Discharge pressure evaluation method, discharge pressure evaluation program, recording medium and substrate processing apparatus

Abstract

To evaluate a discharge pressure imparted to process liquid for discharging the process liquid from a nozzle in a rational time according to propriety of the discharge pressure.SOLUTION: There are provided N pieces of first to N-th evaluation stages for evaluating a discharge pressure with mutually different evaluation items. When it is determined that the discharge pressure is proper in evaluation with an evaluation item according to an I-th evaluation stage, evaluation of the discharge pressure with the evaluation item according to (I+1)-th evaluation stage is executed, on the other hand, when it is determined that the discharge pressure is improper in the evaluation with the evaluation item according to the I-th evaluation stage, evaluation of the discharge pressure with evaluation stages subsequent to the I-th evaluation stage is not executed (in other words, the evaluation is omitted).SELECTED DRAWING: Figure 21

Description

[Technical field]

[0001] The present invention relates to a technique for discharging a treatment liquid from a nozzle by applying a discharge pressure to the treatment liquid. Note that examples of objects onto which the treatment liquid is discharged from the nozzle include semiconductor substrates, photomask substrates, liquid crystal display substrates, organic electroluminescence display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disk substrates, magnetic disk substrates, and magneto-optical disk substrates. [Background technology]

[0002] As shown in Patent Documents 1 and 2, when a processing liquid discharged from a nozzle is applied to a substrate, the discharge pressure applied to the processing liquid significantly affects the thickness of the processing liquid applied to the substrate. In Patent Document 1, the waveform of the discharge pressure is divided into a plurality of sections, and whether or not the discharge pressure is within an allowable range is evaluated based on the slope of the waveform in each section. In Patent Document 2, parameters related to the discharge pressure are optimized for each region, such as the rise region and the steady discharge region. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-005465 A [Patent Document 2] JP 2020-040046 A Summary of the Invention [Problem to be solved by the invention]

[0004] In other words, in Patent Documents 1 and 2, the waveform of the discharge pressure is evaluated in each of a plurality of sections or regions, thereby enabling a highly accurate evaluation of the discharge pressure. On the other hand, evaluating many evaluation items in this way causes a long time required for evaluating the discharge pressure. In particular, it is not necessarily rational to spend a long time evaluating all evaluation items for an inappropriate discharge pressure.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to make it possible to evaluate the ejection pressure applied to a processing liquid in order to eject the processing liquid from a nozzle, within a reasonable period of time according to the suitability of the ejection pressure. [Means for solving the problem]

[0006] The discharge pressure evaluation method according to the present invention includes a step of evaluating the discharge pressure using an evaluation item related to the first evaluation stage among N evaluation stages from 1 to N (N is an integer of 2 or more) in which the discharge pressure of an ejection device that applies an ejection pressure to a treatment liquid and ejects the treatment liquid from a nozzle is evaluated using different evaluation items, and a step of performing an evaluation of the discharge pressure using an evaluation item related to the (I+1)th evaluation stage if the ejection pressure is judged to be appropriate in the evaluation using the evaluation item related to the Ith evaluation stage (I is an integer of 1 or more and less than N) among the N evaluation stages, while not performing an evaluation of the discharge pressure using evaluation stages subsequent to the Ith evaluation stage if the ejection pressure is judged to be inappropriate in the evaluation using the evaluation item related to the Ith evaluation stage.

[0007] The discharge pressure evaluation program of the present invention causes a computer to execute the following steps: evaluating the discharge pressure using an evaluation item related to the first evaluation stage among N evaluation stages from 1 to N (N is an integer of 2 or more) in which the discharge pressure of an ejection device that applies an ejection pressure to a processing liquid and ejects the processing liquid from a nozzle is evaluated using different evaluation items; and if the ejection pressure is judged to be appropriate in the evaluation using the evaluation item related to the Ith evaluation stage (I is an integer of 1 or more and less than N) among the N evaluation stages, evaluating the ejection pressure using the evaluation item related to the (I+1)th evaluation stage, while not evaluating the ejection pressure using evaluation stages subsequent to the Ith evaluation stage if the ejection pressure is judged to be inappropriate in the evaluation using the evaluation item related to the Ith evaluation stage.

[0008] A recording medium according to the present invention records the above-mentioned discharge pressure evaluation program in a computer-readable manner.

[0009] The substrate processing apparatus of the present invention includes a nozzle, a pressure applying unit that applies a discharge pressure to a processing liquid to cause the processing liquid to be discharged from the nozzle, a measurement unit that measures the discharge pressure, and a control unit that stores the execution contents for N evaluation stages from 1 to N (N is an integer of 2 or more) in which the discharge pressure of an ejection apparatus that applies a discharge pressure to the processing liquid to eject the processing liquid from the nozzle is evaluated using different evaluation items, and the control unit evaluates the discharge pressure using the evaluation item related to the first evaluation stage out of the N evaluation stages, and if the discharge pressure is judged to be appropriate in the evaluation using the evaluation item related to the Ith evaluation stage (I is an integer of 1 or more and less than N) out of the N evaluation stages, performs evaluation of the discharge pressure using the evaluation item related to the (I+1)th evaluation stage, while if the discharge pressure is judged to be inappropriate in the evaluation using the evaluation item related to the Ith evaluation stage, does not perform evaluation of the discharge pressure using evaluation stages subsequent to the Ith evaluation stage.

[0010] In the present invention (discharge pressure evaluation method, discharge pressure evaluation program, recording medium, and substrate processing apparatus) configured as described above, N evaluation stages from 1st to Nth are provided in which the discharge pressure is evaluated by different evaluation items, and the evaluation stages from 1st to Nth can be executed in order. However, if the discharge pressure is judged to be appropriate in the evaluation by the evaluation item related to the Ith evaluation stage, the evaluation of the discharge pressure by the evaluation item related to the (I+1)th evaluation stage is executed, while if the discharge pressure is judged to be inappropriate in the evaluation by the evaluation item related to the Ith evaluation stage, the evaluation of the discharge pressure by the evaluation stages after the Ith evaluation stage is not executed. In other words, if the discharge pressure is judged to be inappropriate in any evaluation stage when the discharge pressure is evaluated in order by the 1st to Nth evaluation stages, the evaluation by the subsequent evaluation stages is not executed. This makes it possible to evaluate the discharge pressure applied to the processing liquid in order to discharge the processing liquid from the nozzle in a reasonable time according to the appropriateness of the discharge pressure.

[0011] The discharge pressure evaluation method may be configured to give different evaluation values ​​to the discharge pressure depending on the number of evaluation stages in which the discharge pressure evaluation is performed among N evaluation stages. In this configuration, the discharge pressure having a larger number of evaluation stages performed can be given a better evaluation value, and it becomes possible to give the discharge pressure an appropriate evaluation value according to whether the discharge pressure is appropriate or not.

[0012] The discharge pressure evaluation method may be configured so that the first evaluation step includes an evaluation item of evaluating the discharge pressure by performing a step of extracting a feature quantity of the time change of the discharge pressure in the entire evaluation period as an overall feature quantity based on the result of measuring the discharge pressure in the evaluation period including at least a main period from the start of discharge of the treatment liquid from the nozzle, through the rise of the discharge pressure to a predetermined pressure, to the start of the decrease of the discharge pressure from the predetermined pressure, and a step of evaluating the time change of the discharge pressure based on the overall feature quantity. In this configuration, based on the measured value of the discharge pressure measured in the evaluation period including at least a main period from the start of discharge of the treatment liquid from the nozzle, through the rise of the discharge pressure to a predetermined pressure, to the start of the decrease of the discharge pressure from the predetermined pressure, a feature quantity of the time change of the discharge pressure in the entire evaluation period is extracted as an overall feature quantity, and the time change of the discharge pressure is evaluated based on the overall feature quantity. This makes it possible to reflect the suitability of the discharge pressure in the evaluation of the discharge pressure in the entire period that affects the thickness of the treatment liquid applied to the substrate (in other words, the evaluation period).

[0013] The discharge pressure evaluation method may be configured so that the evaluation period is a main period, and a main characteristic quantity, which is a characteristic quantity of the time change of the discharge pressure throughout the main period, is extracted as an overall characteristic quantity. In this configuration, when the main period has a particularly large effect on the thickness of the treatment liquid applied to the substrate (in other words, when the effect of the period after the main period is small), it is possible to reflect the suitability of the discharge pressure throughout the main period in the evaluation of the discharge pressure.

[0014] The discharge pressure evaluation method may be configured so that the main characteristic amount indicates the difference between a main approximate waveform that approximates the time change of the discharge pressure throughout the main period and the time change of the discharge pressure throughout the main period. In this configuration, the discharge pressure throughout the main period can be appropriately evaluated based on the approximate waveform for the time change of the discharge pressure throughout the main period.

[0015] The discharge pressure evaluation method may be configured so that the main approximation waveform includes a rising approximation line that linearly increases over time from the discharge start pressure to a steady pressure higher than the discharge start pressure, which is a linear approximation of the time change in the discharge pressure that increases over time after the start of discharge of the treatment liquid from the nozzle, a start approximation line that is provided between the start time of discharge of the treatment liquid from the nozzle and the rising approximation line and indicates the discharge start pressure, and a steady line that is provided between the time when the rising approximation line reaches the steady pressure and the end of the main period and indicates the steady pressure. With this configuration, the time change in the discharge pressure during the entire main period can be approximated, and the discharge pressure during the entire period can be appropriately evaluated.

[0016] The discharge pressure evaluation method may be configured such that the evaluation period is a first period from the start of discharge of the treatment liquid from the nozzle to the end of discharge of the treatment liquid from the nozzle, and a first feature quantity, which is a feature quantity of a time change of the discharge pressure throughout the first period, is extracted as an overall feature quantity. With this configuration, when the discharge pressure affects the thickness of the treatment liquid applied to the substrate throughout the first period from the start of discharge of the treatment liquid from the nozzle to the end of discharge of the treatment liquid from the nozzle, it is possible to reflect the suitability of the discharge pressure throughout the first period in the evaluation of the discharge pressure.

[0017] The discharge pressure evaluation method may be configured such that the first characteristic amount indicates a difference between a first approximate waveform that approximates the time change of the discharge pressure during the entire first period and the time change of the discharge pressure during the entire first period. In this configuration, the discharge pressure during the entire period from the start to the end of discharge of the treatment liquid from the nozzle can be appropriately evaluated based on the approximate waveform for the time change of the discharge pressure during the entire period.

[0018] The discharge pressure evaluation method may be configured so that the first approximate waveform has a rising approximate line that linearly increases over time from the discharge start pressure to a steady pressure greater than the discharge start pressure by linearly approximating the time change of the discharge pressure that increases over time after the start of discharge of the treatment liquid from the nozzle, a start approximate line that is provided between the start time of discharge of the treatment liquid from the nozzle and the rising approximate line and indicates the discharge start pressure, a falling approximate line that linearly decreases over time from the steady pressure to a discharge end pressure that is smaller than the steady pressure by linearly approximating the time change of the discharge pressure that decreases over time before the end of discharge of the treatment liquid from the nozzle, a end approximate line that is provided between the falling approximate line and the end time of discharge of the treatment liquid from the nozzle and indicates the discharge end pressure, and a steady line that connects between the rising approximate line and the falling approximate line and indicates the steady pressure. In this configuration, the time change of the discharge pressure during the entire period from the start to the end of discharge of the treatment liquid from the nozzle is approximated by a trapezoidal waveform, so that the discharge pressure during the entire period can be appropriately evaluated.

[0019] The discharge pressure evaluation method may be configured so that the second evaluation stage out of the N evaluation stages has an evaluation item of evaluating the discharge pressure by executing a step of extracting, as a second feature amount, a feature amount possessed by the time change of the discharge pressure in a second period shorter than the evaluation period out of the evaluation period, and a step of evaluating the time change of the discharge pressure based on the second feature amount. With such a configuration, the discharge pressure can be evaluated with high accuracy based on the time change of the discharge pressure in a period shorter than the entire period from the start to the end of the discharge of the treatment liquid from the nozzle.

[0020] The discharge pressure evaluation method may be configured such that a predetermined initial rise period from the start of discharge of the treatment liquid from the nozzle is set as the second period, the discharge pressure increases over time throughout the initial rise period, and a feature value indicating the difference between a regression curve of the time change in the discharge pressure in the initial rise period and the time change in the discharge pressure in the initial rise period is extracted as the second feature value. With this configuration, the discharge pressure can be evaluated by taking into account the time change in the discharge pressure immediately after the start of discharge of the treatment liquid from the nozzle.

[0021] The discharge pressure evaluation method may be configured so that a rise period from when the nozzle starts discharging the treatment liquid until the discharge pressure increases to a predetermined pressure is set as the second period. In this configuration, the discharge pressure can be evaluated by taking into account the change in the discharge pressure over time during the rise period.

[0022] Specifically, the discharge pressure evaluation method may be configured so that the length of the rise period is extracted as the second characteristic amount. In this configuration, the discharge pressure can be evaluated taking into account the speed of the rise of the discharge pressure.

[0023] The discharge pressure evaluation method may be configured to extract the number of times that the first derivative of the time change of the discharge pressure crosses a predetermined threshold during the rise period as the second characteristic amount. With this configuration, the discharge pressure can be evaluated taking into account the smoothness of the time change of the discharge pressure during the rise period.

[0024] The discharge pressure evaluation method may be configured to extract the number of times that the absolute value of the second derivative of the time change of the discharge pressure crosses a predetermined threshold during the rise period as the second characteristic amount. With this configuration, the discharge pressure can be evaluated taking into account the smoothness of the time change of the discharge pressure during the rise period.

[0025] The discharge pressure evaluation method may be configured to extract, as the second characteristic, a ratio between the time during which the second derivative of the time change of the discharge pressure becomes greater than a predetermined positive threshold and the time during which the second derivative of the time change of the discharge pressure becomes smaller than a predetermined negative threshold having the same absolute value as the positive threshold during the rise period. With this configuration, the discharge pressure can be evaluated by taking into account the difference in the time change of the discharge pressure between the beginning and end of the rise period.

[0026] The discharge pressure evaluation method may be configured such that a predetermined rise end period until the discharge pressure increases to a predetermined pressure is set as the second period, a feature value indicating the difference between a rise end approximation waveform that approximates the time change of the discharge pressure in the rise end period and the time change of the discharge pressure in the rise end period is extracted as the second feature value, the rise end approximation waveform overlaps an approximation curve obtained by linearly approximating the time change of the discharge pressure that increases with time in a pressure range smaller than the predetermined pressure, a rise end approximation straight line that increases linearly with time to a steady pressure that is the average value of the time change of the discharge pressure in the steady period after the rise end period, and an extension straight line that indicates the steady pressure that is extended from the rise end approximation straight line to the end point of the rise end period. With such a configuration, the discharge pressure can be evaluated taking into account the degree of stall of the discharge pressure at the end of the rise period.

