Ejection pressure evaluation method, recording medium, and slot coater

Abstract

The present application provides a kind of spray pressure evaluation method, can be in with the proper and not corresponding reasonable time of spray pressure, carry out the evaluation of the spray pressure that is applied to treatment liquid for spraying treatment liquid from nozzle.The N evaluation stages from the first to the Nth of spray pressure are respectively evaluated by different evaluation items.However, in the evaluation based on the evaluation item involved in the Ith evaluation stage, if the spray pressure is appropriate, the evaluation of the spray pressure based on the evaluation item involved in the (I+1) th evaluation stage is performed, on the other hand, in the evaluation based on the evaluation item involved in the Ith evaluation stage, if the spray pressure is not appropriate, the evaluation of the spray pressure in the evaluation stage in order after the Ith evaluation stage is not performed (i.e., is omitted).

Description

Technical Field

[0001] This invention relates to a technique for ejecting a processing liquid from a nozzle by applying ejection pressure to the processing liquid. Furthermore, objects from which the processing liquid is ejected from the nozzle include, for example, semiconductor substrates, photomask substrates, liquid crystal display substrates, organic EL display substrates, plasma display substrates, FED (Field Emission Display) substrates, optical disc substrates, magnetic disk substrates, and optical disc substrates. Background Technology

[0002] As shown in Japanese Patent Application Publication Nos. 2011-005465 and 2020-040046, when a processing liquid ejected from a nozzle is applied to a substrate, the ejection pressure applied to the processing liquid has a significant impact on the thickness of the processing liquid applied to the substrate. Therefore, in Japanese Patent Application Publication No. 2011-005465, the waveform of the ejection pressure is divided into multiple intervals, and the slope of the waveform in each interval is used to evaluate whether the ejection pressure is within the allowable range. Furthermore, in Japanese Patent Application Publication No. 2020-040046, the parameters related to the ejection pressure are optimized for each region, such as the rising region and the constant ejection region.

[0003] That is, as described in Japanese Patent Application Publication Nos. 2011-005465 and 2020-040046, high-precision evaluation of the ejection pressure can be achieved by evaluating the waveform of the ejection pressure in each of multiple intervals or regions. However, this evaluation of multiple items increases the time required for ejection pressure evaluation. In particular, for inappropriate ejection pressures, spending a long time evaluating all items is not necessarily reasonable. Summary of the Invention

[0004] The present invention was made in view of the above-mentioned problems, and its object is to be able to evaluate the spray pressure applied to the treatment liquid for spraying from the nozzle within a reasonable time corresponding to whether the spray pressure is appropriate.

[0005] The ejection pressure evaluation method of the present invention comprises: a step of evaluating the ejection pressure in an ejection device that ejects treatment liquid from a nozzle by applying ejection pressure to the treatment liquid based on evaluation items involved in the first evaluation stage of N evaluation stages from the first to the Nth, where N is an integer of 2 or more; wherein the ejection pressure is evaluated according to different evaluation items in each of the N evaluation stages; and a step of performing an evaluation of the ejection pressure based on the evaluation items involved in the (I+1)th evaluation stage if the ejection pressure is determined to be appropriate in the evaluation based on the evaluation items involved in the Ith evaluation stage of the N evaluation stages, and not performing an evaluation of the ejection pressure in the subsequent evaluation stages if the ejection pressure is determined to be inappropriate in the evaluation based on the evaluation items involved in the Ith evaluation stage, where I is an integer of 1 or more and less than N.

[0006] The ejection pressure evaluation program of the present invention causes a computer to perform the following steps: evaluating the ejection pressure of an ejection device that applies ejection pressure to the treatment liquid and ejects the treatment liquid from a nozzle based on the evaluation items involved in the first evaluation stage of N evaluation stages from the first to the Nth, where N is an integer of 2 or more; evaluating the ejection pressure according to different evaluation items in each of the N evaluation stages; and performing an evaluation of the ejection pressure based on the evaluation items involved in the (I+1)th evaluation stage if the ejection pressure is determined to be appropriate in the evaluation based on the evaluation items involved in the Ith evaluation stage of the N evaluation stages, and not performing an evaluation of the ejection pressure in the evaluation stages following the Ith evaluation stage if the ejection pressure is determined to be inappropriate in the evaluation based on the evaluation items involved in the Ith evaluation stage, where I is an integer of 1 or more and less than N.

[0007] The recording medium involved in this invention records the above-mentioned ejection pressure evaluation procedure in a manner that can be read by a computer.

[0008] The substrate processing apparatus according to the present invention includes: a nozzle; a pressure application unit that applies a spraying pressure to a processing liquid to cause the nozzle to spray the processing liquid; a measurement unit that measures the spraying pressure; and a control unit that stores execution content in N (N is an integer of 2 or more) evaluation stages from the first to the Nth, which evaluate the spraying pressure of the spraying device that applies a spraying pressure to the processing liquid and sprays the processing liquid from the nozzle according to different evaluation items. The control unit evaluates the spraying pressure according to the evaluation items involved in the first evaluation stage of the N evaluation stages. In the N evaluation stages, if it is determined that the spraying pressure is appropriate in the evaluation based on the evaluation items involved in the I (I is an integer of 1 or more and less than N) evaluation stage, the control unit performs an evaluation of the spraying pressure based on the evaluation items involved in the (I+1)th evaluation stage. On the other hand, if it is determined that the spraying pressure is inappropriate in the evaluation based on the evaluation items involved in the I evaluation stage, the control unit does not perform the evaluation of the spraying pressure in the subsequent evaluation stages.

[0009] In this invention (ejection pressure evaluation method, ejection pressure evaluation procedure, recording medium, and substrate processing apparatus) configured in this way, N evaluation stages, from the first to the Nth, are provided to evaluate the ejection pressure according to different evaluation items. These evaluation stages can be executed sequentially. However, if the ejection pressure is determined to be appropriate based on the evaluation items involved in the I-th evaluation stage, an evaluation of the ejection pressure based on the evaluation items involved in the (I+1)-th evaluation stage is performed. Conversely, if the ejection pressure is determined to be inappropriate based on the evaluation items involved in the I-th evaluation stage, the evaluation of the ejection pressure in subsequent evaluation stages is not performed. That is, when evaluating the ejection pressure sequentially through the 1st to Nth evaluation stages, if the ejection pressure is determined to be inappropriate in any evaluation stage, the evaluation of subsequent evaluation stages is not performed. Therefore, the evaluation of the ejection pressure applied to the processing liquid for ejecting the processing liquid from the nozzle can be performed within a reasonable time corresponding to whether the ejection pressure is appropriate.

[0010] Alternatively, the ejection pressure evaluation method can be configured to assign different evaluation values ​​to the ejection pressure based on the number of evaluation stages in N evaluation stages. In this structure, ejection pressures with more evaluation stages can be assigned better evaluation values, and appropriate evaluation values ​​corresponding to whether the ejection pressure is suitable or not can be assigned.

[0011] Alternatively, the ejection pressure evaluation method can be configured to include an evaluation item for ejection pressure in the first evaluation stage by performing the following steps: a step of extracting a characteristic quantity of the time-varying ejection pressure as an overall characteristic quantity based on the results obtained from measuring the ejection pressure during the evaluation period, which includes at least the main period from the start of ejection of the treatment liquid from the nozzle through the rise of the ejection pressure to a specified pressure until the ejection pressure begins to decrease from the specified pressure; and a step of evaluating the time-varying ejection pressure based on the overall characteristic quantity. In this structure, based on the measured value of the ejection pressure during the evaluation period, which includes at least the main period from the start of ejection of the treatment liquid from the nozzle through the rise of the ejection pressure to a specified pressure until the ejection pressure begins to decrease from the specified pressure, a characteristic quantity of the time-varying ejection pressure is extracted as an overall characteristic quantity, and the time-varying ejection pressure is evaluated based on the overall characteristic quantity. Therefore, the appropriateness of the ejection pressure during the entire period (in other words, the evaluation period) that affects the thickness of the treatment liquid coated on the substrate can be reflected in the evaluation of the ejection pressure.

[0012] Alternatively, the ejection pressure evaluation method can be configured such that the evaluation period is the main period, and the characteristic quantity of the time change of ejection pressure throughout the main period, i.e., the main characteristic quantity, is extracted as the overall characteristic quantity. In this structure, when the main period has a particularly large impact on the thickness of the processing liquid coated on the substrate (in other words, when the impact of the period after the main period is small), the appropriateness of the ejection pressure throughout the main period can be reflected in the evaluation of the ejection pressure.

[0013] Alternatively, the ejection pressure evaluation method can be configured such that the main characteristic quantity represents the difference between the main approximation waveform, which approximates the time variation of the ejection pressure throughout the main period, and the time variation of the ejection pressure throughout the main period. In this configuration, the ejection pressure throughout the entire main period can be appropriately evaluated based on the approximation waveform of the time variation of the ejection pressure.

[0014] Alternatively, the ejection pressure evaluation method can be configured such that the main approximate waveform has: an approximate rising straight line, which approximates the time change of the ejection pressure as it increases over time after the start of ejection of the treatment fluid from the nozzle, from the initial ejection pressure to a constant pressure greater than the initial ejection pressure; an approximate starting straight line, set between the start of ejection of the treatment fluid from the nozzle and the approximate rising straight line, representing the initial ejection pressure; and a constant straight line, set during the period from the approximate rising straight line reaching the constant pressure to the end of the main period, representing the constant pressure. In this configuration, the time change of the ejection pressure throughout the entire main period can be approximated, and the ejection pressure throughout the entire period can be appropriately evaluated.

[0015] Alternatively, the ejection pressure evaluation method can be configured such that the evaluation period is a first period from the start of ejecting the processing liquid from the nozzle to the end of ejecting the processing liquid from the nozzle, and the characteristic quantity of the time change of the ejection pressure during the entire first period, i.e., a first characteristic quantity, is extracted as the overall characteristic quantity. In this structure, during the first period from the start of ejecting the processing liquid from the nozzle to the end of ejecting the processing liquid from the nozzle, if the ejection pressure affects the thickness of the processing liquid coated on the substrate, the appropriateness of the ejection pressure during the entire first period can be reflected in the evaluation of the ejection pressure.

[0016] Alternatively, the ejection pressure evaluation method can be configured such that a first characteristic quantity represents the difference between a first approximate waveform that approximates the time variation of the ejection pressure throughout the entire first period and the time variation of the ejection pressure throughout the entire first period. In this configuration, the ejection pressure throughout the entire period can be appropriately evaluated based on the approximate waveform of the time variation of the ejection pressure for the entire period from the start of ejecting the treatment fluid from the nozzle to the end.

[0017] Alternatively, the ejection pressure evaluation method can be configured such that the first approximate waveform has: an ascending approximate straight line, which approximates the time change of the ejection pressure as it increases over time after the start of ejection of the treated liquid from the nozzle, from the initial ejection pressure linearly increasing over time to a constant pressure greater than the initial ejection pressure; an initial approximate straight line, set between the start time of ejection of the treated liquid from the nozzle and the ascending approximate straight line, representing the initial ejection pressure; a descending approximate straight line, which approximates the time change of the ejection pressure as it decreases over time before the end of ejection of the treated liquid from the nozzle, from a constant pressure linearly decreasing over time to an end ejection pressure less than the constant pressure; an end approximate straight line, set between the descending approximate straight line and the end time of ejection of the treated liquid from the nozzle, representing the end ejection pressure; and a constant straight line, connecting the ascending and descending approximate straight lines, representing the constant pressure. In this configuration, a trapezoidal waveform is used to approximate the time change of the ejection pressure throughout the entire period from the start of ejection of the treated liquid from the nozzle to the end, thereby enabling an appropriate evaluation of the ejection pressure throughout this period.

[0018] Alternatively, the ejection pressure evaluation method can be configured such that the second evaluation stage out of N evaluation stages includes an evaluation item for ejection pressure: a step of extracting a characteristic quantity of the time change of ejection pressure in a second period shorter than the evaluation period as a second characteristic quantity; and a step of evaluating the time change of ejection pressure based on the second characteristic quantity. In this configuration, ejection pressure can be evaluated with high precision based on the time change of ejection pressure in a period shorter than the entire period from the start of ejection of the treatment liquid from the nozzle to the end.

[0019] Alternatively, the ejection pressure evaluation method can be configured such that a predetermined initial rising period from the start of ejecting the treated liquid from the nozzle is set as a second period. During this initial rising period, the ejection pressure increases over time, and a feature quantity is extracted as the difference between the regression curve representing the time change of the ejection pressure during the initial rising period and the time change of the ejection pressure during the initial rising period. In this configuration, the ejection pressure can be evaluated by considering the time change of the ejection pressure after the start of ejecting the treated liquid from the nozzle.

[0020] Alternatively, the ejection pressure evaluation method can be configured such that the rise period from the start of ejecting the treatment fluid from the nozzle until the ejection pressure increases to a predetermined pressure is defined as a second period. In this configuration, the time variation of the ejection pressure during the rise period can be taken into account to evaluate the ejection pressure.

[0021] Specifically, the ejection pressure evaluation method can also be configured to extract the length of the rise period as a second feature. In this configuration, the rise rate of the ejection pressure can be considered when evaluating the ejection pressure.

[0022] Alternatively, the ejection pressure evaluation method can be configured such that, during the rise period, the number of times the first derivative of the time-varying ejection pressure intersects with a predetermined threshold is used as a second feature. In this configuration, the smoothness of the time-varying ejection pressure during the rise period can be considered when evaluating the ejection pressure.

[0023] Alternatively, the ejection pressure evaluation method can be configured such that, during the rise period, the absolute value of the second derivative of the time-varying ejection pressure intersects with a predetermined threshold a certain number of times as a second feature. In this configuration, the smoothness of the time-varying ejection pressure during the rise period can be considered when evaluating the ejection pressure.

[0024] Alternatively, the ejection pressure evaluation method can be configured such that, during the rise period, the ratio of the time intervals during which the second derivative of the ejection pressure over time is greater than a predetermined positive threshold, and the time intervals during which the second derivative of the ejection pressure over time is less than a predetermined negative threshold having the same absolute value as the positive threshold, is extracted as a second characteristic quantity. In this configuration, the difference in the time variation of ejection pressure between the initial and final stages of the rise period can be considered when evaluating the ejection pressure.

[0025] Alternatively, the ejection pressure evaluation method can be configured such that a predetermined rise-end period, during which the ejection pressure increases to a predetermined pressure, is defined as a second period. A second characteristic quantity is extracted, representing the difference between the approximate waveform of the rise-end period (which approximates the time change of the ejection pressure during the rise-end period) and the time change of the ejection pressure during the rise-end period. The approximate waveform of the rise-end period has: an approximate straight line that overlaps with an approximate curve obtained by approximating the time change of the ejection pressure, which increases linearly over time within a pressure range smaller than the predetermined pressure, and linearly increases to a constant pressure over time, which is the average value of the time change of the ejection pressure during the constant period following the rise-end period; and an extended straight line that extends from the approximate straight line of the rise-end period to the end of the rise-end period, representing the constant pressure. In this configuration, the degree of stall in the ejection pressure at the end of the rise period can be considered when evaluating the ejection pressure.

