State determination method, substrate processing device, and program

Abstract

To accurately determine a shaking state of a substrate in detaching the substrate.SOLUTION: A state determination method for a substrate processing device that includes a mounting table for mounting a substrate in a processing container, an electrostatic chuck for electrostatically attaching the substrate, a lift pin for moving up and down the substrate from the mounting table, and an image capturing part includes the steps of: capturing a moving image including from a first state where the substrate is held by electrostatic attraction to a second state where the electrostatic attraction to the substrate is released and the substrate is lifted by the lift pin after static elimination processing; detecting a position of a corner of the substrate on the basis of a first image which is obtained by capturing an image of the first state included in the moving image; tracing the position of the corner of the substrate on the basis of a plurality of images which is time-serially captured after the first image; calculating a change amount in a height direction of the traced position of the corner of the substrate; determining a shaking degree of the substrate on the basis of the change amount; and outputting an alert according to the shaking degree of the substrate.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a state determination method, a substrate processing apparatus, and a program. [Background technology]

[0002] Patent Document 1 discloses a measurement method for calculating the residual charge of a wafer before the wafer is detached from an electrostatic chuck. In the measurement method disclosed in Patent Document 1, a substrate placed on a stage in a processing chamber is electrostatically attracted by an electrostatic chuck, and then processed with plasma generated from a gas by applying high-frequency power, and the substrate is vibrated by vertically moving pins supporting the substrate, and the residual charge of the substrate is calculated from an induced current of the attracting electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-107265 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that enables the state of vibration of a substrate when the substrate is detached from an electrostatic chuck to be determined with high accuracy. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a condition determination method to be performed in a substrate processing apparatus having a processing vessel, a mounting stage on which a substrate is placed within the processing vessel, an electrostatic chuck provided on the mounting stage and electrostatically adsorbing the substrate, lift pins for raising and lowering the substrate from the mounting stage, and an imaging unit for imaging the substrate, the condition determination method including the steps of: (a) capturing a video including a first state in which the substrate is held by the electrostatic chuck by electrostatic adsorption, to a second state in which the electrostatic adsorption to the substrate is released and the substrate is raised by the lift pins after a discharge process; (b) detecting positions of corners of the substrate based on a first image captured of the first state included in the video; (c) tracking the positions of the corners of the substrate based on a plurality of images captured in chronological order after the first image included in the video; (d) calculating an amount of change in the height direction of the position of the tracked corner of the substrate; (e) determining a degree of wobble of the substrate based on the amount of change; and (f) outputting a warning depending on the determined degree of wobble of the substrate. Effect of the Invention

[0006] According to one aspect, it is possible to accurately determine the state of vibration of a substrate when the substrate is detached from an electrostatic chuck. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic cross-sectional view illustrating an example of a substrate processing apparatus according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of a hardware configuration of a control device according to an embodiment. [Diagram 3] FIG. 2 is a block diagram showing an example of a functional configuration of a control device according to an embodiment. [Figure 4] 1 is a flowchart illustrating an example of a state determination method according to an embodiment. [Diagram 5] 10 is a flowchart illustrating an example of a vibration detection process according to an embodiment. [Figure 6] FIG. 13 is an explanatory diagram of detection of a corner of a substrate. [Figure 7] FIG. 13 is an explanatory diagram of selection of a corner of a substrate. [Figure 8] FIG. 13 is an explanatory diagram of tracking of a corner of a substrate. [Figure 9] FIG. 11 is an explanatory diagram of a determination of shaking detection. [Figure 10] 3 is a flowchart showing a substrate processing, a charge removal process, and a cleaning process in the substrate processing apparatus; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0009] In a substrate processing apparatus, a DC voltage is applied to an electrode of an electrostatic chuck to attract a substrate to the electrostatic chuck, and after processing the substrate, a discharge process is performed to remove residual charges by generating plasma for discharge when the substrate is detached from the electrostatic chuck. If discharge is insufficient at this time, the substrate may crack or dielectric breakdown may occur due to ESD (Electro Static Discharge) when the substrate is lifted by the lift pins.

[0010] In one example of a substrate vibration detection method, the sides of a rectangular substrate are detected from a video captured by a camera connected to a processing vessel, and the sides are approximated as straight lines, and the fluctuation in the height direction of the straight lines near the corners of the substrate is calculated to detect the substrate vibration.

[0011] However, because the height of the center point of the line is used as the standard when approximating the sides of the board to a straight line, the board's vibration may be underestimated due to board bending, making it impossible to accurately detect the board's vibration due to board bending.In addition, straight lines due to the board pattern may be erroneously detected, which may have a negative impact on the analysis results.

[0012] In one embodiment of the present disclosure, a method is proposed in which the feature points for detecting the vibration of the substrate are the corners of the substrate, not the sides, based on a video of the substrate captured in a processing vessel, and the detected corners are tracked. The video includes at least a state in which the substrate is held on the mounting table (electrostatic chuck) by electrostatic adsorption, a state in which the electrostatic adsorption to the substrate is released, and the substrate is subjected to a charge removal process using plasma and then lifted by the lift pins. In this embodiment, the amount of change in the height direction of the position of the corner of the substrate specified from the video is extracted, and the degree of the vibration of the substrate is determined based on the amount of change. Then, a warning is output based on the determined degree of the vibration of the substrate. This allows the state of the vibration of the substrate when the substrate is detached from the mounting table (electrostatic chuck) to be determined with high accuracy.