[0027] The discharge pressure evaluation method may be configured such that an initial oscillation period from when the discharge pressure reaches its maximum value to when the second derivative of the time change of the discharge pressure crosses zero twice is set as the second period, and the difference between the minimum value of the discharge pressure in the initial oscillation period and the average value of the discharge pressure in a predetermined steady period after the initial oscillation period, whichever is smaller, and the maximum value of the discharge pressure, is extracted as the second characteristic amount. With such a configuration, the discharge pressure can be evaluated taking into account the overshoot of the discharge pressure.

[0028] The discharge pressure evaluation method may be configured such that a predetermined transition period from the time when the discharge pressure exceeds the predetermined pressure is set as the second period, and a feature value indicating a difference in the discharge pressure during the transition period from the average value of the discharge pressure during a predetermined steady period after the transition period is extracted as the second feature value. With such a configuration, the discharge pressure can be evaluated taking into account the stability of the discharge pressure after it reaches the predetermined pressure.

[0029] The discharge pressure evaluation method may be configured such that a constant pressure period from when the discharge pressure exceeds a predetermined pressure to when the discharge pressure starts to decrease toward the end of discharge of the treatment liquid from the nozzle is set as the second period, and a feature value indicating a difference between the maximum and minimum values ​​of the discharge pressure during the constant pressure period is extracted as the second feature value. With such a configuration, the discharge pressure can be evaluated taking into account the stability of the discharge pressure during the constant pressure period.

[0030] Furthermore, in a discharge pressure evaluation method where N is 3 or more, the discharge pressure evaluation method may be configured so that a third evaluation stage out of the N evaluation stages has an evaluation item of evaluating the discharge pressure by executing a step of extracting a feature amount of the time change of the discharge pressure in a third period shorter than the evaluation period as a third feature amount, and a step of evaluating the time change of the discharge pressure based on the third feature amount. With such a configuration, the discharge pressure can be evaluated with high accuracy based on the time change of the discharge pressure in a period shorter than the entire period from the start to the end of the discharge of the treatment liquid from the nozzle.

[0031] The discharge pressure evaluation method may be configured such that a pressure increase period during which the discharge pressure increases over time from a lower reference value to an upper reference value greater than the lower reference value after the start of discharge of the treatment liquid from the nozzle is set as a third period, one measured value among the measured values ​​of the discharge pressure between the lower reference value and the upper reference value is obtained, which is a value that minimizes the sum of the root mean square error between an approximation line obtained by linear regression of the time change in the discharge pressure in the section between the lower reference value and the one measured value and the root mean square error between an approximation line obtained by linear regression of the time change in the discharge pressure in the section between the one measured value and the upper reference value, and the ratio of the slope of the line between the lower reference value and the one measured value to the slope of the line between the one measured value and the upper reference value is extracted as the third characteristic amount. With such a configuration, the discharge pressure can be evaluated taking into account the linearity of the increase in the discharge pressure.

[0032] The discharge pressure evaluation method may be configured such that a predetermined rise end period until the discharge pressure increases to a predetermined pressure is set as a third period, a feature value indicating the difference between a rise end approximation waveform that approximates the time change of the discharge pressure in the rise end period and the time change of the discharge pressure in the rise end period is extracted as a third feature value, the rise end approximation waveform overlaps an approximation curve obtained by linearly approximating the time change of the discharge pressure that increases with time in a pressure range smaller than the predetermined pressure, and has a rise end approximation straight line that increases linearly to the predetermined pressure with time, and an extension straight line that is connected to the rise end approximation straight line and indicates the predetermined pressure. With such a configuration, the discharge pressure can be evaluated taking into account the degree of stall of the discharge pressure at the end of the rise period.

[0033] The discharge pressure evaluation method may be configured such that an initial oscillation period from when the discharge pressure reaches its maximum value to when the second derivative of the time change of the discharge pressure crosses zero twice is set as a third period, and the sum of a value obtained by subtracting a steady pressure, which is an average value of the discharge pressure in a predetermined steady period after the initial oscillation period, from the maximum value of the discharge pressure and a value obtained by subtracting a minimum value of the discharge pressure in the initial oscillation period from the steady pressure is extracted as the third characteristic amount. With such a configuration, the discharge pressure can be evaluated taking into account the overshoot of the discharge pressure. Effect of the Invention

[0034] As described above, according to the present invention, the ejection pressure applied to the treatment liquid for ejecting the treatment liquid from the nozzle can be evaluated within a reasonable time period according to the suitability of the ejection pressure. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a diagram showing a schematic overall configuration of a coating apparatus which is one embodiment of a substrate processing apparatus according to the present invention. [Diagram 2] FIG. 2 is a diagram showing a configuration of a coating liquid supply mechanism. [Diagram 3] FIG. 4 is a block diagram showing an example of the configuration of a control unit. [Figure 4] 5 is a flowchart showing an example of a discharge pressure evaluation method executed based on a discharge pressure evaluation program. [Diagram 5] 5A and 5B are diagrams for explaining periods used in evaluating the discharge pressure. [Figure 6] 6 is a diagram showing an example of a calculation executed by a pressure evaluation unit with respect to a change over time in a discharge pressure; FIG. [Figure 7] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv1. [Figure 8] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv2. [Figure 9] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv3. [Figure 10A]FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on a feature amount Fv4. [Figure 10B] 13 is a graph showing an example of a change over time in a discharge pressure that is determined to be inappropriate by an evaluation based on a feature amount Fv4. [Figure 11A] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on a feature amount Fv5. [Figure 11B] 13 is a graph showing an example of a change over time in a discharge pressure that is determined to be inappropriate by an evaluation based on a feature amount Fv5. [Figure 12] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on a feature amount Fv6. [Figure 13] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on a feature amount Fv7. [Figure 14] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv8. [Figure 15] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on a feature amount Fv9. [Figure 16] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv10. [Figure 17] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv11. [Figure 18] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv12. [Figure 19] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on the feature amount Fv13. [Figure 20] FIG. 13 is a diagram for explaining an evaluation item for evaluating the change over time in the discharge pressure based on a feature amount Fv14. [Figure 21] 10 is a flowchart showing details of measurement result evaluation. [Figure 22] FIG. 22 is a diagram illustrating an example of an operation executed according to the flowchart of FIG. 21. [Diagram 23] 13A and 13B are diagrams for explaining each period used in a modified example of the evaluation item of the discharge pressure. [Figure 24] FIG. 13 is a diagram for explaining a modified example of an evaluation item for evaluating a time change in discharge pressure based on a feature amount Fv1_1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] FIG. 1 is a diagram showing a schematic diagram of an overall configuration of a coating apparatus according to an embodiment of the substrate processing apparatus of the present invention. The coating apparatus 1 is a slit coater that applies a coating liquid to an upper surface Sf of a substrate S that is transported in a horizontal position from the left hand side to the right hand side in FIG. 1. In order to clarify the positional relationship of each part of the apparatus in each of the following figures, the transport direction of the substrate S is referred to as the "X direction", the horizontal direction from the left hand side to the right hand side in FIG. 1 is referred to as the "+X direction", and the opposite direction is referred to as the "-X direction". In addition, in the horizontal direction Y perpendicular to the X direction, the front side of the apparatus is referred to as the "-Y direction", and the back side of the apparatus is referred to as the "+Y direction". Furthermore, the upward and downward directions in the vertical direction Z are referred to as the "+Z direction" and "-Z direction", respectively.

[0037] In the coating device 1, an input conveyor 100, an input transfer section 2, a floating stage section 3, an output transfer section 4, and an output conveyor 110 are arranged in this order in close proximity along the transport direction Dt (+X direction) of the substrate S, and as described in detail below, these form a transport path for the substrate S that extends in a substantially horizontal direction. In the following description, when showing a positional relationship in relation to the transport direction Dt of the substrate S, the "upstream side in the transport direction Dt of the substrate S" may be abbreviated simply to the "upstream side", and the "downstream side in the transport direction Dt of the substrate S" may be abbreviated simply to the "downstream side". In this example, the (-X) side corresponds to the "upstream side" and the (+X) side corresponds to the "downstream side" relative to a certain reference position.

[0038] The substrate S to be processed is carried into the input conveyor 100 from the left hand side of FIG. 1. The input conveyor 100 includes a roller conveyor 101 and a rotation drive mechanism 102 that drives the roller conveyor 101 to rotate, and the substrate S is transported in a horizontal position downstream, that is, in the (+X) direction, by the rotation of the roller conveyor 101. The input transfer unit 2 includes a roller conveyor 21 and a rotation / elevation drive mechanism 22 that has the function of driving the roller conveyor 21 to rotate and the function of raising and lowering it. The substrate S is further transported in the (+X) direction by the rotation of the roller conveyor 21. In addition, the position of the substrate S in the vertical direction Z is changed by the raising and lowering of the roller conveyor 21. The input transfer unit 2 configured in this manner transfers the substrate S from the input conveyor 100 to the floating stage unit 3.

[0039] The floating stage unit 3 includes a flat plate-like stage divided into three parts along the substrate transport direction Dt. That is, the floating stage unit 3 includes an entrance floating stage 31, a coating stage 32, and an exit floating stage 33, and the upper surfaces of these stages form part of the same plane. Furthermore, the floating stage unit 3 includes a lift pin drive mechanism 34, a floating control mechanism 35, and an elevation drive mechanism 36. The lift pin drive mechanism 34 can raise and lower the lift pins provided on the entrance floating stage 31. The floating control mechanism 35 can supply compressed air to each stage of the floating stage unit 3 for floating the substrate S. The elevation drive mechanism 36 can raise and lower the exit floating stage 33.

[0040] A large number of nozzles are provided in a matrix on the upper surface of each of the entrance levitation stage 31 and the exit levitation stage 33, which spray compressed air supplied from a levitation control mechanism 35, and the substrate S is levitated by the buoyancy imparted by the sprayed airflow. In this way, the lower surface Sb of the substrate S is supported in a horizontal position with the lower surface Sb spaced apart from the upper surface of the stage. The distance between the lower surface Sb of the substrate S and the upper surface of the stage, i.e., the levitation amount, can be, for example, 10 micrometers to 500 micrometers.

[0041] On the other hand, on the upper surface of the coating stage 32, the ejection holes for ejecting compressed air and the suction holes for sucking air between the lower surface Sb of the substrate S and the upper surface of the stage are alternately arranged. The floating control mechanism 35 controls the amount of compressed air ejected from the ejection holes and the amount of air sucked from the suction holes, thereby precisely controlling the distance between the lower surface Sb of the substrate S and the upper surface of the coating stage 32. As a result, the position in the vertical direction Z of the upper surface Sf of the substrate S passing above the coating stage 32 is controlled to a specified value. As a specific configuration of the floating stage part 3, for example, one described in Japanese Patent No. 5346643 can be applied. The floating amount on the coating stage 32 is calculated by the control unit 9 based on the detection results by sensors 61 and 62, which will be described in detail later, and can be adjusted with high precision by airflow control.

[0042] The substrate S carried into the floating stage section 3 via the input transfer section 2 is given a propulsive force in the (+X) direction by the rotation of the roller conveyor 21, and is transported onto the entrance floating stage 31. The entrance floating stage 31, the coating stage 32 and the exit floating stage 33 support the substrate S in a floating state, but do not have the function of moving the substrate S in the horizontal direction. The transportation of the substrate S in the floating stage section 3 is performed by the substrate transport section 5 arranged below the entrance floating stage 31, the coating stage 32 and the exit floating stage 33.

[0043] The substrate transport unit 5 includes a chuck mechanism 51 that partially contacts the peripheral portion of the lower surface of the substrate S to support the substrate S from below, and a suction / travel control mechanism 52 that has a function of applying negative pressure to a suction pad (not shown) provided on a suction member at the upper end of the chuck mechanism 51 to suction and hold the substrate S, and a function of reciprocating the chuck mechanism 51 in the X direction. When the chuck mechanism 51 holds the substrate S, the lower surface Sb of the substrate S is located at a position higher than the upper surfaces of the stages of the floating stage unit 3. Therefore, the substrate S maintains a horizontal position as a whole due to the buoyancy applied by the floating stage unit 3 while the peripheral portion is suction-held by the chuck mechanism 51. In addition, a thickness measuring sensor 61 is arranged near the roller conveyor 21 to detect the position of the upper surface of the substrate S in the vertical direction Z at the stage when the lower surface Sb of the substrate S is partially held by the chuck mechanism 51. A chuck (not shown) not holding a substrate S is positioned directly below the sensor 61, so that the sensor 61 can detect the position of the upper surface of the chucking member, that is, the chucking surface, in the vertical direction Z.

[0044] The substrate S carried in from the input transfer unit 2 to the floating stage unit 3 is held by the chuck mechanism 51, and as the chuck mechanism 51 moves in the (+X) direction in this state, the substrate S is transported from above the entrance floating stage 31, via above the coating stage 32, to above the exit floating stage 33. The transported substrate S is delivered to the output transfer unit 4 arranged on the (+X) side of the exit floating stage 33.

[0045] The output transfer unit 4 includes a roller conveyor 41 and a rotation / elevation drive mechanism 42 having the function of rotating and driving the roller conveyor 41 and the function of raising and lowering the roller conveyor 41. As the roller conveyor 41 rotates, a propulsive force in the (+X) direction is imparted to the substrate S, and the substrate S is further transported along the transport direction Dt. As the roller conveyor 41 rises and falls, the position of the substrate S in the vertical direction Z is changed. The output transfer unit 4 transfers the substrate S from above the exit floating stage 33 to the output conveyor 110.

[0046] The output conveyor 110 includes a roller conveyor 111 and a rotation drive mechanism 112 that drives the roller conveyor 111 to rotate, and the substrate S is further transported in the (+X) direction by the rotation of the roller conveyor 111, and is finally discharged outside the coating apparatus 1. The input conveyor 100 and the output conveyor 110 may be provided as part of the configuration of the coating apparatus 1, or may be separate from the coating apparatus 1. For example, a substrate discharging mechanism of a separate unit provided upstream of the coating apparatus 1 may be used as the input conveyor 100. A substrate receiving mechanism of a separate unit provided downstream of the coating apparatus 1 may be used as the output conveyor 110.