[0026] Alternatively, the ejection pressure evaluation method can be configured such that the initial vibration period from the moment the ejection pressure reaches its maximum value until the moment when the second derivative of the ejection pressure's time change crosses zero twice is defined as the second period. The difference between the smaller of the minimum ejection pressure during the initial vibration period and the average ejection pressure during a predetermined constant period following the initial vibration period, and the maximum ejection pressure, is extracted as the second characteristic quantity. In this configuration, ejection pressure overshoot can be considered when evaluating the ejection pressure.

[0027] Alternatively, the ejection pressure evaluation method can be configured such that a predetermined transition period from the moment the ejection pressure exceeds a predetermined pressure is defined as a second period, and a feature quantity representing the difference between the ejection pressure during the transition period and the average value of the ejection pressure during a predetermined constant period following the transition period is extracted as a second feature quantity. In this configuration, the stability of the ejection pressure after it reaches the predetermined pressure can be considered when evaluating the ejection pressure.

[0028] Alternatively, the ejection pressure evaluation method can be configured such that a second period is defined as the constant pressure period from the moment the ejection pressure exceeds a predetermined pressure until the ejection pressure begins to decrease in order to stop ejecting the treatment fluid from the nozzle. A second feature quantity is extracted representing the difference between the maximum and minimum ejection pressure during this constant pressure period. In this configuration, the stability of the ejection pressure during the constant pressure period can be considered when evaluating the ejection pressure.

[0029] Alternatively, the ejection pressure evaluation method can be configured such that N is 3 or more, and by performing the following steps, the third evaluation stage out of N evaluation stages includes an evaluation item for ejection pressure: a step of extracting a characteristic quantity of the time change of ejection pressure in a third period shorter than the evaluation period as a third characteristic quantity; and a step of evaluating the time change of ejection pressure based on the third characteristic quantity. In this structure, the ejection pressure can be evaluated with high accuracy based on the time change of ejection pressure in a period shorter than the entire period from the start of ejecting the treatment liquid from the nozzle to the end.

[0030] Alternatively, the ejection pressure evaluation method can be configured such that, after the treatment fluid begins to be ejected from the nozzle, the period during which the ejection pressure increases from a lower reference value to an upper reference value that is larger than the lower reference value over time is defined as a third period. One of the measured values ​​of the ejection pressure between the lower and upper reference values ​​is calculated. This measured value is the value whose sum of the mean square error of the time-varying straight line obtained by linear regression of the ejection pressure over time within the interval between the lower reference value and this measured value, and the mean square error of the time-varying straight line obtained by linear regression of the ejection pressure over time within the interval between this measured value and the upper reference value, is minimized. The slope of the straight line between the lower reference value and this measured value, and the ratio of the slope of the straight line between this measured value and the upper reference value, are extracted as a third characteristic quantity. In this structure, the linearity of the increase in ejection pressure can be considered when evaluating the ejection pressure.

[0031] Alternatively, the ejection pressure evaluation method can be configured such that a predetermined rise-end period, during which the ejection pressure increases to a predetermined pressure, is defined as a third period. A third characteristic quantity is extracted, representing the difference between the approximate waveform of the rise-end period (which approximates the time change of the ejection pressure during the rise-end period) and the time change of the ejection pressure during the rise-end period. The approximate waveform of the rise-end period has: an approximate straight line that overlaps with an approximate curve obtained by approximating the time change of the ejection pressure, which increases linearly with time within a pressure range smaller than the predetermined pressure, and increases linearly to the predetermined pressure; and an extended straight line connecting to the approximate straight line of the rise-end period, representing the predetermined pressure. In this configuration, the degree of stall in the ejection pressure at the end of the rise period can be considered when evaluating the ejection pressure.

[0032] Alternatively, the ejection pressure evaluation method can be configured such that the initial vibration period from the moment the ejection pressure reaches its maximum value until the moment when the second derivative of the ejection pressure's time change crosses zero twice is defined as the third period. The third characteristic quantity is the sum of the value obtained by subtracting the constant pressure from the maximum ejection pressure and the value obtained by subtracting the minimum ejection pressure during the initial vibration period from the constant pressure. Here, the constant pressure is the average value of the ejection pressure during a predetermined constant period following the initial vibration period. In this configuration, ejection pressure overshoot can be considered when evaluating the ejection pressure.

[0033] As described above, according to the present invention, it is possible to evaluate the spray pressure applied to the treatment liquid for spraying from the nozzle within a reasonable time corresponding to whether the spray pressure is appropriate. Attached Figure Description

[0034] Figure 1This is a schematic diagram showing the overall structure of a coating apparatus as an embodiment of the substrate processing apparatus according to the present invention.

[0035] Figure 2 This is a diagram showing the structure of the coating liquid supply mechanism.

[0036] Figure 3 This is a block diagram illustrating an example of the structure of a control unit.

[0037] Figure 4 This is a flowchart illustrating an example of an ejection pressure evaluation method performed based on an ejection pressure evaluation procedure.

[0038] Figure 5 It is a diagram used to illustrate the various periods used to evaluate ejection pressure.

[0039] Figure 6 This is a diagram illustrating an example of the calculations performed by the pressure evaluation unit in response to the time-varying changes in ejection pressure.

[0040] Figure 7 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv1.

[0041] Figure 8 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv2.

[0042] Figure 9 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv3.

[0043] Figure 10A This is a graph used to illustrate the evaluation items for evaluating the time-varying changes in ejection pressure based on the characteristic quantity Fv4.

[0044] Figure 10B This is a graph showing an example of the time variation of ejection pressure judged as inappropriate based on the evaluation of the characteristic quantity Fv4.

[0045] Figure 11A This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv5.

[0046] Figure 11B This is a graph showing an example of the time variation of ejection pressure judged as inappropriate based on the evaluation of the characteristic quantity Fv5.

[0047] Figure 12 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv6.

[0048] Figure 13This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv7.

[0049] Figure 14 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv8.

[0050] Figure 15 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv9.

[0051] Figure 16 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv10.

[0052] Figure 17 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv11.

[0053] Figure 18 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv12.

[0054] Figure 19 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv13.

[0055] Figure 20 This is a graph used to illustrate the evaluation items for evaluating the time-varying changes in ejection pressure based on the characteristic quantity Fv14.

[0056] Figure 21 It is a flowchart showing the detailed evaluation of the measurement results.

[0057] Figure 22 It is a schematic representation according to Figure 21 The flowchart is a diagram of an example of the actions performed.

[0058] Figure 23 This is a diagram used to illustrate the various periods used in the variation of the evaluation item of ejection pressure.

[0059] Figure 24 This is a diagram illustrating a variation of an evaluation item that assesses the time-varying change in ejection pressure based on the characteristic quantity Fv1_1.

[0060] Explanation of reference numerals in the attached figures

[0061] 1… Coating apparatus (substrate processing apparatus)

[0062] 71… Nozzle (ejection device)

[0063] 8… Application liquid supply mechanism (pressure application unit, spraying device)

[0064] 86… Pressure gauge (measuring section)

[0065] 9…Control unit (computer, control unit)

[0066] 97…Ejection Pressure Evaluation Procedure

[0067] M…recording medium

[0068] Tt… Ejection period (first period)

[0069] Fv1… Feature (First Feature)

[0070] WF1…Approximate waveform (first approximate waveform)

[0071] Pi… Initial pressure (pressure at the start of ejection, pressure at the end of ejection)

[0072] Lr_R…Ascending regression line (ascending approximate line)

[0073] Lr_s… is initially approximately a straight line

[0074] Lr_F…decreasing regression line

[0075] Lr_e… ends with an approximate straight line

[0076] Lr_m…a constant straight line

[0077] Ta_s… Initial stage of rise (second stage)

[0078] Ta… during the rising period (second period)

[0079] Ta_e… during the final stage of the rise (second period)

[0080] Tb_s… Initial vibration period (second period)

[0081] Tb… Transition Period (Second Period)

[0082] Tbc… Constant pressure period (second period)

[0083] Fv2~Fv10… Feature quantity (second feature quantity)

[0084] Nr…regression curve

[0085] WF7…Approximate waveform (approximate waveform at the end of the rising phase)

[0086] Lr…Regression line at the end of the ascent (approximate straight line at the end of the ascent)

[0087] Lm…Extend setting straight line

[0088] Tc… constant period

[0089] Tar… During periods of increased stress (Third period)

[0090] Ta_e… during the final stage of the ascent (third period)

[0091] Tb_s… During the initial vibration period (third period)

[0092] Fv11~Fv14… Feature quantity (third feature quantity)

[0093] P11_l…Lower reference pressure (lower reference value)

[0094] P11_u… Upper reference pressure (upper reference value)

[0095] Tar…During periods of increased stress

[0096] Ta_e… during the final stage of the ascent

[0097] Approximate waveforms of WF12, WF13... (approximate waveforms at the end of the rising phase)

[0098] Lr…Regression line at the end of the ascent (approximate straight line at the end of the ascent)

[0099] Lm…Extend setting straight line

[0100] Tb_s… during the initial vibration period Detailed Implementation

[0101] Figure 1 This is a schematic diagram showing the overall structure of a coating apparatus according to one embodiment of the substrate processing apparatus according to the present invention. The coating apparatus 1 is used to process substrates from... Figure 1 A slot coater applies a coating liquid to the upper surface Sf of a substrate S, which is horizontally transported from the left side to the right side. Furthermore, in the following figures, to clarify the arrangement of the various parts of the apparatus, the transport direction of the substrate S is designated as the "X direction," and will be shown from... Figure 1 The horizontal direction from the left hand side to the right hand side is called the "+X direction", and the opposite direction is called the "-X direction". In addition, in the horizontal direction Y, which is orthogonal to the X direction, the front side of the device is called the "-Y direction", and the back side of the device is called the "+Y direction". Furthermore, the upward and downward directions in the vertical direction Z are called the "+Z direction" and "-Z direction", respectively.

[0102] In the coating apparatus 1, along the transport direction Dt (+X direction) of the substrate S, the input conveyor 100, the input transfer unit 2, the floating platform unit 3, the output transfer unit 4, and the output conveyor 110 are sequentially arranged close to each other, forming a transport path for the substrate S extending in a generally horizontal direction, as detailed below. Furthermore, in the following description, when indicating positional relationships in relation to the transport direction Dt of the substrate S, the "upstream side in the transport direction Dt of the substrate S" is sometimes simply referred to as the "upstream side," and the "downstream side in the transport direction Dt of the substrate S" is sometimes simply referred to as the "downstream side." In this example, viewed from a certain reference position, the (-X) side corresponds to the "upstream side," and the (+X) side corresponds to the "downstream side."

[0103] The substrate S, which is the object of processing, is from... Figure 1 The substrate S is moved into the input conveyor 100 from its left side. The input conveyor 100 includes a roller conveyor 101 and a rotation drive mechanism 102 for rotating it. By rotating the roller conveyor 101, the substrate S is transported horizontally downstream in the (+X) direction. The input transfer unit 2 includes a roller conveyor 21 and a rotation / lifting drive mechanism 22 that has the function of rotating and lifting the roller conveyor 21. By rotating the roller conveyor 21, the substrate S is further transported in the (+X) direction. In addition, the vertical Z position of the substrate S is changed by lifting the roller conveyor 21. Through the input transfer unit 2 configured in this way, the substrate S is transferred from the input conveyor 100 to the floating platform unit 3.

[0104] The floating platform section 3 comprises a flat plate divided into three parts along the substrate transport direction Dt. Specifically, the floating platform section 3 includes an inlet floating platform 31, a coating platform 32, and an outlet floating platform 33, the upper surfaces of which form part of the same plane. Furthermore, the floating platform section 3 includes a lifting pin drive mechanism 34, a floating control mechanism 35, and a lifting drive mechanism 36. The lifting pin drive mechanism 34 can raise and lower the lifting pin provided on the inlet floating platform 31. The floating control mechanism 35 can supply compressed air to each platform of the floating platform section 3 for raising the substrate S. The lifting drive mechanism 36 can raise and lower the outlet floating platform 33.

[0105] Multiple ejection holes, supplied by the levitation control mechanism 35, are arranged in a matrix on the upper surfaces of the inlet levitation platform 31 and the outlet levitation platform 33. The substrate S is levitated by the buoyancy provided by the ejected airflow. Thus, the substrate S is supported in a horizontal position with its lower surface Sb separated from the upper surface of the platform. The distance between the lower surface Sb of the substrate S and the upper surface of the platform, i.e., the levitation amount, can be, for example, from 10 micrometers to 500 micrometers.

[0106] On the other hand, on the upper surface of the coating stage 32, ejection holes for ejecting compressed air and suction holes for attracting air between the lower surface Sb of the substrate S and the upper surface of the stage are alternately arranged. The levitation control mechanism 35 precisely controls the distance between the lower surface Sb of the substrate S and the upper surface of the coating stage 32 by controlling the amount of compressed air ejected from the ejection holes and the amount of air attracted from the suction holes. As a result, the position of the upper surface Sf of the substrate S above the coating stage 32 in the vertical direction Z is controlled to a predetermined value. As a specific structure of the levitation stage 3, the structure described in Japanese Patent No. 5346643 can be applied, for example. In addition, the amount of levitation on the coating stage 32 is calculated by the control unit 9 based on the detection results of the sensors 61 and 62, which will be described in detail later, and can be adjusted with high precision by airflow control.

[0107] The substrate S, which is transferred to the floating platform 3 via the input transfer unit 2, is given a pushing force in the (+X) direction by the rotation of the roller conveyor 21, and is thus transported to the inlet floating platform 31. The inlet floating platform 31, the coating platform 32, and the outlet floating platform 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 transport of the substrate S in the floating platform 3 is carried out by the substrate transport unit 5, which is arranged below the inlet floating platform 31, the coating platform 32, and the outlet floating platform 33.

[0108] The substrate transport unit 5 includes: a chuck mechanism 51 that supports the substrate S from below by partially abutting against the peripheral portion of the lower surface of the substrate S; and an adsorption / travel control mechanism 52 that applies negative pressure to an adsorption pad (not shown) provided on an adsorption member at the upper end of the chuck mechanism 51 to adsorb and hold the substrate S, and reciprocates 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 positioned higher than the upper surfaces of each stage of the lifting platform 3. Therefore, the substrate S is held peripherally by the chuck mechanism 51 and maintained in a horizontal position by the buoyancy supplied from the lifting platform 3. Furthermore, in order to detect the vertical Z position of the upper surface of the substrate S during the stage when the lower surface Sb of the substrate S is partially held by the chuck mechanism 51, a thickness measurement sensor 61 is disposed near the roller conveyor 21. By positioning the chuck (not shown) that is not holding the substrate S directly below the sensor 61, the sensor 61 can detect the position of the upper surface of the adsorption component, i.e., the vertical direction Z of the adsorption surface.