[0013] [Substrate processing equipment] FIG. 1 is a schematic cross-sectional view showing an example of a substrate processing apparatus according to the present embodiment. The substrate processing apparatus 100 is an inductively coupled plasma (ICP) processing apparatus that performs various substrate processing methods on a rectangular substrate (hereinafter simply referred to as a "substrate") G for a flat panel display (FPD). The substrate is mainly made of glass, and transparent synthetic resin may be used depending on the application. Here, the substrate processing includes an etching process and a film formation process using a chemical vapor deposition (CVD) method. An example of an FPD is a liquid crystal display (LCD). An electroluminescence (EL), a plasma display panel (PDP), or the like may also be used. The substrate G includes a support substrate as well as a substrate having a circuit patterned on its surface. The planar dimensions of the FPD substrate are becoming larger with each generation. The planar dimensions of the substrate G processed by the substrate processing apparatus 100 include at least dimensions ranging from about 1500 mm×1800 mm for the sixth generation to about 3000 mm×3400 mm for the 10.5th generation. The thickness of the substrate G is about 0.2 mm to several mm.

[0014] The substrate processing apparatus 100 includes a rectangular parallelepiped box-shaped processing vessel 10, a mounting table 60 having a rectangular outer shape in a plan view that is disposed in the processing vessel 10 and on which a substrate G is mounted, and a control device 90. The processing vessel 10 may have a shape such as a cylindrical box or an elliptical cylindrical box, and in this embodiment, the mounting table 60 is also circular or elliptical, and the substrate G mounted on the mounting table 60 is also circular or the like.

[0015] The processing vessel 10 is divided into two spaces, an upper space and an lower space, by a dielectric plate 11, with the upper space, or antenna chamber, being formed by an upper chamber 12, and the lower space, or processing chamber S, being formed by a lower chamber 13. The processing vessel 10 is made of a metal such as aluminum, and the dielectric plate 11 is made of a ceramic such as alumina (Al2O3) or quartz.

[0016] In the processing vessel 10, a rectangular ring-shaped support frame 14 is disposed at a position that is the boundary between the lower chamber 13 and the upper chamber 12 so as to protrude into the inside of the processing vessel 10, and a dielectric plate 11 is placed on the support frame 14. The processing vessel 10 is grounded by a ground wire 13e.

[0017] A loading / unloading port 13b for loading / unloading a substrate G into / from the lower chamber 13 is provided in a side wall 13a of the lower chamber 13, and the loading / unloading port 13b can be opened and closed by a gate valve 20. A transfer chamber (neither shown) containing a transfer mechanism is adjacent to the lower chamber 13, and the gate valve 20 is controlled to open and close, and the substrate G is loaded and unloaded by the transfer mechanism through the loading / unloading port 13b.

[0018] A viewport 13c made of a light-transmitting material such as quartz is provided on the sidewall 13a of the lower chamber 13. A camera 25, which is an example of an imaging unit, is connected to the outside of the viewport 13c. The camera 25 is a digital camera capable of capturing video. The camera 25 is installed so as to capture an image of the substrate G placed on the mounting table 60 from the side in the horizontal direction through the viewport 13c.

[0019] When the entire substrate G cannot be captured in the field of view of one camera 25, a plurality of viewports 13c and cameras 25 are provided so that any portion of the entire substrate G can be captured in the field of view of any one of the cameras 25. For example, two cameras 25 may be provided, with the first camera 25 capturing an image of the substrate G from a direction perpendicular to a first side surface of the substrate G, and the second camera 25 capturing an image of the substrate G from a direction perpendicular to a second side surface adjacent to the first side surface. The recording format of the video captured by the camera 25 is not limited, but may be, for example, a video captured at 25 frames per second (fps).

[0020] A plurality of exhaust ports 13f are formed in a bottom plate 13d of the lower chamber 13. A gas exhaust pipe 51 is connected to the exhaust port 13f, and the gas exhaust pipe 51 is connected to an exhaust device 53 via a pressure control valve 52. The gas exhaust pipe 51, the pressure control valve 52, and the exhaust device 53 form a gas exhaust section 50. The exhaust device 53 has a vacuum pump such as a turbo molecular pump, and is capable of freely reducing the pressure inside the lower chamber 13 to a predetermined level during the process.

[0021] A support beam for supporting the dielectric plate 11 is provided on the lower surface of the dielectric plate 11, and the support beam also serves as a shower head 30. The shower head 30 is made of a metal such as aluminum, and may be subjected to a surface treatment by anodization. A gas flow passage 31 extending in the horizontal direction is formed inside the shower head 30. The gas flow passage 31 is connected to a gas ejection hole 32 extending downward and facing the processing chamber S below the shower head 30.

[0022] A gas introduction pipe 45 communicating with the gas flow passage 31 is connected from the upper surface of the dielectric plate 11 to the shower head 30 (support beam). The gas introduction pipe 45 airtightly penetrates the supply port 12b opened in the ceiling 12a of the upper chamber 12, and is connected to a processing gas supply source 44 via a gas supply pipe 41 airtightly coupled to the gas introduction pipe 45. An opening / closing valve 42 and a flow rate controller 43 such as a mass flow controller are interposed in the middle of the gas supply pipe 41. The gas introduction pipe 45, the gas supply pipe 41, the opening / closing valve 42, the flow rate controller 43, and the processing gas supply source 44 form a processing gas supply unit 40. The processing gas supplied from the processing gas supply unit 40 is supplied to the shower head 30 via the gas supply pipe 41 and the gas introduction pipe 45, and is discharged into the processing chamber S via the gas flow passage 31 and the gas discharge hole 32.