[0047] A coating mechanism 7 for coating the upper surface Sf of the substrate S is disposed on the transport path of the substrate S transported in this manner. The coating mechanism 7 has a slit nozzle (hereinafter simply referred to as "nozzle") 71 having a slit-shaped discharge port. Although not shown, a positioning mechanism is connected to the nozzle 71, and the nozzle 71 is positioned at a coating position above the coating stage 32 (the position indicated by the solid line in FIG. 1) or at a maintenance position, which will be described later. Furthermore, a coating liquid supply mechanism 8 is connected to the nozzle 71, and the coating liquid is supplied from the coating liquid supply mechanism 8 and discharged from a discharge port that opens downward at the bottom of the nozzle.

[0048] 2 is a diagram showing the configuration of the coating liquid supply mechanism. As shown in FIG. 2, the coating liquid supply mechanism 8 uses a pump 81 that supplies the coating liquid by changing its volume as a supply source for supplying the coating liquid to the nozzle 71. As the pump 81, for example, a bellows type pump described in JP-A-10-61558 can be used. This pump 81 has a flexible tube 811 that is elastically expandable and contractible in the radial direction. One end of this flexible tube 811 is connected to a coating liquid refill unit 83 by a pipe 82, and the other end is connected to the nozzle 71 by a pipe 84.

[0049] A bellows 812 that is elastically deformable in the axial direction is disposed on the outside of the flexible tube 811. The bellows 812 has a small bellows section 813 and a large bellows section 814, and a non-compressible medium is sealed in a pump chamber 815 between the flexible tube 811 and the bellows 812. An operating disk section 816 is provided between the small bellows section 813 and the large bellows section 814. A drive section 817 is connected to the operating disk section 816. When the drive section 817 operates in response to a command from the control unit 9, the operating disk section 816 is displaced in the axial direction in a predetermined movement pattern (a pattern indicating a change in the speed of the operating disk section 816 over time), and the volume inside the bellows 812 is changed. As a result, the flexible tube 13 expands and contracts in the radial direction to perform a pumping operation, and the coating liquid appropriately replenished from the coating liquid refill unit 83 is fed toward the nozzle 71. Therefore, the movement pattern of the operating disk portion 816 is closely related to the discharge characteristics (time change in discharge pressure) of the coating liquid discharged from the nozzle 71, and predetermined discharge characteristics can be obtained according to the movement pattern.

[0050] The coating liquid refill unit 83 has a storage tank 831 that stores the coating liquid. This storage tank 831 is connected to the pump 81 by a pipe 82. An on-off valve 833 is inserted in the pipe 82. This on-off valve 833 opens in response to a refill command from the control unit 9, allowing the coating liquid in the storage tank 831 to be refilled into the flexible tube 811 of the pump 81. Conversely, the on-off valve 833 closes in response to a refill stop command from the control unit 9, restricting the refilling of the coating liquid from the storage tank 831 to the flexible tube 811 of the pump 81.

[0051] An on-off valve 85 is inserted in a pipe 84 connected to the output side (left hand side in the figure) of the pump 81, and opens and closes in response to an on-off command from the control unit 9. This makes it possible to switch between sending and stopping the coating liquid to the nozzle 71. In addition, a pressure gauge 86 is attached to the pipe 84, which detects the pressure (discharge pressure) of the coating liquid sent to the nozzle 71 and outputs the detection result (pressure value) to the control unit 9.

[0052] 2, a floating height detection sensor 62 for detecting the floating height of the substrate S in a non-contact manner is installed on the nozzle 71 to which the coating liquid is supplied from the coating liquid supply mechanism 8. This sensor 62 can measure the distance between the floating substrate S and the upper surface of the stage surface of the coating stage 32, and the control unit 9 controls a positioning mechanism (not shown) according to the detection value to adjust the position to which the nozzle 71 descends. Note that an optical sensor, an ultrasonic sensor, or the like can be used as the sensor 62.

[0053] 1, in order to perform predetermined maintenance on the nozzle 71, the coating mechanism 7 is provided with a nozzle cleaning standby unit 72. The nozzle cleaning standby unit 72 mainly includes a roller 721, a cleaning section 722, a roller pad 723, and the like. These are used to clean the nozzle and form a liquid pool, thereby preparing the discharge port of the nozzle 71 for a state suitable for the next coating process. In addition, the nozzle 71 is positioned at the position where the nozzle cleaning standby unit 72 is provided, i.e., at the maintenance position, and a simulated discharge is performed in which the coating liquid is discharged from the nozzle 71 in order to evaluate the discharge pressure applied to the coating liquid.

[0054] Furthermore, the coating apparatus 1 is provided with a control unit 9 (FIG. 3) for controlling the operation of each part of the apparatus. FIG. 3 is a block diagram showing an example of the configuration of the control unit. As shown in FIG. 3, the control unit 9 is a computer including a calculation unit 91, a storage unit 93, and a UI (User Interface) 95. The calculation unit 91 is a processor including a CPU (Central Processing Unit) and the like, and executes a discharge pressure evaluation program 97 to construct a measurement execution unit 911 that executes measurement of the discharge pressure and a pressure evaluation unit 913 that evaluates the measured discharge pressure. The storage unit 93 is a storage device such as an HDD (Hard Disk Drive) or an SDD (Solid State Drive), and stores the above-mentioned discharge pressure evaluation program 97 and discharge pressure measurement data 99 measured in association with the execution of the discharge pressure evaluation program 97. The discharge pressure evaluation program 97 is provided, for example, by a recording medium M provided separately from the control unit 9. The recording medium M records the discharge pressure evaluation program 97 so that it can be read by a computer (control unit 9). Examples of the recording medium M include a USB (Universal Serial Bus) memory, a memory card, or a storage device of an external server computer. The UI 95 also includes a display for displaying information to the user and an input device for receiving input operations by the user. As the control unit 9 having such a configuration, various types of computers, such as desktop, laptop, or tablet computers, can be used.

[0055] 4 is a flow chart showing an example of a discharge pressure evaluation method executed based on a discharge pressure evaluation program. In step 101, the measurement execution unit 911 moves the operating disk unit 816 based on a movement pattern defined in the discharge pressure evaluation program 97, thereby discharging the coating liquid from the nozzle 71 (pseudo discharge). As a result, the operating disk unit 816 accelerates from a speed of zero to a predetermined target speed in a global sense, moves at a constant speed at the target speed, and then decelerates from the target speed to a speed of zero. However, as shown in Patent Document 2, in a local period from when the speed of the operating disk unit 816 reaches the maximum speed until it stabilizes at the target speed, the speed (parameter) of the operating disk unit 816 is adjusted to set the movement pattern.

[0056] Specifically, the discharge pressure is as follows: The discharge pressure increases from the initial pressure Pi to a target pressure Pt that is greater than the initial pressure Pi. Discharge pressure stabilizes at the target pressure Pt The discharge pressure decreases from the target pressure Pt to the initial pressure Pi. The movement pattern of the operating disk portion 816 is defined in the discharge pressure evaluation program 97 so that the discharge pressure changes as follows.

[0057] Furthermore, in step S101, the measurement execution unit 911 periodically acquires the measured value of the discharge pressure by the pressure gauge 86 at a predetermined sampling period in parallel with the discharge of the coating liquid from the nozzle 71 accompanying the movement of the operating disk unit 816. In this manner, the result of measuring the discharge pressure applied to the coating liquid during the discharge period Tt (FIG. 5) during which the coating liquid is discharged from the nozzle 71 is acquired and stored in the storage unit 93 as discharge pressure measurement data 99. This discharge pressure measurement data 99 indicates a time and a value of the discharge pressure measured at that time in association with each other.

[0058] In step S102, the pressure evaluation unit 913 evaluates the time change of the discharge pressure indicated by the discharge pressure measurement data 99 according to predetermined evaluation items. As described below, these evaluation items extract predetermined feature amounts from the time change of the discharge pressure indicated by the discharge pressure measurement data 99, and evaluate the time change of the discharge pressure based on these feature amounts. Next, each evaluation item for evaluating the time change of the discharge pressure indicated by the discharge pressure measurement data 99 will be described in detail.

[0059] FIG. 5 is a diagram for explaining each period used in the evaluation of the discharge pressure. In FIG. 5, the time change of the discharge pressure is shown in a graph in which the horizontal axis represents time and the vertical axis represents the discharge pressure. The graph notation is the same in each figure shown later. In the example of FIG. 5, the discharge pressure measurement data 99 is acquired from before the discharge of the coating liquid from the nozzle 71 is started to after the discharge of the coating liquid from the nozzle 71 is completed (i.e., before and after the discharge period Tt). In this example, the discharge pressure at the time ta when the discharge of the coating liquid from the nozzle 71 is started and the discharge pressure at the time te when the discharge of the coating liquid from the nozzle 71 is completed are the initial pressure Pi. However, the pressures at the start and end of discharge do not always match the initial pressure Pi.

[0060] 5, the discharge period Tt can be divided into four periods Ta, Tb, Tc, and Td. The details of the rise period Ta, the transition period Tb, the steady period Tc, and the fall period Td are as follows.

[0061] The rise period Ta is the period from time ta when the coating liquid supply mechanism 8 starts discharging the coating liquid from the nozzle 71 (i.e., time ta when the coating liquid supply mechanism 8 starts moving the operating disk portion 816) to time tb when the discharge pressure reaches the target pressure Pt. In other words, when the discharge of the coating liquid from the nozzle 71 starts at time ta, the discharge pressure increases from the initial pressure Pi to the target pressure Pt during the period from time ta to time tb.

[0062] The transition period Tb is a period from time tb to time tc when a predetermined vibration damping period has elapsed. This vibration damping period is a period required for the time change of the discharge pressure to stabilize, and is set, for example, by a user through an input operation on the UI 95 and stored in the storage unit 93.

[0063] The steady period Tc is the period from time tc to time td when the coating liquid supply mechanism 8 starts to reduce the discharge pressure (i.e., time td when the coating liquid supply mechanism 8 starts to decelerate the operating disk portion 816 from the target speed). That is, the coating liquid supply mechanism 8 moves the operating disk portion 816 at a constant speed from time tc to time td, and starts to decelerate the operating disk portion 816 at time td. Note that in the steady period Tc, the discharge pressure is basically stable at the target pressure Pt. However, even in the steady period Tc, the time change in the discharge pressure includes minute vibrations, and the discharge pressure becomes larger or smaller than the target pressure Pt.

[0064] The transition period Tb and the steady period Tc constitute a constant pressure period Tbc, which is the period between time tb and time td.

[0065] The falling period Td is the period from time td to time te when the coating liquid supply mechanism 8 finishes discharging the coating liquid from the nozzle 71 (i.e., time te when the coating liquid supply mechanism 8 stops the operating disk portion 816). In other words, the discharge pressure decreases to the initial pressure Pi between time td and time te, and at time te, the discharge of the coating liquid from the nozzle 71 stops.

[0066] Fig. 6 is a diagram showing an example of a calculation executed by the pressure evaluation unit for the time change of the discharge pressure. As shown in Fig. 6, the pressure evaluation unit 913 calculates a first derivative D1 of the time change of the discharge pressure by differentiating the time change of the discharge pressure. Furthermore, the pressure evaluation unit 913 calculates a second derivative D2 of the time change of the discharge pressure by differentiating the first derivative D1 of the time change of the discharge pressure by time. Moreover, the pressure evaluation unit 913 calculates the second derivative D2 of the time change of the discharge pressure by using the following equations: MAE(α, β)=(1 / n)·(Σ|α-β|) RMSE(α, β)=((1 / n)·(Σ(α-β) 2 )) 1 / 2 n = number of data Based on this, we calculate the mean absolute error (MAE) and the root mean square error (RMSE).

[0067] Fig. 7 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv1. The evaluation item in Fig. 7 evaluates the time change of the discharge pressure indicated by the discharge pressure measurement data 99 based on the error (ideal trapezoid absolute error) between a trapezoidal waveform having an amplitude corresponding to the difference between the average value of the discharge pressure in the steady period Tc (i.e., the steady pressure Pm) and the initial pressure Pi and the discharge pressure measurement data 99.

[0068] Specifically, a linear regression analysis is performed on the time change of the discharge pressure between a predetermined lower reference pressure and a predetermined upper reference pressure higher than the lower reference pressure during the rise period Ta, and the rise regression line Lr_R is calculated. This rise regression line Lr_R increases linearly from the initial pressure Pi to the steady pressure Pm between time t11 and time t12.

[0069] Similarly, a linear regression analysis is performed on the time change of the discharge pressure between the upper and lower reference pressures during the falling period Td to calculate a falling regression line Lr_F. This falling regression line Lr_F linearly decreases from the steady pressure Pm to the initial pressure Pi between time t13 and time t14.

[0070] The lower reference pressure and the upper reference pressure are pressures that are greater than the initial pressure Pi and less than the target pressure Pt, and are set, for example, by a user through an input operation on the UI 95 and stored in the storage unit 93. In this example, the lower reference pressure is a pressure obtained by adding, to the initial pressure Pi, a pressure that is 20% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt, and the upper reference pressure is a pressure obtained by adding, to the initial pressure Pi, a pressure that is 80% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt.

[0071] Also, for the period from time ta to time t11, an initial approximation straight line Lr_s is set. This initial approximation straight line Lr_s is a straight line with a slope of zero indicating the initial pressure Pi. That is, the initial approximation straight line Lr_s is a straight line connecting from the start point of the discharge of the coating liquid from the nozzle 71 (time ta) to the start point of the rising regression straight line Lr_R. Note that depending on the state (slope) of the regression straight line, time t11 may be earlier than time ta, and time t12 may be later than time tb. As a result, when t11 < ta, the initial approximation straight line Lr_s is omitted.

[0072] Also, for the period from time t14 to time te, an end approximation straight line Lr_e is set. This end approximation straight line Lr_e is a straight line with a slope of zero indicating the initial pressure Pi. That is, the end approximation straight line Lr_e is a straight line connecting from the end point of the falling regression straight line Lr_F to the end point of the discharge of the coating liquid from the nozzle 71 (time te). Note that when te < t14, the end approximation straight line Lr_e is omitted.

[0073] Furthermore, for the period from time t12 to time t13, a steady straight line Lr_m is set. This steady straight line Lr_m is a straight line with a slope of zero indicating the steady pressure Pm. That is, the steady straight line Lr_m is a straight line indicating the steady pressure Pm that connects the end point (time t12) of the rising regression straight line Lr_R and the start point (time t13) of the falling regression straight line Lr_F.