[0109] The chuck mechanism 51 holds the substrate S that has been moved from the input transfer unit 2 to the floating stage unit 3. In this state, the substrate S is moved in the (+X) direction by the chuck mechanism 51 and transported from above the inlet floating stage 31 to above the outlet floating stage 33 via above the coating stage 32. The transported substrate S is then handed over to the output transfer unit 4 located on the (+X) side of the outlet floating stage 33.

[0110] The output transfer unit 4 includes a roller conveyor 41 and a rotation / lifting drive mechanism 42 that specifically drives its rotation and lifts it. By rotating the roller conveyor 41, a pushing force is applied to the substrate S in the (+X) direction, and the substrate S is further conveyed along the conveying direction Dt. Furthermore, the vertical Z position of the substrate S is changed by lifting the roller conveyor 41. Through the output transfer unit 4, the substrate S is transferred from above the outlet floating platform 33 onto the output conveyor 110.

[0111] The output conveyor 110 includes a roller conveyor 111 and a rotary drive mechanism 112 for rotating it. Through the rotation of the roller conveyor 111, the substrate S is further conveyed in the (+X) direction and finally discharged out of the coating apparatus 1. Alternatively, the input conveyor 100 and the output conveyor 110 can be provided as part of the structure of the coating apparatus 1, or they can be provided separately from the coating apparatus 1. Furthermore, for example, a substrate feeding mechanism from another unit located upstream of the coating apparatus 1 can be used as the output conveyor 100. Additionally, for example, a substrate receiving mechanism from another unit located downstream of the coating apparatus 1 can be used as the output conveyor 110.

[0112] Along the transport path of the substrate S being transported, a coating mechanism 7 is provided for applying a coating liquid to the upper surface Sf of the substrate S. The coating mechanism 7 includes a slit nozzle (hereinafter referred to as "nozzle") 71 with a slit-shaped nozzle outlet. Furthermore, although not shown in the figure, a positioning mechanism is connected to the nozzle 71, which positions the nozzle 71 at a coating position above the coating stage 32. Figure 1 (The position indicated by the solid line in the middle) or the maintenance position described later. Furthermore, a coating liquid supply mechanism 8 is connected to the nozzle 71, from which coating liquid is supplied and sprayed out from the spray outlet that opens downward at the bottom of the nozzle.

[0113] Figure 2 This is a diagram showing the structure of the application liquid supply mechanism. For example... Figure 2As shown, the coating liquid supply mechanism 8 uses a pump 81 that delivers the coating liquid through volume changes as a delivery source for delivering the coating liquid to the nozzle 71. For example, a bellows-type pump as described in Japanese Patent Application Publication No. 10-61558 can be used as the pump 81. This pump 81 has a flexible tube 811 that expands and contracts elastically in the radial direction. One end of this flexible tube 811 is connected to the coating liquid replenishment unit 83 via a pipe 82, and the other end is connected to the nozzle 71 via a pipe 84.

[0114] A bellows 812, capable of free elastic deformation 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. An incompressible medium is sealed in a pump chamber 815 between the flexible tube 811 and the bellows 812. An actuating disc section 816 is provided between the small bellows section 813 and the large bellows section 814. A drive unit 817 is connected to the actuating disc section 816. When the drive unit 817 operates according to a command from the control unit 9, the actuating disc section 816 displaces axially in a predetermined movement pattern (representing the change in the speed of the actuating disc section 816 relative to the passage of time), causing a change in the volume inside the bellows 812. As a result, the flexible tube 811 expands and contracts radially, performing a pumping action to deliver the coating liquid appropriately replenished from the coating liquid replenishment unit 83 to the nozzle 71. Therefore, the movement pattern of the actuation disc 816 is closely related to the ejection characteristics (time variation of ejection pressure) of the coating liquid ejected from the nozzle 71, and the specified ejection characteristics are obtained according to the movement pattern.

[0115] The coating fluid replenishment unit 83 has a storage tank 831 for storing the coating fluid. This storage tank 831 is connected to the pump 81 via a piping 82. Additionally, an on / off valve 833 is installed on the piping 82. This on / off valve 833 opens upon a replenishment command from the control unit 9, allowing the coating fluid in the storage tank 831 to be replenished into the flexible conduit 811 of the pump 81. Conversely, it closes upon a replenishment stop command from the control unit 9, restricting the replenishment of coating fluid from the storage tank 831 to the flexible conduit 811 of the pump 81.

[0116] An on / off valve 85 is installed on the piping 84 connected to the output side of pump 81 (left side of the figure), which opens and closes according to the opening / closing command from control unit 9. This allows switching between supplying coating liquid to nozzle 71 and stopping the supply of coating liquid. Additionally, a pressure gauge 86 is installed on piping 84 to detect the pressure (ejection pressure) of the coating liquid supplied to nozzle 71, and outputs the detection result (pressure value) to control unit 9.

[0117] On the nozzle 71 that supplies the coating liquid from the coating liquid supply mechanism 8, such as Figure 2As shown, a floating height detection sensor 62 is provided for non-contact detection of the floating height of the substrate S. This sensor 62 measures the distance between the floating substrate S and the upper surface of the coating stage 32. The control unit 9 controls the positioning mechanism (not shown) based on this detection value, thereby adjusting the descent position of the nozzle 71. Furthermore, the sensor 62 can be an optical sensor or an ultrasonic sensor, etc.

[0118] In order to perform the prescribed maintenance on nozzle 71, such as Figure 1 As shown, a nozzle cleaning standby unit 72 is provided in the coating mechanism 7. The nozzle cleaning standby unit 72 mainly includes a roller 721, a cleaning section 722, and a roller groove 723. Nozzle cleaning and liquid storage are performed thereon, adjusting the nozzle 71's outlet position to be suitable for the next coating process. Furthermore, by positioning the nozzle 71 in the position where the nozzle cleaning standby unit 72 is provided, i.e., the maintenance position, a simulated spraying of coating liquid from the nozzle 71 is performed to evaluate the spraying pressure applied to the coating liquid.

[0119] Furthermore, the coating apparatus 1 includes a control unit 9 for controlling the operation of each part of the apparatus. Figure 3 ). Figure 3 This is a block diagram illustrating an example of the structure of a control unit. For example... Figure 3 As shown, the control unit 9 is a computer equipped with an arithmetic unit 91, a storage unit 93, and a user interface (UI) 95. The arithmetic unit 91 is a processor, such as a CPU (Central Processing Unit), which executes a jet pressure evaluation program 97, and constructs a measurement execution unit 911 for measuring the jet pressure and a pressure evaluation unit 913 for evaluating the measured jet pressure. The storage unit 93 is a storage device such as an HDD (Hard Disk Drive) or SDD (Solid State Drive), storing the aforementioned jet pressure evaluation program 97 and the jet pressure measurement data 99 measured during the execution of the jet pressure evaluation program 97. The jet pressure evaluation program 97 is provided, for example, by a recording medium M provided separately from the control unit 9. This recording medium M records the jet pressure evaluation program 97 in a manner that 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 an external server computer's storage device. In addition, UI95 has a display for showing information to the user and an input device for accepting user input. As a control unit 9 with this structure, various computers, such as desktop, laptop, or tablet computers, can be used.

[0120] Figure 4This is a flowchart illustrating an example of a jet pressure evaluation method performed based on a jet pressure evaluation procedure. In step 101, the measurement execution unit 911 moves the actuation disc 816 according to the movement pattern specified in the jet pressure evaluation procedure 97, thereby jetting the coating liquid from the nozzle 71 (simulated jetting). Thus, the actuation disc 816 moves at a constant speed from 0 to a specified target speed, and then decelerates from that target speed back to 0. However, as shown in Japanese Patent Application Publication No. 2020-040046, the movement pattern is set by adjusting the speed (parameter) of the actuation disc 816 during the local period from when the speed of the actuation disc 816 reaches its maximum speed until it stabilizes at the target speed.

[0121] Specifically, the movement pattern of the actuation disc 816 is specified in the ejection pressure evaluation procedure 97 in such a manner that the ejection pressure changes in the following order:

[0122] • The ejection pressure increases from the initial pressure Pi to a target pressure Pt that is greater than the initial pressure Pi.

[0123] • The ejection pressure stabilizes at the target pressure Pt.

[0124] • The ejection pressure decreases from the target pressure Pt to the initial pressure Pi.

[0125] Furthermore, in step S101, the measuring actuator 911 and the accompanying actuation disc 816 move in parallel, spraying the coating liquid from the nozzle 71, and periodically acquiring the measured value of the spray pressure of the pressure gauge 86 at a predetermined sampling period. Thus, during the spraying period of the coating liquid from the nozzle 71, Tt ( Figure 5 In the process, the result of measuring the spray pressure applied to the coating liquid is obtained and stored in the storage unit 93 as spray pressure measurement data 99. This spray pressure measurement data 99 represents a time and the value of the spray pressure measured at that time.

[0126] In step S102, the pressure evaluation unit 913 evaluates the time change of the ejection pressure represented by the ejection pressure measurement data 99 according to prescribed evaluation items. As described later, these evaluation items involve extracting prescribed characteristic quantities from the time change of the ejection pressure represented by the ejection pressure measurement data 99, and evaluating the time change of the ejection pressure based on these characteristic quantities. Next, each evaluation item used to evaluate the time change of the ejection pressure represented by the ejection pressure measurement data 99 will be described in detail.

[0127] Figure 5 This is a graph used to illustrate the various periods used to evaluate ejection pressure. In Figure 5In the graph, where time is represented on the horizontal axis and ejection pressure on the vertical axis, the change in ejection pressure over time is schematically shown. Furthermore, the labeling of this graph is the same in the subsequent graphs. Figure 5 In this example, spray pressure measurement data 99 is obtained from before the start of spraying the coating liquid from nozzle 71 to after the end of spraying the coating liquid from nozzle 71 (i.e., throughout the spraying period Tt). Furthermore, in this example, the spray pressure at the start time ta of spraying the coating liquid from nozzle 71 and the spray pressure at the end time te of spraying the coating liquid from nozzle 71 are defined as the initial pressure Pi. However, the pressures at the start and end of spraying are not always consistent with the initial pressure Pi.

[0128] like Figure 5 As shown, the ejection period Tt can be divided into four periods: Ta, Tb, Tc, and Td. Details of the rising period Ta, the transition period Tb, the constant period Tc, and the falling period Td are described below.

[0129] The rising period Ta is the period from the moment when the coating liquid supply mechanism 8 starts to spray coating liquid from the nozzle 71 (i.e., the moment when the coating liquid supply mechanism 8 starts to move the actuating disc 816) to the moment when the spray pressure reaches the target pressure Pt. That is, when the coating liquid starts to be sprayed from the nozzle 71 at moment ta, the spray pressure increases from the initial pressure Pi to the target pressure Pt between moment ta and moment tb.

[0130] The transition period Tb is the period from time tb to time tc after a predetermined vibration decay period. This vibration decay period is the period required for the time variation of the ejection pressure to stabilize, and is set, for example, by user input on the UI95 and stored in the storage unit 93.

[0131] The constant period Tc is the period from time tc to time td (i.e., the time td when the coating liquid supply mechanism 8 begins to reduce the ejection pressure) from the target speed. In other words, the coating liquid supply mechanism 8 moves the actuating disc 816 at a constant speed from time tc to time td, and begins to decelerate the actuating disc 816 at time td. Furthermore, during the constant period Tc, the ejection pressure is essentially stable at the target pressure Pt. However, the time variation of the ejection pressure during the constant period Tc also includes slight fluctuations, with the ejection pressure sometimes exceeding and sometimes falling below the target pressure Pt.

[0132] Furthermore, the constant pressure period Tbc is composed of the transition period Tb and the constant period Tc. That is, the constant pressure period Tbc is the period from time tb to time td.

[0133] The descent period Td is the period from time td to time te when the coating liquid supply mechanism 8 stops spraying coating liquid from nozzle 71 (i.e., time te when the coating liquid supply mechanism 8 stops the actuation disc 816). That is, the spray pressure decreases to the initial pressure Pi between time td and time te, and at time te, the spraying of coating liquid from nozzle 71 stops.

[0134] Figure 6 This is a diagram illustrating an example of the calculations performed by the pressure evaluation unit in response to changes in ejection pressure over time. (See diagram for example.) Figure 6 As shown, the pressure evaluation unit 913 calculates the first derivative D1 of the time-varying ejection pressure by differentiating the ejection pressure over time. Furthermore, the pressure evaluation unit 913 calculates the second derivative D2 of the time-varying ejection pressure by differentiating the first derivative D1 over time. Additionally, the pressure evaluation unit 913 calculates the mean absolute error (MAE) and root mean square error (RMSE) based on the following formulas:

[0135] MAE(α, β) = (1 / n) (Σ|α-β|);

[0136] RMSE(α,β)=((1 / n) (Σ(α-β)) 2 )) 1 / 2 ;

[0137] n = number of data points.

[0138] Figure 7 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv1. Figure 7 The evaluation criteria are based on the error (ideal trapezoidal absolute error) between the trapezoidal waveform with an amplitude equivalent to the difference between the average ejection pressure during the constant period Tc (i.e., constant pressure Pm) and the initial pressure Pi, and the ejection pressure measurement data 99, to evaluate the time variation of the ejection pressure represented by the ejection pressure measurement data 99.

[0139] Specifically, a linear regression analysis is performed on the time variation of the ejection pressure between a specified lower reference pressure and a specified upper reference pressure that is greater than the lower reference pressure in Ta during the ascent period, and the ascent regression line Lr_R is calculated. This ascent regression line Lr_R increases linearly from the initial pressure Pi to the constant pressure Pm between time t11 and time t12.

[0140] Similarly, a linear regression analysis is performed on the time variation of the ejection pressure between the upper reference pressure and the lower reference pressure during the descent period Td, and the descent regression line Lr_F is calculated. The descent regression line Lr_F linearly decreases from the constant pressure Pm to the initial pressure Pi between time t13 and time t14.

[0141] In addition, 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, through a user input operation on the UI95 and stored in the storage unit 93. In the example here, the lower reference pressure is the pressure obtained by adding the 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 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.

[0142] In addition, for the interval from time ta to time t11, an initial approximation line Lr_s is set. The initial approximation line Lr_s is a line with a slope of 0 representing the initial pressure Pi. That is, the initial approximation line Lr_s is a line connecting the start time (time ta) when the coating liquid is ejected from the nozzle 71 to the start time of the ascending regression line Lr_R. In addition, depending on the state (slope) of the regression line, sometimes time t11 is earlier than time ta, and sometimes time t12 is later than time tb. As a result, when t11 < ta, the initial approximation line Lr_s is omitted.