[0023] A high frequency antenna 15 is disposed in the upper chamber 12 which forms the antenna room. The high frequency antenna 15 is formed by winding an antenna wire 15a made of a conductive metal such as copper in a circular or spiral shape. For example, multiple circular antenna wires 15a may be disposed.

[0024] A power supply member 16 extending above the upper chamber 12 is connected to the terminal of the antenna line 15a, and a power supply line 17 is connected to the upper end of the power supply member 16, and the power supply line 17 is connected to a high-frequency power source 19 via a matching device 18 that performs impedance matching. When high-frequency power of, for example, 13.56 MHz is supplied to the high-frequency antenna 15 from the high-frequency power source 19, an inductive electric field is formed in the lower chamber 13. This inductive electric field converts the processing gas supplied from the shower head 30 to the processing chamber S into plasma, generating inductively coupled plasma, and ions, neutral radicals, etc. in the plasma are provided to the substrate G. The high-frequency power source 19 is a source for generating plasma, and the high-frequency power source 73 connected to the mounting table 60 is a bias source that attracts the generated ions and gives them kinetic energy. In this way, the ion source generates plasma using inductive coupling, and a bias source, which is a separate power source, is connected to the mounting table 60 to control the ion energy. This allows the generation of plasma and the control of ion energy to be performed independently, increasing the degree of freedom of the process.

[0025] The mounting table 60 includes a base material 63 and an electrostatic chuck 66 formed on an upper surface 63a of the base material 63. The base material 63 has a rectangular shape in a plan view and has planar dimensions similar to those of the substrate G mounted on the mounting table 60, with the long side length being about 1800 mm to 3400 mm and the short side length being about 1500 mm to 3000 mm. With respect to these planar dimensions, the thickness of the base material 63 can be, for example, about 50 mm to 100 mm. The base material 63 is formed of stainless steel, aluminum, an aluminum alloy, or the like. The base material 63 is provided with a temperature control medium flow passage 62a that meanders to cover the entire area of ​​the rectangular plane. The temperature control medium flow passage 62a may be provided in, for example, the electrostatic chuck 66. The base material 63 may be formed of a laminate of two members, not a single member as in the illustrated example.

[0026] Both ends of the temperature control medium flow path 62a are connected to a feed pipe 62b through which the temperature control medium is supplied to the temperature control medium flow path 62a, and a return pipe 62c through which the temperature control medium that has been heated by flowing through the temperature control medium flow path 62a is discharged. The feed pipe 62b and the return pipe 62c are connected to a feed flow path 82 and a return flow path 83, respectively, and the feed flow path 82 and the return flow path 83 are connected to a chiller 81. The chiller 81 has a main body that controls the temperature and discharge flow rate of the temperature control medium, and a pump that pressure-feeds the temperature control medium (neither is shown). A refrigerant is used as the temperature control medium, and Galden (registered trademark), Fluorinert (registered trademark), or the like is used as this refrigerant. The temperature control form in the illustrated example is a form in which the temperature control medium is circulated through the base material 63, but the base material 63 may have a built-in heater or the like and the temperature may be controlled by the heater, or the temperature may be controlled by both the temperature control medium and the heater. Also, instead of using a heater, a high-temperature temperature control medium may be circulated to control the temperature by heating. The heater, which is a resistor, is made of tungsten or molybdenum, or a compound of any one of these metals with alumina, titanium, or the like. In the illustrated example, the temperature control medium flow path 62a is formed in the base material 63, but for example, the electrostatic chuck 66 may have a temperature control medium flow path.

[0027] A box-shaped pedestal 68 made of an insulating material and having a step on the inside is fixed on the bottom plate 13d of the lower chamber 13, and the mounting table 60 is mounted on the step of the pedestal 68. An electrostatic chuck 66 on which the substrate G is directly mounted is formed on the upper surface of the base material 63. The electrostatic chuck 66 has a ceramic layer 64 which is a dielectric coating formed by thermally spraying ceramics such as alumina, and an adsorption electrode 65 which is a conductive layer having an electrostatic adsorption function and is embedded inside the ceramic layer 64. The adsorption electrode 65 is connected to a DC power source 75 via a power supply line 74 and a switch 76. When the control device 90 turns on the switch 76, a DC voltage is applied from the DC power source 75 to the adsorption electrode 65, generating a Coulomb force. The Coulomb force electrostatically adsorbs the substrate G to the electrostatic chuck 66 and holds it on the upper surface of the base material 63. During static elimination, when the switch 76 is turned off and a switch 77 interposed in the static elimination line branched off from the power supply line 74 is turned on, the charge accumulated in the chucking electrode 65 flows to the ground through the static elimination line. In this manner, the mounting table 60 forms a lower electrode on which the substrate G is placed. Note that instead of connecting the static elimination line branched off from the power supply line 74 to the ground, a DC power supply (not shown) that applies a DC voltage of the opposite polarity to the chucking electrode 65 may be provided, and the interposed switch 77 may be turned on to allow the charge accumulated in the chucking electrode 65 to flow to the ground.