[0074] In this way, an approximate waveform WF1 composed of the initial approximation straight line Lr_s, the rising regression straight line Lr_R, the steady straight line Lr_m, the falling regression straight line Lr_F, and the end approximation straight line Lr_e arranged in time series is calculated. Then, the pressure evaluation unit 913 calculates the mean absolute error MAE (ideal trapezoid absolute error) between the discharge pressure measurement data 99 and the approximate waveform WF1 as a feature quantity Fv1 over the entire discharge period Tt from time ta to time te. Also, the pressure evaluation unit 913 normalizes the feature quantity Fv1 to a range of 0 or more and 2 or less based on a predetermined threshold Th1 (for example, 0.05). Specifically, the following formula Fv1 <Th1であるなら、Fv1=0 If Fv1 ≧ Th1, Fv1 = (Fv1 + 1 - Th1) × c1 The feature value Fv1 is converted into a normalized feature value Fv1 (i.e., evaluation value V1) based on the above. Here, the coefficient c1 is a normalization coefficient, and is preset to a value (e.g., 15) that causes the feature value Fv1 to fall within a range of 2 or less.

[0075] According to the evaluation based on the feature Fv1 in Figure 7, if the change in the discharge pressure over time throughout the entire discharge period Tt deviates significantly from an ideal shape (i.e., a trapezoidal shape), a high score (i.e., a poor evaluation) can be given to this discharge pressure.

[0076] Fig. 8 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv2. The evaluation item in Fig. 8 evaluates the smoothness of the rise of the discharge pressure. Specifically, during the rise period Ta, a curve regression analysis is performed on the time change of the discharge pressure between the lower reference pressure P2_l and the upper reference pressure P2_u that is greater than the lower reference pressure P2_l, and a rise regression curve Nr is calculated. This curve regression analysis is performed using a quadratic curve.

[0077] The lower reference pressure P2_l is set to the initial pressure Pi. On the other hand, the upper reference pressure P2_u is a pressure that is greater than the lower reference pressure P2_l and less than the target pressure Pt, and is set, for example, by a user through an input operation to the UI 95 and stored in the storage unit 93. In this example, the upper reference pressure P2_u is a pressure obtained by adding a pressure that is 20% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi. This rising regression curve Nr increases from the lower reference pressure P2_l (initial pressure Pi) to the upper reference pressure P2_u between time t21 and time t22. Note that time t21 coincides with time ta, and time t22 is later than time ta and earlier than time tb.

[0078] In this way, the waveform WF2 composed of the rising regression curve Nr is calculated. Then, the pressure evaluation unit 913 calculates the root mean square error RMSE between the discharge pressure measurement data 99 and the waveform WF2 during the initial rising period Ta_s from time t21 to time t22 as the feature amount Fv2. Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv2 to a range of 0 to 2 based on a predetermined threshold value Th2 (for example, 0.05). Specifically, the following equation Fv2 <Th2であるなら、Fv2=0 If Fv2 ≧ Th2, then Fv2 = 2 Based on this, the feature value Fv2 is converted into a normalized feature value Fv2 (i.e., the evaluation value V2).

[0079] 8, when an abnormality occurs in the discharge pressure immediately after the start of discharge due to the influence of the state before the start of discharge of the coating liquid from the nozzle 71, a large score (i.e., a poor evaluation) can be given to this discharge pressure. Note that the curve that can be used in the curve regression analysis is not limited to a quadratic curve, and may be another curve such as an exponential function.

[0080] FIG. 9 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv3. The evaluation item in FIG. 9 evaluates whether the rise period Ta is within a certain period. Specifically, the pressure evaluation unit 913 calculates the length of the rise period Ta (=tb-ta) from time ta to time tb required for the discharge pressure to increase from the initial pressure Pi to the target pressure Pt as the feature amount Fv3. In addition, the pressure evaluation unit 913 normalizes the feature amount Fv3 to a range of 0 to 1 based on a predetermined threshold value Th3 (e.g., 350 ms). Specifically, the following equation Fv3 <Th3であるなら、Fv3=0 If Fv3 ≧ Th3, then Fv2 = 1 Based on this, the feature value Fv3 is converted into a normalized feature value Fv3 (i.e., the evaluation value V3).

[0081] According to the evaluation based on the feature amount Fv3 in FIG. 9, a large score (that is, a poor evaluation) can be given to a discharge pressure that takes a long time to rise to the target pressure Pt.

[0082] Fig. 10A is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv4, and Fig. 10B is a diagram showing an example of the time change of the discharge pressure that is determined to be inappropriate by the evaluation based on the feature amount Fv4. The evaluation item in Fig. 10A evaluates the presence or absence of an abnormality in the rise of the discharge pressure. Specifically, the pressure evaluation unit 913 calculates a first derivative D1 of the time change of the discharge pressure for the rise period Ta from time ta to time tb, and obtains a first derivative waveform WF4.

[0083] The pressure evaluation unit 913 then determines the number of times that the first-time differential waveform WF4 crosses a predetermined threshold value Th4 during the rising period Ta as the feature value Fv4. In the example of FIG. 10A, the first-time differential waveform WF4 crosses the threshold value Th4 (for example, 0.002) at both time t41 and time t42, and the number of crossings (feature value Fv4) is two. The pressure evaluation unit 913 also normalizes the feature value Fv4 to a range of 0 to 1. Specifically, the following equation If Fv4≦2, then Fv4=0 If Fv4>2, then Fv4=1 Based on this, the feature value Fv4 is converted into a normalized feature value Fv4 (i.e., the evaluation value V4).

[0084] According to the evaluation based on the feature Fv4 in FIG. 10A, if a step occurs in the time change of the discharge pressure during the rise period Ta (for example, as shown in FIG. 10B), a large score (i.e., a bad evaluation) can be given to this discharge pressure.

[0085] Fig. 11A is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv5, and Fig. 11B is a diagram showing an example of the time change of the discharge pressure that is determined to be inappropriate by the evaluation based on the feature amount Fv5. The evaluation item in Fig. 11A evaluates the presence or absence of an abnormality in the rise of the discharge pressure. Specifically, the pressure evaluation unit 913 calculates the second derivative D2 of the time change of the discharge pressure for the rise period Ta from time ta to time tb to obtain the second derivative waveform WF5.

[0086] The pressure evaluation unit 913 then determines the number of times that the absolute value of the twice-differentiated waveform WF5 crosses a predetermined threshold value Th5 during the rising period Ta as the feature value Fv5. In the example of FIG. 11A, the absolute value of the twice-differentiated waveform WF5 crosses the threshold value Th5 (e.g., 0.0002) at each of times t51, t52, t53, and t54, and the number of crossings (feature value Fv5) is four. The pressure evaluation unit 913 also normalizes the feature value Fv5 to a range of 0 to 1. Specifically, the following equation If Fv5=4, then Fv5=0 If Fv5≠4, then Fv5=1 Based on this, the feature value Fv5 is converted into a normalized feature value Fv5 (i.e., the evaluation value V5).

[0087] According to the evaluation based on the feature Fv5 in FIG. 11A, if a step occurs in the time change of the discharge pressure during the rise period Ta (for example, as shown in FIG. 11B), a large score (i.e., a bad evaluation) can be given to this discharge pressure.

[0088] Fig. 12 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv6. The evaluation item in Fig. 12 evaluates whether the rise of the discharge pressure stalls in the latter half. Specifically, the pressure evaluation unit 913 calculates the second derivative D2 of the time change of the discharge pressure for the rise period Ta from time ta to time tb to obtain the second derivative waveform WF6.

[0089] The pressure evaluation unit 913 then determines the time T_1st at which the second derivative waveform WF6 becomes greater than a predetermined positive threshold (Th5) during the rising period Ta, and the time T_2nd at which the second derivative waveform WF6 becomes smaller than a predetermined negative threshold (-Th5). Here, the positive threshold and the negative threshold have the same absolute value (Th5) and different signs. The absolute value (Th5) of the positive and negative thresholds is equal to that of the threshold Th5 used in the evaluation based on the above-mentioned feature Fv5. The pressure evaluation unit 913 then determines the ratio of these times (=T_1st / T_2nd) as the feature Fv6. Furthermore, the pressure evaluation unit 913 calculates the following equation: Fv6 = |1-Fv6| The feature Fv6 is transformed based on the above.

[0090] Furthermore, the pressure evaluation unit 913 normalizes the thus converted feature quantity Fv6 to a range of 0 to 2 using a predetermined threshold value Th6 (for example, 0.2). Fv6 <Th6であるなら、Fv6=0 If Fv6 ≧ Th6, then Fv6 = f(Fv6) f(γ)=4×γ-0.8 The feature value Fv6 is converted into a normalized feature value Fv6 (i.e., evaluation value V6) based on the above. Note that the function f(γ) with γ as a variable is not limited to the example given here, and can be changed arbitrarily.

[0091] The transport speed of the substrate S to be coated with the coating liquid reaches the target speed without stalling even in the latter half of the acceleration period. Therefore, it is preferable that the discharge pressure applied to the coating liquid also reaches the target pressure Pt without stalling during the rise period Ta. In contrast, according to the evaluation based on the feature Fv6 in FIG. 12, if the discharge pressure stalls during the rise period Ta, a high score (i.e., a poor evaluation) can be given to this discharge pressure.

[0092] FIG. 13 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv7. The evaluation item in FIG. 13 evaluates the sharpness of the time change of the discharge pressure at the end of the rise. Specifically, in the rise period Ta, linear regression analysis is performed on the time change of the discharge pressure between the lower reference pressure P7_l and the upper reference pressure P7_u greater than the lower reference pressure P7_l, and the regression line Lr at the end of the rise is calculated. Here, the lower reference pressure P7_l is the pressure obtained by adding the pressure of 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 the pressure of 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_l to the upper reference pressure P7_u between the time t71 and the time t72.

[0093] This regression line Lr at the end of the rise increases with the passage of time and reaches the steady pressure Pm (the average value of the discharge pressure in the steady period Tc) at the time t73. Thus, the regression line Lr at the end of the rise is set for the section from the time t71 to the time t73. Further, the pressure evaluation unit 913 sets an extended line Lm with a slope of zero indicating the steady pressure Pm between the time t73 and the time tb. As described above, the time tb is the time when the discharge pressure reaches the target pressure Pt and corresponds to the end time of the rise period Ta. That is, this extended line Lm is provided so as to extend from the end point of the regression line Lr at the end of the rise to the end point of the rise period Ta. Note that when tb < t73, the extended line Lm is omitted.

[0094] Thus, an approximate waveform WF7 composed of the regression line Lr at the end of the rise and the extended line Lm arranged in time series is calculated. Then, the pressure evaluation unit 913 calculates, as the feature amount Fv7, a value indicating the difference between the discharge pressure measurement data 99 and the approximate waveform WF7 in the rise end period Ta_e from the time t72 when the discharge pressure becomes 90% of the target pressure Pt to the time tb when it becomes 100%. Specifically, a weighted reference time width Tw = t73 - t72 is set. And the weighted sum of the square root of the errors is given by the following formula Fv7 = (Σ(P_measure-WF7) 2 ×W) 1 / 2 P_measure = Discharge pressure measurement data 99 W=1 in the range of time tb≦t73+2×Tw When tb>t73+2×Tw, W=w w is a weighting factor greater than 1, e.g. 10 It is calculated based on:

[0095] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv7 to a range of 0 to 2 based on a predetermined threshold value Th7 (for example, 0.6). Fv7 <Th7であるなら、Fv7=0 If Fv7≧Th7, then Fv7=Fv7 / c7 c7 is any positive constant, e.g. 1.1 Based on this, the feature value Fv7 is converted into a normalized feature value Fv7 (i.e., the evaluation value V7).

[0096] According to the evaluation based on the feature Fv7 in FIG. 13, if the time change in the ejection pressure shows a rounded waveform with a weak rising momentum, a large score (i.e., a poor evaluation) can be given to this ejection pressure.

[0097] FIG. 14 is a diagram for explaining evaluation items for evaluating the time change of the discharge pressure based on the feature amount Fv8. The evaluation items in FIG. 14 evaluate the degree of overshoot that occurs at the rise of the discharge pressure. Specifically, the pressure evaluation unit 913 obtains the sign (positive / negative) of the second derivative D2 of the discharge pressure at time t81 when the discharge pressure reaches the maximum value Pmax. Then, the pressure evaluation unit 913 calculates the time t82 when the sign of the second derivative D2 of the discharge pressure switches twice from the sign at time t81. Then, the time change of the discharge pressure in the initial vibration period Tb_s from time t81 to time t82 is evaluated.

[0098] Specifically, the minimum value P8min of the time change of the discharge pressure in this initial vibration period Tb_s is obtained, and the smaller pressure of the steady pressure Pm and the pressure P8min is selected as the target pressure Pg. Then, the difference between the maximum pressure Pmax and the target pressure Pg, that is, the following equation is used. Fv8 = Pmax-Pg The feature value Fv8 is calculated based on the above.

[0099] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv8 to a range of 0 to 2 using a predetermined threshold value Th8 (for example, 0.035). Fv8 <Th8であるなら、Fv8=0 If Fv8 ≧ Th8, then Fv8 = Fv8 / c8 c8 is any positive constant, e.g. 0.12 Based on this, the feature value Fv8 is converted into a normalized feature value Fv8 (i.e., the evaluation value V8).

[0100] According to the evaluation based on the feature Fv8 in FIG. 14, when the time change of the discharge pressure shows a strong rising momentum and a large overshoot, a large score (that is, a poor evaluation) can be given to this discharge pressure.

[0101] Fig. 15 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv9. The evaluation item in Fig. 15 evaluates the stability of the time change of the discharge pressure in the transition period Tb. Specifically, the pressure evaluation unit 913 evaluates the stability of the time change of the discharge pressure in the transition period Tb and the steady pressure Pm which is the average value of the discharge pressure in the steady period Tc by using the following equation: Fv9 = RMSE(P_measure, Pm) P_measure = Discharge pressure measurement data 99 Based on this, the root mean square error RMSE(P_measure, Pm) is calculated as the feature Fv9.

[0102] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv9 to a range of 0 to 2. Specifically, the following equation Fv9=Fv9 / c9 c9 is any positive constant, e.g. 0.04 Based on this, the feature value Fv9 is converted into a normalized feature value Fv9 (i.e., the evaluation value V9).

[0103] According to the evaluation based on the feature amount Fv9 in FIG. 15, when the change over time in the discharge pressure shows ringing in the transition period Tb, a large score (that is, a poor evaluation) can be given to this discharge pressure.

[0104] FIG. 16 is a diagram for explaining the evaluation items for evaluating the time change of the discharge pressure based on the feature amount Fv10. The evaluation items in FIG. 16 evaluate the stability of the time change of the discharge pressure during the constant pressure period Tbc. Specifically, the pressure evaluation unit 913 obtains the maximum value Pmax and the minimum value P10min of the discharge pressure during the constant pressure period Tbc. Then, the pressure evaluation unit 913 calculates the difference between the maximum pressure Pmax and the minimum pressure P10min during the constant pressure period Tbc, that is, the following equation Fv10 = Pmax-P10min Based on this, the feature value Fv10 is calculated.