[0143] In addition, for the interval from time t14 to time te, an end approximation line Lr_e is set. The end approximation line Lr_e is a line with a slope of 0 representing the initial pressure Pi. That is, the end approximation line Lr_e is a line connecting the end time of the descent regression line Lr_F to the end time (time te) when the coating liquid is ejected from the nozzle 71. In addition, when te < t14, the end approximation line Lr_e is omitted.

[0144] Furthermore, a constant line Lr_m is set for the interval from time t12 to time t13. The constant line Lr_m is a line with a slope of 0 representing the constant pressure Pm. That is, the constant line Lr_m is a line connecting the end time (time t12) of the ascending regression line Lr_R and the start time (time t13) of the descent regression line Lr_F, representing the constant pressure Pm.

[0145] In this way, an approximate waveform WF1 is calculated, which consists of an approximate straight line Lr_s at the start, an ascending regression line Lr_R, a constant line Lr_m, a descending regression line Lr_F, and an approximate straight line Lr_e arranged in a time series. Then, during the entire ejection period Tt from time ta to time te, the pressure evaluation unit 913 calculates the mean absolute error MAE (ideal trapezoidal absolute error) between the ejection pressure measurement data 99 and the approximate waveform WF1 as the feature quantity Fv1. In addition, the pressure evaluation unit 913 normalizes the feature quantity Fv1 to a range of 0 or more and 2 or less based on a prescribed threshold Th1 (for example, 0.05). Specifically, based on the following formula:

[0146] If Fv1 < Th1, then Fv1 = 0

[0147] If Fv1 ≥ Th1, then Fv1 = (Fv1 + 1 - Th1) × c1

[0148] The feature quantity Fv1 is transformed into a normalized feature quantity Fv1 (i.e., evaluation value V1). Here, the coefficient c1 is a normalization coefficient, which is preset to a value that converges the feature quantity Fv1 within a range of 2 or less (for example, 15).

[0149] According to the evaluation based on Figure 7 the feature quantity Fv1, when the temporal change of the ejection pressure during the entire ejection period Tt deviates significantly from the ideal shape (i.e., trapezoidal shape), a large score (i.e., poor evaluation) can be given to the ejection pressure.

[0150] Figure 8 is a diagram for explaining the evaluation item for evaluating the temporal change of the ejection pressure based on the feature quantity Fv2. Figure 8 The evaluation item evaluates the smoothness of the rise of the ejection pressure. Specifically, a curve regression analysis is performed on the temporal change of the ejection pressure between the lower reference pressure P2_l and the upper reference pressure P2_u, which is larger than the lower reference pressure P2_l, during the rise period Ta, and an ascending regression curve Nr is calculated. This curve regression analysis is performed by a quadratic curve.

[0151] 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's input operation on the UI95 and stored in the storage unit 93. In the example here, the upper reference pressure P2_u is a pressure obtained by adding the 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. The 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. Also, time t21 coincides with time ta, and time t22 is a time that is later than time ta and earlier than time tb.

[0152] In this way, the waveform WF2 formed by the rising regression curve Nr is calculated. Then, the pressure evaluation unit 913 calculates the root mean square error RMSE between the ejection pressure measurement data 99 and the waveform WF2 as the feature quantity Fv2 during the initial rising period Ta_s from time t21 to time t22. Also, the pressure evaluation unit 913 normalizes the feature quantity Fv2 to a range of 0 or more and 2 or less based on a prescribed threshold Th2 (for example, 0.05). Specifically, based on the following formula:

[0153] If Fv2 < Th2, then Fv2 = 0

[0154] If Fv2 ≥ Th2, then Fv2 = 2

[0155] The feature quantity Fv2 is transformed into a normalized feature quantity Fv2 (that is, the evaluation value V2).

[0156] According to the evaluation based on Figure 8 the feature quantity Fv2, in the case where the ejection pressure at the beginning of ejection is abnormal due to the influence of the state before the nozzle 71 starts ejecting the coating liquid, a large score (that is, a poor evaluation) can be given to the ejection pressure. Also, the curve that can be used for curve regression analysis is not limited to a quadratic curve, and other curves such as an exponential function can also be used.

[0157] Figure 9 It is a diagram for explaining the evaluation item for evaluating the time change of the ejection pressure based on the feature quantity Fv3. Figure 9 The evaluation item evaluates whether the rising period Ta converges within a certain period. Specifically, the pressure evaluation unit 913 calculates the length (= tb - ta) of the rising period Ta from time ta to time tb required for the ejection pressure to increase from the initial pressure Pi to the target pressure Pt as the feature quantity Fv3. Also, the pressure evaluation unit 913 normalizes the feature quantity Fv3 to a range of 0 or more and 1 or less based on a prescribed threshold Th3 (for example, 350 ms). Specifically, based on the following formula:

[0158] If Fv3 < Th3, then Fv3 = 0

[0159] If Fv3 ≥ Th3, then Fv3 = 1

[0160] Transform the feature quantity Fv3 into a standardized feature quantity Fv3 (i.e., evaluation value V3).

[0161] Based on Figure 9 the evaluation of the feature quantity Fv3, a large score (i.e., poor evaluation) can be given to the ejection pressure that takes time to rise to the target pressure Pt.

[0162] Figure 10A is a diagram for explaining an evaluation item for evaluating the time change of the ejection pressure based on the feature quantity Fv4, Figure 10B [[ID=I9]]is a diagram showing an example of the time change of the ejection pressure determined to be inappropriate through the evaluation based on the feature quantity Fv4. Figure 10A The evaluation item evaluates whether there is an abnormality in the rise of the ejection pressure. Specifically, the pressure evaluation unit 913 calculates the first derivative D1 of the time change of the ejection pressure during the rise period Ta from time ta to time tb, and obtains the first derivative waveform WF4.

[0163] [[ID=ID=24]]Then, the pressure evaluation unit I913 obtains the number of times the first derivative waveform WF4 crosses a specified threshold Th4 as the feature quantity Fv4 during the rise period Ta. In Figure 10A the example, the first derivative waveform WF4 and the threshold Th4 (for example, 0.002) cross at time t41 and time t42 respectively, and the number of crossings (feature quantity Fv4) is 2 times. In addition, the pressure evaluation unit 913 normalizes the feature quantity Fv4 to a range of 0 or more and 1 or less. Specifically, based on the following formula:

[0164] If Fv4 ≤ 2, then Fv4 = 0 <ID=31]

[0165] If Fv4 > 2, then Fv4 = 1

[0166] Transform the feature quantity Fv4 into a standardized feature quantity Fv4 (i.e., evaluation value V4).

[0167] Based on Figure 10A the evaluation of the feature quantity Fv4, when there is a step in the time change of the ejection pressure during the rise period Ta (for example, as shown in Figure 10B ), a large score (i.e., poor evaluation) can be given to the ejection pressure.

[0168] Figure 11A is a diagram for explaining an evaluation item for evaluating the time change of the ejection pressure based on the feature quantity Fv5, Figure 11BThis is a graph showing an example of the time variation of ejection pressure that was judged to be inappropriate based on the evaluation of the characteristic quantity Fv5. Figure 11A The evaluation item assesses whether there are any abnormalities in the rise of the ejection pressure. Specifically, the pressure evaluation unit 913 calculates the second derivative D2 of the time change of the ejection pressure during the rise period Ta from time ta to time tb, and obtains the second derivative waveform WF5.

[0169] Then, during the rising period Ta, the pressure evaluation unit 913 calculates the number of times the absolute value of the second differential waveform WF5 intersects with a predetermined threshold Th5 as the characteristic quantity Fv5. Figure 11A In the example, the absolute value of the second-order differential waveform WF5 and the threshold Th5 (e.g., 0.0002) intersect at times t51, t52, t53, and t54, respectively, with the number of intersections (feature quantity Fv5) being 4. Furthermore, the pressure evaluation unit 913 normalizes the feature quantity Fv5 to a range greater than 0 and less than 1. Specifically, based on the following formula:

[0170] If Fv5=4, then Fv5=0

[0171] If Fv5 ≠ 4, then Fv5 = 1

[0172] Transform the feature quantity Fv5 into a standardized feature quantity Fv5 (i.e., the evaluation value V5).

[0173] Based on Figure 11A The evaluation of the characteristic quantity Fv5, in the case where the time change of the ejection pressure in Ta during the rise produces a step (e.g., as... Figure 11B As shown), it is possible to assign a high score (i.e., a poor rating) to the ejection pressure.

[0174] Figure 12 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv6. Figure 12 The evaluation item assesses whether the rise in ejection pressure stalls in the latter half. Specifically, the pressure evaluation unit 913 calculates the second derivative D2 of the time change of ejection pressure during the rise period Ta from time ta to time tb, and obtains the second derivative waveform WF6.

[0175] Furthermore, during the rising period Ta, the pressure evaluation unit 913 respectively obtains the time T_1st when the second differential waveform WF6 is greater than a specified positive threshold (Th5), and the time T_2nd when the second differential waveform WF6 is less than a specified 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 the absolute value of the threshold Th5 used in the evaluation of the above-described characteristic quantity Fv5. Then, the pressure evaluation unit 913 obtains the ratio of their times (=T_1st / T_2nd) as the characteristic quantity Fv6. Furthermore, the pressure evaluation unit 913 transforms the characteristic quantity Fv6 based on the following formula.

[0176] Fv6 = |1 - Fv6|

[0177] In addition, the pressure evaluation unit 913 uses a specified threshold Th6 (for example, 0.2) to normalize the thus-transformed characteristic quantity Fv6 to a range of 0 or more and 2 or less. Specifically, based on the following formula:

[0178] If Fv6 < Th6, then Fv6 = 0

[0179] If Fv6 ≥ Th6, then Fv6 = f(Fv6)

[0180] f(γ) = 4 × γ - 0.8​​​​​​​​​​​​​The evaluation item evaluates the sharpness of the time change of the ejection pressure at the end of the rise. Specifically, linear regression analysis is performed on the time change of the ejection pressure between the lower reference pressure P7_l and the upper reference pressure P7_u greater than the lower reference pressure P7_l during the rise period Ta, 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 ejection pressure increases from the lower reference pressure P7_l to the upper reference pressure P7_u between time t71 and time t72.

[0184] The regression line Lr at the end of the rise increases with the passage of time and reaches a constant pressure Pm (the average value of the ejection pressure during the constant period Tc) at time t73. Thus, for the interval from time t71 to time t73, the regression line Lr at the end of the rise is set. Further, the pressure evaluation unit 913 sets an extended setting line Lm with a slope of 0 representing the constant pressure Pm between time t73 and time tb. As described above, time tb is the time when the ejection pressure reaches the target pressure Pt, corresponding to the end time of the rise period Ta. That is, the extended setting line Lm is set to extend from the end time of the regression line Lr at the end of the rise to the end time of the rise period Ta. In addition, when tb < t73, the extended setting line Lm is omitted.

[0185] Thus, an approximate waveform WF7 composed of the regression line Lr at the end of the rise and the extended setting line Lm arranged in time series is calculated. Then, the pressure evaluation unit 913 calculates the value of the difference between the ejection pressure measurement data 99 and the approximate waveform WF7 as a feature quantity Fv7 during the end-of-rise period Ta_e from the time t72 when the ejection 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 root mean square error is calculated based on the following formula.

[0186] Fv7 = (Σ(P_measure - WF7) 2 × W) 1 / 2

[0187] P_measure = ejection pressure measurement data 99

[0188] W = 1 within the range of tb ≤ t73 + 2 × Tw

[0189] W = w within the range of tb > t73 + 2 × Tw [[ID=…]]

[0190] w is a weighting coefficient greater than 1, for example, 10.

[0191] In addition, the pressure evaluation unit 913 normalizes the feature amount Fv7 to a range of 0 or more and 2 or less based on a prescribed threshold Th7 (for example, 0.6). Specifically, based on the following formula:

[0192] If Fv7 < Th7, then Fv7 = 0

[0193] If Fv7 ≥ Th7, then Fv7 = Fv7 / c7

[0194] c7 is an arbitrary positive constant, for example, 1.1

[0195] The feature amount Fv7 is transformed into a normalized feature amount Fv7 (that is, the evaluation value V7).

[0196] According to the evaluation based on Figure 13 When the time change of the ejection pressure shows a weak upward trend and a circular waveform, a large score (that is, a poor evaluation) can be given to the ejection pressure.

[0197] Figure 14 is a diagram for explaining the evaluation item for evaluating the time change of the ejection pressure based on the feature amount Fv8. Figure 14 The evaluation item evaluates the degree of overshoot that occurs during the rise of the ejection pressure. Specifically, at the moment t81 when the ejection pressure reaches the maximum value Pmax, the pressure evaluation unit 913 obtains the sign (positive / negative) of the second derivative D2 of the ejection pressure. Then, the pressure evaluation unit 913 calculates the moment t82 when the sign of the second derivative D2 of the ejection pressure switches twice from the sign at the moment t81. Then, the time change of the ejection pressure during the initial vibration period Tb_s from the moment t81 to the moment t82 is evaluated.

[0198] Specifically, the minimum value P8min of the time change of the ejection pressure during the initial vibration period Tb_s is obtained, and the pressure of the smaller one between the constant pressure Pm and the pressure P8min is selected as the target pressure Pg. And based on the difference between the maximum pressure Pmax and the target pressure Pg, that is, the following formula:

[0199] Fv8 = Pmax - Pg

[0200] The feature amount Fv8 is calculated.

[0201] Furthermore, the pressure evaluation unit 913 normalizes the feature amount Fv8 to a range of 0 or more and 2 or less using a prescribed threshold Th8 (for example, 0.035). Specifically, based on the following formula:

[0202] If Fv8 < Th8, then Fv8 = 0

[0203] If Fv8 ≥ Th8, then Fv8 = Fv8 / c8

[0204] c8 is any positive constant, for example, 0.12.

[0205] Transform the feature quantity Fv8 into a standardized feature quantity Fv8 (i.e., the evaluation value V8).

[0206] Based on Figure 14 The evaluation of the characteristic quantity Fv8 can assign a large score (i.e., a poor evaluation) to the ejection pressure when the time change of the ejection pressure indicates a strong upward trend and a large overshoot.

[0207] Figure 15 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv9. Figure 15 The evaluation item assesses the stability of the time variation of the ejection pressure in the transition period Tb. Specifically, the pressure evaluation unit 913 evaluates the average value of the ejection pressure in the transition period Tb and the ejection pressure in the constant period Tc, i.e., the constant pressure Pm, based on the following formula:

[0208] Fv9 = RMSE(P_measure, Pm)

[0209] P_measure = Ejection pressure measurement data 99

[0210] Calculate the root mean square error RMSE(P_measure, Pm) as a feature quantity Fv9.

[0211] Furthermore, the pressure evaluation unit 913 standardizes the characteristic quantity Fv9 to a range of 0 or higher and 2 or lower. Specifically, based on the following formula:

[0212] Fv9=Fv9 / c9

[0213] c9 is any positive constant, such as 0.04.

[0214] Transform the feature quantity Fv9 into a standardized feature quantity Fv9 (i.e., the evaluation value V9).