[0028] A temperature sensor such as a thermocouple is disposed on the base material 63, and monitor information from the temperature sensor is transmitted to the control device 90 as needed. The control device 90 performs temperature control of the base material 63 and the substrate G based on the transmitted temperature monitor information. More specifically, the control device 90 adjusts the temperature and flow rate of the temperature control medium supplied from the chiller 81 to the feed flow path 82. The temperature control medium whose temperature and flow rate have been adjusted is then circulated through the temperature control medium flow path 62a, thereby performing temperature control of the mounting table 60. The temperature sensor such as a thermocouple may be disposed on the electrostatic chuck 66, for example.

[0029] A rectangular frame-shaped focus ring 69 is placed on the upper surface of base 68 around the outer periphery of electrostatic chuck 66 and base material 63, and is set so that the upper surface of focus ring 69 is lower than the upper surface of electrostatic chuck 66. Focus ring 69 is made of ceramics such as alumina, quartz, or the like.

[0030] A power supply member 70 is connected to the lower surface of the base material 63. A power supply line 71 is connected to the lower end of the power supply member 70, and the power supply line 71 is connected to a high frequency power supply 73, which is a bias source, via a matcher 72 that performs impedance matching. When high frequency power of, for example, 3.2 MHz is supplied from the high frequency power supply 73 to the mounting table 60, ions generated by the high frequency power supply 19, which is a source for generating plasma, can be attracted to the substrate G. Therefore, in the plasma etching process, it is possible to increase both the etching rate and the etching selectivity.

[0031] A plurality of lift pins 78, for example twelve lift pins 78, are provided inside the mounting table 60 to raise and lower the substrate G in order to transfer the substrate G to and from an external transfer arm (not shown). For simplification, two lift pins 78 are shown in FIG. 1. The lift pins 78 penetrate the mounting table 60 and move up and down by the power of a motor transmitted via a connecting member. A bottom bellows (not shown) is provided in the through hole of the lift pin 78 that penetrates toward the outside of the processing vessel, and maintains airtightness between the vacuum side and the atmospheric side inside the processing vessel.

[0032] [Control device hardware configuration] Fig. 2 is a block diagram showing an example of a hardware configuration of the control device 90 according to this embodiment. As shown in Fig. 2, the control device 90 includes a CPU (Central Processing Unit) 500, a RAM (Random Access Memory) 501, a ROM (Read Only Memory) 502, an auxiliary storage device 503, a communication interface (I / F) 504, an input / output interface (I / F) 505, and a media interface (I / F) 506.

[0033] The CPU 500 operates based on a program stored in the ROM 502 or the auxiliary storage device 503, and controls each unit. The ROM 502 stores a boot program executed by the CPU 500 when the control device 90 is started, a program dependent on the hardware of the control device 90, and the like.

[0034] The auxiliary storage device 503 is, for example, a hard disk drive (HDD) or a solid state drive (SSD). The auxiliary storage device 503 stores programs executed by the CPU 500 and data used by the programs. The CPU 500 reads the programs from the auxiliary storage device 503, loads them onto the RAM 501, and executes the loaded programs.

[0035] The communication I / F 504 communicates with each part of the substrate processing apparatus 100 via a communication line such as a LAN (Local Area Network). The communication I / F 504 receives data from each part of the substrate processing apparatus 100 via the communication line and sends it to the CPU 500, and transmits data generated by the CPU 500 to each part of the substrate processing apparatus 100 via the communication line.

[0036] The CPU 500 controls an input device such as a keyboard and an output device such as a display via the input / output I / F 505. The CPU 500 acquires signals input from the input devices via the input / output I / F 505 and sends them to the CPU 500. The CPU 500 also outputs generated data to the output device via the input / output I / F 505.

[0037] The media I / F 506 reads a program or data stored in a recording medium 507 and stores it in the auxiliary storage device 503. The recording medium 507 is, for example, an optical recording medium such as a DVD (Digital Versatile Disc) or a PD (Phase change rewritable Disc), a magneto-optical recording medium such as an MO (Magneto-Optical disk), a tape medium, a magnetic recording medium, or a semiconductor memory.

[0038] The CPU 500 of the control device 90 reads the program to be loaded onto the RAM 501 from the recording medium 507 and stores it in the auxiliary storage device 503, but as another example, the program may be obtained from another device via a communication line and stored in the auxiliary storage device 503.

[0039] The control device 90 controls the operations of each component of the substrate processing apparatus 100, such as the chiller 81, the high frequency power supplies 19 and 73, the DC power supply 75, the process gas supply unit 40, the gas exhaust unit 50, and the camera 25. The CPU 500 executes a predetermined process according to a recipe (process recipe) stored in a storage area of ​​the RAM 501 or the ROM 502. The recipe contains control information for the substrate processing apparatus 100 with respect to process conditions. The control information includes, for example, the gas flow rate, the pressure in the process vessel 10, the temperature in the process vessel 10, the temperature of the substrate 63, and the process time.

[0040] The recipes and the programs applied by the control device 90 may be stored, for example, on a hard disk, a compact disk, a magneto-optical disk, etc. Furthermore, the recipes and the like may be stored in a portable computer-readable recording medium such as a CD-ROM, a DVD, a memory card, etc., and set in the control device 90 and read out.

[0041] [Control device functional configuration] 3 is a block diagram showing an example of the functional configuration of the control device 90 according to the present embodiment. As shown in FIG. 3, the control device 90 according to the present embodiment includes an imaging control unit 91, a video storage unit 92, a vibration detection unit 93, an output unit 94, and a substrate processing unit 95.