[0105] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv10 to a range of 0 to 2 using a threshold value Th10 (for example, 0.12). Fv10 <Th10であるなら、Fv10=0 If Fv10 ≧ Th10, Fv10 = Fv10 / Th10 Based on this, the feature value Fv10 is converted into a normalized feature value Fv10 (i.e., the evaluation value V10).

[0106] According to the evaluation based on the feature Fv10 in FIG. 16, if the change in the ejection pressure over time shows a large variation in the steady period Tc, which has a large impact on the film thickness of the coating liquid, a large score (i.e., a poor evaluation) can be given to this ejection pressure.

[0107] FIG. 17 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv11. The evaluation item in FIG. 17 evaluates the straightness of the time change of the discharge pressure in the rising period Ta. Specifically, in the rising period Ta, a pressure rise period Tar is obtained from time t111 when the discharge pressure becomes the lower reference pressure P11_l to time t113 when the discharge pressure becomes the upper reference pressure P11_u, which is larger than the lower reference pressure P11_l. Here, the lower reference pressure P11_l is a pressure obtained by adding a pressure of 20% 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 P11_u is a pressure obtained by adding a pressure of 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 discharge pressure increases from the lower reference pressure P11_l to the upper reference pressure P11_u between time t111 and time t113.

[0108] Furthermore, the pressure evaluation unit 913 obtains specific data Dm that satisfies a predetermined condition from the discharge pressure measurement data 99 between the lower reference pressure P11_l and the upper reference pressure P11_u. The predetermined condition will be described in detail below.

[0109] Among the discharge pressure measurement data 99, one measurement data between the lower reference pressure P11_l and the upper reference pressure P11_u is selected as the candidate data Dc. Then, a regression line obtained by performing a linear regression analysis on the time change of the discharge pressure between the measurement data Dl indicating the lower reference pressure P11_l and the candidate data Dc is set as an approximate line Lr_1. Also, a regression line obtained by performing a linear regression analysis on the time change of the discharge pressure between the measurement data Du indicating the upper reference pressure P11_u and the candidate data Dc is set as an approximate line Lr_2. Furthermore, in the section between the measurement data Dl and the candidate data Dc, the root mean square error RMSE (P_measure, Lr1) between the time change of the discharge pressure and the approximate line Lr_1 is obtained. Similarly, in the section between the candidate data Dc and the measurement data Du, the root mean square error RMSE (P_measure, Lr2) between the time change of the discharge pressure and the approximate line Lr_2 is obtained. Here, P_measure indicates the discharge pressure measurement data 99.

[0110] Furthermore, the sum of these is expressed as follows: Er=RMSE(P_measure,Lr1)+RMSE(P_measure,Lr2) Then, among the discharge pressure measurement data 99, the candidate data Dc with the smallest sum Er is identified as the specific data Dm.

[0111] Then, the slopes of the approximate straight lines Lr_1 and Lr_2 obtained for the specific data Dm are K1 and K2, respectively, and the feature amount Fv11 is calculated by the following formula: If K1>K2, Fv11=1-K1 / K2 If K1≦K2, then Fv11=1-K2 / K1 It is calculated based on:

[0112] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv11 to a range of 0 to 1 based on a predetermined threshold value Th11 (for example, 0.25). Fv11 <Th11であるなら、Fv11=0 If Fv11 ≧ Th11, then Fv11 = f(Fv11) f(γ)=4×γ-1 The feature value Fv11 is converted into a normalized feature value Fv11 (that is, the evaluation value V11) based on the above. Note that the function f(γ) with γ as a variable is not limited to the above example, and can be changed arbitrarily.

[0113] According to the evaluation based on the feature amount Fv11 in FIG. 17, when the discharge pressure shows a time change with poor straightness in the rise period Ta, a large score (that is, a poor evaluation) can be given to this discharge pressure.

[0114] FIG. 18 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv12. The evaluation item in FIG. 18 evaluates the sharpness of the time change of the discharge pressure at the end of the rise. Specifically, in the rise period Ta, a linear regression analysis is performed on the time change of the discharge pressure between the lower reference pressure P12_l and the upper reference pressure P12_u greater than the lower reference pressure P12_l, and a regression line Lr at the end of the rise is calculated. Here, the lower reference pressure P12_l is the pressure obtained by adding the pressure of 70% 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 P12_u is the pressure obtained by adding the pressure of 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 P12_l to the upper reference pressure P12_u between the time t121 and the time t122.

[0115] This regression line Lr at the end of the rise increases with the passage of time and reaches the target pressure Pt at the time t123. Thus, for the section from the time t121 to the time t123, a regression line Lr at the end of the rise is set. Further, the pressure evaluation unit 913 sets an extended straight line Lm with a slope of zero indicating the target pressure Pt between the time t123 and the time tb. As described above, the time tb is the time when the discharge pressure reaches the target pressure Pt and corresponds to the end time of the rise period Ta. That is, this extended straight line Lm is provided so as to extend from the end point of the regression line Lr at the end of the rise to the end point of the rise period Ta. When tb < t123, the extended straight line Lm is omitted.

[0116] Thus, an approximate waveform WF12 composed of the regression line Lr at the end of the rise and the extended straight line Lm arranged in time series is calculated. Then, the pressure evaluation unit 913 calculates, as the feature amount Fv12, a value indicating the difference between the discharge pressure measurement data 99 and the approximate waveform WF12 in the rise end period Ta_e from the time t122 when the discharge pressure becomes 90% of the target pressure Pt to the time tb when it becomes 100%. Specifically, the sum of the square root of the mean square error is expressed by the following formula Fv12=(Σ(P_measure - WF12)2 ) 1 / 2 P_measure = Discharge pressure measurement data 99 Calculated based on:

[0117] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv12 to a range of 0 to 1 based on a predetermined threshold value Th12 (for example, 0.8). Fv12 <Th12であるなら、Fv12=0 If Fv12 ≧ Th12, then Fv12 = f(Fv12) f(γ)=5×γ-4 The feature value Fv12 is converted into a normalized feature value Fv12 (that is, the evaluation value V12) based on the above. Note that the function f(γ) with γ as a variable is not limited to the above example, and can be changed arbitrarily.

[0118] According to the evaluation based on the feature Fv12 in Figure 18, if the change in the ejection pressure over time shows a waveform that has a weak rising momentum and is rounded overall, a high score (i.e., a bad evaluation) can be given to this ejection pressure.

[0119] FIG. 19 is a diagram for explaining an evaluation item for evaluating the time change of the discharge pressure based on the feature amount Fv13. The evaluation item in FIG. 19 evaluates the sharpness of the time change of the discharge pressure at the end of the rise. Specifically, during the rise period Ta, a linear regression analysis is performed on the time change of the discharge pressure between the lower reference pressure P13_l and the upper reference pressure P13_u that is greater than the lower reference pressure P13_l, and the rise end regression line Lr is calculated. Here, the lower reference pressure P13_l is a 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, and the upper reference pressure P13_u is a pressure obtained by adding 95% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi, and the discharge pressure increases from the lower reference pressure P13_l to the upper reference pressure P13_u between time t131 and time t132.

[0120] This rising final regression line Lr increases with the passage of time and reaches the target pressure Pt at time t133. Thus, for the period from time t131 to time t133, the rising final regression line Lr is set. Further, the pressure evaluation unit 913 sets an extended straight line Lm with a slope of zero indicating the target pressure Pt between time t133 and time tb. As described above, time tb is the time when the discharge pressure reaches the target pressure Pt and corresponds to the end time of the rising period Ta. That is, this extended straight line Lm is provided so as to extend from the end point of the rising final regression line Lr to the end point of the rising period Ta. Note that when tb < t133, the extended straight line Lm is omitted.

[0121] Thus, an approximate waveform WF13 composed of the rising final regression line Lr and the extended straight line Lm arranged in time series is calculated. Then, the pressure evaluation unit 913 calculates, as a feature quantity Fv13, a value indicating the difference between the discharge pressure measurement data 99 and the approximate waveform WF13 in the rising final period Ta_e from the time t132 when the discharge pressure becomes 95% of the target pressure Pt to the time tb when it becomes 100%. Specifically, the sum of the square root of the errors is given by the following formula Fv13=(Σ(P_measure - WF13) 2 ) 1 / 2 P_measure = discharge pressure measurement data 99 is calculated based on.

[0122] Also, the pressure evaluation unit 913 normalizes the feature quantity Fv13 to a range of 0 or more and 1 or less based on a predetermined threshold Th13 (for example, 0.1). Specifically, the following formula If Fv13 < Th13, then Fv13 = 0 If Fv13 ≧ Th13, then Fv13 = f(Fv13) f(γ)=(10×γ - 1) / 3 is used to convert the feature quantity Fv13 into a normalized feature quantity Fv13 (that is, the evaluation value V13). Note that the function f(γ) with γ as a variable is not limited to this example and can be arbitrarily changed.

[0123] According to the evaluation based on the feature Fv13 in Figure 19, if the change in the ejection pressure over time shows a waveform that has a weak rising momentum and is locally rounded, a high score (i.e., a bad evaluation) can be given to this ejection pressure.

[0124] FIG. 20 is a diagram for explaining evaluation items for evaluating the time change of the discharge pressure based on the feature amount Fv14. The evaluation items in FIG. 20 evaluate the degree of overshoot that occurs at the rise of the discharge pressure. Specifically, the pressure evaluation unit 913 obtains the sign (positive / negative) of the second derivative D2 of the discharge pressure at time t141 when the discharge pressure reaches the maximum value Pmax. Then, the pressure evaluation unit 913 calculates the time t142 when the sign of the second derivative D2 of the discharge pressure switches twice from the sign at time t141. Then, the time change of the discharge pressure in the initial vibration period Tb_s from time t141 to time t142 is evaluated.

[0125] Specifically, the minimum value P14min of the time change of the discharge pressure in this initial vibration period Tb_s is obtained. Then, the difference between the maximum pressure Pmax and the steady pressure Pm is expressed by the following equation. OVER=Pmax-Pm The difference between the steady pressure Pm and the minimum pressure P14min is calculated based on the following formula: UNDER=Pm-P14min The calculation is based on the sum of OVER and UNDER, that is, the following formula: Fv14=OVER+UNDER The feature value Fv14 is calculated based on the above.

[0126] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv14 to a range of 0 to 1 using a predetermined threshold value Th14 (for example, 0.01). Fv14 <Th14であるなら、Fv14=0 If Fv14 ≧ Th14, then Fv14 = f(Fv14) f(γ)=(100×γ-1) / 9 Based on this, the feature value Fv14 is converted into a normalized feature value Fv14 (i.e., the evaluation value V14).

[0127] According to the evaluation based on the feature Fv14 in Fig. 20, the error from the target pressure Pt is calculated for each point of overshoot and ring-back (a phenomenon in which pressure drops in reaction after a sudden rise). Therefore, if the time change in the discharge pressure shows a large overshoot or ring-back, a large score (i.e., a bad evaluation) can be given to this discharge pressure.

[0128] The above is an explanation of each evaluation item that can be used to evaluate the time change of the discharge pressure, and the feature quantities Fv1 to Fv14 and evaluation values ​​V1 to V14 extracted for each evaluation item. Note that in the measurement result evaluation in step S102, evaluation using all of the above evaluation items is not always performed, and the number of evaluation items to be performed changes depending on the appropriateness of the time change of the discharge pressure. This point will be explained next.

[0129] Fig. 21 is a flowchart showing the details of the measurement result evaluation, and Fig. 22 is a diagram showing a schematic example of an operation executed according to the flowchart of Fig. 21. The measurement result evaluation of Fig. 21 is executed by the pressure evaluation unit 913. In addition, in this measurement result evaluation, N evaluation stages (N is an integer of 2 or more, and N=3 in this example) are prepared, and these N evaluation stages are executed in order.

[0130] As shown in FIG. 22, the first evaluation stage (I=1) is assigned an evaluation item based on the feature Fv1 shown in FIG. 7. The second evaluation stage (I=2) is assigned evaluation items based on the feature Fv2-Fv10 shown in FIG. 8-FIG. 16. The third evaluation stage (I=3) is assigned evaluation items based on the feature Fv11-Fv14 shown in FIG. 17-FIG. 20. In each evaluation stage I, the time change of the discharge pressure is evaluated based on the assigned evaluation items. Note that I is a number for identifying the evaluation stage, and is an integer greater than or equal to 1 and less than or equal to N.

[0131] Thus, for N evaluation levels, different evaluation items are assigned respectively. Further, for N evaluation levels, final evaluation values Vf within different ranges (value ranges) are assigned respectively. Therefore, as will be described below, for the discharge pressure evaluated by the evaluation up to the I-th evaluation level, the final evaluation value Vf within the value range assigned to the I-th evaluation level is given.

[0132] As shown in FIG. 21, in step S201, I is reset to zero, and in step S202, I is incremented by 1. In step S203, the discharge pressure is evaluated based on the evaluation item of the I-th evaluation level. Here, since I = 1, the feature quantity Fv1 is calculated and the evaluation value V1 is obtained. And this evaluation value V1 becomes the evaluation result of the first evaluation level.

[0133] In step S204, it is judged whether I = N. Here, since I < N, the process proceeds to step S205. In step S205, based on the evaluation result in step S203, it is judged whether the time change of the discharge pressure is good. When the evaluation result (evaluation value V1) is equal to or greater than the predetermined sorting threshold At1, it is judged as defective (NO) in step S205, and the evaluation by the 2nd to 3rd evaluation levels (that is, the evaluation levels after the I-th evaluation level) is omitted, and the process proceeds to step S206.

[0134] In step S206, the final evaluation value Vf corresponding to the number of executed evaluation levels (I) and the evaluation result at the I-th evaluation level is determined. In this example here, since only the first evaluation level has been executed, according to the example in FIG. 22, the value obtained by adding the evaluation result (evaluation value V1) of the first evaluation level to the minimum evaluation value (= 20) of the value range for the first evaluation level is determined as the final evaluation value Vf. Thereby, the final evaluation value Vf within the value range (20 to 40) provided for the first evaluation level is given to the time change of the discharge pressure.

[0135] Alternatively, if the evaluation result (evaluation value V1) in step S204 is less than the distribution threshold At1, it is determined to be good (YES) in step S205, and the process returns to step S202, where I is incremented by 1.