[0215] Based on Figure 15 The evaluation of the characteristic quantity Fv9, in the case that the time change of the ejection pressure represents the damped oscillation in Tb during the transition period, can assign a large score (i.e., a poor evaluation) to the ejection pressure.

[0216] Figure 16 This is a graph used to illustrate the evaluation items for evaluating the time change of ejection pressure based on the characteristic quantity Fv10. Figure 16The evaluation item evaluates the stability of the time change of the ejection pressure in Tbc during the constant pressure period. Specifically, the pressure evaluation unit 913 obtains the maximum value Pmax and the minimum value P10min of the ejection pressure within the constant pressure period Tbc. Then, the pressure evaluation unit 913 is based on the difference between the maximum pressure Pmax and the minimum pressure P10min during the constant pressure period Tbc, that is, the following formula:

[0217] Fv10 = Pmax - P10min

[0218] Calculate the characteristic quantity Fv10.

[0219] Furthermore, the pressure evaluation unit 913 uses the threshold value Th10 (for example, 0.12) to normalize the characteristic quantity Fv10 to a range of 0 or more and 2 or less. Specifically, based on the following formula:

[0220] If Fv10 < Th10, then Fv10 = 0

[0221] If Fv10 ≥ Th10, then Fv10 = Fv10 / Th10

[0222] Transform the characteristic quantity Fv10 into a normalized characteristic quantity Fv10 (that is, the evaluation value V10).

[0223] According to the evaluation based on Figure 16 the characteristic quantity Fv10, when the time change of the ejection pressure shows a large deviation during the constant period Tc that has a large impact on the film thickness of the coating liquid, a large score (that is, a poor evaluation) can be given to the ejection pressure.

[0224] Figure 17 is a diagram for explaining the evaluation item for evaluating the time change of the ejection pressure based on the characteristic quantity Fv11. <00A0547>The evaluation item evaluates the linearity of the time change of the ejection pressure during the rising period Ta. Specifically, during the rising period Ta, the pressure rising period Tar from the moment t111 when the ejection pressure becomes the lower reference pressure P11_l to the moment t113 when the ejection pressure becomes the upper reference pressure P11_u that is larger than the lower reference pressure P11_l is obtained. Here, the lower reference pressure P11_l is the pressure obtained by adding the 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 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. The ejection pressure increases from the lower reference pressure P11_l to the upper reference pressure P11_u between the moment t111 and the moment t113.

[0225] Furthermore, the pressure evaluation unit 913 obtains specific data Dm that satisfies a specified condition from the ejection pressure measurement data 99 between the lower reference pressure P11_l and the upper reference pressure P11_u. The specified condition will be described in detail below.

[0226] From the ejection pressure measurement data 99, one measurement data between the lower reference pressure P11_l and the upper reference pressure P11_u is selected as candidate data Dc. And, a linear regression analysis is performed on the time variation of the ejection pressure between the measurement data Dl representing the lower reference pressure P11_l and the candidate data Dc, and the obtained regression line is set as the approximate line Lr_1. In addition, a linear regression analysis is performed on the time variation of the ejection pressure between the measurement data Du representing the upper reference pressure P11_u and the candidate data Dc, and the obtained regression line is set as the approximate line Lr_2. Furthermore, in the interval between the measurement data Dl and the candidate data Dc, the root mean square error RMSE(P_measure, Lr1) between the time variation of the ejection pressure and the approximate line Lr_1 is obtained. Similarly, in the interval between the candidate data Dc and the measurement data Du, the root mean square error RMSE(P_measure, Lr2) between the time variation of the ejection pressure and the approximate line Lr_2 is obtained. Here, P_measure represents the ejection pressure measurement data 99.

[0227] Furthermore, their sum is obtained based on the following formula:

[0228] Er = RMSE(P_measure, Lr1) + RMSE(P_measure, Lr2)

[0229] Then, the candidate data Dc in the ejection pressure measurement data 99 for which Er is the smallest is specified as the specific data Dm.

[0230] Then, the slopes of the above approximate lines Lr_1 and Lr_2 obtained for the specific data Dm are set as K1 and K2, respectively, and the characteristic quantity Fv11 is calculated based on the following formula.

[0231] If K1 > K2, then Fv11 = 1 - K1 / K2

[0232] [[ID=2']]If K1 ≤ K2, then Fv11 = 1 - K2 / K1

[0233] [[ID=2']]In addition, the pressure evaluation unit 913 normalizes the characteristic quantity Fv11 to a range of 0 or more and 1 or less based on a specified threshold Th11 (for example, 0.25). Specifically, based on the following formula:

[0234] [[ID=2']]If Fv11 < Th11, then Fv11 = 0

[0235] It should be noted that in the above translation, in the formula in item 21, the original text has a wrong numbering. It should be item 21 instead of item 2'. The same correction is made in the subsequent translation for the formula in item 24.If Fv11 ≥ Th11, then Fv11 = f(Fv11)

[0236] f(γ) = 4 × γ - 1

[0237] The characteristic quantity Fv11 is transformed into a standardized characteristic quantity Fv11 (i.e., evaluation value V11). In addition, the function f(γ) with γ as a variable is not limited to the example here and can be arbitrarily changed.

[0238] According to the evaluation based on Figure 17 the characteristic quantity Fv11, when the time change of the ejection pressure shows poor linearity during the rising period Ta, a large score (i.e., a poor evaluation) can be given to the ejection pressure.

[0239] Figure 18 is a diagram for explaining the evaluation item for evaluating the time change of the ejection pressure based on the characteristic quantity Fv12. Figure 18 The evaluation item evaluates the sharpness of the time change of the ejection pressure at the end of the rise. Specifically, a linear regression analysis is performed on the time change of the ejection pressure between the lower reference pressure P12_l and the upper reference pressure P12_u greater than the lower reference pressure P12_l during the rising period Ta to calculate the regression line Lr at the end of the rise. 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 ejection pressure increases from the lower reference pressure P12_l to the upper reference pressure P12_u between time t121 and time t122.

[0240] The regression line Lr at the end of the rise increases with time and reaches the target pressure Pt at time t123. Thus, for the interval from time t121 to time t123, the regression line Lr at the end of the rise is set. Furthermore, the pressure evaluation unit 913 sets an extended setting line Lm with a slope of 0 representing the target pressure Pt between time t123 and time tb. As described above, time tb is the time when the ejection pressure reaches the target pressure Pt and corresponds to the end time of the rising period Ta. That is, the extended setting line Lm is set to extend from the end time of the regression line Lr at the end of the rise to the end time of the rising period Ta. In addition, when tb < t123, the extended setting line Lm is omitted.

[0241] In this way, an approximate waveform WF12 composed of the regression line Lr at the end of the rise arranged in time series and the extended setting line Lm is calculated. Then, during the end-of-rise period Ta_e from the time t122 when the ejection pressure is 90% of the target pressure Pt to the time tb when it becomes 100%, the pressure evaluation unit 913 calculates the value representing the difference between the ejection pressure measurement data 99 and the approximate waveform WF12 as the feature quantity Fv12. Specifically, the root mean square error sum is calculated based on the following formula.

[0242] Fv12 = (Σ(P_measure - WF12) 2 ) 1 / 2

[0243] P_measure = ejection pressure measurement data 99

[0244] In addition, the pressure evaluation unit 913 normalizes the feature quantity Fv12 to a range of 0 or more and 1 or less based on a prescribed threshold Th12 (for example, 0.8). Specifically, based on the following formula:

[0245] If Fv12 < Th12, then Fv12 = 0

[0246] If Fv12 ≥ Th12, then Fv12 = f(Fv12)

[0247] f(γ) = 5 × γ - 4

[0248] The feature quantity Fv,2 is transformed into a normalized feature quantity Fv12 (that is, the evaluation value V12). In addition, the function f(γ) with γ as a variable is not limited to the example here and can be arbitrarily changed.

[0249] According to the evaluation based on Figure 18 the feature quantity Fv12, when the time change of the ejection pressure shows a weak upward trend and has a circular waveform as a whole, a large score (that is, a poor evaluation) can be given to the ejection pressure.

[0250] Figure 19 It is a diagram for explaining the evaluation item for evaluating the time change of the ejection pressure based on the feature quantity Fv13. Figure 19The evaluation item evaluates the sharpness of the time change of the ejection pressure at the end of the rise. Specifically, linear regression analysis is performed on the time change of the ejection pressure between the lower reference pressure P13_l and the upper reference pressure P13_u greater than the lower reference pressure P13_l during the rise period Ta, and the regression line Lr at the end of the rise is calculated. Here, the lower reference pressure P13_l 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, and the upper reference pressure P13_u is the pressure obtained by adding the pressure of 95% of the absolute value of the difference between the initial pressure Pi and the target pressure Pt to the initial pressure Pi. The ejection pressure increases from the lower reference pressure P13_l to the upper reference pressure P13_u between time t131 and time t132.

[0251] The regression line Lr at the end of the rise increases with the passage of time and reaches the target pressure Pt at time t133. In this way, the regression line Lr at the end of the rise is set for the interval from time t131 to time t133. Furthermore, the pressure evaluation unit 913 sets an extended setting line Lm with a slope of 0 representing the target pressure Pt between time t133 and time tb. As described above, time tb is the time when the ejection pressure reaches the target pressure Pt and corresponds to the end time of the rise period Ta. That is, the extended setting line Lm is set to extend from the end time of the regression line Lr at the end of the rise to the end time of the rise period Ta. In addition, when tb < t133, the extended setting line Lm is omitted.

[0252] In this way, an approximate waveform WF13 composed of the regression line Lr at the end of the rise and the extended setting line Lm arranged in time series is calculated. Then, the pressure evaluation unit 913 calculates the value representing the difference between the ejection pressure measurement data 99 and the approximate waveform WF13 as a feature quantity Fv13 during the end-of-rise period Ta_e from time t132 when the ejection pressure is 95% of the target pressure Pt to time tb when it becomes 100%. Specifically, the root mean square error sum is calculated based on the following formula.

[0253] Fv13 = (Σ(P_measure - WF13) 2 ) 1 / 2

[0254] P_measure = ejection pressure measurement data 99

[0255] In addition, the pressure evaluation unit 913 normalizes the feature quantity Fv13 to a range of 0 or more and 1 or less based on a prescribed threshold Th13 (for example, 0.1). Specifically, based on the following formula:

[0256] If Fv13 < Th13, then Fv13 = 0

[0257] If Fv13≥Th13, then Fv13=f(Fv13).

[0258] f(γ) = (10 × γ - 1) / 3

[0259] The feature quantity Fv13 is transformed into a standardized feature quantity Fv13 (i.e., the evaluation value V13). Furthermore, the function f(γ) with γ as the variable is not limited to the example here and can be arbitrarily changed.

[0260] Based on Figure 19 The evaluation of the characteristic quantity Fv13 can assign a large score (i.e., a poor evaluation) to the ejection pressure when the time change of the ejection pressure shows a weak upward trend and, locally, a circular waveform.

[0261] Figure 20 This is a graph used to illustrate the evaluation items for evaluating the time-varying changes in ejection pressure based on the characteristic quantity Fv14. Figure 20 The evaluation item assesses the degree of overshoot that occurs during the rise of ejection pressure. Specifically, at the moment t141 when the ejection pressure reaches its maximum value Pmax, the pressure evaluation unit 913 calculates the sign (positive / negative) of the second derivative D2 of the ejection pressure. Then, the pressure evaluation unit 913 calculates the moment t142 when the sign of the second derivative D2 of the ejection pressure switches twice from the sign at time t141. Then, the time change of the ejection pressure during the initial oscillation period Tb_s from time t141 to time t142 is evaluated.

[0262] Specifically, the minimum time variation of the ejection pressure within Tb_s during the initial vibration period, P14min, is determined. Then, the difference between the maximum pressure Pmax and the constant pressure Pm is calculated based on the following formula.

[0263] OVER=Pmax-Pm

[0264] The difference between constant pressure Pm and minimum pressure P14min is calculated based on the following formula.

[0265] UNDER = Pm - P14min

[0266] Then, based on the sum of OVER and UNDER, i.e. the following formula, the characteristic quantity Fv14 is calculated.

[0267] Fv14=OVER+UNDER

[0268] Furthermore, the pressure evaluation unit 913 uses a prescribed threshold Th14 (e.g., 0.01) to standardize the characteristic quantity Fv14 to a range of 0 or higher and 1 or lower. Specifically, it is based on the following formula:

[0269] If Fv14 < Th14, then Fv14 = 0

[0270] If Fv14 ≥ Th14, then Fv14 = f(Fv14)

[0271] f(γ) = (100×γ - 1) / 9

[0272] The characteristic quantity Fv14 is transformed into a standardized characteristic quantity Fv14 (i.e., evaluation value V14).

[0273] Based on Figure 20 the evaluation of the characteristic quantity Fv14, the error from the target pressure Pt is calculated respectively for the overshoot points and the ringing (the phenomenon that the pressure drops due to the reaction after a sudden rise) points. Therefore, in the case where the time change of the ejection pressure shows a large overshoot or ringing (ring back), a large score (i.e., poor evaluation) can be given to the ejection pressure.

[0274] The above is the description of each evaluation item that can be used to evaluate the time change of the ejection pressure, and the characteristic quantities Fv1 - Fv14 or evaluation values V1 - V14 extracted in each evaluation item. In addition, in the measurement result evaluation of step S102, the evaluation based on all the above evaluation items is not always performed, but the number of evaluation items to be performed changes according to the appropriateness of the time change of the ejection pressure. Next, this point will be explained.

[0275] Figure 21 is a flowchart showing the details of the measurement result evaluation, Figure 22 is a diagram schematically showing an example of the actions performed according to the Figure 21 flowchart. Figure 21 The measurement result evaluation of

[0276] is performed by the pressurization evaluation unit 913. In addition, in this measurement result evaluation, N evaluation stages (N is an integer of 2 or more, and in this example, N = 3) are prepared, and these N evaluation stages are executed in sequence. Figure 22 As Figure 7 shown, the evaluation item based on the characteristic quantity Fv1 is assigned to the first (I = 1) evaluation stage. The evaluation item based on the characteristic quantities Fv2 - Fv10 is assigned to the second (I = 2) evaluation stage. The evaluation item based on the characteristic quantities Fv11 - Fv14 is assigned to the third (I = 3) evaluation stage. And in each evaluation stage I, the time change of the ejection pressure is evaluated based on the assigned evaluation item. In addition, I is the number for identifying the evaluation stage, and is an integer of 1 or more and N or less. Figures 8 to 16 Figures 17 to 20 shown,

[0277] ​In this way, different evaluation items are assigned to N evaluation stages. Further, different ranges (value ranges) of the final evaluation value Vf are assigned to the N evaluation stages. Therefore, as will be described below, for the ejection pressure evaluated based on the evaluation stages up to the I-th stage, the final evaluation value Vf within the value range assigned to the I-th evaluation stage is given.

