Control parameter adjustment method and storage medium

Abstract

The present invention provides a control parameter adjustment method that can efficiently adjust movement control parameters even when there are constraints on movement control for moving a substrate relative to a nozzle. The control parameter adjustment method includes: a discharge data preparation step (S20) for preparing discharge data representing time changes in the discharge amount of a treatment liquid discharged by a nozzle (71); and a movement control parameter adjustment step for adjusting movement control parameters of a moving mechanism (5) for controlling the relative movement of a substrate (S) relative to the nozzle after the discharge data preparation step. The movement control parameter adjustment step includes: a movement speed measurement step (S24) for measuring the movement speed when the moving mechanism is controlled according to the set movement control parameters; and an evaluation value derivation step (S28) for deriving an evaluation value of the speed data obtained in the movement speed measurement step using the discharge data and a speed data evaluation function to which the movement control constraints in the moving mechanism are applied.

Description

Technical Field

[0001] The subject matter disclosed in this specification relates to a control parameter adjustment method and a storage medium. Background Art

[0002] In the manufacturing process of flat panel displays (FPDs), substrate processing devices called coaters are used. Coating machines spray a treatment liquid, such as a resist, from a nozzle onto a substrate such as glass, scanning the nozzle across the substrate. The coater applies pressure to the treatment liquid, such as the resist, causing it to be ejected from the nozzle. Furthermore, a moving mechanism moves the substrate relative to the nozzle, forming a coating film of the treatment liquid on the substrate's surface.

[0003] In such substrate processing devices, it is sometimes required to achieve a uniform film thickness across the entire substrate. Appropriate adjustments are made to the coating conditions and control parameters to achieve a uniform film thickness. During this adjustment, a technician visually confirms the waveform of the ejection pressure and adjusts multiple control parameters. Therefore, this adjustment operation relies heavily on the technician's knowledge and experience. Consequently, adjusting control parameters requires a significant amount of time and effort on the technician's part. Furthermore, this may consume a significant amount of processing fluid. Therefore, techniques for efficiently adjusting control parameters have been proposed.

[0004] For example, Patent Document 1 proposes a method for adjusting a pump drive command based on the theoretical assumption that if the ratio of the discharge flow rate of the treatment liquid to the travel speed of the coating unit (30) relative to the substrate (10) is constant, the thickness of the coating film on the substrate (10) will be constant. Specifically, for each predetermined interval, the slope of the discharge flow rate waveform and the slope of the travel speed waveform are calculated, and the pump drive command is adjusted so that the error of the calculated slope is within an allowable range.

[0005] In addition, patent document 2 proposes the following method: a formula is defined to calculate the estimated film thickness (Th) based on the physical properties of the liquid such as the concentration of the dried and solidified portion of the processing liquid on the substrate (G) and the substrate adhesion coefficient (μ) of the processing liquid, and the moving speed of the substrate (G) is calculated using this formula.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-005465;

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-206114.

[0010] However, the method described in Patent Document 2 does not consider the movement control constraints imposed on the moving mechanism (e.g., acceleration and deceleration control constraints). Consequently, there is no guarantee that the substrate movement speed calculated using the formula is actually controllable. If the speed calculated using the formula is not controllable, it becomes difficult to efficiently adjust the movement control parameters used to control the moving mechanism. Summary of the Invention

[0011] An object of the present invention is to provide a technique for efficiently adjusting movement control parameters even when there are constraints on movement control for moving a substrate relative to a nozzle.

[0012] In order to solve the above-mentioned problems, the first technical solution is a control parameter adjustment method for adjusting the control parameters of a substrate processing device, which sprays a processing liquid from a nozzle while moving the substrate relative to the nozzle to apply the processing liquid to the substrate, including: a) a spray data preparation process for preparing spray data representing the time change of the spray amount of the processing liquid sprayed from the nozzle; and b) after the spray data preparation process, a movement control parameter adjustment process for adjusting the movement control parameters of the moving mechanism for controlling the relative movement of the substrate relative to the nozzle, the movement control parameter adjustment process including: b-1) a movement speed measurement process for measuring the movement speed when the moving mechanism is controlled according to the set movement control parameters; and b-2) an evaluation process for evaluating the speed data obtained in the movement speed measurement process using the spray data and an evaluation function to which the movement control constraints in the moving mechanism are applied.

[0013] A second technical means is the control parameter adjustment method according to the first technical means, wherein the evaluation function is a function that derives an evaluation value indicating a difference between the ejection data and the velocity data.

[0014] The third technical solution is the control parameter adjustment method of the second technical solution, and the evaluation process includes: b-21) a first regression process, obtaining a first regression parameter by regressing the ejection data to a first regression function; and b-22) a second regression process, obtaining a second regression parameter by regressing the speed data to the first regression function, wherein the first regression function is a function to which the restriction conditions of the movement control are imposed, and the evaluation function is a function for deriving an evaluation value representing the difference between the first regression parameter and the second regression parameter.

[0015] A fourth technical solution is the control parameter adjustment method of the third technical solution, wherein the evaluation step includes a step of b-23) normalizing the ejection data or the velocity data so that the ejection data and the velocity data have the same scale.

[0016] The fifth technical solution is a control parameter adjustment method of any one of the first to fourth technical solutions, and the evaluation process includes: b-24) a first extraction process, extracting partial ejection data during the increase period when the ejection amount increases from zero to a specified stable ejection amount from the ejection data; b-25) a second extraction process, extracting partial speed data during the increase period from the speed data; and b-26) a process for evaluating the partial speed data based on the partial ejection data and the evaluation function.

[0017] The sixth technical solution is the control parameter adjustment method of any one of the first to fifth technical solutions, wherein the first regression function is an asymmetric logic function.

[0018] A seventh technical means is the control parameter adjustment method according to any one of the first to sixth technical means, wherein the discharge data is data indicating a discharge pressure applied to the processing liquid in order to discharge the processing liquid from the nozzle.

[0019] The eighth technical solution is a computer-executable program, which enables the computer to execute the control parameter adjustment method of any one of the first to seventh technical solutions.

[0020] The ninth technical solution is a computer-readable storage medium storing the program of the eighth technical solution.

[0021] According to the control parameter adjustment methods of the first to seventh technical solutions, by evaluating the speed data using an evaluation function that imposes movement control constraints, the movement control parameters can be adjusted while taking into account the movement control constraints. Therefore, the movement control parameters can be adjusted efficiently.

[0022] According to the control parameter adjustment method of the second aspect, the velocity data can be evaluated based on the difference between the discharge data and the velocity data.

[0023] According to the control parameter adjustment method of the third technical solution, the speed data can be evaluated based on the difference between the first regression parameter and the second regression parameter.

[0024] According to the control parameter adjustment method of the fourth aspect, since the scales can be made consistent, the discharge data and the velocity data can be easily compared.

[0025] According to the control parameter adjustment method of the sixth technical solution, when the movement control is S-shaped acceleration / deceleration control, the movement speed can be well fitted.

[0026] According to the control parameter adjustment method of the seventh aspect, the movement control parameter can be evaluated by comparing the ejection pressure and the movement speed based on the movement control parameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a diagram schematically showing the overall structure of a coating apparatus according to an embodiment.

[0028] Figure 2 It is a diagram showing the structure of a coating liquid supply mechanism.

[0029] Figure 3 Yes Figure 2 A graph showing the movement pattern of the working disc of the pump is shown.

[0030] Figure 4 It is a graph showing the discharge pressure waveform.

[0031] Figure 5 This is a block diagram showing a configuration example of a control unit.

[0032] Figure 6 This is a flowchart showing the parameter optimization process executed by the control unit of the coating device.

[0033] Figure 7 Yes Figure 6 Flowchart showing details of the ejection control parameter optimization process.

[0034] Figure 8 Yes Figure 6 Flowchart showing details of the movement control parameter optimization process.

[0035] Figure 9 This is a diagram showing partial discharge data during the increase period and a first regression curve obtained by regressing the partial discharge data onto a regression function.

[0036] Figure 10 This is a diagram showing normalized partial velocity data during the normalized increase period and a second regression curve obtained by regressing the normalized partial discharge data.

[0037] Figure 11 It is a diagram for explaining each period of the discharge pressure waveform.

[0038] Figure 12 This is a diagram schematically showing an example of calculation performed on the discharge pressure waveform by the discharge control parameter optimization unit.

[0039] Figure 13 This is a diagram for explaining evaluation items for evaluating the temporal change in discharge pressure based on the feature amount Fv1.

[0040] Figure 14 This is a diagram for explaining evaluation items for evaluating the temporal change in discharge pressure based on the feature amount Fv2.

[0041] Figure 15 This is a diagram for explaining evaluation items for evaluating the temporal change in discharge pressure based on the feature amount Fv3.