[0136] In step S203, the discharge pressure is evaluated based on the evaluation items at the I-th evaluation stage. Here, since I = 2, feature quantities Fv2 to Fv10 are calculated, and evaluation values V2 to V10 are obtained. Then, the sum of the evaluation values V2 to V10 becomes the evaluation result at the second evaluation stage. That is, the sum of the evaluation values by the evaluation items belonging to the I-th evaluation stage becomes the evaluation result at the I-th evaluation stage.

[0137] In step S204, it is determined whether I = N. Here, since I < N, the process proceeds to step S205. In step S205, based on the evaluation result in step S203, it is determined whether the temporal change of the discharge pressure is good. If the evaluation result (the sum of the evaluation values V2 to V10) is equal to or greater than a predetermined distribution threshold At2, it is determined to be bad (NO) in step S205, the evaluation at the third evaluation stage is omitted, and the process proceeds to step S206.

[0138] In step S206, a final evaluation value Vf is determined according to the number of executed evaluation stages (I) and the evaluation result at the I-th evaluation stage. In this example, since the first to second evaluation stages have been executed, according to the example in FIG. 22, the value obtained by adding the evaluation result (the sum of the evaluation values V2 to V10) at the second evaluation stage to the minimum evaluation value (= 4) of the value range for the second evaluation stage is determined as the final evaluation value Vf. Thereby, the final evaluation value Vf within the value range (4 to 20) provided for the second evaluation stage is given to the temporal change of the discharge pressure.

[0139] Alternatively, if the evaluation result (the sum of the evaluation values V2 to V10) in step S205 is less than the distribution threshold At2, it is determined to be good (YES) in step S205, and the process returns to step S202, where I is incremented by 1.

[0140] Then, in step S203, the discharge pressure is evaluated based on the evaluation items of the Ith evaluation stage. Here, since I=3, the feature amounts Fv11 to Fv14 are calculated to obtain the evaluation values ​​V11 to V14. Then, similarly to the above, the sum of the evaluation values ​​V11 to V14 becomes the evaluation result of the third evaluation stage.

[0141] In step S204, it is determined whether I=N. ​​Since I=N in this case, the process proceeds to step S206. In step S206, a final evaluation value Vf is determined according to the number (I) of evaluation stages that have been performed and the evaluation result in the I-th evaluation stage. In this example, the first to third evaluation stages have been performed, so according to the example in FIG. 22, the final evaluation value Vf is determined to be the sum of the minimum evaluation value (=0) in the third evaluation stage and the evaluation result of the third evaluation stage (the sum of evaluation values ​​V11 to V14). As a result, the final evaluation value Vf within the range (0 to 4) set for the third evaluation stage is applied to the time change in the discharge pressure.

[0142] In the embodiment described above, N evaluation stages from 1st to Nth are provided in which the discharge pressure is evaluated by different evaluation items, and the evaluation stages from 1st to Nth can be executed in order. However, if the discharge pressure is judged to be appropriate in the evaluation by the evaluation item related to the Ith evaluation stage ("YES" in step S205), the evaluation of the discharge pressure is executed by the evaluation item related to the (I+1)th evaluation stage, whereas if the discharge pressure is judged to be inappropriate in the evaluation by the evaluation item related to the Ith evaluation stage ("NO" in step S205), the evaluation of the discharge pressure by the evaluation stages after the Ith evaluation stage is not executed (i.e., omitted). In other words, when the discharge pressure is evaluated in order by the 1st to Nth evaluation stages, if the discharge pressure is judged to be inappropriate in any evaluation stage, the evaluation by the subsequent evaluation stages is not executed. This makes it possible to evaluate the discharge pressure applied to the coating liquid to discharge the coating liquid from the nozzle 71 in a reasonable time according to the appropriateness of the discharge pressure.

[0143] Furthermore, different final evaluation values ​​Vf (evaluation values) are assigned to the discharge pressure depending on the number (I) of evaluation stages in which the discharge pressure has been evaluated out of the N evaluation stages. In this configuration, a better final evaluation value Vf can be assigned to a discharge pressure for which a larger number of evaluation stages have been executed, and it becomes possible to assign an appropriate final evaluation value Vf to the discharge pressure depending on whether the discharge pressure is appropriate.

[0144] In the first evaluation stage, the discharge pressure is measured during a discharge period Tt (first period, period to be evaluated) from the start of discharge of the coating liquid (treatment liquid) from the nozzle 71 to the end of discharge of the coating liquid from the nozzle 71 (step S101). Then, an ideal trapezoid absolute error of the time change of the discharge pressure during the entire discharge period Tt is extracted as a feature amount Fv1 (first feature amount, overall feature amount), and the time change of the discharge pressure is evaluated based on this feature amount Fv1 (step S102). This makes it possible to reflect the suitability of the discharge pressure during the entire discharge period Tt from the start to the end of discharge of the coating liquid from the nozzle 71 in the evaluation of the discharge pressure.

[0145] 7, the feature amount Fv1 indicates the difference between an approximate waveform WF1 (first approximate waveform) that approximates the time change of the discharge pressure during the entire discharge period Tt and the time change of the discharge pressure during the entire discharge period Tt. In this configuration, the discharge pressure during the entire discharge period Tt can be appropriately evaluated based on the approximate waveform WF1 of the time change of the discharge pressure during the entire discharge period Tt from the start to the end of the discharge of the coating liquid from the nozzle 71.

[0146] In particular, the approximate waveform WF1 is A rising regression line Lr_R (rising approximation line) that linearly increases over time from an initial pressure Pi (discharge start pressure) to a steady pressure Pm that is greater than the initial pressure Pi by linearly approximating the time change in the discharge pressure that increases over time after the discharge of the coating liquid from the nozzle 71 starts, and A start time approximation line Lr_s that indicates the initial pressure Pi and is provided between the start time (time ta) of the discharge of the coating liquid from the nozzle 71 and the rising regression line Lr_R; Before the end of the discharge of the coating liquid from the nozzle 71, a linear approximation of the time change in the discharge pressure that decreases over time is performed to obtain a falling regression line Lr_F (falling approximation line) that linearly decreases over time from the steady pressure Pm to an initial pressure Pi (discharge end pressure) that is smaller than the steady pressure Pm; an end-time approximation line Lr_e that is provided between the falling regression line Lr_F and the end time (time te) of the discharge of the coating liquid from the nozzle 71 and indicates the initial pressure Pi (discharge end pressure); Connect the rising regression line Lr_R and the falling regression line Lr_F to form a steady line Lr_m, which indicates the steady pressure Pm. In this configuration, the time change in the discharge pressure during the entire discharge period Tt from the start to the end of the discharge of the coating liquid from the nozzle 71 is approximated by a trapezoidal waveform, and the discharge pressure during the entire discharge period Tt can be appropriately evaluated.

[0147] In the second evaluation stage, feature quantities Fv2 to Fv10 (second feature quantities) of the time change of the discharge pressure in a period (second period) shorter than the discharge period Tt are extracted, and the time change of the discharge pressure is evaluated based on the feature quantities Fv2 to Fv10 (step S102). With this configuration, the discharge pressure can be evaluated with high accuracy based on the time change of the discharge pressure in a period shorter than the discharge period Tt from the start to the end of the discharge of the coating liquid from the nozzle 71.

[0148] 8, the discharge pressure is evaluated during a predetermined initial rise period Ta_s (second period) from the start of discharge of the application liquid from the nozzle 71. Throughout this initial rise period Ta_s, the discharge pressure increases over time, and a feature value Fv2 (second feature value) indicating the difference between the rise regression curve Nr of the time change in the discharge pressure during the initial rise period Ta_s and the time change in the discharge pressure during the initial rise period Ta_s is extracted. With this configuration, the discharge pressure can be evaluated taking into account the time change in the discharge pressure immediately after the start of discharge of the application liquid from the nozzle 71.

[0149] Furthermore, the discharge pressure is evaluated during a rise period Ta (second period) from the start of discharge of the coating liquid from the nozzle 71 until the discharge pressure increases to a target pressure Pt (predetermined pressure). In this configuration, the discharge pressure can be evaluated taking into account the change over time of the discharge pressure during the rise period Ta.

[0150] 9, the length of the rise period Ta is extracted as a feature amount Fv2 (second feature amount). In this configuration, the discharge pressure can be evaluated by taking into account the speed of the rise of the discharge pressure.

[0151] 10A and 10B, the number of times that the first derivative D1 of the time change of the discharge pressure crosses a predetermined threshold Th4 during the rise period Ta is extracted as a feature Fv4 (second feature). In this configuration, the discharge pressure can be evaluated taking into account the smoothness of the time change of the discharge pressure during the rise period.

[0152] 11, the number of times that the absolute value of the second derivative D2 of the time change of the discharge pressure crosses a predetermined threshold Th5 during the rise period Ta is extracted as a feature Fv5 (second feature). With this configuration, the discharge pressure can be evaluated taking into account the smoothness of the time change of the discharge pressure during the rise period Ta.

[0153] 12, the ratio of the time T_1st at which the second derivative D2 of the time change in the discharge pressure becomes greater than a predetermined positive threshold (Th5) during the rise period Ta to the time T_2nd at which the second derivative D2 of the time change in the discharge pressure becomes smaller than a negative threshold (-Th5) having the same absolute value as the positive threshold is extracted as a feature Fv6 (second feature). With this configuration, the discharge pressure can be evaluated by taking into account the difference in the time change in the discharge pressure between the beginning and the end of the rise period Ta.

[0154] In addition, in the evaluation item shown in FIG. 13, the discharge pressure in the rising end period Ta_e (second period) until the discharge pressure increases to the target pressure Pt (predetermined pressure) is evaluated. That is, an approximate waveform WF7 (rising end approximate waveform) that approximates the time change of the discharge pressure in the rising end period Ta_e and a feature amount Fv7 (second feature amount) that indicates the difference between the time change of the discharge pressure in the rising end period Ta_e are extracted. This approximate waveform WF7 is composed of a rising end regression line Lr (rising end approximate line) and an extension line Lm. The rising end regression line Lr overlaps with an approximation curve obtained by linearly approximating the time change of the discharge pressure that increases with the passage of time in a pressure range (P7_l to P7_u) smaller than the target pressure Pt, and increases linearly to a steady pressure Pm with the passage of time. The extension line Lm is extended from (the end point of) the rising end regression line Lr to the end point of the rising end period Ta_e to indicate the steady pressure Pm. In this configuration, the discharge pressure can be evaluated taking into account the degree of stall of the discharge pressure at the end of the rise period Ta.

[0155] 14, the discharge pressure is evaluated during an initial oscillation period Tb_s (second period) from the time when the discharge pressure reaches the maximum value Pmax (time t81) to the time when the second derivative D2 of the time change of the discharge pressure crosses zero twice (time t82). Specifically, the minimum value P8min of the discharge pressure during the initial oscillation period Tb_s is obtained, and the difference between the smaller pressure of this minimum value P8min or the steady pressure Pm and the maximum value Pmax of the discharge pressure is extracted as a feature Fv8 (second feature). With this configuration, the discharge pressure can be evaluated taking into account the overshoot of the discharge pressure.

[0156] 15, the discharge pressure is evaluated during a predetermined transition period Tb (second period) from the time tb when the discharge pressure exceeds the target pressure Pt (predetermined pressure). Specifically, a feature Fv9 (second feature) indicating the difference between the discharge pressure during the rise period Ta and the steady pressure Pm is extracted. In this configuration, the discharge pressure can be evaluated taking into account the stability of the discharge pressure after it reaches the target pressure Pt.

[0157] 16, the discharge pressure is evaluated during a constant pressure period Tbc from the time (time tb) when the discharge pressure exceeds the target pressure Pt (predetermined pressure) to the time (time td) when the discharge pressure starts to decrease toward the end of the discharge of the coating liquid from the nozzle 71. Specifically, a feature value Fv10 indicating the difference between the maximum value Pmax and the minimum value P10min of the discharge pressure during the constant pressure period Tbc is extracted. In this configuration, the discharge pressure can be evaluated taking into account the stability of the discharge pressure during the constant pressure period Tbc.

[0158] In the third evaluation stage, feature quantities Fv11 to Fv14 (third feature quantities) of the time change of the discharge pressure in a period (third period) shorter than the discharge period Tt are extracted, and the time change of the discharge pressure is evaluated based on the feature quantities Fv11 to Fv14 (step S102). With this configuration, the discharge pressure can be evaluated with high accuracy based on the time change of the discharge pressure in a period shorter than the discharge period Tt from the start to the end of the discharge of the coating liquid from the nozzle 71.

[0159] 17, the discharge pressure is evaluated during a pressure increase period Tar (third period) in which the discharge pressure increases over time from the lower reference pressure P11_l (lower reference value) to the upper reference pressure P11_u (upper reference value) after the start of discharge of the coating liquid from the nozzle 71. Specifically, a single measurement value is obtained that is one of the discharge pressure measurement data 99 between the lower reference pressure P11_l and the upper reference pressure P11_u, and that minimizes the sum of the root mean square error between an approximate straight line Lr_1 obtained by linear regression of the time change in the discharge pressure in the section (t111 to t112) between the lower reference pressure P11_l and the single measurement data and the root mean square error between an approximate straight line Lr_2 obtained by linear regression of the time change in the discharge pressure in the section (t112 to t113) between the single measurement data and the upper reference pressure P11_u. Then, the ratio of the slope K1 of the line between the lower reference pressure P11_l and the one measurement data and the slope K2 of the line between the one measurement data and the upper reference pressure P11_u is extracted as a feature Fv11 (third feature). With this configuration, the discharge pressure can be evaluated taking into account the linearity of the increase in the discharge pressure.

[0160] In addition, in the evaluation item shown in FIG. 18, the discharge pressure in the rising end period Ta_e (third period) until the discharge pressure increases to the target pressure Pt (predetermined pressure) is evaluated. That is, an approximate waveform WF12 (rising end approximate waveform) that approximates the time change of the discharge pressure in the rising end period Ta_e and a feature amount Fv12 (third feature amount) that indicates the difference between the time change of the discharge pressure in the rising end period Ta_e are extracted. Here, the rising end approximate waveform WF12 is composed of a rising end regression line Lr and an extension line Lm. The rising end regression line Lr overlaps with an approximate curve obtained by linearly approximating the time change of the discharge pressure that increases with time in a pressure range (P12_l to P12_u) smaller than the target pressure Pt, and increases linearly to the target pressure Pt with the passage of time. The extension line Lm is extended from the end of the rise end regression line Lr to the end of the rise end period Ta_e, and indicates the target pressure Pt. In this configuration, the discharge pressure can be evaluated taking into account the degree of stall of the discharge pressure at the end of the rise period Ta.

