Cleaning method, computer storage medium and substrate processing system

Abstract

A method for cleaning a supply flow path connected to an ejection unit that ejects a processing liquid to a substrate includes: a step (A) of supplying a cleaning liquid to the ejection unit via the supply flow path and ejecting the cleaning liquid from the ejection unit; and a step (B) of estimating whether or not cleaning has been completed on the basis of a detection result by a foreign matter detector configured to detect foreign matters in the cleaning liquid supplied to the supply flow path, the step (B) including: a step (C) of determining whether or not cleaning has been completed on the basis of a history of the detection result by the foreign matter detector; estimating that the detection result of the foreign matter detector reaches a stable cleaning completion point when the total discharge amount of the cleaning liquid is increased; and a step (D) for estimating whether or not the cleaning has been completed on the basis of the estimated cleaning completion point.

Description

Technical Field

[0001] The present disclosure relates to a cleaning method, a computer storage medium and a substrate processing system. Background Art

[0002] Japanese Patent Application Laid-Open No. 2003-218022 discloses that, in order to eliminate defects caused by the presence of bubbles in a resist supply pipe connected to the resist nozzle or particles in the resist, dummy dispensing of the resist nozzle is performed by detecting the bubbles or particles. Summary of the invention

[0003] One aspect of the present disclosure is a method for cleaning a flow path connected to a discharge portion that discharges a processing liquid onto a substrate, the method comprising: a step (A), supplying a cleaning liquid to the discharge portion via the flow path, and discharging the cleaning liquid from the discharge portion; and a step (B), estimating whether the cleaning has been completed based on a detection result of a foreign matter detector, the foreign matter detector being configured to detect foreign matter in the cleaning liquid supplied to the flow path, wherein step (B) comprises: a step (C), estimating a cleaning completion point at which the detection result of the foreign matter detector stabilizes when a total discharge amount of the cleaning liquid increases, based on a history of the detection result of the foreign matter detector; and a step (D), estimating whether the cleaning has been completed based on the estimated cleaning completion point. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 is a diagram schematically showing an outline of a configuration of a coating and developing system as a substrate processing system according to an embodiment.

[0005] Figure 2 It is an explanatory diagram schematically showing the arrangement of the processing liquid supply device.

[0006] Figure 3 is a diagram showing the state of the processing liquid supply device during a normal discharge operation.

[0007] Figure 4 This is a flowchart for explaining an example of cleaning the supply flow path by the processing liquid supply device.

[0008] Figure 5 It is a diagram showing the state of the processing liquid supply device during cleaning of the supply flow path.

[0009] Figure 6 : is a diagram showing an example of the detection result of the foreign matter detector during cleaning of the supply flow path.

[0010] Figure 7 is a diagram showing another arrangement example of the foreign matter detector. DETAILED DESCRIPTION

[0011] In the photolithography step in the manufacturing process of semiconductor devices, etc., a processing liquid such as a resist liquid, a developer, etc. is used to form a coating film such as a resist film on a substrate such as a semiconductor wafer (hereinafter referred to as a "wafer"), or to develop the resist film after exposure. In a liquid processing device that processes a substrate using a processing liquid, the processing liquid is discharged from a discharge nozzle as a discharge portion toward the substrate. The processing liquid is supplied to the discharge nozzle via a supply flow path.

[0012] The treatment liquid from the discharge nozzle sometimes contains foreign matter (particles). In addition, even if there is no foreign matter in the original treatment liquid, if the foreign matter adheres to the inside of the supply flow path connected to the discharge nozzle, the foreign matter may be mixed into the treatment liquid discharged from the discharge nozzle. Therefore, a filter is provided in the supply flow path leading to the discharge nozzle so that the foreign matter is removed by the filter.

[0013] However, even if a filter is provided, foreign matter generated in the supply flow path on the downstream side of the filter cannot be removed. For this reason and other reasons, before operating a liquid processing device, etc., a pre-spray is performed to discharge cleaning liquid from a discharge nozzle via the supply flow path to clean the supply flow path, etc. However, the technology related to the previous pre-spray has room for improvement in terms of convenience. For example, in the past, a pre-spray was performed until a predetermined amount of cleaning liquid passed through, and then the amount of foreign matter in the cleaning liquid discharged from the discharge nozzle was detected by a device provided outside the substrate processing system equipped with the liquid processing device, and then the pre-spray and the detection of the amount of foreign matter using a device outside the system were performed alternately until the amount of foreign matter became below a predetermined value. This method may require a large amount of cleaning liquid and a long time to clean the supply flow path.

[0014] Therefore, the technology according to the present disclosure improves convenience when cleaning the supply flow path connected to the discharge portion that discharges the processing liquid to the substrate with the cleaning liquid.

[0015] Hereinafter, a cleaning method and a control device of a treatment liquid supply device according to an embodiment will be described with reference to the accompanying drawings. It should be noted that in the description, components having substantially the same functional configuration are denoted by the same reference numerals to omit repeated explanations.

[0016] <Coating and developing system>

[0017] Figure 1 is a diagram schematically showing an outline of a configuration of a coating and developing system as a substrate processing system according to an embodiment.