[0042] Figure 16 It is a diagram for explaining the feature value Fv4.

[0043] Figure 17 It is a diagram for explaining the feature value Fv5.

[0044] Figure 18 This is a diagram for explaining evaluation items for evaluating the temporal change in discharge pressure based on the feature amount Fv6.

[0045] Figure 19 This is a diagram for explaining evaluation items for evaluating the temporal change in discharge pressure based on the feature amount Fv7.

[0046] Figure 20 This is a diagram for explaining evaluation items for evaluating the time change of the discharge pressure based on the feature amount Fv8.

[0047] Figure 21 This is a diagram for explaining evaluation items for evaluating the temporal change in discharge pressure based on the feature amount Fv9.

[0048] Figure 22 This is a diagram for explaining evaluation items for evaluating the temporal change in discharge pressure based on the feature amount Fv10.

[0049] Description of Reference Numerals

[0050] 1 coating device

[0051] 5 Mobile mechanism

[0052] 7 Coating mechanism

[0053] 9 Control Unit

[0054] 51 Chuck mechanism

[0055] 52 Adsorption travel mechanism

[0056] 71 Nozzle

[0057] 912 Mobile Control Department

[0058] 913 Speed ​​Measurement Department

[0059] 915 Discharge Control Parameter Optimization Department

[0060] 917 Motion Control Parameter Optimization Department

[0061] 931 Procedure

[0062] Rc1 first regression curve

[0063] Rc2 second regression curve

[0064] S substrate DETAILED DESCRIPTION

[0065] 1. Implementation Method

[0066] Below, embodiments of the present invention are described with reference to the accompanying drawings. It should be noted that the structural components described in this embodiment are merely illustrative and the scope of the present invention is not limited thereto. In the accompanying drawings, the dimensions or quantities of various components may be exaggerated or simplified as necessary for ease of understanding.

[0067] Figure 1 Schematic diagram of the overall structure of a coating apparatus 1 according to an embodiment. The coating apparatus 1 is a substrate processing apparatus that applies a coating liquid to the upper surface Sf of a substrate S. The substrate S is, for example, a glass substrate for a liquid crystal display device. It should be noted that the substrate S can be a variety of substrates to be processed for electronic devices, such as semiconductor wafers, glass substrates for photomasks, glass substrates for plasma displays, glass or ceramic substrates for magnetic and optical disks, glass substrates for organic EL, glass substrates or silicon substrates for solar cells, other flexible substrates, and printed circuit boards. The coating apparatus 1 is, for example, a slit coater.

[0068] exist Figure 1 In order to illustrate the configuration relationship of each element of the coating device 1, an XYZ coordinate system is defined. The moving direction of the substrate S is the "X direction". The direction in which the substrate S moves in the X direction (the direction toward the downstream of the moving direction) is the +X direction, and the opposite direction (the direction toward the upstream of the moving direction) is the -X direction. In addition, the direction perpendicular to the X direction is the Y direction, and the direction perpendicular to the X and Y directions is the Z direction. In the following description, the Z direction is set as the vertical direction, and the X and Y directions are set as horizontal directions. In the Z direction, the +Z direction is set as the upward direction, and the -Z direction is set as the downward direction.

[0069] The coating apparatus 1 includes, in order, an input conveyor 100, an input transfer unit 2, a floating platform 3, an output transfer unit 4, and an output conveyor 110, arranged in the +X direction. The input conveyor 100, the input transfer unit 2, the floating platform 3, the output transfer unit 4, and the output conveyor 110 form a movement path for the substrate S. The coating apparatus 1 also includes a moving mechanism 5, a coating mechanism 7, a coating liquid supply mechanism 8, and a control unit 9.

[0070] The substrate S is conveyed from the upstream side to the input conveyor 100. The input conveyor 100 includes a roller conveyor 101 and a rotation drive mechanism 102. The rotation drive mechanism 102 rotates the rollers of the roller conveyor 101. The rotation of the rollers of the roller conveyor 101 causes the substrate S to be conveyed downstream (in the +X direction) in a horizontal position. The "horizontal position" refers to a state in which the main surface (the surface with the largest area) of the substrate S is parallel to the horizontal plane (XY plane).

[0071] The input transfer unit 2 includes a roller conveyor 21 and a rotary lift drive mechanism 22. The rotary lift drive mechanism 22 rotates the rollers of the roller conveyor 21 and lifts and lowers the roller conveyor 21. The rotation of the roller conveyor 21 conveys the substrate S in a horizontal position downstream (in the +X direction). Furthermore, the lifting and lowering of the roller conveyor 21 changes the position of the substrate S in the Z direction. The substrate S is transferred from the input conveyor 100 to the floating platform 3 via the input transfer unit 2.

[0072] like Figure 1 As shown, the floating platform portion 3 is roughly flat. The floating platform portion 3 is divided into three parts along the X direction. The floating platform portion 3 has an inlet floating platform 31, a coating platform 32, and an outlet floating platform 33 in sequence along the +X direction. The upper surface of the inlet floating platform 31, the upper surface of the coating platform 32, and the upper surface of the outlet floating platform 33 are on the same plane. The floating platform portion 3 also has a lifting pin drive mechanism 34, a floating control mechanism 35, and a lifting drive mechanism 36. A plurality of lifting pins are arranged on the inlet floating platform 31. The lifting pin drive mechanism 34 lifts and lowers the plurality of lifting pins. The floating control mechanism 35 supplies compressed air for floating the substrate S to the inlet floating platform 31, the coating platform 32, and the outlet floating platform 33. The lifting drive mechanism 36 lifts and lowers the outlet floating platform 33.

[0073] A plurality of ejection holes, which eject compressed air supplied from the flotation control mechanism 35, are arranged in a matrix on the upper surfaces of the inlet flotation stage 31 and the outlet flotation stage 33. When compressed air is ejected from each ejection hole, the substrate S floats upward relative to the flotation stage 3. As a result, the lower surface Sb of the substrate S separates from the upper surface of the flotation stage 3 and is supported in a horizontal position. The distance (floatation distance) between the lower surface Sb of the substrate S and the upper surface of the flotation stage 3 when the substrate S is floating is, for example, not less than 10 μm and not more than 500 μm.

[0074] The ejection holes for ejecting the compressed air supplied from the floating control mechanism 35 and the suction holes for sucking the gas are alternately arranged on the upper surface of the coating table 32 in the X direction and the Y direction. The floating control mechanism 35 controls the ejection amount of the compressed air from the ejection holes and the suction amount of the air from the suction holes. Thus, the floating amount of the substrate S relative to the coating table 32 is precisely controlled so that the position in the Z direction of the upper surface Sf of the substrate S passing above the coating table 32 reaches a specified value. It should be noted that the floating amount of the substrate S relative to the coating table 32 is calculated by the control unit 9 based on the detection results of the sensor 61 or the sensor 62 described later. In addition, it is preferred that the floating amount of the substrate S relative to the coating table 32 can be adjusted with high precision by airflow control.

[0075] The substrate S loaded onto the floatation stage 3 is pushed in the +X direction by the roller conveyor 21 and conveyed onto the entrance floatation stage 31. The entrance floatation stage 31, the coating stage 32, and the exit floatation stage 33 support the substrate S in a floating state. For example, the structure described in Japanese Patent No. 5346643 can be used as the floatation stage 3.

[0076] The moving mechanism 5 is disposed below the float stage 3. It includes a chuck mechanism 51 and a suction travel mechanism 52. The chuck mechanism 51 includes a suction pad (not shown) provided on a suction member. The chuck mechanism 51 supports the substrate S from below, with the suction pad in contact with the peripheral edge of the lower surface Sb of the substrate S. The suction travel mechanism 52 applies negative pressure to the suction pad, thereby adsorbing the substrate S onto the suction pad. Furthermore, the suction travel mechanism 52 reciprocates the chuck mechanism 51 in the X-direction.

[0077] The chuck mechanism 51 holds the substrate S with its lower surface Sb positioned higher than the upper surface of the floatation table 3 . With the periphery of the substrate S held by the chuck mechanism 51 , the substrate S maintains a horizontal posture due to the buoyancy provided by the floatation table 3 .

[0078] like Figure 1 As shown, the coating apparatus 1 includes a sensor 61 for measuring the plate thickness. The sensor 61 is disposed near the roller conveyor 21. The sensor 61 detects the position in the Z direction of the upper surface Sf of the substrate S held by the chuck mechanism 51. Furthermore, by positioning the chuck (not shown) without holding the substrate S directly below the sensor 61, the sensor 61 can detect the position in the vertical direction Z of the suction surface, which is the upper surface of the suction member.