[0161] In addition, in the evaluation item shown in FIG. 19, the discharge pressure in the rising end period Ta_e (third period) until the discharge pressure increases to the target pressure Pt (predetermined pressure) is evaluated. That is, an approximate waveform WF13 (rising end approximate waveform) that approximates the time change of the discharge pressure in the rising end period Ta_e and a feature amount Fv13 (third feature amount) that indicates the difference between the time change of the discharge pressure in the rising end period Ta_e are extracted. Here, the rising end approximate waveform WF13 is composed of a rising end regression line Lr and an extension line Lm. The rising end regression line Lr overlaps with an approximate curve obtained by linearly approximating the time change of the discharge pressure that increases with time in a pressure range (P13_l to P13_u) smaller than the target pressure Pt, and increases linearly to the target pressure Pt with the passage of time. The extension line Lm is extended from the end of the rise end regression line Lr to the end of the rise end period Ta_e, and indicates the target pressure Pt. In this configuration, the discharge pressure can be evaluated taking into account the degree of stall of the discharge pressure at the end of the rise period Ta.

[0162] 20, the discharge pressure is evaluated during an initial oscillation period Tb_s (third period) from the time when the discharge pressure reaches the maximum value Pmax (time t141) to the time when the second derivative D2 of the time change of the discharge pressure crosses zero twice (time t142). Specifically, the sum of the value obtained by subtracting the steady pressure Pm from the maximum value Pmax of the discharge pressure and the value obtained by subtracting the minimum value P14min of the discharge pressure during the initial oscillation period Tb_s from the steady pressure Pm is extracted as the feature Fv14 (third feature). With this configuration, the discharge pressure can be evaluated taking into account the overshoot of the discharge pressure.

[0163] As described above, in the above embodiment, the coating apparatus 1 corresponds to an example of a "substrate processing apparatus" of the present invention, the nozzle 71 corresponds to an example of a "nozzle" of the present invention, the coating liquid supply mechanism 8 corresponds to an example of a "pressure applying section" of the present invention, the nozzle 71 and the coating liquid supply mechanism 8 cooperate to form an example of a "discharge apparatus" of the present invention, the pressure gauge 86 corresponds to an example of a "measurement section" of the present invention, the control unit 9 corresponds to an example of a "computer" and "control section" of the present invention, the discharge pressure evaluation program 97 corresponds to an example of a discharge pressure evaluation program of the present invention, the recording medium M corresponds to an example of a "recording medium" of the present invention, the coating liquid corresponds to an example of a "treatment liquid" of the present invention, and the pressure measured by the pressure gauge 86 corresponds to an example of a "discharge pressure" of the present invention.

[0164] In addition, the ejection period Tt corresponds to an example of the "first period" of the present invention, the feature Fv1 corresponds to an example of the "first feature" of the present invention, the approximate waveform WF1 corresponds to an example of the "first approximate waveform" of the present invention, the initial pressure Pi corresponds to an example of the "ejection start pressure" and "ejection end pressure" of the present invention, the rising regression line Lr_R corresponds to an example of the "rising approximate line" of the present invention, the start time approximate line Lr_s corresponds to an example of the "start time approximate line" of the present invention, the falling regression line Lr_F corresponds to an example of the "falling approximate line" of the present invention, the end time approximate line Lr_e corresponds to an example of the "end time approximate line" of the present invention, and the steady line Lr_m corresponds to an example of the "steady line" of the present invention.

[0165] Furthermore, the initial rise period Ta_s, the rise period Ta, the rise final period Ta_e, the initial vibration period Tb_s, the transition period Tb and the constant pressure period Tbc correspond to an example of the "second period" of the present invention, the feature amounts Fv2 to Fv10 correspond to an example of the "second feature amount" of the present invention, the initial period Ta_s corresponds to an example of the "initial rise period" of the present invention, the regression curve Nr corresponds to an example of the "regression curve" of the present invention, the rise period Ta corresponds to an example of the "rise period" of the present invention, and the rise final period Ta_e corresponds to an example of the "second period" of the present invention. the approximate waveform WF7 corresponds to an example of a "rise end approximate waveform" of the present invention, the rise end regression line Lr corresponds to an example of a "rise end approximate line" of the present invention, the extended line Lm corresponds to an example of an "extended line" of the present invention, the initial vibration period Tb_s corresponds to an example of an "initial vibration period" of the present invention, the steady period Tc corresponds to an example of a "steady period" of the present invention, the transition period Tb corresponds to an example of a "transition period" of the present invention, and the constant pressure period Tbc corresponds to an example of a "constant pressure period" of the present invention.

[0166] In addition, the pressure rise period Tar, the rising end period Ta_e and the initial vibration period Tb_s correspond to an example of the "third period" of the present invention, the feature amounts Fv11 to Fv14 correspond to an example of the "third feature amount" of the present invention, the lower reference pressure P11_l corresponds to an example of the "lower reference value" of the present invention, the upper reference pressure P11_u corresponds to an example of the "upper reference value" of the present invention, the pressure rise period Tar corresponds to an example of the "pressure rise period" of the present invention, the rising end period Ta_e corresponds to an example of the "rising end period" of the present invention, the approximate waveforms WF12 and WF13 correspond to an example of the "rising end approximate waveform" of the present invention, the rising end regression line Lr corresponds to an example of the "rising end approximate line" of the present invention, the extension line Lm corresponds to an example of the "extension line" of the present invention, and the initial vibration period Tb_s corresponds to an example of the "initial vibration period" of the present invention.

[0167] The present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-mentioned embodiment, the discharge characteristics are measured based on the pressure value detected by the pressure gauge 86 attached to the pipe 82, but the attachment position of the pressure gauge 86 is not limited to this, and the attachment position can be arbitrary as long as it is a position where the pressure of the coating liquid fed to the nozzle 71 can be detected.

[0168] In addition, in the above embodiment, a bellows type pump 81 is used, but the type of pump is not limited to this, and for example, a syringe type pump using a piston (for example, JP 2008-101510 A) may be used.

[0169] In addition, in the above embodiment, the present invention is applied to a coating apparatus 1 that supplies a coating liquid to the surface Sf of the substrate S in a floating state, but the application of the present invention is not limited to this, and the present invention can be applied to general substrate processing techniques in which a processing liquid is supplied to a nozzle and then supplied from the nozzle to the upper surface of a substrate to perform a predetermined process.

[0170] In the second evaluation stage, it is not essential to evaluate the discharge pressure based on all of the above feature amounts Fv2 to Fv10, and the discharge pressure may be evaluated based on only some of these. Similarly, in the third evaluation stage, the discharge pressure may be evaluated based on only some of the above feature amounts Fv11 to Fv14.

[0171] Furthermore, when calculating the approximate waveform WF1 in FIG. 7, a straight line with a zero gradient indicating the target pressure Pt may be used instead of the steady straight line Lr_m.

[0172] Also, it is not necessarily necessary to prepare all three evaluation stages. Therefore, among the above-mentioned first to third evaluation stages, only the first and second evaluation stages may be configured to be executed, or only the second and third evaluation stages may be configured to be executed, or only the first and third evaluation stages may be configured to be executed. Alternatively, an evaluation stage may be provided in which the discharge pressure is evaluated using an evaluation item different from the above-mentioned three evaluation stages.

[0173] Furthermore, when calculating the final evaluation value Vf, the evaluation values ​​at the corresponding evaluation stages (for example, V2 to V10, V11 to V14) may be summed up and weighted by multiplying the sum by a weighting coefficient that varies depending on the evaluation value.

[0174] Furthermore, instead of the feature Fv1 shown in FIG. 7, a feature Fv1_1 described in the following modification may be calculated, and the time change of the discharge pressure may be evaluated based on this feature Fv1_1. FIG. 23 is a diagram for explaining each period used in a modification of the evaluation item of the discharge pressure, and FIG. 24 is a diagram for explaining a modification of the evaluation item for evaluating the time change of the discharge pressure based on the feature Fv1_1. Here, the differences between FIG. 23 and the above-mentioned FIG. 5 will be mainly described, and the common points will be denoted by corresponding symbols and the description will be omitted as appropriate. Similarly, the differences between FIG. 24 and the above-mentioned FIG. 7 will be mainly described, and the common points will be denoted by corresponding symbols and the description will be omitted as appropriate.

[0175] As shown in Fig. 23, in the modified evaluation item, a period of interest Troi is used. This period of interest Troi is the period from time ta to time td. That is, the period of interest Troi is composed of a rise period Ta, a transition period Tb, and a steady period Tc, in other words, composed of the rise period Ta and a constant pressure period Tbc. In this way, the period of interest Troi corresponds to an example of "a main period from the start of ejection of the treatment liquid from the nozzle, through the rise of the ejection pressure to a predetermined pressure, to the start of the decrease of the ejection pressure from the predetermined pressure" in the present invention, and the target pressure Pt corresponds to an example of the "predetermined pressure" in the present invention.

[0176] 24, in this modification, the rising regression line Lr_R is calculated and the start time approximation line Lr_s is set in the same manner as in the case of the above-mentioned feature Fv1. Furthermore, in the period from time t12 to time td, a steady line Lr_m_1 is set, which is a line with a zero slope indicating the steady pressure Pm (i.e., the average of the measured values ​​of the discharge pressure in the steady period Tc).

[0177] In this way, an approximate waveform WF1_1 is calculated that is composed of the start approximate line Lr_s, the rising regression line Lr_R, and the stationary line Lr_m_1 arranged in chronological order. Then, the pressure evaluation unit 913 calculates the mean absolute error MAE between the discharge pressure measurement data 99 and the approximate waveform WF1_1 over the entire period of interest Troi from time ta to time td as a feature amount Fv1_1. Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv1_1 to a predetermined range based on a predetermined threshold value Th1_1 (e.g., 0.05). Specifically, the following equation Fv1_1 <Th1_1であるなら、Fv1_1=0 If Fv1_1≧Th1_1, then Fv1_1=(Fv1_1+1-Th1_1)×c1_1 Based on this, the feature Fv1_1 is converted into a normalized feature Fv1_1 (i.e., evaluation value V1_1). Here, the upper limit of Fv1_1 is 2×c1_1, and the coefficient c1_1 is a normalization coefficient and is an arbitrary positive constant. Note that the specific method of normalizing the feature Fv1_1 is not limited to this example, and may be changed as appropriate.

[0178] According to the evaluation based on the feature amount Fv1_1 in FIG. 24, if the time change in the discharge pressure over the entire period of interest Troi deviates significantly from an ideal shape, a large score (ie, a poor evaluation) can be given to this discharge pressure.

[0179] In this modified example, in the measurement result evaluation (step S102) of the discharge pressure evaluation shown in Fig. 4, the pressure evaluation unit 913 calculates an evaluation value V1_1 based on the result of extracting the feature amount Fv1_1 from the discharge pressure, instead of the feature amount Fv1. In particular, for the first evaluation stage (I=1), an evaluation based on the feature amount Fv1_1 shown in Fig. 24 is assigned, instead of an evaluation based on the feature amount Fv1 shown in Fig. 7. Then, the measurement result evaluation shown in Fig. 21 is executed. That is, in the table of Fig. 22, the feature amount of the evaluation item when the evaluation stage I is 1 is the feature amount Fv1_1 shown in Fig. 24, instead of the feature amount Fv1.

[0180] In this modified example, N evaluation stages from 1st to Nth are provided in which the discharge pressure is evaluated by different evaluation items, and the evaluation stages from 1st to Nth can be executed in order. However, if the discharge pressure is judged to be appropriate in the evaluation by the evaluation item related to the Ith evaluation stage ("YES" in step S205), the evaluation of the discharge pressure is executed by the evaluation item related to the (I+1)th evaluation stage, whereas if the discharge pressure is judged to be inappropriate in the evaluation by the evaluation item related to the Ith evaluation stage ("NO" in step S205), the evaluation of the discharge pressure by the evaluation stages after the Ith evaluation stage is not executed (i.e., omitted). In other words, if the discharge pressure is judged to be inappropriate in any evaluation stage when the discharge pressure is evaluated in order by the 1st to Nth evaluation stages, the evaluation by the subsequent evaluation stages is not executed. This makes it possible to evaluate the discharge pressure applied to the coating liquid to discharge the coating liquid from the nozzle 71 in a reasonable time according to the appropriateness of the discharge pressure.

[0181] The discharge pressure is measured during a period of interest Troi (main period, period to be evaluated) from the start of discharge of the processing liquid from the nozzle 71, through the increase of the discharge pressure to a target pressure Pt (predetermined pressure), until the discharge pressure starts to decrease from the target pressure Pt. Then, in the first evaluation stage (I=1), a feature amount Fv1_1 (overall feature amount) of the time change of the discharge pressure during the entire period of interest Troi is extracted, and the time change of the discharge pressure is evaluated based on the feature amount Fv1_1. This makes it possible to reflect the suitability of the discharge pressure during the entire period of interest Troi, which affects the thickness of the processing liquid applied to the substrate S, in the evaluation of the discharge pressure.

[0182] Furthermore, in this modified example, when the effect of the period of interest Troi on the thickness of the processing liquid applied to the substrate S is particularly large (in other words, when the effect of the period after the period of interest Troi is small), it is possible to reflect the appropriateness of the discharge pressure throughout the entire period of interest Troi in the evaluation of the discharge pressure.

[0183] Furthermore, the feature Fv1_1 (main feature) indicates the difference between an approximate waveform WF1_1 (main approximate waveform) that approximates the time change of the discharge pressure throughout the entire period of interest Troi (main period) and the time change of the discharge pressure throughout the entire period of interest Troi. With this configuration, the discharge pressure throughout the entire period of interest Troi can be appropriately evaluated based on the approximate waveform WF1_1 of the time change of the discharge pressure throughout the entire period of interest Troi.

[0184] In particular, the approximate waveform WF1_1 is A rising regression line Lr_R (rising approximation line) that linearly increases with time from an initial pressure Pi (discharge start pressure) to a steady pressure Pm that is greater than the initial pressure Pi, which is a linear approximation of the time change in the discharge pressure that increases with time after the start of discharge of the coating liquid from the nozzle 71; and A start time approximation line Lr_s that indicates the initial pressure Pi and is provided between the start time (time ta) of the discharge of the coating liquid from the nozzle 71 and the rising regression line Lr_R; The rising regression line Lr_R is set between the time when it reaches the steady pressure Pm and the end of the attention period Troi (between time t12 and time td), and the steady line Lr_m_1 which indicates the steady pressure Pm. In this configuration, the time change of the discharge pressure during the entire period of interest Troi is approximated, and the discharge pressure during the entire period of interest Troi can be appropriately evaluated.