[0042] The imaging control unit 91, the vibration detection unit 93, the output unit 94, and the substrate processing unit 95 are realized, for example, by the CPU 500 shown in Fig. 2 executing a program loaded on the RAM 501. The moving image storage unit 92 is realized, for example, by the RAM 501 or the auxiliary storage device 503 shown in Fig. 2.

[0043] The imaging control unit 91 controls the camera 25 to capture an image of the substrate G placed on the mounting table 60. The imaging control unit 91 stores the video captured by the camera 25 in the video storage unit 92.

[0044] The photography control unit 91 controls the camera 25 to capture a video (hereinafter also referred to as a "substrate video") that includes a state in the processing vessel 10 in which the substrate G is held by electrostatic adsorption on the mounting table 60 (electrostatic chuck 66) (hereinafter also referred to as the "first state"), to a state in which the electrostatic adsorption to the substrate G is released, the substrate G is subjected to a plasma de-electrification process, and then is lifted by the lift pins 78 (hereinafter also referred to as the "second state").

[0045] The video storage unit 92 stores a substrate video captured by the camera 25. The substrate video is stored in association with information indicating the time when the substrate G starts to rise due to the lift pins 78 and the time when the rise ends.

[0046] The wobble detection unit 93 detects the degree of wobble of the board. The wobble detection unit 93 includes a corner detection unit 931, a corner tracking unit 932, a difference calculation unit 933, and a determination unit 934. The corner detection unit 931 detects the position of a corner of the board based on a first image captured in a first state included in the board video. The corner detection unit 931 detects the corner of the board that is closest to the camera 25 at the same time as starting detection of the wobble of the board.

[0047] The corner detection unit 931 may extract a plurality of frame images from the board video, either consecutively in chronological order or at predetermined intervals, and may detect the position of the corner of the board based on the earliest frame, with the earliest frame being regarded as a first image among the plurality of frame images.

[0048] The corner tracking unit 932 tracks the position of the corner of the board based on a plurality of images captured in time series after a first image included in the board video. The corner tracking unit 932 tracks the position of the detected corner and acquires the height of the corner of the board.

[0049] The corner tracker 932 may sequentially track the position of the corner of the substrate in each frame image subsequent to the first image among the plurality of frame images.

[0050] The difference calculation unit 933 calculates the amount of change in the height direction (Y coordinate) of the position of the tracked corner of the board. The determination unit 934 determines the degree of the board shaking based on the amount of change. The difference calculation unit 933 may detect, for example, the difference value of the Y coordinate between adjacent frames among each frame image of the board video as the board shaking.

[0051] When the amount of change in the Y coordinate exceeds a predetermined threshold, the output unit 94 outputs a warning. The warning notifies the user that the degree of the determined board vibration may have exceeded the normal range.

[0052] The substrate processing section 95 performs substrate processing such as film formation, etching, etc. The substrate processing is performed in a state where the substrate G is electrostatically attracted to the mounting table 60 by the electrostatic chuck 66.

[0053] [Procedure for determining status] 4 is a flowchart showing an example of a state determination method according to the present embodiment. The state determination method according to the present embodiment is executed by the control device 90.

[0054] In step S1, the photography control unit 91 controls the camera 25 to capture a video (substrate video) of the substrate G placed on the mounting table 60. The photography control unit 91 controls to capture a substrate video in which the progress of the substrate G rising is recorded so as to include a first state in which the substrate G is held by electrostatic adsorption on the mounting table 60 (electrostatic chuck 66) to a second state in which the substrate G is lifted by the lift pins 78 after the electrostatic adsorption to the substrate G is released and the substrate G is subjected to a discharging process by plasma.

[0055] The substrate video captured by the camera 25 may include other states as well as the first state to the second state. For example, the imaging control unit 91 may capture a series of processes performed on the substrate G from start to finish.

[0056] The photography control unit 91 stores the substrate video captured by the camera 25 in the video storage unit 92. The photography control unit 91 stores information indicating the time when the substrate G started to be lifted by the lift pins 78 after the charge removal process and the time when the lifting ended, in association with the substrate video. When the substrate G is photographed by multiple cameras 25, the photography control unit 91 stores the multiple substrate videos captured by the cameras 25 in the video storage unit 92 in synchronization with a reference photography time. The reference photography time is, for example, the time when the substrate G started to be lifted by the lift pins 78.

[0057] In step S2, the vibration detection unit 93 reads out the substrate video stored in the video storage unit 92. Next, a vibration detection process is executed to detect, from the read out substrate video, any up and down vibrations that occur in the substrate G due to the lifting by the lift pins 78. The details of the vibration detection process will be described later with reference to FIG.

[0058] The substrate video is a video obtained by capturing the substrate G being pinned up from the side in a horizontal direction. The substrate G has a size of at least 1800 mm to 3400 mm in long sides and 1500 mm to 3000 mm in short sides. On the other hand, since the thickness is about 0.2 mm to several mm, distortion and bending are likely to occur. The generated distortion and bending fluctuate with the pinning up, and cause the substrate G to shake. If the static elimination process is insufficient, the substrate G becomes difficult to detach from the mounting table 60 due to the electric charge remaining on the mounting table 60, and further distortion and bending occur in the substrate G when the pinning up. Therefore, if the static elimination process is insufficient, the shaking generated in the substrate G with the lifting by the lift pins 78 depicted in the substrate video is different from that in the normal state in which the static elimination process is sufficiently performed.

[0059] (Shake detection processing) 5 is a flowchart showing an example of the vibration detection process (step S2 in FIG. 4) according to this embodiment. The vibration detection process is executed by the vibration detection unit 93 and the output unit 94.