[0079] The chuck mechanism 51 moves in the +X direction while holding the substrate S loaded onto the float stage 3. As a result, the substrate S is transported from above the entrance float stage 31, through above the coating stage 32, and to above the exit float stage 33. The substrate S then moves from the exit float stage 33 to the output transfer unit 4.

[0080] The output transfer unit 4 moves the substrate S from a position above the exit floating platform 33 to the output conveyor 110. The output transfer unit 4 includes a roller conveyor 41 and a rotary lift drive mechanism 42. The rotary lift drive mechanism 42 rotates the roller conveyor 41 and lifts it in the Z direction. The rotation of the rollers of the roller conveyor 41 moves the substrate S in the +X direction. Furthermore, the lifting and lowering of the roller conveyor 41 causes the substrate S to be displaced in the Z direction.

[0081] The output conveyor 110 includes a roller conveyor 111 and a rotation drive mechanism 112. The output conveyor 110 conveys the substrate S in the +X direction by rotating the rollers of the roller conveyor 111, and discharges the substrate S out of the coating apparatus 1. It should be noted that the input conveyor 100 and the output conveyor 110 are part of the coating apparatus 1. However, the input conveyor 100 and the output conveyor 110 may be incorporated into a separate apparatus from the coating apparatus 1.

[0082] The coating mechanism 7 applies the coating liquid to the upper surface Sf of the substrate S. The coating mechanism 7 is arranged above the moving path of the substrate S. The coating mechanism 7 has a nozzle 71. The nozzle 71 is a slit nozzle having a slit-shaped nozzle on the lower surface. The nozzle 71 is connected to a positioning mechanism (not shown). The positioning mechanism positions the nozzle 71 at a coating position ( Figure 1 The coating liquid supply mechanism 8 is connected to the nozzle 71. The coating liquid supply mechanism 8 supplies the coating liquid to the nozzle 71, so that the coating liquid is ejected from the ejection port arranged on the lower surface of the nozzle 71.

[0083] In the coating apparatus 1, the substrate S is moved relative to the nozzle 71 ejecting the coating liquid by the moving mechanism 5, thereby applying the coating liquid to the substrate S. However, the moving mechanism 5 may be configured to move the nozzle 71 relative to the substrate S disposed at a predetermined position. Alternatively, the moving mechanism 5 may be configured to move both the nozzle 71 and the substrate S. In this case, the transport mechanism 5 may transport the nozzle 71 and the substrate S so that the nozzle 71 catches up with the substrate S at a speed faster than the substrate S being transported.

[0084] Figure 2: is a diagram showing the structure of the coating liquid supply mechanism 8. The coating liquid supply mechanism 8 includes a pump 81, a pipe 82, a coating liquid replenishing unit 83, a pipe 84, an on-off valve 85, a pressure gauge 86, and a drive unit 87. The pump 81 is a supply source for supplying the coating liquid to the nozzle 71, and supplies the coating liquid according to the volume change. For example, the pump 81 can be a bellows pump described in Japanese Patent Application Laid-Open No. 10-61558. Figure 2 As shown, the pump 81 includes a flexible tube 811 that is elastically expandable and contractible in the radial direction. One end of the flexible tube 811 is connected to the coating liquid replenishing unit 83 via a pipe 82. The other end of the flexible tube 811 is connected to the nozzle 71 via a pipe 84.

[0085] Pump 81 includes a bellows 812 that is elastically deformable in the axial direction. Bellows 812 comprises a small bellows portion 813, a large bellows portion 814, a pump chamber 815, and a working disc portion 816. Pump chamber 815 is disposed between flexible tube 811 and bellows 812. An incompressible medium is enclosed in pump chamber 815. Working disc portion 816 is connected to drive unit 87.

[0086] The coating liquid replenishing unit 83 includes a storage tank 831 for storing the coating liquid. The storage tank 831 is connected to the pump 81 via a pipe 82. An on-off valve 833 is installed in the pipe 82. The on-off valve 833 opens and closes according to commands from the control unit 9. When the on-off valve 833 is open, the coating liquid can be replenished from the storage tank 831 to the flexible tube 811 of the pump 81. When the on-off valve 833 is closed, the coating liquid is restricted from being replenished from the storage tank 831 to the flexible tube 811 of the pump 81.

[0087] Pipe 84 is connected to the output side of pump 81. An on-off valve 85 is installed in pipe 84. Valve 85 opens and closes in response to commands from control unit 9. Opening and closing valve 85 switches between supplying the coating liquid to nozzle 71 and stopping the supply of the coating liquid. A pressure gauge 86 is located in pipe 84. Pressure gauge 86 detects the pressure (discharge pressure) of the coating liquid being supplied to nozzle 71 and outputs a signal indicating the detected pressure value to control unit 9.

[0088] Figure 3 Yes Figure 2 Graph showing the movement pattern of the working disk portion 816 of the pump 81. Figure 3 In FIG. 8 , the horizontal axis represents time, and the vertical axis represents the moving speed of the working disk portion 816. The driving portion 87 moves the working disk portion 816 in accordance with the instruction from the control unit 9. Figure 3The movement pattern shown (a pattern indicating the change in the speed of the working disk portion 816 relative to the passage of time) is displaced in the axial direction. Due to the displacement of the working disk portion 816, the volume inside the bellows 812 changes. As a result, the flexible tube 13 expands and contracts in the radial direction to perform a pumping action, and the coating liquid supplied from the coating liquid replenishing unit 83 is transported to the nozzle 71. The movement pattern of the working disk portion 816 is closely related to the ejection characteristics of the coating liquid ejected from the nozzle 71. Therefore, according to the movement pattern, it can be obtained Figure 4 The discharge pressure waveform shown here represents the temporal variation of the discharge pressure. It should be noted that the discharge amount (the amount of coating liquid discharged from the nozzle 71) also increases or decreases as the discharge pressure increases or decreases. That is, the discharge pressure waveform is an example of "discharge data" representing the discharge amount.

[0089] Figure 4 It is a graph showing the discharge pressure waveform. Figure 4 (a) is a diagram showing a target pressure waveform as a preferred discharge pressure waveform. Figure 4 (b) is an example of an actually measured discharge pressure waveform. Figure 4 In FIG, the horizontal axis represents time, and the vertical axis represents discharge pressure (or discharge speed).

[0090] In this embodiment, by adjusting various parameters (acceleration time, steady speed, steady speed time, deceleration time, etc.) that determine the movement of the work plate portion 816, the ejection characteristics (specifically, the time variation of the ejection speed (ejection pressure)) of the coating liquid ejected from the nozzle 71 are appropriately adjusted to match the desired target characteristics ( Figure 4 This will be described in detail later.

[0091] like Figure 1 and Figure 2 As shown, a sensor 62 is configured in the nozzle 71 that supplies the coating liquid from the coating liquid supply mechanism 8. The sensor 62 detects the height of the substrate S in the Z direction in a non-contact manner. The sensor 62 is electrically connected to the control unit 9. Based on the detection result of the sensor 62, the control unit 9 measures the distance (separation distance) between the floating substrate S and the upper surface of the coating table 32. The control unit 9 then uses the positioning mechanism to adjust the coating position of the nozzle 71 based on the measured separation distance. It should be noted that an optical sensor or an ultrasonic sensor can be applied as the sensor 62.

[0092] The coating mechanism 7 includes a nozzle cleaning standby unit 72. The nozzle cleaning standby unit 72 performs prescribed maintenance on the nozzle 71 positioned in the maintenance position. The nozzle cleaning standby unit 72 includes a roller 721, a cleaning portion 722, and a roller tank (roller bat) 723. The nozzle cleaning standby unit 72 cleans the nozzle 71 and forms a liquid accumulation, thereby adjusting the nozzle 71's discharge port to a state suitable for coating processing. Furthermore, in the coating device 1, a virtual discharge of the coating liquid from the nozzle 71 is performed while the nozzle 71 is positioned in the maintenance position to evaluate the discharge pressure applied to the coating liquid.

[0093] Figure 5 : This is a block diagram showing an example of the structure of the control unit 9. The control unit 9 controls the operation of each element of the coating device 1. The control unit 9 is a computer, and has a calculation unit 91, a storage unit 93, and a user interface 95. The calculation unit 91 is a processor composed of a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The storage unit 93 is composed of a transient storage device such as a RAM (Random Access Memory), and a non-transient auxiliary storage device such as an HDD (Hard Disk Drive) and an SDD (Solid State Drive).

[0094] The user interface 95 includes a display for displaying information to the user and an input device for accepting input operations from the user. As the control unit 9, for example, a desktop, laptop, or tablet computer can be used.

[0095] The storage unit 93 stores a program 931. The program 931 is provided by a storage medium M. That is, the storage medium M stores the program 931 so that the control unit 9, which is a computer, can read it. The storage medium M is, for example, a USB (Universal Serial Bus) memory, an optical disk such as a DVD (Digital Versatile Disc), or a magnetic disk.