[0185] Incidentally, when evaluating the discharge pressure using the feature amount Fv1_1 shown in FIG. 24, it is not necessary to measure the discharge pressure in the period after the period of interest Troi (that is, the falling period Td) in step S101.

[0186] Also, the UI 95 may be configured to select which of the two feature quantities Fv1 and Fv1_1 to use to evaluate the discharge pressure. In this case, in step S102, the discharge pressure is evaluated using one of the feature quantities Fv1 and Fv1_1 selected by a user's input operation to the UI 95. In addition, in the measurement result evaluation of FIG. 21, for the first evaluation stage (I=1), the discharge pressure is evaluated using one of the feature quantities Fv1 and Fv1_1 selected. [Industrial Applicability]

[0187] The present invention is applicable to substrate processing techniques in general in which a processing liquid is fed to a nozzle, and then discharged from the nozzle to a substrate with target characteristics. [Explanation of symbols]

[0188] 1... Coating device (substrate processing device) 71...Nozzle (discharge device) 8... Coating liquid supply mechanism (pressure applying unit, discharge device) 86... Pressure gauge (measurement part) 9...Control unit (computer, control unit) 97…Discharge pressure evaluation program M…Recording medium Tt: Discharge period (first period) Fv1: feature (first feature) WF1…Approximate waveform (1st approximate waveform) Pi: Initial pressure (discharge start pressure, discharge end pressure) Lr_R…Rising regression line (rising approximation line) Lr_s…Approximate straight line at start Lr_F…Falling regression line Lr_e: Approximate straight line at end Lr_m: Stationary straight line Ta_s: Initial rise period (second period) Ta: Rising period (second period) Ta_e: Final rising period (second period) Tb_s: Initial vibration period (second period) Tb…Transition period (second period) Tbc: constant pressure period (second period) Fv2~Fv10…Features (second features) Nr…Regression curve WF7…Approximate waveform (approximate rising end waveform) Lr…Rising end regression line (rising end approximation line) Lm…Extended straight line Tc: Steady-state period Tar: Pressure rise period (third period) Ta_e: Final rising period (third period) Tb_s: Initial vibration period (third period) Fv11~Fv14…Features (third features) P11_l…Lower reference pressure (lower reference value) P11_u…Upper reference pressure (upper reference value) Tar…pressure rise period Ta_e: Final rising period WF12, WF13: Approximate waveform (approximate rising end waveform) Lr…Rising end regression line (rising end approximation line) Lm…Extended straight line Tb_s: Initial vibration period

Claims

1. a step of evaluating the discharge pressure of a discharge device that applies a discharge pressure to a treatment liquid and discharges the treatment liquid from a nozzle, using an evaluation item related to a first evaluation stage among N evaluation stages from 1st to Nth (N is an integer of 2 or more) that evaluate the discharge pressure using different evaluation items; a step of evaluating the discharge pressure using evaluation items related to an (I+1)th evaluation stage when the discharge pressure is judged to be appropriate in the evaluation using evaluation items related to an I-th evaluation stage (I is an integer of 1 or more and less than N) among the N evaluation stages, and not evaluating the discharge pressure using evaluation items related to the (I+1)th evaluation stage when the discharge pressure is judged to be inappropriate in the evaluation using evaluation items related to the I-th evaluation stage; A discharge pressure evaluation method comprising:

2. 2. The method for evaluating a discharge pressure according to claim 1, wherein different evaluation values ​​are assigned to the discharge pressure depending on the number of evaluation stages in which the evaluation of the discharge pressure has been performed among the N evaluation stages.

3. extracting, based on a result of measuring the discharge pressure during an evaluation period including at least a main period from when the discharge of the treatment liquid from the nozzle starts, through when the discharge pressure increases to a predetermined pressure, until when the discharge pressure starts to decrease from the predetermined pressure, a feature quantity of a time change of the discharge pressure during the entire evaluation period as an overall feature quantity; evaluating a time change of the discharge pressure based on the overall characteristic amount; 3. The discharge pressure evaluation method according to claim 1, wherein the first evaluation step has an evaluation item of evaluating the discharge pressure by executing the following:

4. the evaluation period is the main period, The discharge pressure evaluation method according to claim 3 , wherein a main characteristic amount, which is a characteristic amount possessed by a time change of the discharge pressure throughout the main period, is extracted as the overall characteristic amount.

5. The discharge pressure evaluation method according to claim 4 , wherein the main characteristic amount indicates a difference between a main approximate waveform that approximates the time change of the discharge pressure during the entire main period and the time change of the discharge pressure during the entire main period.

6. The main approximation waveform is a rising approximation straight line that linearly increases with time from a discharge start pressure to a steady pressure that is greater than the discharge start pressure, the rise approximation straight line being a linear approximation of a time change in the discharge pressure that increases with time after discharge of the treatment liquid from the nozzle is started; a start approximation line that is provided between a start time point of ejection of the treatment liquid from the nozzle and the rising approximation line and indicates the ejection start pressure; a steady line indicating the steady pressure, which is provided between the time when the rising approximation line reaches the steady pressure and the end of the main period; The method for evaluating discharge pressure according to claim 5 , further comprising:

7. the evaluation period is a first period from when the discharge of the treatment liquid from the nozzle starts to when the discharge of the treatment liquid from the nozzle ends, The discharge pressure evaluation method according to claim 3 , wherein a first characteristic amount, which is a characteristic amount possessed by a time change of the discharge pressure throughout the first period, is extracted as the overall characteristic amount.

8. The discharge pressure evaluation method according to claim 7 , wherein the first characteristic quantity indicates a difference between a first approximate waveform that approximates the time change of the discharge pressure over the entire first period and the time change of the discharge pressure over the entire first period.

9. The first approximation waveform is a rising approximation line that linearly increases with time from the ejection start pressure to a steady pressure that is greater than the ejection start pressure by linearly approximating the time change of the ejection pressure that increases with time after the ejection of the treatment liquid from the nozzle starts; a start approximation line that is provided between a start time point of ejection of the treatment liquid from the nozzle and the rising approximation line and indicates the ejection start pressure; a falling approximation line that linearly reduces the discharge pressure from the steady pressure to a discharge end pressure that is smaller than the steady pressure over time by linearly approximating the time change of the discharge pressure that decreases over time before the discharge of the treatment liquid from the nozzle is completed; an end approximation line that is provided between the falling approximation line and a time point at which the discharge of the treatment liquid from the nozzle is ended and indicates the discharge end pressure; A steady line indicating the steady pressure is formed by connecting the rising approximation line and the falling approximation line. The method for evaluating discharge pressure according to claim 8, further comprising:

10. extracting, as a second feature amount, a feature amount of a time change of the discharge pressure in a second period shorter than the evaluation period from among the evaluation period; evaluating a time change of the discharge pressure based on the second characteristic amount; 10. The discharge pressure evaluation method according to claim 3, wherein a second evaluation step among the N evaluation steps has an evaluation item of evaluating the discharge pressure by executing the following:

11. a predetermined initial rise period from the start of ejection of the treatment liquid from the nozzle is set as the second period; Throughout the initial rise period, the discharge pressure increases over time, The discharge pressure evaluation method according to claim 10 , wherein a feature value indicating a difference between a regression curve of the time change of the discharge pressure in the initial rise period and the time change of the discharge pressure in the initial rise period is extracted as the second feature value.

12. 12. The discharge pressure evaluation method according to claim 10, wherein a rise period from when the discharge of the treatment liquid from the nozzle starts until the discharge pressure increases to the predetermined pressure is set as the second period.

13. The discharge pressure evaluation method according to claim 12 , wherein a length of the rise period is extracted as the second characteristic amount.

14. The method for evaluating a discharge pressure according to claim 12 or 13, wherein the number of times that a first derivative of a change in the discharge pressure with respect to time crosses a predetermined threshold during the rise period is extracted as the second characteristic amount.

15. The discharge pressure evaluation method according to claim 12 , wherein the number of times that an absolute value of a second-order differential of a time change in the discharge pressure crosses a predetermined threshold during the rise period is extracted as the second characteristic amount.

16. The discharge pressure evaluation method according to any one of claims 12 to 15, wherein the ratio of the time during the rise period during which the second derivative of the time change in the discharge pressure becomes greater than a predetermined positive threshold value to the time during which the second derivative of the time change in the discharge pressure becomes smaller than a predetermined negative threshold value having the same absolute value as the positive threshold value is extracted as the second characteristic quantity.

17. a predetermined rise end period until the discharge pressure increases to the predetermined pressure is set as the second period, a feature quantity indicating a difference between a rise end approximation waveform that approximates the time change of the discharge pressure in the rise end period and the time change of the discharge pressure in the rise end period is extracted as the second feature quantity; The rising end approximation waveform is a rise end approximation line that overlaps with an approximation curve obtained by linearly approximating the time change of the discharge pressure that increases with time in a pressure range smaller than the predetermined pressure, and that linearly increases with time to a steady pressure that is an average value of the time change of the discharge pressure in a steady period after the rise end period; an extension line indicating the steady pressure, which is extended from the rise end approximation line to the end point of the rise end period; The method for evaluating a discharge pressure according to any one of claims 10 to 16, further comprising:

18. an initial vibration period from a time when the discharge pressure reaches a maximum value to a time when a second derivative of a time change in the discharge pressure crosses zero twice is set as the second period; A discharge pressure evaluation method according to any one of claims 10 to 17, wherein the difference between the smaller of the minimum value of the discharge pressure during the initial vibration period and the average value of the discharge pressure during a predetermined steady period after the initial vibration period and the maximum value of the discharge pressure is extracted as the second characteristic.

19. A predetermined transition period from the time when the discharge pressure exceeds the predetermined pressure is set as the second period, A discharge pressure evaluation method according to any one of claims 10 to 18, wherein a feature indicating a difference between the discharge pressure during the transition period and an average value of the discharge pressure during a predetermined steady period after the transition period is extracted as the second feature.

20. a constant pressure period from a time when the discharge pressure exceeds the predetermined pressure to a time when the discharge pressure starts to decrease toward the end of the discharge of the treatment liquid from the nozzle is set as the second period, The discharge pressure evaluation method according to claim 10 , wherein a feature value indicating a difference between a maximum value and a minimum value of the discharge pressure during the constant pressure period is extracted as the second feature value.

21. 21. The discharge pressure evaluation method according to claim 10, wherein N is 3 or more, extracting, as a third feature amount, a feature amount of a time change of the discharge pressure in a third period shorter than the evaluation period from among the evaluation period; evaluating a time change of the discharge pressure based on the third characteristic amount; The discharge pressure evaluation method, in which a third evaluation stage among the N evaluation stages has an evaluation item of evaluating the discharge pressure by executing the above-mentioned step.

22. a pressure increase period during which the discharge pressure increases over time from a lower reference value to an upper reference value that is greater than the lower reference value after the discharge of the treatment liquid from the nozzle is started is set as the third period; one of the discharge pressure measurements between the lower reference value and the upper reference value, a root mean square error between an approximation line obtained by linear regression of the change in the discharge pressure over time in the section between the lower reference value and the one measured value and the change in the discharge pressure over time; a root mean square error between an approximation line obtained by linear regression of the time change of the discharge pressure in the section between the one measured value and the upper reference value and the time change of the discharge pressure; The one measurement value that minimizes the sum of The discharge pressure evaluation method according to claim 21, wherein the ratio of the slope of a straight line between the lower reference value and the one measured value to the slope of a straight line between the one measured value and the upper reference value is extracted as the third characteristic.

23. a predetermined rise end period until the discharge pressure increases to the predetermined pressure is set as the third period, a feature quantity indicating a difference between a rise end approximation waveform that approximates the time change of the discharge pressure in the rise end period and the time change of the discharge pressure in the rise end period is extracted as the third feature quantity; The rising end approximation waveform is a rising end approximation line that overlaps with an approximation curve obtained by linearly approximating the time change of the discharge pressure that increases with time in a pressure range smaller than the predetermined pressure, and that linearly increases up to the predetermined pressure with the passage of time; an extension line connected to the rising end approximation line and indicating the predetermined pressure; The method for evaluating a discharge pressure according to claim 21 or 22, further comprising:

24. an initial vibration period from a time when the discharge pressure reaches a maximum value to a time when a second derivative of a time change in the discharge pressure crosses zero twice is set as the third period; A discharge pressure evaluation method according to any one of claims 21 to 23, wherein the sum of a value obtained by subtracting a steady pressure, which is the average value of the discharge pressure in a predetermined steady period after the initial vibration period, from the maximum value of the discharge pressure and a value obtained by subtracting the minimum value of the discharge pressure in the initial vibration period from the steady pressure, is extracted as the third characteristic quantity.

25. a step of evaluating the discharge pressure of a discharge device that applies a discharge pressure to a treatment liquid and discharges the treatment liquid from a nozzle, using an evaluation item related to a first evaluation stage among N evaluation stages from 1st to Nth (N is an integer of 2 or more) that evaluate the discharge pressure using different evaluation items; a step of evaluating the discharge pressure using evaluation items related to an (I+1)th evaluation stage when the discharge pressure is judged to be appropriate in the evaluation using evaluation items related to an I-th evaluation stage (I is an integer of 1 or more and less than N) among the N evaluation stages, and not evaluating the discharge pressure using evaluation items related to the (I+1)th evaluation stage when the discharge pressure is judged to be inappropriate in the evaluation using evaluation items related to the I-th evaluation stage; A discharge pressure evaluation program that causes a computer to execute the above.

26. A recording medium for recording the discharge pressure evaluation program according to claim 25 in a computer-readable manner.

27. A nozzle; a pressure applying unit that applies a discharge pressure to the treatment liquid to discharge the treatment liquid from the nozzle; A measurement unit for measuring the discharge pressure; a control unit that stores execution details at N evaluation stages (N is an integer of 2 or more) from 1st to Nth evaluation stages in which the discharge pressure of a discharge device that applies a discharge pressure to a treatment liquid to discharge the treatment liquid from a nozzle is evaluated according to different evaluation items; Equipped with The control unit is Evaluate the discharge pressure according to an evaluation item related to a first evaluation stage among the N evaluation stages; A substrate processing apparatus, in which if the discharge pressure is judged to be appropriate in the evaluation using the evaluation items related to the Ith evaluation stage (I is an integer greater than or equal to 1 and less than N) among the N evaluation stages, then evaluation of the discharge pressure is performed using the evaluation items related to the (I+1)th evaluation stage, whereas if the discharge pressure is judged to be inappropriate in the evaluation using the evaluation items related to the Ith evaluation stage, then evaluation of the discharge pressure is not performed using the evaluation stages subsequent to the Ith evaluation stage.

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