[0060] In step S2-1, the corner detection unit 931 of the shaking detection unit 93 acquires the x-th frame (hereinafter also referred to as the "target frame") from the board video, where x is a positive integer. The target frame is an example of a first image included in the video.

[0061] In step S2-2, the corner detection unit 931 detects the corner of the substrate G from the x-th frame. The corner detection unit 931 detects the corner closest to the camera 25 among the four corners of the substrate. When two or more corners of the four different corners of the substrate are detected, the corner detection unit 931 may determine one corner from the four different corners of the substrate, or may execute the processes from step S2-3 onward for each angle of the two or more different corners detected. The corner detection unit 931 may detect the corner of the substrate G after converting the x-th frame to grayscale or dividing it.

[0062] The corner detection method may be, for example, using a Harris corner detector or the like, to define a point where the pixel value changes significantly with respect to all neighboring pixels as a corner point, which is an image feature point, and detect the corners. However, the corner detection method is not limited to this. In the example of Fig. 6, the corner detection unit 931 detects image feature points such as B1, B2, B3, etc., which are candidates for corners.

[0063] In step S2-3, the corner detection unit 931 selects a corner within a predetermined area. That is, corners outside the predetermined area are deleted. In the example of Fig. 7, for one corner of the board, the corner detection unit 931 selects a corner B1 within a predetermined area A.

[0064] The predetermined area (e.g., area A in FIG. 7) is specified in advance to be a size that does not erroneously detect other corners within the processing vessel 10 and can detect the substrate even if it is placed slightly misaligned on the mounting table 60.

[0065] In step S2-4, the corner tracking unit 932 tracks the position of the corner of the board based on a plurality of frames captured in chronological order after the xth frame included in the board video. For example, n frames from the x+1th to the x+nth frames captured in chronological order after the xth frame are obtained from the board video. Here, n is a predetermined positive integer, and is the number of frames used to track the position of the corner. In this embodiment, n is, for example, 100.

[0066] The corner tracking unit 932 tracks the corner of the substrate G selected in S2-3 in chronological order for the n frames from the x+1th to the x+nth frames, and obtains the height position (referred to as the Y coordinate) perpendicular to the mounting surface of the substrate G.

[0067] As a result, in the example of Fig. 8 following Fig. 7, as the substrate G rises due to pin-up, the corner tracking unit 932 tracks the corner B1 of the substrate G upward in the height direction indicated by the arrow T, and acquires the Y coordinate of the corner for each frame. The corner tracking method may be, for example, the Lucas-Kanade method. However, the corner tracking method is not limited to this.

[0068] In step S2-5, the difference calculation unit 933 calculates the difference value (amount of change) between the acquired Y coordinate frames. The difference value between the Y coordinate frames is detected as the magnitude of the vibration of the board.

[0069] Fig. 9 shows an example of the result of calculating the difference value between the acquired Y coordinate frames. The horizontal axis of Fig. 9 indicates time, and the vertical axis indicates the Y coordinate (pixels). However, for convenience of calculation, the numerical value of the Y coordinate is set to increase in the downward direction. Therefore, the smaller the Y coordinate (pixels) value on the vertical axis, the more the substrate G rises. Note that, for the sake of simplicity, the unit of position in the height direction is expressed in pixels constituting the image, since the camera 25 is fixed and the distance between the object being photographed does not change, but a common unit of distance such as centimeters (cm) may also be used.

[0070] In the enlarged view of part C in FIG. 9, the Y coordinate of corner B1 fluctuates and gradually descends. In other words, the board G rises while fluctuating up and down. The difference value of the Y coordinate between frames is the difference value of the Y coordinate between adjacent frames. The maximum difference value of the Y coordinate between frames is the maximum swing of the board when the pin is up. Therefore, the difference calculation unit 933 calculates the maximum upward difference value and the maximum downward difference value of the Y coordinate between adjacent frames of the position of the tracked corner of the board.

[0071] 9, the maximum value Max1 of the upward difference value between adjacent frames of the Y coordinate is the maximum value of the Y coordinate when the substrate G swings downward. Also, the maximum value Max2 of the downward difference value between adjacent frames of the Y coordinate is the maximum value of the Y coordinate when the substrate G swings upward.

[0072] In step S2-6, the determination unit 934 determines whether the maximum value of the difference values ​​exceeds a predetermined threshold value. The determination unit 934 determines whether the maximum value Max1 of the upward difference values ​​(the maximum value when the substrate G swings downward, shown as facing upward in FIG. 9) exceeds a predetermined first threshold value. The determination unit 934 also determines whether the maximum value Max2 of the downward difference values ​​(the maximum value when the substrate G swings upward, shown as facing downward in FIG. 9) exceeds a predetermined second threshold value. The first and second threshold values ​​are preset within a range of about 1 to 2 cm.

[0073] If the determination unit 934 determines that the maximum value of the upward difference value exceeds a predetermined first threshold value, or if the maximum value of the downward difference value exceeds a predetermined second threshold value, the determination result is YES. In this case, in step S2-7, the output unit 94 outputs a warning and then ends the process.

[0074] In step S2-7, if the maximum value of the difference values ​​does not exceed a predetermined threshold value, that is, if the determination unit 934 determines that the maximum value of the upward difference values ​​does not exceed the first threshold value and the maximum value of the downward difference values ​​does not exceed the second threshold value, the result is NO. In this case, the process ends without outputting a warning.