[0096] The calculation unit 91 executes the program 931 to function as a discharge control unit 910 , a discharge characteristic measurement unit 911 , a movement control unit 912 , a speed measurement unit 913 , a discharge control parameter optimization unit 915 , and a movement control parameter optimization unit 917 .

[0097] The discharge control unit 910 controls the operation (delivery operation) of the pump 81 that delivers the coating liquid to the nozzle 71. The discharge control unit 910 controls the delivery operation of the pump 81 based on a preset discharge control parameter.

[0098] The ejection characteristic measurement unit 911 measures the ejection characteristics. Specifically, the ejection characteristic measurement unit 911 measures a pressure waveform representing the temporal change in the ejection pressure based on the ejection pressure (pressure value of the coating liquid) output by the pressure gauge 86 during virtual ejection. That is, the ejection characteristic measurement unit 911 periodically obtains the ejection pressure measured by the pressure gauge 86 at a predetermined sampling period. Thus, the ejection pressure applied to the coating liquid during the ejection of the coating liquid from the nozzle 71 is obtained and stored as ejection data in the storage unit 93. The ejection data is data representing the relationship between a moment and the ejection pressure measured at that moment (i.e., the temporal change in the ejection pressure).

[0099] The movement control unit 912 controls the operation (movement operation) of the suction travel mechanism 52 that moves the substrate S relative to the nozzle 71 based on preset movement control parameters.

[0100] The speed measurement unit 913 measures the movement speed of the substrate S by the chuck mechanism 51 and the suction travel mechanism 52. The speed measurement unit 913 measures the movement speed of the substrate S based on the output of the suction travel mechanism 52 (e.g., the output of a rotary encoder). The speed measurement unit 913 stores the acquired speed as speed data in the storage unit 93. The speed data represents the relationship between a time and the movement speed measured at that time (i.e., the temporal change in the movement speed).

[0101] The discharge control parameter optimization unit 915 optimizes the discharge control parameters. Using a discharge data evaluation function, the discharge control parameter optimization unit 915 calculates an evaluation value for the discharge data (discharge characteristics) obtained from the virtual discharge, and updates the discharge control parameters based on this evaluation value. Furthermore, the discharge control parameter optimization unit 915 performs another virtual discharge based on the updated discharge control parameters. The discharge control parameter optimization unit 915 repeatedly performs virtual discharges, evaluates discharge data, and updates discharge control parameters until the evaluation value falls within the allowable range, thereby optimizing the discharge control parameters. The discharge data evaluation function will be described later.

[0102] In order to coat the coating liquid ejected from the nozzle 71 with a uniform film thickness on the upper surface Sf of the substrate S in the coating apparatus 1, it is important to adjust the ejection speed, that is, the ejection pressure, of the coating liquid when ejected from the nozzle 71. For example, by Figure 4 The coating liquid is ejected from the nozzle 71 as shown in (a) of the target, which can improve the uniformity of the film thickness. Therefore, the ejection control parameters closely related to the ejection pressure waveform are optimized so that the ejection pressure waveform is close to the target ejection pressure waveform. Specifically, the movement of the working disk portion 816 is specified. Figure 3The 16 pump control setting values ​​shown below are the discharge control parameters to be optimized.

[0103] Stable speed V1

[0104] Acceleration time T1: the time from a stopped state to a stable speed V1

[0105] Stable speed time T2: the time for maintaining stable speed V1

[0106] Stable speed V2

[0107] Acceleration time T3: the time it takes to decelerate from the stable speed V1 to the stable speed V2

[0108] Stable speed time T4: the time for maintaining stable speed V2

[0109] Stable speed V3

[0110] Acceleration time T5: the time it takes to accelerate from the stable speed V2 to the stable speed V3

[0111] Stable speed time T6: the time for maintaining stable speed V3

[0112] Stable speed V4

[0113] Acceleration time T7: the time it takes to decelerate from the stable speed V3 to the stable speed V4

[0114] Stable speed time T8: the time for maintaining stable speed V4

[0115] Stable speed V5

[0116] Acceleration time T9: Time to accelerate from stable speed V4 to stable speed V5

[0117] Stable speed time T10: the time for maintaining a stable speed of V5

[0118] Deceleration time T11: The time it takes to decelerate from the stable speed V5 to a stop state

[0119] The 16 ejection control parameters described above correspond to control quantities for controlling the operation (delivery operation) of the pump 81 that delivers the coating liquid to the nozzle 71. It should be noted that there is no particular limitation on the type or number of ejection control parameters, and any control quantity may be set as long as it controls the delivery operation of the pump 81.

[0120] The motion control parameter optimization unit 917 optimizes the motion control parameters. Using a predetermined evaluation function, the motion control parameter optimization unit 917 calculates an evaluation value for the velocity data (motion characteristics) obtained through virtual transport and updates the motion control parameters based on this evaluation value. The motion control parameter optimization unit 917 then performs virtual transport again based on the updated motion control parameters. In this manner, the motion control parameter optimization unit 917 repeatedly performs virtual transport, evaluates velocity data, and updates motion control parameters until the evaluation value falls within the acceptable range, thereby optimizing the motion control parameters.

[0121] It should be noted that "virtual transport" refers to the movement control unit 912 controlling the adsorption travel mechanism 52 based on the movement control parameters to move the chuck mechanism 51, thereby virtually transporting the substrate S. It should be noted that during virtual transport, the chuck mechanism 51 may actually hold the substrate S or a simulated component other than the substrate S, or may not hold either.

[0122] <About the Discharge Control Parameter Optimization Step S1>

[0123] Figure 6 1 is a flowchart showing the parameter optimization process executed by the control unit 9 of the coating device 1. For example, when the process plan is changed according to the type of coating process or the user inputs an instruction, the process is executed. Figure 6 Parameter optimization process shown.

[0124] like Figure 6 As shown, when the parameter optimization process begins, the ejection control parameter optimization unit 915 first optimizes the ejection control parameters (ejection control parameter optimization step S1). The ejection control parameter optimization step S1 is an example of a process for adjusting the ejection control parameters. After the ejection control parameter optimization step S1, the movement control parameter optimization unit 917 performs a process for optimizing the movement control parameters (movement control parameter optimization step S2). The movement control parameter optimization step S2 is an example of a process for adjusting the movement control parameters. The ejection control parameter optimization step S1 and the movement control parameter optimization step S2 are described below in sequence.

[0125] <Details of Discharge Control Parameter Optimization Step S1>

[0126] Figure 7 Yes Figure 6 Flowchart showing details of the ejection control parameter optimization step S1. When the ejection control parameter optimization step S1 is started, the nozzle 71 is first moved to the maintenance position (nozzle moving step S11). The nozzle moving step S11 enables dummy ejection.

[0127] After the nozzle movement process S11, the ejection control parameter optimization unit 915 sets the ejection control parameters (ejection control parameter setting process S12). Specifically, the above-mentioned 16 ejection control parameters are set. It should be noted that the initial value of the ejection control parameter is, for example, a value generated by a random number or a value specified by the user. After the ejection control parameter setting process S12, the ejection control unit 910 performs a virtual ejection based on the set ejection control parameters. During this virtual ejection, the ejection characteristic measurement unit 911 measures the ejection pressure (ejection pressure measurement process S13). Thus, the ejection data relative to the set ejection control parameters is obtained.

[0128] The discharge control parameter optimization unit 915 uses a predetermined discharge data evaluation function to derive an evaluation value for the acquired discharge data (evaluation value deriving step S14). This evaluation value is a value indicating the evaluation result of the discharge data. Specifically, the discharge pressure waveform ( Figure 4 (b)) and target ejection pressure waveform ( Figure 4 The ejection data evaluation function is designed in such a way that the greater the difference between (a)), the greater the evaluation value.

[0129] After the evaluation value derivation step S14, the ejection control parameter optimization unit 915 determines whether the derived evaluation value falls within a predetermined allowable range (determination step S15). If the evaluation value falls within the allowable range ("Yes" in determination step S15), the ejection control parameter optimization unit 915 terminates the ejection control parameter optimization step S1. If the evaluation value falls outside the allowable range ("No" in determination step S15), the ejection control parameter optimization unit 915 obtains the next search point (i.e., a new ejection control parameter) based on the currently set ejection control parameter and the evaluation value corresponding to the ejection control parameter (search point acquisition step S16). Any algorithm, such as Bayesian optimization or a genetic algorithm, can be used as the search algorithm.

[0130] When new discharge control parameters are acquired in the search point acquisition step S16, the discharge control parameter setting step S12 is executed again. Thus, in the discharge control parameter optimization step S1, the discharge control parameters are optimized by changing the discharge control parameters and performing dummy discharges until the evaluation value falls within the allowable range.