[0018] Figure 1 The coating and developing system 1 in the invention is a semiconductor manufacturing apparatus, specifically, used for forming a resist film on a wafer as a substrate, developing the resist film after exposure, heating the wafer before exposure, heating the wafer after exposure, and the like.

[0019] For example, the coating and developing system 1 includes a liquid processing device 11 , a processing liquid supply device 12 , and a control device 13 .

[0020] The liquid processing device 11 includes a resist film forming device (coating a resist as a processing liquid on a wafer to form a resist film), a developing device (supplying a developer as a processing liquid to the exposed wafer to develop the resist film on the wafer), and the like.

[0021] Each liquid processing device 11 has a spin chuck as a holding portion for holding a wafer (see Figure 2 11a in the figure) and a discharge nozzle (see the following description) as a discharge portion for discharging the processing liquid to the wafer. Figure 2 Specifically, the spin chuck can rotatably hold the wafer. Specifically, the ejection nozzle ejects the processing liquid toward the wafer held on the spin chuck.

[0022] In addition, each liquid processing device 11 applies the processing liquid to the wafer by a spin coating method. The spin coating method discharges the processing liquid from a discharge nozzle to the wafer and rotates the wafer to spread the processing liquid on the surface of the wafer.

[0023] For each liquid processing device, a known configuration can be used.

[0024] The processing liquid supply device 12 supplies the processing liquid to the discharge nozzle of the liquid processing device 11. This discharges the processing liquid from the discharge nozzle. The specific structure of the processing liquid supply device 12 will be described below.

[0025] The control device 13 controls at least the process liquid supply device 12. The control device 13 may also be used as a control device for controlling the entire coating and developing system 1. In addition, the control device 13 may constitute a part of the process liquid supply device 12.

[0026] In addition, the control device 13 is a computer including, for example, a processor (e.g., CPU), a memory, etc., and has a program storage device (not shown) storing a program including a command to be executed by the processor. The program storage device stores a program including a command to supply the processing liquid to the spitting nozzle through the processing liquid supply device 12, and a program including a command to clean the supply flow path described later through the processing liquid supply device 12. In the case where the control device 13 is also used as a control device for controlling the entire coating and developing system 1, the program storage device also stores a program including a command to perform wafer processing through the coating and developing system 1. Note that the above-mentioned program may be a program recorded in a computer-readable storage medium M and installed from the storage medium M into the control device 13. The storage medium M may be a temporary storage medium or a non-temporary storage medium.

[0027] Note that the coating and developing system 1 is provided with a box station (not shown) and a wafer transfer mechanism (not shown). A box containing a plurality of wafers is moved in and out of the box station. In addition, the wafer transfer mechanism is used for wafer transfer between the box station and each processing device, wafer transfer between each processing device, etc.

[0028] <Processing Liquid Supply Device 12>

[0029] Figure 2 It is an explanatory diagram schematically showing the configuration of the processing liquid supply device 12 .

[0030] As mentioned above, Figure 2 The processing liquid supply device 12 in the liquid processing device 11 supplies the processing liquid to the discharge nozzle 11b of the liquid processing device 11. The processing liquid supplied from the processing liquid supply device 12 and discharged from the discharge nozzle 11b may differ depending on the discharge nozzle 11b and is, for example, a resist liquid, a developer, or the like.

[0031] The processing liquid supply device 12 includes a supply flow path 150 connected to the discharge nozzle 11b. The supply flow path 150 is connected to the discharge nozzle 11b at one end and connected to the processing liquid bottle 101 as a processing liquid supply source at the other end, for example.

[0032] The treatment liquid bottle 101 stores the treatment liquid therein and is replaceable. A supply flow path 151 in which an opening and closing valve V1 is provided is also connected to the treatment liquid bottle 101. The supply flow path 151 connects a gas supply source 110 as an inert gas (e.g., nitrogen) supply source and the treatment liquid bottle 101, and an electric pneumatic regulator 111 for pressure regulation is provided on the upstream side of the opening and closing valve V1.

[0033] It should be noted that, instead of the processing liquid bottle 101 , a storage source of the processing liquid constituting equipment within a factory in which the coating and developing system 1 is installed may be used.

[0034] The supply flow path 150 is provided with a buffer tank 102 , a pump 103 , and a filter 104 in this order from the upstream side.

[0035] An on-off valve V2 is provided between the processing liquid bottle 101 and the buffer tank 102 in the supply flow path 150. In addition, an on-off valve V3 is provided between the buffer tank 102 and the pump 103 in the supply flow path 150. In addition, an on-off valve V4 is provided between the pump 103 and the filter 104 in the supply flow path 150. In addition, an on-off valve V5 and a supply control valve V6 are provided in order from the upstream side between the filter 104 and the discharge nozzle 11b in the supply flow path 150.