[0075] According to this, when the magnitude of the fluctuation of the Y coordinate exceeds a threshold value, it is determined that the degree (magnitude) of the fluctuation of the substrate exceeds a normal range, and a warning is output. In response to this, the user can instruct the control device 90 to perform cleaning inside the processing vessel 10. This allows cleaning to be performed before the phenomenon of the substrate cracking or bouncing occurs when the substrate is detached.

[0076] In step 2-4, the corner tracking unit 932 tracks the position of the corner of the board based on a plurality of frames captured in time series after the x-th frame included in the board moving image.

[0077] In this case, the maximum upward difference value and the maximum downward difference value may be calculated from the height difference value of the positions of the corners of the board between chronologically consecutive frame images among the multiple frame images.

[0078] Furthermore, the maximum upward difference value and the maximum downward difference value may be calculated from the height difference value of the positions of the corners of the board between frame images spaced apart in time series among the multiple frame images.

[0079] [Example of effect] Fig. 10 is a diagram showing the flow of substrate processing, charge removal processing (start of charge removal, completion of charge removal), and cleaning in the substrate processing apparatus 100. The substrate processing shown to the left of the dotted line in Fig. 10 indicates processing of the first to m-th substrates after cleaning from top to bottom in the substrate processing apparatus 100.

[0080] In the substrate processing apparatus 100, a DC voltage is applied to the attraction electrode 65 of the electrostatic chuck 66 to attract the substrate to the electrostatic chuck 66, and substrate processing such as film formation is performed in this state. In the charge removal process shown on the right side of the vertical dotted line in Fig. 10, when the substrate G is detached from the electrostatic chuck 66 after the substrate processing, a plasma for charge removal is generated and the attraction electrode 65 is connected to, for example, ground. As a result, the substrate G is lifted by the lift pins 78 in a state where residual charges have been removed. At this time, if charge removal is insufficient, the substrate may crack or insulation breakdown due to ESD (Electro Static Discharge) may occur.

[0081] Immediately after cleaning as shown in Fig. 10, no by-products are attached to the electrostatic chuck 66, and the adsorption of the substrate G is completely released by removing the charge. At this time, the vibration of the substrate G is small when the pin is up. When the number of substrates processed increases, by-products (dirt) adhere to the electrostatic chuck 66 during substrate processing, and the by-products become charged, so that even when the charge is removed, the charge remains, and the adsorption of the substrate G to the electrostatic chuck 66 is not completely released. At this time, it is considered that the substrate G becomes difficult to peel off from the electrostatic chuck 66, and the vertical vibration of the substrate G increases when the pin is up.

[0082] Furthermore, if the amount of by-products (dirt) adhering to the electrostatic chuck 66 increases, the adhesion of the substrate G to the electrostatic chuck 66 becomes even worse. That is, even if a charge removal process is performed, the charge is not sufficiently removed, and the adhesion force of the substrate G to the electrostatic chuck 66 remains strong. At this time, the substrate G may shake significantly up and down when pinned up. As a result, the substrate G may crack or bounce when pinned up.

[0083] In the state determination method according to the present embodiment, the degree of contamination (degree of adhesion of by-products) of the electrostatic chuck 66 can be indirectly predicted from the magnitude of the vertical vibration of the substrate G. Thus, the magnitude of the vertical vibration of the substrate G is used as an index when cleaning the inside of the processing vessel 10 including the electrostatic chuck 66.

[0084] The magnitude of the vertical vibration of the substrate G can be the difference in Y coordinate between adjacent frames. Therefore, when the difference in Y coordinate between adjacent frames exceeds a predetermined threshold, a warning is output to prompt the user to clean the inside of the processing vessel 10 before the substrate G breaks. This allows cleaning to be performed at an appropriate time, and damage to the substrate G during pin-up can be avoided.

[0085] During detachment of the substrate, there is almost no lateral shaking of the substrate. Therefore, in the state determination method according to this embodiment, the difference value of the Y coordinate between chronologically adjacent frames is compared with a threshold value, and the degree of contamination of the electrostatic chuck 66 is predicted based on the comparison result.

[0086] As described above, the state determination method according to this embodiment includes the steps of: (a) capturing a video including a first state in which the substrate is held on the mounting table (electrostatic chuck) by electrostatic adsorption, to a second state in which the electrostatic adsorption to the substrate is released and the substrate is lifted by the lift pins after a discharge process; (b) detecting the position of a corner of the substrate based on a first image capturing the first state included in the video; (c) tracking the position of the corner of the substrate based on a plurality of images captured in chronological order after the first image included in the video; (d) calculating the amount of change in the height direction of the tracked position of the corner of the substrate; (e) determining the degree of wobble of the substrate based on the amount of change; and (f) outputting a warning if the determined degree of wobble of the substrate exceeds a predetermined threshold.

[0087] In the state determination method according to the present embodiment, steps (b) to (f) are performed based on the video captured and stored in step (a), i.e., after step (a) is completed. Alternatively, steps (b) to (f) may be performed before step (a) is completed, i.e., the corners of the substrate may be tracked in real time while continuing to capture images, and the degree of shaking may be determined. In this way, a warning may be output in real time based on the determined degree of shaking of the substrate until the neutralization of the substrate is completed, or before the processing of the next substrate is started.

[0088] As described above, according to the state determining method executed in the substrate processing apparatus of this embodiment, the state of vibration of the substrate when the substrate is detached from the electrostatic chuck can be determined with high accuracy.