[0131] <About the Movement Control Parameter Optimization Step S2>

[0132] Figure 8 Yes Figure 6Flowchart showing details of the movement control parameter optimization step S2. Theoretically, by maintaining a constant ratio between the amount of coating liquid ejected from the nozzle 71 and the movement speed of the substrate S, a uniform film thickness can be applied to the upper surface Sf of the substrate S. Therefore, the movement control parameter optimization unit 917 optimizes the movement control parameters for controlling the adsorption travel mechanism 52 so that the ratio between the ejection pressure corresponding to the ejection amount and the movement speed is constant.

[0133] like Figure 4 As shown in (a), the discharge period of the coating liquid from the nozzle 71 includes an increasing period T01, a stable discharge period T02, and a decreasing period T03. The increasing period T01 is a period during which the discharge pressure increases, that is, a period during which the discharge volume increases. The stable discharge period T02 is a period during which the discharge pressure is substantially constant, that is, a period during which the discharge volume is constant. The decreasing period T03 is a period during which the discharge pressure decreases, that is, a period during which the discharge volume decreases.

[0134] During the stable discharge period T02, the discharge volume remains approximately constant. Therefore, during the stable discharge period T02, the movement speed is maintained at a speed corresponding to the discharge volume. During the increasing period T01, the discharge volume increases in response to the increase in discharge pressure. Therefore, during the increasing period T01, the film thickness can be made uniform by increasing the movement speed as the discharge pressure increases. Therefore, in the movement control parameter optimization step S2, the movement control parameters are optimized based on the discharge data during the increasing period T01.

[0135] Specifically, first, ejection data based on the ejection control parameters optimized in the ejection control parameter optimization step S1 is prepared in advance (ejection data preparation step S20). The ejection data may be data acquired during the ejection control parameter adjustment phase in the ejection control parameter optimization step S1 or newly acquired data.

[0136] Next, the movement control parameter optimization unit 917 extracts data for the increased period T01 from the prepared ejection data (first extraction step S21). Hereinafter, the data extracted from the ejection data will be referred to as "partial ejection data." After the first extraction step S21, the movement control parameter optimization unit 917 regresses the partial ejection data onto a predetermined regression function (first regression step S22). Through this first regression step S22, regression parameters for the ejection data are obtained. Hereinafter, the obtained regression parameters will be referred to as "first regression parameters."

[0137] Figure 9 : is a diagram showing the partial discharge data Dp1 during the increase period T01 and a first regression curve Rc1 obtained by regressing the partial discharge data Dp1 to a regression function. Figure 9 In the figure, the horizontal axis represents time, and the vertical axis represents discharge pressure.

[0138] As a regression function, the nonlinear logistic function described in Non-Patent Document 1 ("A five-parameter logistic equation for investigating asymmetry of curvature in baroreflex studies," JH Ricketts, GA Head, Am. J. Physiol., 1999 Aug; 277(2): R441-54) can be used. Specifically, this nonlinear function is represented by the following equations (1) to (3).

[0139]

[0140]

[0141]

[0142] For the asymmetric logic function represented by equations (1) to (3), the relationship between the explanatory variable (x) and the target variable (y) is an S-shaped relationship (refer to Figure 9 ). In formulas (1) to (3), "P1" is the minimum value of the platform of the target variable (y), and "P1+P2" is the maximum value of the platform of the target variable (y). That is, "P2" is the range of the target variable (y) (the difference between the maximum and minimum values ​​of the platform). "P3" is the first curvature parameter representing the curvature of the lower part of the S-shaped part. "P4" is the value of the explanatory variable (x) when the target variable (y) is 50%. "P5" is the second curvature parameter representing the curvature of the upper part of the S-shaped part.

[0143] After the first regression step S22, the movement control parameter optimization unit 917 sets the movement control parameters (movement control parameter setting step S23). The initial values ​​of the movement control parameters are set to values ​​generated by random numbers or values ​​specified by the user. After the movement control parameter setting step S23, the movement control unit 912 performs virtual transportation. During the virtual transportation, the speed measurement unit 913 measures the movement speed (movement speed measurement step S24). This obtains speed data relative to the set movement control parameters.

[0144] Next, the movement control parameter optimization unit 917 extracts data of the increase period T01 from the acquired speed data (second extraction step S25 ). Hereinafter, the data extracted from the speed data will be referred to as “partial speed data”.

[0145] The movement control parameter optimization unit 917 normalizes the partial speed data (normalization process S26). Specifically, the movement control parameter optimization unit 917 changes the partial speed data so that the scale (the size of the numerical value) of the vertical axis (movement speed) in the partial speed data is consistent with the scale (the size of the numerical value) of the vertical axis (discharge pressure) in the discharge data. More specifically, the partial speed data is normalized so that the size of the range of movement speed (the difference between the maximum and the minimum) is consistent with the size of the range of discharge pressure (the difference between the maximum and the minimum). Hereinafter, the normalized partial speed data will be referred to as "normalized partial speed data". In this way, by performing normalization, it is easy to compare the partial discharge data with the partial speed data.

[0146] It should be noted that the original velocity data can be normalized in advance, and the data for the increased period T01 (normalized partial velocity data) can be extracted from the normalized velocity data. Alternatively, the partial ejection data can be normalized to match the scale of the moving velocity. Alternatively, the original ejection data can be normalized in advance, and the data for the increased period T01 (normalized partial ejection data) can be extracted from the normalized ejection data.

[0147] After the normalization step S26, the movement control parameter optimization unit 917 regresses the normalized partial speed data representing the normalized movement speed onto a regression function (second regression step S27). The regression function used in the second regression step S27 is the same as the regression function used in the first regression step S22.

[0148] Figure 10 : is a diagram showing the normalized partial velocity data Ds1 during the normalized increase period T01 and the second regression curve Rc2 obtained by regressing the normalized partial ejection data. Figure 10 In the figure, the horizontal axis represents time and the vertical axis represents movement speed.

[0149] The adsorption travel mechanism 52 performs "S-shaped acceleration and deceleration control" to accelerate and decelerate the chuck mechanism 51 in an S-shaped manner. That is, the restriction condition of the movement control in the adsorption travel mechanism 52 is S-shaped acceleration and deceleration. The relationship between the time and the movement speed during the increase period T01 becomes S-shaped (refer to Figure 10 ) to perform S-shaped acceleration and deceleration control. Therefore, by using an asymmetric logistic function as the regression function, a second regression curve Rc2 that fits the movement speed with high accuracy can be obtained. The asymmetric logistic function used in the first regression step S22 and the second regression step S27 is a function that imposes the constraint conditions (S-shaped acceleration and deceleration) on the movement control of the adsorption travel mechanism 52.

[0150] Return to Figure 8After the second regression step S27, the movement control parameter optimization unit 917 derives an evaluation value Fv for the speed data (evaluation value deriving step S28). This evaluation value Fv represents the evaluation result for the speed data (more specifically, partial speed data). The evaluation value Fv is derived using, for example, a speed data evaluation function represented by the following equation (4).

[0151] Fv=α|P′3-P3|+β|P′5-P5| (4)

[0152] In equation (4), P3 and P5 represent the first and second curvature parameters of the first regression curve Rc1 for the discharge pressure. Furthermore, P3′ and P5′ represent the first and second curvature parameters of the second regression curve Rc1 for the movement velocity. Furthermore, α and β are arbitrarily set weight constants.

[0153] As mentioned above, to achieve uniform film thickness, the ratio of discharge pressure to movement speed is preferably constant. When the ratio of discharge pressure to movement speed is maintained constant during the increase period T01, the slope of the S-shaped portion of the second regression curve Rc2 for movement speed can be made parallel to the slope of the S-shaped portion of the first regression curve Rc1 for discharge pressure. The slopes of the S-shaped portions of the first and second regression curves Rc1 and Rc2 are represented by first curvature parameters P3 and P3′, and second curvature parameters P5 and P5′, respectively. Therefore, the difference in these parameters between the first and second regression curves Rc1 and Rc2 is used as the evaluation value.

[0154] In the velocity data evaluation function shown in equation (4), the linear sum of the absolute differences between the first curvature parameters P3 and P3' and the absolute differences between the second curvature parameters P5 and P5' is calculated as the evaluation value Fv. The closer the slopes of the first regression curve Pc1 and the second regression curve Pc2 become to parallelism, the smaller the evaluation value Fv (i.e., a positive evaluation).

[0155] It should be noted that the speed data evaluation function is not limited to equation (4). For example, the ratio of P3′ to P3 (= P3′ / P3) and the ratio of P5′ to P5 (= P5′ / P5) can be used as evaluation functions. The closer these ratios are to 1, the more parallel the slope of the first regression curve Pc1 and the slope of the second regression curve Pc2 are. Therefore, for example, as shown in the following equation, the evaluation function can be designed to derive the linear sum of the absolute differences between 1 and the values ​​of each ratio as the evaluation value.

