the substrate, The system includes an analysis unit that analyzes the image captured by the imaging unit and detects the pixel position at the edge of the substrate, The image captured by the imaging unit of the substrate being held in the reference position of the substrate holding part in the above image and not rotating is used as the reference image. In the reference region, which is the region including the edge of the substrate in the reference image, the pixel position of the edge of the substrate is set as the reference pixel position. The image captured by the imaging unit of a substrate that is placed in the substrate holding unit and is not rotating is used as a comparison image. In the comparison region, which is the region including the edge of the substrate in the comparison image, the pixel position of the edge of the substrate is defined as the comparison pixel position. The analysis unit detects the reference pixel position and the comparison pixel position, and determines whether the difference between the reference pixel position and the comparison pixel position exceeds a threshold value. The aforementioned analysis unit, A reference score is calculated by accumulating the difference between the brightness of the target pixel in the reference region and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction orthogonal to the radial direction. Furthermore, while sequentially shifting the position of the target pixel along the radial direction in the reference region, the accumulation of the difference between the brightness of the target pixel and the brightness of the adjacent pixel in the reference region is repeated to calculate a plurality of reference scores. The position of the target pixel corresponding to the reference score with the largest reference score is detected as the reference pixel position. In the comparison region, the difference between the brightness of the target pixel and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate is calculated for each pixel in the comparison region. A comparison score is calculated by accumulating the values ​​of the comparison scores obtained by sequentially shifting the position of the target pixel along the radial direction in the comparison region and repeatedly accumulating the difference between the brightness of the target pixel and the brightness of the adjacent pixel in the comparison region. The position of the target pixel corresponding to the largest comparison score among the multiple comparison scores calculated is detected as the comparison pixel position. Position determination device.

10. A substrate holding part for holding a substrate, The substrate holding section includes an imaging unit for imaging the substrate, The system includes an analysis unit that analyzes the image captured by the imaging unit and detects the pixel position at the edge of the substrate, The image captured by the imaging unit of the substrate being held in the reference position of the substrate holding part in the above image and not rotating is used as the reference image. In the reference region, which is the region including the edge of the substrate in the reference image, the pixel position of the edge of the substrate is set as the reference pixel position. The image captured by the imaging unit of a substrate that is placed in the substrate holding unit and is not rotating is used as a comparison image. In the comparison region, which is the region including the edge of the substrate in the comparison image, the pixel position of the edge of the substrate is defined as the comparison pixel position. The analysis unit detects the reference pixel position and the comparison pixel position, and determines whether the difference between the reference pixel position and the comparison pixel position exceeds a threshold value. The aforementioned analysis unit, A reference score is calculated by accumulating the difference between the brightness of the target pixel in the reference region and the brightness of adjacent pixels adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction. Furthermore, the position of the target pixel corresponding to the maximum reference score among a plurality of reference scores sequentially calculated in the radial direction of the reference region is detected as the reference pixel position. In the comparison region, the difference between the brightness of the target pixel and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate is calculated for each pixel in the comparison region. A comparison score is calculated by accumulating the values ​​of the adjacent pixels adjacent to the target pixel in a direction perpendicular to the radial direction. Furthermore, the position of the target pixel corresponding to the largest comparison score among the multiple comparison scores sequentially calculated in the radial direction of the comparison region is detected as the comparison pixel position. The corrected reference score is obtained by multiplying the aforementioned reference score by a distribution coefficient based on the luminance distribution in the aforementioned reference region. The reference pixel position is the position of the target pixel corresponding to the correction reference score that is maximized in the reference region. Position determination device.

11. A substrate holding part for holding a substrate, The substrate holding section includes an imaging unit for imaging the substrate, The system includes an analysis unit that analyzes the image captured by the imaging unit and detects the pixel position at the edge of the substrate, The image captured by the imaging unit of the substrate being held in the reference position of the substrate holding part in the above image and not rotating is used as the reference image. In the reference region, which is the region including the edge of the substrate in the reference image, the pixel position of the edge of the substrate is set as the reference pixel position. The image captured by the imaging unit of a substrate that is placed in the substrate holding unit and is not rotating is used as a comparison image. In the comparison region, which is the region including the edge of the substrate in the comparison image, the pixel position of the edge of the substrate is defined as the comparison pixel position. The analysis unit detects the reference pixel position and the comparison pixel position, and determines whether the difference between the reference pixel position and the comparison pixel position exceeds a threshold value. The aforementioned analysis unit, A reference score is calculated by accumulating the difference between the brightness of the target pixel in the reference region and the brightness of adjacent pixels adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction. Furthermore, the position of the target pixel corresponding to the maximum reference score among a plurality of reference scores sequentially calculated in the radial direction of the reference region is detected as the reference pixel position. In the comparison region, the difference between the brightness of the target pixel and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate is calculated for each pixel in the comparison region. A comparison score is calculated by accumulating the values ​​of the adjacent pixels adjacent to the target pixel in a direction perpendicular to the radial direction. Furthermore, the position of the target pixel corresponding to the largest comparison score among the multiple comparison scores sequentially calculated in the radial direction of the comparison region is detected as the comparison pixel position. The corrected comparison score is obtained by multiplying the aforementioned comparison score by a distribution coefficient based on the luminance distribution in the comparison region. The comparison pixel position is the position of the target pixel corresponding to the correction comparison score that is maximized in the comparison region. Position determination device.

12. A substrate holding part for holding a substrate, The substrate holding section includes an imaging unit for imaging the substrate, The system includes an analysis unit that analyzes the image captured by the imaging unit and detects the pixel position at the edge of the substrate, The image captured by the imaging unit of the substrate being held in the reference position of the substrate holding part in the above image and not rotating is used as the reference image. In the reference region, which is the region including the edge of the substrate in the reference image, the pixel position of the edge of the substrate is set as the reference pixel position. The image captured by the imaging unit of a substrate that is placed in the substrate holding unit and is not rotating is used as a comparison image. In the comparison region, which is the region including the edge of the substrate in the comparison image, the pixel position of the edge of the substrate is defined as the comparison pixel position. The analysis unit detects the reference pixel position and the comparison pixel position, and determines whether the difference between the reference pixel position and the comparison pixel position exceeds a threshold value. The aforementioned analysis unit, A reference score is calculated by accumulating the difference between the brightness of the target pixel in the reference region and the brightness of adjacent pixels adjacent to the target pixel in the radial direction of the substrate, with respect to pixels adjacent to the target pixel in a direction perpendicular to the radial direction. Furthermore, the position of the target pixel corresponding to the maximum reference score among a plurality of reference scores sequentially calculated in the radial direction of the reference region is detected as the reference pixel position. In the comparison region, the difference between the brightness of the target pixel and the brightness of the adjacent pixel adjacent to the target pixel in the radial direction of the substrate is calculated for each pixel in the comparison region. A comparison score is calculated by accumulating the values ​​of the adjacent pixels adjacent to the target pixel in a direction perpendicular to the radial direction. Furthermore, the position of the target pixel corresponding to the largest comparison score among the multiple comparison scores sequentially calculated in the radial direction of the comparison region is detected as the comparison pixel position. The pixels in the reference region and the comparison region are remapped so that they are arranged along the radial direction. Position determination device.

Images