[0278] As Figure 21 shown, in step S201, I is reset to 0, and in step S202, I is incremented by 1 only. In step S203, the ejection pressure is evaluated based on the evaluation items of the I-th evaluation stage. Here, since I = 1, the characteristic quantity Fv1 is calculated, and the evaluation value V1 is obtained. Then, this evaluation value V1 becomes the evaluation result of the first evaluation stage.

[0279] 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 temporal change of the ejection pressure is good. When the evaluation result (evaluation value V1) is above the prescribed assignment threshold At1, it is judged as bad (no) in step S205, the evaluations of the 2nd to 3rd evaluation stages (i.e., the evaluation stages after the I-th stage) are omitted, and the process proceeds to step S206.

[0280] In step S206, the final evaluation value Vf corresponding to the number of executed evaluation stages (I) and the evaluation result in the I-th evaluation stage is determined. In the example here, since only the first evaluation stage has been executed, according to Figure 22 the example, the value obtained by adding the minimum evaluation value (= 20) of the value range for the first evaluation stage to the evaluation result (evaluation value V1) of the first evaluation stage is determined as the final evaluation value Vf. Thus, the final evaluation value Vf within the value range (20 to 40) set for the first evaluation stage is given to the temporal change of the ejection pressure.

[0281] Alternatively, when the evaluation result (evaluation value V1) in step S204 is less than the assignment threshold At1, it is judged as good (yes) in step S205, and the process returns to step S202, where I is incremented by 1 only.

[0282] Then, in step S203, the ejection pressure is evaluated based on the evaluation items of the I-th evaluation stage. Here, since I = 2, the characteristic quantities Fv2 to Fv10 are calculated, and the evaluation values V2 to V10 are obtained. Then, the sum of the evaluation values V2 to V10 becomes the evaluation result of the second evaluation stage. That is, the sum of the evaluation values belonging to the evaluation items of the I-th evaluation stage becomes the evaluation result in the I-th evaluation stage.

[0283] In step S204, it is judged whether I = N. Here, since I < N, step S205 is entered. In step S205, based on the evaluation result in step S203, it is judged whether the temporal change of the ejection pressure is good. When the evaluation result (the sum of evaluation values V2 to V10) is greater than or equal to a prescribed distribution threshold At2, it is judged as bad (no) in step S205, the evaluation of the third evaluation stage is omitted, and step S206 is entered.

[0284] In step S206, the final evaluation value Vf corresponding to the number of executed evaluation stages (I) and the evaluation result in the I-th evaluation stage is determined. In the example here, since the first to second evaluation stages have been executed, according to Figure 22 the example, the value obtained by adding the minimum evaluation value (= 4) for the value range of the second evaluation stage to the evaluation result (the sum of evaluation values V2 to V10) of the second evaluation stage is determined as the final evaluation value Vf. Thus, the final evaluation value Vf within the value range (4 to 20) set for the second evaluation stage is assigned to the temporal change of the ejection pressure.

[0285] Or, when the evaluation result (the sum of evaluation values V2 to V10) in step S205 is less than the distribution threshold At2, it is judged as good (yes) in step S205, and step S202 is returned, and I is only incremented by 1.

[0286] Then, in step S203, the ejection pressure is evaluated based on the evaluation items of the I-th evaluation stage. Here, since I = 3, the characteristic quantities Fv11 to Fv14 are calculated, and the evaluation values V11 to V14 are obtained. Then, similarly to above, the sum of the evaluation values V11 to V14 becomes the evaluation result of the third evaluation stage.

[0287] In step S204, it is judged whether I = N. Here, since I = N, step S206 is entered. In step S206, the final evaluation value Vf corresponding to the number of executed evaluation stages (I) and the evaluation result in the I-th evaluation stage is determined. In the example here, since the first to third evaluation stages have been executed, according to Figure 22 the example, the value obtained by adding the minimum evaluation value (= 0) for the third evaluation stage to the evaluation result (the sum of evaluation values V11 to V14) of the third evaluation stage is determined as the final evaluation value Vf. Thus, the final evaluation value Vf within the value range (0 to 4) set for the third evaluation stage is assigned to the temporal change of the ejection pressure.

[0288] In the embodiments described above, N evaluation stages, from the 1st to the Nth, are provided to evaluate the ejection pressure according to different evaluation items, and the evaluation stages from the 1st to the Nth can be executed sequentially. However, if the ejection pressure is determined to be appropriate based on the evaluation items involved in the 1st evaluation stage ("Yes" in step S205), the evaluation of the ejection pressure based on the evaluation items involved in the (1+1)th evaluation stage is performed. On the other hand, if the ejection pressure is determined to be inappropriate based on the evaluation items involved in the 1st evaluation stage ("No" in step S205), the evaluation of the ejection pressure based on the evaluation stages following the 1st evaluation stage is not performed (i.e., it is omitted). That is, when evaluating the ejection pressure sequentially according to the 1st to Nth evaluation stages, if the ejection pressure is determined to be inappropriate in any evaluation stage, the evaluation of the subsequent evaluation stages is not performed. Therefore, it is possible to evaluate the spray pressure applied to the coating liquid in order to spray the coating liquid from the nozzle 71 within a reasonable time corresponding to whether the spray pressure is appropriate.

[0289] Furthermore, depending on the number (I) of evaluation stages in the N evaluation stages that performed the evaluation of the ejection pressure, different final evaluation values ​​Vf (evaluation values) are assigned to the ejection pressure. In this structure, a better final evaluation value Vf can be assigned to the ejection pressure that has more evaluation stages performed, and an appropriate final evaluation value Vf can be assigned to the ejection pressure that corresponds to whether the ejection pressure is appropriate or not.

[0290] Furthermore, in the first evaluation stage, the spraying pressure is measured during the spraying period Tt (first period, evaluation period) from the start of spraying the coating liquid (treatment liquid) from nozzle 71 to the end of spraying the coating liquid from nozzle 71 (step S101). Then, the ideal trapezoidal absolute error of the time change of the spraying pressure during the entire spraying period Tt is extracted as a characteristic quantity Fv1 (first characteristic quantity, overall characteristic quantity), and the time change of the spraying pressure is evaluated based on this characteristic quantity Fv1 (step S102). Thus, the appropriateness of the spraying pressure during the entire spraying period Tt from the start of spraying the coating liquid from nozzle 71 to the end can be reflected in the evaluation of the spraying pressure.

[0291] In addition, such as Figure 7 As shown, the characteristic quantity Fv1 represents the difference between the approximate waveform WF1 (the first approximate waveform), which approximates the time change of the ejection pressure during the entire ejection period Tt, and the time change of the ejection pressure during the entire ejection period Tt. In this structure, the ejection pressure during the entire ejection period Tt can be appropriately evaluated based on the approximate waveform WF1 of the time change of the ejection pressure during the entire ejection period Tt, from the start of ejection of the coating liquid from nozzle 71 to the end.

[0292] In particular, the approximate waveform WF1 has:

[0293] The rising regression line Lr_R (approximate rising line) is a linear approximation of the time change of the spray pressure that increases with time after the coating liquid is sprayed from nozzle 71. It is obtained by linearly approximating the time change of the spray pressure that increases with time, from the initial pressure Pi (spray start pressure) to a constant pressure Pm that is greater than the initial pressure Pi.

[0294] Initially, it is approximately a straight line Lr_s, set between the starting moment (time ta) when the coating liquid is sprayed from nozzle 71 and the rising regression line Lr_R, and represents the initial pressure Pi;

[0295] The descending regression line Lr_F (descending approximation line) is a linear approximation of the time change of the spray pressure that decreases with the passage of time before the coating liquid is sprayed from nozzle 71. It is obtained by linearly reducing the constant pressure Pm with the passage of time to an initial pressure Pi (spray end pressure) that is smaller than the constant pressure Pm.

[0296] The approximate straight line Lr_e at the end is set between the descending regression line Lr_F and the end time (time te) when the coating liquid is ejected from nozzle 71, and represents the initial pressure Pi (ejection end pressure).

[0297] The constant straight line Lr_m connects the ascending regression line Lr_R and the descending regression line Lr_F to each other, and represents the constant pressure Pm.

[0298] In this structure, a trapezoidal waveform is used to approximate the time change of the spray pressure during the entire spraying period Tt from the start of spraying the coating liquid from the nozzle 71 to the end, thereby enabling an appropriate evaluation of the spray pressure during the entire spraying period Tt.

[0299] Furthermore, in the second evaluation stage, characteristic quantities Fv2 to Fv10 (second characteristic quantities) of the time change of the ejection pressure during a period shorter than the ejection period Tt (second period) are extracted, and the time change of the ejection pressure is evaluated based on characteristic quantities Fv2 to Fv10 (step S102). In this structure, the ejection pressure can be evaluated with high accuracy based on the time change of the ejection pressure during a period shorter than the ejection period Tt from the start of ejection of the coating liquid from the nozzle 71 to the end.

[0300] In addition, Figure 8In the evaluation items shown, the ejection pressure is evaluated during a predetermined initial rising period Ta_s (second period) from the start of ejection of the coating liquid from nozzle 71. During this initial rising period Ta_s, the ejection pressure increases over time, and a characteristic quantity Fv2 (second characteristic quantity) is extracted as the difference between the rising regression curve Nr representing the time change of the ejection pressure during the initial rising period Ta_s and the time change of the ejection pressure during the initial rising period Ta_s. In this structure, the ejection pressure can be evaluated by considering the time change of the ejection pressure after the initial ejection of the coating liquid from nozzle 71.

[0301] Furthermore, the ejection pressure during the rising period Ta (second period), from the start of ejecting the coating liquid from nozzle 71 until the ejection pressure increases to the target pressure Pt (specified pressure), is evaluated. In this structure, the ejection pressure can be evaluated by taking into account the time change of the ejection pressure during the rising period Ta.

[0302] Specifically, in Figure 9 In the evaluation project shown, the length of Ta during the rise is extracted as a feature quantity Fv2 (the second feature quantity). In this structure, the rise rate of the ejection pressure can be taken into account to evaluate the ejection pressure.

[0303] In addition, Figure 10A and Figure 10B In the evaluation project shown, during the rise period Ta, the number of times the first derivative D1 of the time change of the ejection pressure intersects with a predetermined threshold Th4 is extracted as a feature quantity Fv4 (the second feature quantity). In this structure, the smoothness of the time change of the ejection pressure during the rise period can be taken into account to evaluate the ejection pressure.

[0304] Furthermore, in the evaluation project shown in Figure 11, during the rise period Ta, the number of times the absolute value of the second derivative D2 of the time-varying ejection pressure intersects with a predetermined threshold Th5 is used as a feature quantity Fv5 (the second feature quantity). In this structure, the smoothness of the time-varying ejection pressure during the rise period Ta can be taken into account to evaluate the ejection pressure.

[0305] In addition, Figure 12 In the evaluation items shown, during the rise period Ta, the ratio of the second derivative D2 of the ejection pressure over time to a specified positive threshold (Th5) for the time T_1st, and the ratio of the second derivative D2 of the ejection pressure over time to a negative threshold (-Th5) with the same absolute value as the positive threshold for the time T_2nd, is extracted as a characteristic quantity Fv6 (the second characteristic quantity). This structure allows for the evaluation of ejection pressure by considering the difference in the time variation of ejection pressure during the initial and final stages of the rise period Ta.

[0306] In addition, Figure 13In the evaluation items shown, the ejection pressure during the final rise period (Ta_e, the second period) before the ejection pressure increases to the target pressure Pt (specified pressure) is evaluated. Specifically, a feature quantity Fv7 (the second feature quantity) is extracted, representing the difference between the approximate waveform WF7 (approximate waveform at the end of the rise period) that approximates the time change of the ejection pressure during the final rise period (Ta_e) and the time change of the ejection pressure during the final rise period (Ta_e). This approximate waveform WF7 consists of the final rise regression line Lr (approximate straight line at the end of the rise period) and the extended setting line Lm. The final rise regression line Lr overlaps with an approximate curve obtained by linearly approximating the time change of the ejection pressure, which increases with time within a pressure range (P7_l to P7_u) smaller than the target pressure Pt, and linearly increases to a constant pressure Pm over time. The extended setting line Lm extends from the end of the final rise regression line Lr (at the end time) to the end of the final rise period (Ta_e) and represents the constant pressure Pm. In this structure, the stall degree of the ejection pressure at the end of the ascent period of Ta can be taken into account to evaluate the ejection pressure.

[0307] In addition, Figure 14 The evaluation project shown evaluates the ejection pressure during the initial vibration period Tb_s (the second period), from the moment the ejection pressure reaches its maximum value Pmax (time t81) to the moment when the second differential of the time change of the ejection pressure D2 crosses 0 twice (time t82). Specifically, the minimum ejection pressure P8min within the initial vibration period Tb_s is calculated, and the difference between the smaller of this minimum value P8min and the constant pressure Pm and the maximum ejection pressure Pmax is extracted as the characteristic quantity Fv8 (the second characteristic quantity). In this structure, the overshoot of the ejection pressure can be considered when evaluating the ejection pressure.

[0308] In addition, Figure 15 The evaluation items shown evaluate the ejection pressure during a specified transition period Tb (second period) starting from the moment (time tb) when the ejection pressure exceeds the target pressure Pt (specified pressure). Specifically, a feature quantity Fv9 (second feature quantity) representing the difference between the ejection pressure during the rise period Ta and the constant pressure Pm is extracted. In this structure, the stability of the ejection pressure after reaching the target pressure Pt can be considered when evaluating the ejection pressure.

[0309] In addition, Figure 16In the evaluation items shown, the ejection pressure during the constant pressure period Tbc is evaluated from the moment when the ejection pressure exceeds the target pressure Pt (specified pressure) (time tb) to the moment when the ejection pressure begins to decrease in order to stop ejecting the coating liquid from nozzle 71 (time td). Specifically, a feature quantity Fv10 representing the difference between the maximum value Pmax and the minimum value P10min of the ejection pressure during the constant pressure period Tbc is extracted. In this structure, the stability of the ejection pressure during the constant pressure period Tbc can be taken into account to evaluate the ejection pressure.

[0310] Furthermore, in the third evaluation stage, characteristic quantities Fv11 to Fv14 (third characteristic quantities) of the time change of the ejection pressure during a period shorter than the ejection period Tt (the third period) are extracted, and the time change of the ejection pressure is evaluated based on characteristic quantities Fv11 to Fv14 (step S102). In this structure, the ejection pressure can be evaluated with high accuracy based on the time change of the ejection pressure during a period shorter than the ejection period Tt from the start of ejection of the coating liquid from the nozzle 71 to the end.