[0156]

[0157] After the evaluation value derivation step S28, the motion control parameter optimization unit 917 determines whether the derived evaluation value Fv falls within a predetermined allowable range (determination step S29). If the evaluation value Fv falls within the allowable range ("Yes" in determination step S29), the motion control parameter optimization unit 917 terminates the motion control parameter optimization step S2. On the other hand, if the evaluation value Fv falls outside the allowable range ("No" in determination step S29), the motion control parameter optimization unit 917 acquires the next search point (new motion control parameter) based on the currently set motion control parameter and the evaluation value Fv corresponding to the motion control parameter (search point acquisition step S30). Any algorithm, such as Bayesian optimization or a genetic algorithm, can be employed as the search algorithm.

[0158] When new movement control parameters are acquired in the search point acquisition step S30, the movement control parameter setting step S23 and subsequent steps are executed again. Thus, in the movement control parameter optimization step S2, the movement control parameters are optimized by changing the movement control parameters and performing virtual transport until the evaluation value Fv falls within the allowable range.

[0159] As described above, according to this embodiment, an evaluation value is derived using the speed data evaluation function (Equation (4)) that imposes movement control constraints, and the movement control parameters are adjusted based on this evaluation value. Therefore, since the movement control parameters are adjusted in consideration of the movement control constraints, the movement control parameters can be efficiently optimized.

[0160] It should be noted that the regression function used in the first regression step S22 and the second regression step S27 is not limited to an asymmetric logic function. The regression function may be, for example, a symmetric logic function, a Sigmoid function, or a broken line function. In addition, the movement control applied to the adsorption travel mechanism 52 is not limited to the S-shaped acceleration and deceleration control. For example, linear acceleration and deceleration control may also be applied to the adsorption travel mechanism 52. When linear acceleration and deceleration control is applied, a linear function may be used as a regression function to which the restriction condition of the movement control is imposed. When a regression function different from an asymmetric logic function is used, a speed data evaluation function may be used which derives the linear sum of the absolute differences of the regression parameters obtained by respectively regressing the ejection data and the speed data as an evaluation value.

[0161] Evaluation Function for Discharge Data

[0162] Then, yes Figure 7The velocity data evaluation function used to evaluate discharge data, described in the evaluation value derivation step S14, will now be described. This velocity data evaluation function derives an evaluation value for the discharge pressure waveform represented by the discharge data. The velocity data evaluation function is designed to derive the linear sum of feature quantities Fv1 to Fv10 for each of multiple evaluation items of the discharge pressure waveform as an evaluation value. The feature quantities Fv1 to Fv10 for each evaluation item will be described below.

[0163] Figure 11 It is a diagram for explaining each period of the discharge pressure waveform. Figure 11 In the figure, the horizontal axis represents time and the vertical axis represents ejection pressure. Figure 11 In each subsequent graph, the horizontal axis represents time and the vertical axis represents discharge pressure.

[0164] like Figure 11 As shown, the discharge pressure at time ta when the coating liquid starts to be discharged from the nozzle 71 and the discharge pressure at time te when the coating liquid ends to be discharged from the nozzle 71 are the initial pressure Pi. However, the pressure at the start and end of discharge is not always the same as the initial pressure Pi.

[0165] like Figure 11 As shown, the discharge period Tt is divided into a rising period Ta, a transition period Tb, a stabilization period Tc, and a falling period Td. The rising period Ta is the period from the time ta when the coating liquid supply mechanism 8 begins discharging the coating liquid from the nozzle 71 (i.e., the time ta when the coating liquid supply mechanism 8 begins moving the working plate 816) to the time tb when the discharge pressure reaches the target pressure Pt. In other words, when the coating liquid starts to be discharged from the nozzle 71 at time ta, the discharge pressure increases from the initial pressure Pi to the target pressure Pt from time ta to time tb.

[0166] The transition period Tb is the period from time tb to time tc after the predetermined vibration damping period. The vibration damping period is the period required for the temporal variation of the ejection pressure to stabilize, and is set in advance by, for example, the user input operation to the user interface 95 and stored in the storage unit 93. The rising period Ta and the transition period Tb correspond to Figure 4 The increase period T01 is shown.

[0167] The stable period Tc is the period from moment tc to moment td when the coating liquid supply mechanism 8 starts to reduce the discharge pressure (i.e., moment td when the coating liquid supply mechanism 8 starts to decelerate the working disk portion 816 from the target speed). That is, the coating liquid supply mechanism 8 moves the working disk portion 816 at a constant speed (V5 described above) from moment tc to moment td, and starts to decelerate the working disk portion 816 at moment td. It should be noted that during the stable period Tc, the discharge pressure is basically stable at the target pressure Pt. However, during the stable period Tc, the temporal variation of the discharge pressure also includes slight vibrations. Therefore, during the stable period Tc, the discharge pressure is greater or less than the target pressure Pt. The transition period Tb and the stable period Tc constitute the constant pressure period Tbc. That is, the constant pressure period Tbc is the period from moment tb to moment td.

[0168] The falling period Td is the period from time td to time te at which the coating liquid supply mechanism 8 stops discharging the coating liquid from the nozzle 71 (i.e., time te at which the coating liquid supply mechanism 8 stops the working disk portion 816). In other words, the discharge pressure decreases to the initial pressure Pi during the period from time td to time te, and at time te, the discharge of the coating liquid from the nozzle 71 stops.

[0169] Figure 12 : is a diagram schematically showing an example of the calculation performed by the discharge control parameter optimization unit 915 on the discharge pressure waveform. Figure 12 As shown, the discharge control parameter optimization unit 915 performs a temporal differentiation on the discharge pressure waveform to calculate the first differential D1 of the discharge pressure waveform. Furthermore, the discharge control parameter optimization unit 915 differentiates the first differential D1 of the temporal variation of the discharge pressure with respect to time to calculate the second differential D2 of the temporal variation of the discharge pressure. Furthermore, the discharge control parameter optimization unit 915 calculates the mean absolute error (MAE) and the root mean square error (RMSE) based on the following equations.

[0170] MAE(α,β)=(1 / n)·(Σ|α-β|)

[0171] RMSE(α,β)=((1 / n)·(Σ(α-β)2))1 / 2

[0172] n is the number of data.

[0173] Figure 13 This is a diagram for explaining the evaluation items for evaluating the time change of the discharge pressure based on the feature value Fv1. Figure 13 Among the evaluation items shown, the discharge pressure waveform is evaluated based on the error (ideal trapezoidal absolute error) between a trapezoidal waveform having an amplitude corresponding to the difference between the average value of the discharge pressure within the stable period Tc (i.e., the stable pressure Pm) and the initial pressure Pi and the actual discharge pressure waveform.

[0174] Specifically, during the rising period Ta, a linear regression analysis is performed on the temporal variation in discharge pressure between a predetermined lower reference pressure and a predetermined upper reference pressure greater than the lower reference pressure, to calculate a rising regression line Lr_R. This rising regression line Lr_R linearly increases from the initial pressure Pi to the steady-state pressure Pm during the period from time t11 to time t12.

[0175] Similarly, during the descending period Td, linear regression analysis is performed on the temporal variation of the discharge pressure between the upper and lower reference pressures to calculate a descending regression line Lr_F. This descending regression line Lr_F linearly decreases from the steady pressure Pm to the initial pressure Pi during the period from time t13 to time t14.

[0176] It should be noted that the lower and upper reference pressures are pressures greater than the initial pressure Pi and less than the target pressure Pt, and are set, for example, by a user input operation on the user interface 95 and stored in the storage unit 93. For example, the lower reference pressure may be the pressure obtained by adding 20% ​​of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi. Alternatively, the upper reference pressure may be the pressure obtained by adding 80% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi.

[0177] Furthermore, a starting approximate line Lr_s is set for the interval from time ta to time t11. This starting approximate line Lr_s is a line with a slope of zero, representing the initial pressure Pi. Specifically, the starting approximate line Lr_s is a line connecting the time at which the coating liquid begins to be ejected from the nozzle 71 (time ta) to the time at which the rising regression line Lr_R begins. It should be noted that, depending on the state (slope) of the regression line, time t11 may be before time ta, while time t12 may be after time tb. Thus, when t11 < ta, the starting approximate line Lr_s is omitted.

[0178] Furthermore, for the interval from time t14 to time te, an end approximation line Lr_e is defined. This end approximation line Lr_e is a line whose slope, representing the initial pressure Pi, is zero. Specifically, the end approximation line Lr_e is a line extending from the end point of the descending regression line Lr_F to the end point (time te) of the coating liquid discharge from the nozzle 71. Note that if te < t14, the end approximation line Lr_e is omitted.