[0089] The state determination method, substrate processing apparatus, and program according to the disclosed embodiments should be considered as illustrative and not restrictive in all respects. The embodiments can be modified and improved in various forms without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be configured in other ways as long as they are not inconsistent, and can be combined as long as they are not inconsistent.

[0090] The substrate processing apparatus 100 of the present disclosure can be applied to any type of apparatus for plasma enhanced atomic layer deposition (PE-ALD), plasma enhanced chemical vapor deposition (PE-CVD), and dry etching. [Explanation of symbols]

[0091] G board 10 Processing vessel 12 Upper chamber 13 Lower chamber 25 Camera (photography department) 30. Shower Head 50 Gas exhaust section 60 Placement table 65 Adsorption electrode 66 Electrostatic Chuck 74 Power line 75 DC power supply 78 Lift Pin 90 Control device 91 Shooting control section 92 Video storage section 93 Shake detection unit 931 Corner detection unit 932 Corner Tracking Unit 933 Difference calculation part 934 Judgment section 94 Output section 95 Substrate Processing Section 100 Substrate processing apparatus

Claims

1. A processing vessel; a mounting table for mounting a substrate within the processing chamber; an electrostatic chuck provided on the mounting table and configured to electrostatically attract the substrate; a lift pin for lifting and lowering the substrate from the mounting table; An imaging unit that images the substrate; A state determination method performed in a substrate processing apparatus having the following features: (a) taking a video including a first state in which the substrate is held by an electrostatic chuck by electrostatic attraction, to a second state in which the electrostatic attraction to the substrate is released and the substrate is lifted by lift pins after a discharge process; (b) detecting a position of a corner of the substrate based on a first image captured in the first state and included in the moving image; (c) tracking a position of a corner of the substrate based on a plurality of images captured in time series after the first image included in the moving image; (d) calculating an amount of change in the position of the tracked corner of the substrate in the height direction; (e) determining a degree of wobble of the substrate based on the amount of change; (f) outputting a warning according to the determined degree of shaking of the substrate; A state determination method comprising the steps of:

2. The step (d) comprises: Calculating a maximum value of an upward change in a height direction of the tracked corner position of the substrate relative to a placement surface of the substrate and a maximum value of a downward change in the height direction as a degree of vibration of the substrate; The step (f) comprises: outputting a warning when the maximum value of the downward change amount exceeds a predetermined first threshold value or when the maximum value of the upward change amount exceeds a predetermined second threshold value; The state determination method according to claim 1 .

3. The step (b) comprises: extracting a plurality of frame images from the video, either successively in time series or at predetermined time intervals in time series, and detecting a position of a corner of the board based on the first image among the plurality of frame images; The state determination method according to claim 2 .

4. The step (c) comprises: tracking a position of a corner of the substrate in each of the frame images that chronologically follow the first image among the plurality of frame images; The state determination method according to claim 3 .

5. The maximum value of the upward change amount and the maximum value of the downward change amount are The amount of change in the height direction of the position of the corner of the board is calculated from the amount of change in the height direction of the frame images spaced at predetermined intervals in a time series among the plurality of frame images. The state determination method according to claim 3 or 4.

6. The maximum value of the upward change amount and the maximum value of the downward change amount are The change amount is calculated from the amount of change in the height direction of the position of the corner of the board in chronologically consecutive frame images among the plurality of frame images. The state determination method according to claim 3 or 4.

7. After the step (a) is completed, steps (b) to (f) are carried out. The state determination method according to any one of claims 1 to 4.

8. executing the steps (b) to (f) before the step (a) is completed, and outputting the warning before the processing of the next substrate is started based on the determined degree of vibration of the substrate; The state determination method according to any one of claims 1 to 4.

9. The substrate processing apparatus is a flat panel display (FPD) manufacturing apparatus. The state determination method according to any one of claims 1 to 4.

10. A processing vessel; a mounting table for mounting a substrate within the processing chamber; an electrostatic chuck provided on the mounting table and configured to electrostatically attract the substrate; a lift pin for lifting and lowering the substrate from the mounting table; An imaging unit that images the substrate; A control device; A substrate processing apparatus comprising: The control device includes: an imaging control unit that captures a video including a first state in which the substrate is held by the electrostatic chuck by electrostatic attraction, to a second state in which the electrostatic attraction to the substrate is released and the substrate is lifted by lift pins after a discharge process; and a corner detection unit that detects a position of a corner of the board based on a first image captured in the first state and included in the moving image; a corner tracking unit that tracks a position of a corner of the board based on a plurality of images captured in time series after the first image included in the video; a difference calculation unit that calculates a change amount in a height direction of a position of the tracked corner of the substrate; a determination unit that determines a degree of shaking of the substrate based on the amount of change; an output unit that outputs a warning according to the determined degree of shaking of the substrate; A substrate processing apparatus comprising:

11. The control device includes: (a) taking a video including a first state in which the substrate is held by the electrostatic chuck by electrostatic attraction, to a second state in which the electrostatic attraction to the substrate is released and the substrate is lifted by lift pins after a discharge process; (b) detecting a position of a corner of the substrate based on a first image captured in the first state and included in the moving image; (c) tracking a position of a corner of the substrate based on a plurality of images captured in time series after the first image included in the moving image; (d) calculating an amount of change in the position of the tracked corner of the substrate in the height direction; (e) determining a degree of wobble of the substrate based on the amount of change; (f) outputting a warning according to the determined degree of shaking of the substrate; A program for executing the above.

Images