[0311] In addition, Figure 17 In the evaluation items shown, after the coating liquid is sprayed from nozzle 71, the spray pressure is evaluated during the third period (Tar) of the pressure rise from the lower reference pressure P11_l (lower reference value) to the upper reference pressure P11_u (upper reference value) over time. Specifically, one of the spray pressure measurement data 99 between the lower reference pressure P11_l and the upper reference pressure P11_u is determined. This measurement data is the value whose mean square error between the approximate straight line Lr_1 obtained by linear regression of the time change of spray pressure in the interval (t111~t112) between the lower reference pressure P11_l and the measurement data and the time change of spray pressure, and whose mean square error between the approximate straight line Lr_2 obtained by linear regression of the time change of spray pressure in the interval (t112~t113) between the measurement data and the upper reference pressure P11_u is minimized. Furthermore, the ratio of the slope K1 of the straight line between the lower reference pressure P11_l and a measured data point to the slope K2 of the straight line between a measured data point and the upper reference pressure P11_u is extracted as a characteristic quantity Fv11 (the third characteristic quantity). In this structure, the linearity of the increase in ejection pressure can be taken into account to evaluate the ejection pressure.

[0312] In addition, Figure 18In the evaluation items shown, the ejection pressure during the final rise period Ta_e (the third period) before the ejection pressure increases to the target pressure Pt (specified pressure) is evaluated. Specifically, a characteristic quantity Fv12 (the third characteristic quantity) is extracted, representing the difference between the approximate waveform WF12 (approximate waveform at the final rise period) that approximates the time change of the ejection pressure during the final rise period Ta_e and the time change of the ejection pressure during the final rise period Ta_e. Here, the approximate waveform WF12 at the final rise period consists of the final rise period regression line Lr and the extended setting line Lm. The final rise period regression line Lr coincides with the approximate curve obtained by linearly approximating the time change of the ejection pressure, which increases with time within a pressure range (P12_l to P12_u) smaller than the target pressure Pt, and increases linearly with time to the target pressure Pt. The extended setting line Lm extends from the final rise period regression line Lr (at the end time) to the end time of the final rise period Ta_e, representing the target pressure Pt. In this structure, the ejection pressure can be evaluated by taking into account the degree of stall of the ejection pressure at the end of the ascent period.

[0313] In addition, Figure 19 In the evaluation items shown, the ejection pressure during the final rise period (Ta_e, the third period) until the ejection pressure increases to the target pressure Pt (specified pressure) is evaluated. Specifically, a feature quantity Fv13 (the third feature quantity) is extracted, representing the difference between the approximate waveform WF13 (approximate waveform at the final rise period) that approximates the time change of the ejection pressure during the final rise period (Ta_e) and the time change of the ejection pressure during the final rise period (Ta_e). Here, the approximate waveform WF13 at the final rise period consists of the final rise period regression line Lr and the extended setting line Lm. The final rise period regression line Lr overlaps with the approximate curve obtained by linearly approximating the time change of the ejection pressure, which increases with time within a pressure range (P13_l to P13_u) smaller than the target pressure Pt, and linearly increases to the target pressure Pt over time. The extended setting line Lm extends from the final rise period regression line Lr (at the end time) to the end time of the final rise period (Ta_e) and represents the target pressure Pt. In this structure, the ejection pressure can be evaluated by taking into account the degree of stall of the ejection pressure at the end of the ascent period.

[0314] In addition, Figure 20In the evaluation project shown, the ejection pressure during the initial vibration period Tb_s (the third period) is evaluated from the moment the ejection pressure reaches its maximum value Pmax (time t141) to the moment when the second derivative of the time change of the ejection pressure D2 crosses 0 twice (time t142). Specifically, the sum of the value obtained by subtracting the constant pressure Pm from the maximum ejection pressure Pmax and the value obtained by subtracting the minimum ejection pressure P14min during the initial vibration period Tb_s from the constant pressure Pm is extracted as the characteristic quantity Fv14 (the third characteristic quantity). In this structure, the ejection pressure overshoot can be taken into account when evaluating the ejection pressure.

[0315] As described above, in the above embodiments, the coating apparatus 1 corresponds to an example of the "substrate processing apparatus" of the present invention, the nozzle 71 corresponds to an example of the "nozzle" of the present invention, the coating liquid supply mechanism 8 corresponds to an example of the "pressure application unit" of the present invention, the nozzle 71 and the coating liquid supply mechanism 8 cooperate to form an example of the "ejection apparatus" of the present invention, the pressure gauge 86 corresponds to an example of the "measuring unit" of the present invention, the control unit 9 corresponds to an example of the "computer" and "control unit" of the present invention, the ejection pressure evaluation program 97 corresponds to an example of the ejection pressure evaluation program of the present invention, the recording medium M corresponds to an example of the "recording medium" of the present invention, the coating liquid corresponds to an example of the "processing liquid" of the present invention, and the pressure measured by the pressure gauge 86 corresponds to an example of the "ejection pressure" of the present invention.

[0316] Furthermore, the ejection period Tt corresponds to an example of the "first period" of the present invention, the characteristic quantity Fv1 corresponds to an example of the "first characteristic quantity" 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 initial approximate line Lr_s corresponds to an example of the "initial 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 ending approximate line Lr_e corresponds to an example of the "ending approximate line" of the present invention, and the constant line Lr_m corresponds to an example of the "constant line" of the present invention.

[0317] Furthermore, the initial rise period Ta_s, the rise period Ta, the final rise period Ta_e, the initial oscillation 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 characteristic quantities Fv2 to Fv10 correspond to an example of the "second characteristic quantity" 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; the final rise period Ta_e corresponds to an example of the "final rise period" of the present invention; the approximate waveform WF7 corresponds to an example of the "final rise approximate waveform" of the present invention; the final rise period regression line Lr corresponds to an example of the "final rise approximate line" of the present invention; the extended setting line Lm corresponds to an example of the "extended setting line" of the present invention; the initial oscillation period Tb_s corresponds to an example of the "initial oscillation period" of the present invention; the constant period Tc corresponds to an example of the "constant period" of the present invention; the transition period Tb corresponds to an example of the "transition period" of the present invention; and the constant pressure period Tbc corresponds to an example of the "constant pressure period" of the present invention.

[0318] Furthermore, the pressure rise period Tar, the final rise period Ta_e, and the initial vibration period Tb_s correspond to an example of the "third period" of the present invention; the characteristic quantities Fv11 to Fv14 correspond to an example of the "third characteristic quantity" 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 final rise period Ta_e corresponds to an example of the "final rise period" of the present invention; the approximate waveforms WF12 and WF13 correspond to an example of the "final rise approximate waveform" of the present invention; the final rise period regression line Lr corresponds to an example of the "final rise period approximate line" of the present invention; the extended setting line Lm corresponds to an example of the "extended setting 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.

[0319] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from its spirit. For example, in the above-described embodiments, the ejection characteristics are measured based on the pressure value detected by the pressure gauge 86 installed on the piping 82, but the installation position of the pressure gauge 86 is not limited to this, as long as it can detect the pressure of the coating liquid delivered to the nozzle 71, its installation position is arbitrary.

[0320] In addition, in the above embodiment, a bellows type pump 81 was used, but the type of pump is not limited to this. For example, a syringe type pump that utilizes a piston can also be used (e.g., Japanese Patent Application Publication No. 2008-101510).

[0321] Furthermore, in the above embodiments, the present invention is applied to a coating apparatus 1 that supplies coating liquid to the surface Sf of the substrate S while the substrate S is in a floating state. However, the application of the present invention is not limited to this. The present invention can be applied to all substrate processing techniques that perform a specified treatment by supplying a treatment liquid from a nozzle to the upper surface of the substrate through the nozzle.

[0322] Furthermore, in the second evaluation stage, it is not necessary to evaluate the ejection pressure based on all of the aforementioned characteristic quantities Fv2 to Fv10; it can be configured to evaluate the ejection pressure based only on a portion of them. Similarly, in the third evaluation stage, the ejection pressure can also be evaluated based only on a portion of the aforementioned characteristic quantities Fv11 to Fv14.

[0323] In addition, in calculation Figure 7 When the approximate waveform WF1 is obtained, a straight line with a slope of 0 representing the target pressure Pt can be used instead of the constant straight line Lr_m.

[0324] Furthermore, it is not necessary to prepare all three evaluation stages. Therefore, among the evaluation stages 1 to 3 mentioned above, it is possible to configure only evaluation stages 1 and 2, only evaluation stages 2 and 3, or only evaluation stages 1 and 3. Alternatively, an evaluation stage can be set up to evaluate the ejection pressure using evaluation items different from the three evaluation stages mentioned above.

[0325] Alternatively, when calculating the final evaluation value Vf, the sum of the evaluation values ​​in the corresponding evaluation stages (e.g., V2 to V10, V11 to V14) can be multiplied by a weighting coefficient that varies depending on the evaluation value to apply the weighting.

[0326] Furthermore, it can also replace Figure 7 The characteristic quantity Fv1 shown is used to calculate the characteristic quantity Fv1_1 described in the following variation example, and the time change of the ejection pressure is evaluated based on the characteristic quantity Fv1_1. Figure 23 This is a diagram used to illustrate the various periods used in a variation of the evaluation item for ejection pressure. Figure 24 This diagram illustrates a variation of an evaluation item that assesses the time-varying nature of ejection pressure based on the characteristic quantity Fv1_1. Here, we will primarily explain... Figure 23 With the above Figure 5 The differences are noted, and the commonalities are labeled with the same reference numerals in the accompanying drawings with appropriate omitting of descriptions. Similarly, the main descriptions are... Figure 24 With respect to the above-mentioned Figure 7 differences, the same reference numerals are assigned to these common points and the description is appropriately omitted.

[0327] As Figure 23 shown, in a modified example of the evaluation item, the attention period Troi is used. That is, the attention period Troi is the period from time ta to time td. That is, the attention period Troi is composed of a rising period Ta, a transition period Tb, and a constant period Tc, or in other words, is composed of a rising period Ta and a constant pressure period Tbc. Thus, the attention period Troi corresponds to an example of the "main period from when the treatment liquid starts to be ejected from the nozzle until the ejection pressure rises to a specified pressure until the ejection pressure starts to decrease from the specified pressure" in the present invention, and the target pressure Pt corresponds to an example of the "specified pressure" in the present invention.

[0328] As Figure 24 shown, in this modified example, in the same manner as in the case of the above-mentioned characteristic quantity Fv1, a rising regression line Lr_R is calculated, and an initial approximation line Lr_s is set. Further, in the period from time t12 to time td, a constant line Lr_m_1 having a slope of 0 representing the constant pressure Pm (i.e., the average of the measured values of the ejection pressure in the constant period Tc) is set.

[0329] Thus, an approximate waveform WF1_1 composed of the initial approximation line Lr_s, the rising regression line Lr_R, and the constant line Lr_m_1 arranged in time series is calculated. Then, the pressure evaluation unit 913 calculates the mean absolute error MAE between the ejection pressure measurement data 99 and the approximate waveform WF1_1 as the characteristic quantity Fv1_1 during the entire attention period Troi from time ta to time td. In addition, the pressure evaluation unit 913 normalizes the characteristic quantity Fv1_1 to a specified range based on a specified threshold Th1_1 (for example, 0.05). Specifically, based on the following formula:

[0330] If Fv1_1 < Th1_1, then Fv1_1 = 0

[0331] If Fv1_1 ≥ Th1_1, then Fv1_1 = (Fv1_1 + 1 - Th1_1) × c1_1

[0332] The characteristic quantity Fv1_1 is transformed into a normalized characteristic quantity 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. In addition, the specific method for normalizing the characteristic quantity Fv1_1 is not limited to the example here and can be appropriately changed.

[0333] According to based on Figure 24The evaluation of the characteristic quantity Fv1_1 is able to assign a large score (i.e., a poor evaluation) to the ejection pressure when the temporal variation of the ejection pressure in the Troi deviates significantly from the ideal shape throughout the entire period of attention.

[0334] In this variation, Figure 4 In the evaluation of the ejection pressure measurement results (step S102) shown, the pressure evaluation unit 913 calculates the evaluation value V1_1 based on the result of extracting the characteristic quantity Fv1_1 from the ejection pressure instead of the characteristic quantity Fv1. Specifically, for the first (I=1) evaluation stage, the allocation is not based on... Figure 7 The evaluation of the feature quantity Fv1 shown is not based on the assignment of features. Figure 24 The evaluation of the feature quantity Fv1_1 is shown. Then, the following is performed. Figure 21 The measurement results shown are evaluated. That is, in Figure 22 In the table, the characteristic quantity of the evaluation item when evaluation stage I is 1 is not characteristic quantity Fv1, but... Figure 24 The characteristic quantity Fv1_1 is shown.

[0335] In this modified example, N evaluation stages are also provided, each evaluating the ejection pressure according to different evaluation items, from the first to the Nth. These evaluation stages can be executed sequentially. However, if the ejection pressure is determined to be appropriate based on the evaluation items involved in the first evaluation stage ("Yes" in step S205), the evaluation of the ejection pressure based on the evaluation items involved in the (I+1)th evaluation stage is performed. Conversely, if the ejection pressure is determined to be inappropriate based on the evaluation items involved in the first evaluation stage ("No" in step S205), the evaluation of the ejection pressure in the subsequent evaluation stages is not performed (i.e., it is omitted). In other words, when evaluating the ejection pressure sequentially according to the first to Nth evaluation stages, if the ejection pressure is determined to be inappropriate in any evaluation stage, the evaluation in subsequent evaluation stages is not performed. Therefore, it is possible to evaluate the spray pressure applied to the coating liquid in order to spray the coating liquid from the nozzle 71 within a reasonable time corresponding to whether the spray pressure is appropriate.

[0336] Furthermore, the ejection pressure is measured during the Troi period (the main period, the evaluation period), from the start of ejection of the processing liquid from nozzle 71 through the rise of the ejection pressure to the target pressure Pt (specified pressure) until the ejection pressure begins to decrease from the target pressure Pt. In the first (I=1) evaluation stage, a characteristic quantity Fv1_1 (overall characteristic quantity) of the time-varying ejection pressure during the entire Troi period is extracted, and the time-varying ejection pressure is evaluated based on the characteristic quantity Fv1_1. Therefore, the appropriateness of the ejection pressure during the entire Troi period, which affects the thickness of the processing liquid coated on the substrate S, can be reflected in the evaluation of the ejection pressure.

[0337] Furthermore, in this modified example, when the influence of the Troi period on the thickness of the processing liquid coated on the substrate S is particularly large (in other words, when the influence of the period after the Troi period is small), the appropriateness of the ejection pressure throughout the Troi period can be reflected in the evaluation of the ejection pressure.

[0338] Furthermore, the feature quantity Fv1_1 (primary feature quantity) represents the difference between the approximate waveform WF1_1 (primary approximate waveform), which approximates the time variation of the ejection pressure in the Troi (primary period) throughout the entire period of interest, and the time variation of the ejection pressure in the Troi throughout the entire period of interest. In this structure, based on the approximate waveform WF1_1 of the time variation of the ejection pressure in the Troi throughout the entire period of interest, the ejection pressure in the Troi throughout the entire period of interest can be appropriately evaluated.