[0179] Furthermore, a stable line Lr_m is set for the interval from time t12 to time t13. This stable line Lr_m is a line with a slope of zero, representing the stable pressure Pm. Specifically, the stable line Lr_m is a line representing the stable pressure Pm, connecting the end time (time t12) of the rising regression line Lr_R and the start time (time t13) of the falling regression line Lr_F.

[0180] As described above, the discharge control parameter optimization unit 915 calculates an approximate waveform WF1, which is composed of the time-series start approximate line Lr_s, the rising regression line Lr_R, the steady state line Lr_m, the falling regression line Lr_F, and the end approximate line Lr_e. Furthermore, the discharge control parameter optimization unit 915 calculates the mean absolute error (MAE) (ideal trapezoidal absolute error) between the pressure values ​​of the discharge pressure waveform and the approximate waveform WF1 during the entire discharge period Tt from time ta to time te as a feature value Fv1. The discharge control parameter optimization unit 915 stores the calculated feature value Fv1 in the storage unit 93.

[0181] According to the evaluation based on the feature amount Fv1, when the temporal variation of the discharge pressure in the entire discharge period Tt deviates significantly from the ideal shape (ie, trapezoidal shape), the discharge pressure can be given a high score (ie, negative evaluation).

[0182] Figure 14 This is a diagram for explaining the evaluation items for evaluating the temporal change of the discharge pressure based on the feature value Fv2. Figure 14 The smoothness of the discharge pressure rise is evaluated as an evaluation item. Specifically, a curve regression analysis is performed on the temporal variation in discharge pressure between the lower reference pressure P2_1 and the upper reference pressure P2_u, which is greater than the lower reference pressure P2_1, during the rising period Ta, to calculate the rising regression curve Nr. This curve regression analysis is performed using a quadratic curve.

[0183] The lower reference pressure P2_l is set to the initial pressure Pi. In addition, the upper reference pressure P2_u is a pressure greater than the lower reference pressure P2_l and less than the target pressure Pt. The upper reference pressure P2_u is set, for example, by a user input operation to the user interface 95 and is stored in the storage unit 93. The upper reference pressure P2_u can be a pressure obtained by adding 20% ​​of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi. The rising regression curve Nr increases from the lower reference pressure P2_l (initial pressure Pi) to the upper reference pressure P2_u during the period from time t21 to time t22. It should be noted that time t21 coincides with time ta, and time t22 is a time after time ta and before time tb.

[0184] The discharge control parameter optimization unit 915 calculates a waveform WF2 formed by the rising regression curve Nr. Furthermore, the discharge control parameter optimization unit 915 calculates the root mean square error (RMSE) between the pressure value of the discharge pressure waveform measured during the rising initial period Ta_s from time t21 to time t22 and the waveform WF2 as a feature value Fv2. The discharge control parameter optimization unit 915 stores the calculated feature value Fv2 in the storage unit 93.

[0185] According to the evaluation based on the feature value Fv2, if the discharge pressure immediately after the start of discharge is abnormal due to the influence of the state before the coating liquid is discharged from the nozzle 71, a higher score (i.e., a negative evaluation) can be given to the discharge pressure. It should be noted that the curve that can be used for curve regression analysis is not limited to a quadratic curve, and other curves such as an exponential function can also be used.

[0186] Figure 15 This is a diagram for explaining the evaluation items for evaluating the temporal change of the discharge pressure based on the feature value Fv3. Figure 15 Among the evaluation items, the rising period Ta is evaluated to determine whether it falls within a predetermined period. Specifically, the discharge control parameter optimization unit 915 calculates the length of the rising period Ta (tb - ta) from time ta, the time required for the discharge pressure to increase from the initial pressure Pi to the target pressure Pt, as the feature value Fv3. The discharge control parameter optimization unit 915 then stores the calculated feature value Fv3 in the storage unit 93.

[0187] According to the evaluation based on the feature amount Fv3 , a larger score (ie, a negative evaluation) can be given to a discharge pressure whose rising period to the target pressure Pt is shorter or longer than a predetermined period.

[0188] Figure 16 It is a diagram for explaining the feature value Fv4. Figure 16 (A) is a diagram for explaining evaluation items for evaluating the time change of the discharge pressure based on the feature amount Fv4. Figure 16 (B) is a diagram showing an example of a time change of a discharge pressure that is judged to be inappropriate based on the evaluation based on the feature value Fv4. Figure 16 In the evaluation item (A), whether or not there is abnormality in the increase of the discharge pressure is evaluated.

[0189] Specifically, the ejection control parameter optimization unit 915 calculates the first differential D1 of the time variation of the ejection pressure for the rising period Ta from time ta to time tb, and obtains the first differential waveform WF4. Furthermore, the ejection control parameter optimization unit 915 obtains the number of times the first differential waveform WF4 crosses the predetermined threshold value Th4 during the rising period Ta as the feature value Fv4. Figure 16In the example (A), the first differential waveform WF4 intersects the threshold value Th4 (e.g., 0.002) at time t41 and time t42, respectively, and the number of intersections (feature value Fv4) is twice. The discharge control parameter optimization unit 915 stores the calculated feature value Fv4 in the storage unit 93.

[0190] According to the evaluation based on the feature amount Fv4, when the temporal change of the discharge pressure in the rising period Ta has a step (for example, Figure 16 (B)), a large score (ie, a negative evaluation) can be given to the discharge pressure.

[0191] Figure 17 It is a diagram for explaining the feature value Fv5. Figure 17 (A) is a diagram for explaining evaluation items for evaluating the temporal change in the discharge pressure based on the feature amount Fv5. Figure 17 (B) is a diagram showing an example of a time change of the ejection pressure determined to be inappropriate based on the evaluation based on the feature value Fv5. Figure 17 In the evaluation item (A), whether or not there is abnormality in the increase of the discharge pressure is evaluated.

[0192] Specifically, the ejection control parameter optimization unit 915 calculates the second differential D2 of the time variation of the ejection pressure for the rising period Ta from time ta to time tb, and obtains the second differential waveform WF5. Furthermore, the ejection control parameter optimization unit 915 obtains the number of times the absolute value of the second differential waveform WF5 crosses the predetermined threshold value Th5 during the rising period Ta as the feature value Fv5. Figure 17 In the example (A), the absolute value of the second-order differential waveform WF5 intersects the threshold value Th5 (e.g., 0.0002) at times t51, t52, t53, and t54, respectively, and the number of intersections (feature value Fv5) is four. The ejection control parameter optimization unit 915 stores the calculated feature value Fv5 in the storage unit 93.

[0193] According to the evaluation based on the feature amount Fv5, when the temporal change of the discharge pressure in the rising period Ta is stepped (for example, Figure 17 (B)), a high score (i.e., a negative evaluation) can be given to the discharge pressure.

[0194] Figure 18 This is a diagram for explaining the evaluation items for evaluating the temporal change of the discharge pressure based on the feature value Fv6. Figure 18Specifically, the discharge control parameter optimization unit 915 calculates the second differential D2 of the time variation of the discharge pressure for the rising period Ta from time ta to time tb, and obtains the second differential waveform WF6.

[0195] Furthermore, the ejection control parameter optimization unit 915 determines the time T_1st during which the quadratic differential waveform WF6 exceeds a predetermined positive threshold value (Th5), and the time T_2nd during which the quadratic differential waveform WF6 falls below a predetermined negative threshold value (-Th5) within the rising period Ta. Here, the positive threshold and the negative threshold have the same absolute value (Th5) but have different signs. The absolute values ​​(Th5) of the positive and negative thresholds are equal to the threshold value Th5 used in the evaluation based on the above-mentioned feature value Fv5. Furthermore, the ejection control parameter optimization unit 915 determines the ratio of these times (=T_1st / T_2nd) as the feature value Fv6. Furthermore, the ejection control parameter optimization unit 915 converts the feature value Fv6 based on the following equation.

[0196] Fv6=|1-Fv6|

[0197] The discharge control parameter optimization unit 915 stores the converted feature value Fv6 in the storage unit 93 .

[0198] The moving speed of the substrate S, to which the coating liquid is applied, reaches the target speed without stalling during the second half of the acceleration period. Therefore, it is preferable that the ejection pressure applied to the coating liquid also reaches the target pressure Pt without stalling during the ramp period Ta. Based on the evaluation based on the feature value Fv6, if the ejection pressure stalls during the ramp period Ta, a higher score (i.e., a negative evaluation) can be assigned to that ejection pressure.

[0199] Figure 19 This is a diagram for explaining the evaluation items for evaluating the temporal change of the discharge pressure based on the feature value Fv7. Figure 19 The sharpness of the temporal variation in discharge pressure at the end of the ascent is evaluated as an evaluation item. Specifically, linear regression analysis is performed on the temporal variation in discharge pressure between the lower reference pressure P7_1 and the upper reference pressure P7_u, which is greater than the lower reference pressure P7_1, during the ascent period Ta to calculate the end-of-ascent regression line Lr. Here, the lower reference pressure P7_1 is the pressure obtained by adding 80% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi, and the upper reference pressure P7_u is the pressure obtained by adding 90% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi. The discharge pressure increases from the lower reference pressure P7_1 to the upper reference pressure P7_u from time t71 to time t72.

[0200] The rising end regression line Lr increases with time and reaches the stable pressure Pm (the average value of the discharge pressure during the stable period Tc) at time t73. In this way, the rising end regression line Lr is set for the interval from time t71 to time t73. Furthermore, the discharge control parameter optimization unit 915 sets an extended straight line Lm with a slope of zero representing the stable pressure Pm during the period from time t73 to time tb. As mentioned above, time tb is the time when the discharge pressure reaches the target pressure Pt, which is equivalent to the end time of the rising period Ta. That is, the extended straight line Lm is set to extend from the end time of the rising end regression line Lr to the end time of the rising period Ta. It should be noted that in the case of tb<t73, the extended straight line Lm is omitted.

[0201] As described above, an approximate waveform WF7 is calculated, consisting of the time-series ascending end regression line Lr and the extended line Lm. Furthermore, during the ascending end period Ta_e, from time t72 when the discharge pressure reaches 90% of the target pressure Pt to time tb when the discharge pressure reaches 100%, the discharge control parameter optimization unit 915 calculates the difference between the pressure value P_measure representing the discharge pressure waveform and the approximate waveform WF7 as a feature value Fv7. Specifically, the weighted reference time width Tw is set to t73 - t72. Furthermore, the weighted root mean square error sum is calculated using the following equation.

[0202] Fv7=(Σ(P_measure-WF7)2×W)1 / 2

[0203] In the range of time t≤t73+2×Tw, W=1

[0204] In the range of time t>t73+2×Tw, W=w

[0205] w is a weight coefficient greater than 1, for example, 10.

[0206] The discharge control parameter optimization unit 915 stores the calculated feature value Fv7 in the storage unit 93. According to the evaluation based on the feature value Fv7, if the temporal variation of the discharge pressure shows a waveform with a weak upward trend and rounded corners, a high score (i.e., a negative evaluation) can be given to the discharge pressure.

[0207] Figure 20 This is a diagram for explaining the evaluation items for evaluating the temporal change of the discharge pressure based on the feature value Fv8. Figure 20Among the evaluation items, the degree of overshoot generated during the rise of the discharge pressure is evaluated. Specifically, at time t81, when the discharge pressure reaches its maximum value Pmax, the discharge control parameter optimization unit 915 determines the sign (positive / negative) of the second differential D2 of the discharge pressure. Furthermore, the discharge control parameter optimization unit 915 calculates the time at which the sign of the second differential D2 of the discharge pressure changes twice from the sign at time t81. Furthermore, the time variation of the discharge pressure during the initial vibration period Tb_s from time t81 to time t82 is evaluated.

[0208] Specifically, the minimum value P8min of the temporal variation in the discharge pressure during the initial vibration period Tb_s is determined, and the smaller of the steady-state pressure Pm and the pressure P8min is selected as the target pressure Pg. Furthermore, the characteristic value Fv8 is calculated using the following equation: the difference between the maximum pressure Pmax and the target pressure Pg.

[0209] Fv8=Pmax-Pg

[0210] The discharge control parameter optimization unit 915 stores the calculated feature value Fv8 in the storage unit 93. According to the evaluation based on the feature value Fv8, if the temporal variation of the discharge pressure shows a strong upward trend and a large overshoot, the discharge pressure can be given a high score (i.e., a negative evaluation).

[0211] Figure 21 This is a diagram for explaining the evaluation items for evaluating the temporal change of the discharge pressure based on the feature value Fv9. Figure 21 Among the evaluation items, the stability of the temporal variation of the discharge pressure during the transition period Tb is evaluated. Specifically, the discharge control parameter optimization unit 915 calculates the root mean square error (RMSE(P_measure, Pm)) between the discharge pressure during the transition period Tb and the average value of the discharge pressure during the stable period Tc (the stable pressure Pm) using the following equation as a feature value Fv9.

[0212] Fv9 = RMSE(P_measure, Pm)

[0213] The discharge control parameter optimization unit 915 stores the calculated feature value Fv9 in the storage unit 93. According to the evaluation based on the feature value Fv9, if the temporal variation of the discharge pressure shows ringing during the transition period Tb, a high score (i.e., a negative evaluation) can be given to the discharge pressure.

[0214] Figure 22 This is a diagram for explaining the evaluation items for evaluating the time change of the discharge pressure based on the feature value Fv10. Figure 22Among the evaluation items shown, the stability of the temporal variation of the discharge pressure during the constant pressure period Tbc is evaluated. Specifically, the discharge control parameter optimization unit 915 determines the maximum value Pmax and the minimum value P10min of the discharge pressure during the constant pressure period Tbc. Furthermore, the discharge control parameter optimization unit 915 calculates the difference between the maximum pressure Pmax and the minimum pressure P10min during the constant pressure period Tbc as the feature value Fv10 using the following equation.

[0215] Fv10=Pmax-P10min

[0216] The discharge control parameter optimization unit 915 stores the calculated feature value Fv10 in the storage unit 93. According to the evaluation based on the feature value Fv10, if the temporal variation of the discharge pressure within the stable period Tc, which has a significant influence on the film thickness of the coating liquid, shows a large deviation, a high score (i.e., a negative evaluation) can be given to the discharge pressure.

[0217] It should be noted that the above-mentioned feature quantities Fv1 to Fv10 are examples. Therefore, other feature quantities may be used to calculate the evaluation value. In addition, only a portion of the feature quantities Fv1 to Fv10 may be used to calculate the evaluation value.

[0218] While the present invention has been described in detail, the foregoing description is illustrative in all respects and the present invention is not limited thereto. It should be understood that numerous modifications not shown are contemplated without departing from the scope of the present invention. The various structures described in the above embodiments and modifications may be appropriately combined or omitted as long as they do not conflict with each other.

Claims

1. A control parameter adjustment method for adjusting control parameters of a substrate processing apparatus that applies a processing liquid to a substrate by moving the substrate relative to the nozzle while ejecting the processing liquid from the nozzle, wherein: The control parameter adjustment method includes: a) a discharge data preparation step of preparing discharge data representing a temporal change in discharge pressure of the treatment liquid discharged from the nozzle; and b) a movement control parameter adjustment step of adjusting movement control parameters for controlling a movement mechanism for moving the substrate relative to the nozzle after the ejection data preparation step; The movement control parameter adjustment process includes: b-1) a moving speed measuring step of measuring, based on the output of the moving mechanism, the moving speed of the moving mechanism when the moving mechanism is controlled according to the set moving control parameters; b-2) an evaluation step of evaluating the speed data obtained in the moving speed measurement step using the ejection data and an evaluation function to which a constraint condition for movement control in the moving mechanism is applied; and b-3) a step of repeatedly performing the movement speed measurement step and the evaluation step based on the movement control parameters updated according to the result of the evaluation step to optimize the movement control parameters; The evaluation function is a function for deriving an evaluation value representing a difference between the ejection data and the velocity data. The evaluation process includes: b-21) a first regression step of regressing the ejection data onto a first regression function to obtain a first regression parameter; and b-22) a second regression step, obtaining a second regression parameter by regressing the speed data to the first regression function, The first regression function is a function to which the restriction condition of the movement control is imposed, The evaluation function is a function that derives an evaluation value indicating a difference between the first regression parameter and the second regression parameter.

2. The control parameter adjustment method according to claim 1, wherein: The evaluation step includes: b-23) normalizing the ejection data or the velocity data so that the ejection data and the velocity data have the same scale.

3. The control parameter adjustment method according to claim 1, wherein: The evaluation process includes: b-24) a first extraction step of extracting, from the discharge data, partial discharge data during a period in which the discharge volume increases from zero to a predetermined stable discharge volume; b-25) a second extraction step of extracting partial speed data during the increase period from the speed data; and b-26) A step of evaluating the partial velocity data based on the partial ejection data and the evaluation function.

4. The control parameter adjustment method according to claim 1, wherein: The first regression function is an asymmetric logistic function.

5. The control parameter adjustment method according to claim 1, wherein: The discharge data is data indicating the discharge pressure applied to the processing liquid in order to discharge the processing liquid from the nozzle.

6. A storage medium, which is a computer-readable storage medium, wherein: A program for causing the computer to execute the control parameter adjustment method according to any one of claims 1 to 5 is stored.

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