[0339] In particular, the approximate waveform WF1_1 has:

[0340] The rising regression line Lr_R (approximate rising line) is a linear approximation of the time change of the spray pressure that increases with time after the coating liquid is sprayed from nozzle 71. It is obtained by linearly approximating the time change of the spray pressure that increases with time, from the initial pressure Pi (spray start pressure) to a constant pressure Pm that is greater than the initial pressure Pi.

[0341] Initially, it is approximately a straight line Lr_s, set between the starting moment (time ta) when the coating liquid is sprayed from nozzle 71 and the rising regression line Lr_R, and represents the initial pressure Pi;

[0342] The constant line Lr_m_1 is set from the time the rising regression line Lr_R reaches the constant pressure Pm until the end of the Troi period of interest (the period from time t12 to time td), and represents the constant pressure Pm.

[0343] This structure allows for an approximation of the temporal variation of the ejection pressure in the Troi throughout the entire period of interest, enabling an appropriate evaluation of the ejection pressure in the Troi during that period.

[0344] In addition, in use Figure 24 When evaluating the ejection pressure using the characteristic quantity Fv1_1 shown, in step S101, it is not necessary to measure the ejection pressure during the period after the period of interest Troi (i.e., the falling period Td).

[0345] Alternatively, the system can be configured to allow selection via UI95 of which of the two feature quantities, Fv1 and Fv1_1, to use for evaluating the ejection pressure. In this case, in step S102, the ejection pressure is evaluated using one of the feature quantities, Fv1 and Fv1_1, selected by the user through input to UI95. Figure 21 In the evaluation of the measurement results, for the first (I=1) evaluation stage, one of the characteristic quantities selected from characteristic quantity Fv1 and characteristic quantity Fv1_1 is used to evaluate the ejection pressure.

[0346] This invention can be applied to all substrate processing technologies that supply processing liquid to a substrate by delivering processing liquid to a nozzle and spraying the processing liquid onto the substrate with the desired characteristics from the nozzle.

Claims

1. A method of evaluating a discharge pressure for evaluating the discharge pressure when a treatment liquid is discharged from a slit-like discharge port of a nozzle possessed by a slit coater, wherein Possessing: a process of evaluating an ejection pressure in an ejection device that ejects a treatment liquid from a nozzle by applying the ejection pressure to the treatment liquid by a pump, based on an evaluation item related to a first evaluation stage among N evaluation stages from the first to the Nth, N being an integer of 2 or more, the ejection pressure being evaluated in the N evaluation stages according to evaluation items different from each other; and in a case where the ejection pressure is judged to be appropriate in the evaluation based on the evaluation item related to the Ith evaluation stage among the N evaluation stages, a process of performing the evaluation of the ejection pressure based on an evaluation item related to an (I+1)th evaluation stage, on the other hand, in a case where the ejection pressure is judged to be inappropriate in the evaluation based on the evaluation item related to the Ith evaluation stage, a process of not performing the evaluation of the ejection pressure in the evaluation stage in order after the Ith evaluation stage, I being an integer of 1 or more and less than N, the first evaluation stage is provided with the evaluation item of evaluating the ejection pressure by performing the following processes: a process of extracting, as a global feature amount, a feature amount possessed by a time change of the ejection pressure in the entire evaluation target period, based on a result of measuring the ejection pressure in an evaluation target period including at least a main period from when the treatment liquid starts to be ejected from the nozzle until when the ejection pressure starts to decrease from a prescribed pressure after the ejection pressure rises to the prescribed pressure; and a process of evaluating the time change of the ejection pressure based on the global feature amount.

2. The ejection pressure evaluation method according to claim 1, wherein different evaluation values are given to the ejection pressure according to a number of the evaluation stages in which the evaluation of the ejection pressure is performed among the N evaluation stages.

3. The ejection pressure evaluation method according to claim 1, wherein the evaluation target period is the main period, a main feature amount possessed by a time change of the ejection pressure in the entire main period is extracted as the global feature amount.

4. The ejection pressure evaluation method according to claim 3, wherein the main feature amount represents a difference between a main approximate waveform approximated to the time change of the ejection pressure in the entire main period and the time change of the ejection pressure in the entire main period.

5. The ejection pressure evaluation method according to claim 4, wherein the main approximate waveform has: a rising approximate straight line provided from when the treatment liquid starts to be ejected from the nozzle until when a constant pressure larger than an ejection start pressure linearly increases with time elapse, by linearly approximating the time change of the ejection pressure that increases with time elapse; a start time approximate straight line provided between a start time of ejecting the treatment liquid from the nozzle and the rising approximate straight line and representing the ejection start pressure; and a constant straight line provided in a period from when the rising approximate straight line reaches the constant pressure until the end of the main period and representing the constant pressure.

6. The discharge pressure evaluation method according to claim 1, wherein the evaluation target period is a first period from the start of the discharge of the treatment liquid from the nozzle to the end of the discharge of the treatment liquid from the nozzle, a first characteristic quantity possessed by the time variation of the discharge pressure in the entire first period is extracted as the overall characteristic quantity.

7. The discharge pressure evaluation method according to claim 6, wherein the first characteristic quantity represents a difference between a first approximate waveform approximated to the time variation of the discharge pressure in the entire first period and the time variation of the discharge pressure in the entire first period.

8. The discharge pressure evaluation method according to claim 7, wherein the first approximate waveform has: a rising approximate straight line that is set between the start of the discharge of the treatment liquid from the nozzle and the rising approximate straight line, and represents the discharge start pressure; a falling approximate straight line that is set between the falling approximate straight line and the end of the discharge of the treatment liquid from the nozzle, and represents the discharge end pressure; and a constant straight line that connects the rising approximate straight line and the falling approximate straight line to each other, and represents the constant pressure.

9. The discharge pressure evaluation method according to any one of claims 1 to 8, wherein the second evaluation stage among the N evaluation stages is caused to have the evaluation item of evaluating the discharge pressure by executing: a process of extracting, as a second characteristic quantity, a characteristic quantity possessed by the time variation of the discharge pressure in a second period shorter than the evaluation target period among the evaluation target period; and a process of evaluating the time variation of the discharge pressure on the basis of the second characteristic quantity.

10. The discharge pressure evaluation method according to claim 9, wherein a prescribed rising initial period from the start of the discharge of the treatment liquid from the nozzle is set as the second period, the discharge pressure increases with the passage of time in the rising initial period, a characteristic quantity representing a difference between a regression curve of the time variation of the discharge pressure in the rising initial period and the time variation of the discharge pressure in the rising initial period is extracted as the second characteristic quantity.

11. The discharge pressure evaluation method according to claim 9, wherein a rising period from the start of the discharge of the treatment liquid from the nozzle to the increase of the discharge pressure to the prescribed pressure is set as the second period.

12. The discharge pressure evaluation method according to claim 11, wherein ​ ​ ​ extracting a length of the rising period as the second characteristic quantity.

13. The discharge pressure evaluation method according to claim 11, wherein in the rising period, extracting a number of times that a first derivative of a time change of the discharge pressure crosses a prescribed threshold value as the second characteristic quantity.

14. The discharge pressure evaluation method according to claim 11, wherein in the rising period, extracting a number of times that an absolute value of a second derivative of a time change of the discharge pressure crosses a prescribed threshold value as the second characteristic quantity.

15. The discharge pressure evaluation method according to claim 11, wherein in the rising period, extracting a ratio of a time at which a second derivative of a time change of the discharge pressure is larger than a prescribed positive threshold value, to a time at which the second derivative of the time change of the discharge pressure is smaller than a prescribed negative threshold value having the same absolute value as the positive threshold value, as the second characteristic quantity.

16. The discharge pressure evaluation method according to claim 9, wherein a prescribed end-of-rising period during which the discharge pressure is increased to the prescribed pressure is set as the second period, extracting, as the second characteristic quantity, a characteristic quantity representing a difference between an end-of-rising period approximate waveform approximated to a time change of the discharge pressure in the end-of-rising period period and the time change of the discharge pressure in the end-of-rising period period, the end-of-rising period approximate waveform has: an end-of-rising period approximate straight line that overlaps an approximate curve obtained by linearly approximating a time change of the discharge pressure that increases in a pressure range lower than the prescribed pressure along with the passage of time, and that linearly increases to a constant pressure along with the passage of time, the constant pressure being an average value of the time change of the discharge pressure in a constant period after the end-of-rising period period; and a straight line that is extended from the end-of-rising period approximate straight line to an end time of the end-of-rising period period and that represents the constant pressure.

17. The discharge pressure evaluation method according to claim 9, wherein an initial vibration period from a time at which the discharge pressure reaches a maximum value to a time at which a second derivative of a time change of the discharge pressure crosses zero twice is set as the second period, extracting, as the second characteristic quantity, a difference between a smaller one of a minimum value of the discharge pressure in the initial vibration period and an average value of the discharge pressure in a prescribed constant period after the initial vibration period and the maximum value of the discharge pressure.

18. The discharge pressure evaluation method according to claim 9, wherein a prescribed transition period from a time at which the discharge pressure exceeds the prescribed pressure is set as the second period, extracting, as the second characteristic quantity, a characteristic quantity representing a difference of the discharge pressure in the transition period with respect to an average value of the discharge pressure in a prescribed constant period after the transition period.

19. The discharge pressure evaluation method according to claim 9, wherein the second period is set to a constant pressure period from a time when the discharge pressure exceeds the prescribed pressure to a time when the discharge pressure starts to decrease in order to end the discharge of the treatment liquid from the nozzle, a feature quantity representing a difference between a maximum value and a minimum value of the discharge pressure in the constant pressure period is extracted as the second feature quantity.

20. The discharge pressure evaluation method according to claim 9, wherein N is 3 or more, the third evaluation stage among the N evaluation stages is caused to have an evaluation item of evaluating the discharge pressure by executing the following process: a process of extracting, as a third feature quantity, a feature quantity possessed by a time change of the discharge pressure in a third period shorter than the evaluation target period among the evaluation target period; and a process of evaluating the time change of the discharge pressure based on the third feature quantity.

21. The discharge pressure evaluation method according to claim 20, wherein a pressure rise period in which the discharge pressure increases from a lower reference value to an upper reference value larger than the lower reference value with the passage of time after the start of the discharge of the treatment liquid from the nozzle is set to the third period, one of measured values of the discharge pressure between the lower reference value and the upper reference value is found, the one measured value being a measured value in which a sum of a mean square error of the time change of the discharge pressure and an approximate straight line found by linear regression with respect to the time change of the discharge pressure in an interval between the lower reference value and the one measured value is the smallest, a ratio of a slope of a straight line between the lower reference value and the one measured value and a slope of a straight line between the one measured value and the upper reference value is extracted as the third feature quantity.

22. The discharge pressure evaluation method according to claim 20, wherein a prescribed rise end period in which the discharge pressure increases to the prescribed pressure is set to the third period, a feature quantity representing a difference between an rise end period approximate waveform approximated to 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 rise end period approximate waveform has: a rise end period approximate straight line which overlaps an approximate curve found by linear approximation with respect to the time change of the discharge pressure which increases with the passage of time in a pressure range smaller than the prescribed pressure and which linearly increases to the prescribed pressure with the passage of time; and an extension setting straight line which is connected to the rise end period approximate straight line and represents the prescribed pressure.

23. The discharge pressure evaluation method according to claim 20, wherein an initial vibration period from a time when the discharge pressure reaches a maximum value to a time when a second differential of the time change of the discharge pressure crosses zero twice is set to the third period, The third characteristic quantity is extracted as the sum of a value obtained by subtracting a constant pressure from the maximum value of the discharge pressure and a value obtained by subtracting the minimum value of the discharge pressure during the initial vibration period from the constant pressure, the constant pressure being an average value of the discharge pressure in a prescribed constant period after the initial vibration period.

24. A recording medium recording, in a manner capable of being read by a computer, an ejection pressure evaluation program that evaluates an ejection pressure when a treatment liquid is ejected from a slit-like ejection port of a nozzle possessed by a slit coater, wherein The computer is caused to execute the following procedures: a procedure of evaluating a discharge pressure in a discharge device that discharges a treatment liquid from a nozzle by applying a discharge pressure to the treatment liquid by a pump, based on an evaluation item related to a first evaluation stage among N evaluation stages from the first to the Nth, N being an integer of 2 or more, the discharge pressure being evaluated according to mutually different evaluation items in the N evaluation stages; and a procedure of executing an evaluation of the discharge pressure based on an evaluation item related to an (I+1)th evaluation stage, if it is determined that the discharge pressure is appropriate in an evaluation based on an evaluation item related to an Ith evaluation stage among the N evaluation stages, I being an integer of 1 or more and less than N, on the other hand, not executing an evaluation of the discharge pressure in an evaluation stage subsequent to the Ith evaluation stage, if it is determined that the discharge pressure is not appropriate in the evaluation based on the evaluation item related to the Ith evaluation stage, the first evaluation stage is caused to have the evaluation item of evaluating the discharge pressure by causing the computer to execute the following procedures: a procedure of extracting a characteristic quantity possessed by a time variation of the discharge pressure in the entire evaluation target period as an overall characteristic quantity, based on a result of measuring the discharge pressure in an evaluation target period including at least a main period from when the treatment liquid starts to be discharged from the nozzle until when the discharge pressure starts to decrease from a prescribed pressure until the discharge pressure starts to decrease from the prescribed pressure; and a procedure of evaluating the time variation of the discharge pressure based on the overall characteristic quantity.

25. A slot die coater, wherein, provided with: a discharge device having a nozzle having a slit-shaped discharge port and a pressure applying portion that discharges a treatment liquid from the nozzle by applying a discharge pressure to the treatment liquid by a pump; a measuring portion that measures the discharge pressure; and a control portion that stores execution contents in N evaluation stages from a first to an Nth, N being an integer of 2 or more, of evaluating the discharge pressure in the discharge device that discharges a treatment liquid from a nozzle by applying a discharge pressure to the treatment liquid by a pump according to mutually different evaluation items, the control portion evaluates the discharge pressure based on an evaluation item related to a first evaluation stage among the N evaluation stages, ​ In a case where it is determined that the discharge pressure is appropriate in the evaluation based on the evaluation item related to the Ith evaluation stage among the N evaluation stages, evaluation of the discharge pressure based on the evaluation item related to the (I+1)th evaluation stage is performed, whereas in a case where it is determined that the discharge pressure is inappropriate in the evaluation based on the evaluation item related to the Ith evaluation stage, evaluation of the discharge pressure in the evaluation stage that is sequential to the Ith evaluation stage is not performed, I being an integer of 1 or more and less than N, The first evaluation stage is provided with the evaluation item of evaluating the discharge pressure by performing the following steps: a step of extracting, as an overall feature amount, a feature amount possessed by the temporal change in the discharge pressure in the entire evaluation target period, based on a result of measuring the discharge pressure in an evaluation target period including at least a main period from when the processing liquid starts to be discharged from the nozzle until when the discharge pressure starts to decrease from a prescribed pressure; and a step of evaluating the temporal change in the discharge pressure based on the overall feature amount.

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