[0036] The buffer tank 102 is a storage portion for storing the treatment liquid to be transferred from the treatment liquid bottle 101 and sent to the pump 103. The buffer tank 102 is provided with a liquid level sensor (not shown) for detecting the storage remaining amount, and the on-off valves V1, V2 are opened / closed according to the detection result of the liquid level sensor to start / stop supplying (i.e., replenishing) the treatment liquid from the treatment liquid bottle 101 to the buffer tank 102.

[0037] The pump 103 pressure-feeds the process liquid. The pump 103 is, for example, a variable displacement pump, more specifically, a diaphragm pump. The pump 103 may be configured to draw the process liquid from the buffer tank 102 .

[0038] The filter 104 filters the process liquid to remove foreign matter. Specifically, the filter 104 filters the process liquid sent from the pump 103 to remove foreign matter in the process liquid.

[0039] In addition, the processing liquid supply device 12 has a foreign matter detector 120 that detects foreign matter in the processing liquid supplied to the supply flow path 150. The foreign matter detector 120 is provided, for example, on the downstream side of the filter 104 in the supply flow path 150, specifically, between the on-off valve V5 and the supply control valve V6 in the supply flow path 150.

[0040] For the foreign matter detector 120, a known configuration can be used. For example, the foreign matter detector 120 has: an irradiation unit (not shown) that irradiates light to the treatment liquid flowing through the supply flow path 150; a light receiving unit (not shown) that receives light irradiated by the irradiation unit and reflected by foreign matter in the treatment liquid flowing through the supply flow path 150; and a control unit (not shown) that detects foreign matter based on the light reception result of the light receiving unit. The control unit of the foreign matter detector 120 is, for example, a control board on which a processor such as a CPU is installed. In addition, the control unit of the foreign matter detector 120 specifically calculates (i.e., detects) the amount of foreign matter based on the light reception result of the light receiving unit.

[0041] The detection result of the foreign matter detector 120 (specifically, the measurement result of the amount of foreign matter by the foreign matter detector 120) is output to the control device 13. The detection result of the foreign matter detector 120 output to the control device 13 is specifically a detection signal corresponding to the detection result, and more specifically, a detection signal of an intensity corresponding to the amount of foreign matter detected.

[0042] For each valve provided in the treatment liquid supply device 12, a solenoid valve or a pneumatic valve controllable by the control device 13 is used, and each valve is electrically connected to the control device 13. In addition, the control device 13 is electrically connected to the pump 103. With this configuration, the discharge of the treatment liquid of the treatment liquid supply device 12 and the cleaning of the supply flow path 150 can be automatically performed under the control of the control device 13.

[0043] <Normal Discharging Operation of the Processing Liquid Supply Device 12>

[0044] Next, based on Figure 3 The normal discharge operation of the processing liquid supply device 12 will be described. Figure 3 is a diagram showing the state of the processing liquid supply device 12 during a normal discharge operation. Figure 3 In the figure, valves in the open state are indicated in white, valves in the closed state are indicated in black, and pipelines through which the process fluid flows are indicated by thick lines. This also applies to the Figure 5 It should be noted that it is assumed that the supply flow path 150 is previously filled with the processing liquid before the normal discharge operation described below.

[0045] like Figure 3 As shown, in the normal discharge of the processing liquid from the discharge nozzle 11b to the product wafer W, the on-off valves V3 to V5 and the supply control valve V6 enter the open state, and the pump 103 is driven by the control of the control device 13. As a result, a predetermined amount of the processing liquid (and the processing liquid sent from the pump 103) filled in the downstream side of the pump 103 of the supply flow path 150 is supplied to the discharge nozzle 11b, and discharged onto the product wafer W through the discharge nozzle 11b.

[0046] <Example of Cleaning the Supply Path 150 by the Processing Liquid Supply Device 12>

[0047] based on Figures 4 to 6 , an example of cleaning the supply flow path 150 by the processing liquid supply device 12 is described. Figure 4 is a flowchart for explaining the above example. Figure 5 It is a diagram showing the state of the processing liquid supply device 12 during cleaning of the supply flow path 150 . Figure 6 is a diagram showing an example of the detection result of the foreign matter detector 120 during cleaning of the supply flow path 150, that is, the result when PGMEA is used as the cleaning liquid. Figure 6 In the graph, the horizontal axis represents the number of steps S2 corresponding to the total discharge amount of the cleaning liquid from the discharge nozzle 11b, that is, the number of pre-sprays, and the vertical axis represents the amount of foreign matter per 1 ml (hereinafter referred to as "foreign matter amount") as the foreign matter detection result of the foreign matter detector 120. It should be noted that the cleaning of the supply flow path 150 is performed, for example, when the treatment liquid supply device 12 is started and when the type of treatment liquid discharged from the discharge nozzle 11b is changed.

[0048] (Step S1)

[0049] For example, first, under the control of the control device 13, as shown in FIG. Figure 4 As shown, the supply flow path 150 is filled with cleaning fluid.

[0050] The cleaning liquid is a processing liquid supplied to the ejection nozzle 11 b through the supply flow path 150 after cleaning of the supply flow path 150 , or a chemical liquid suitable for cleaning other than the above-mentioned processing liquid.

[0051] In the case where the cleaning liquid is the above-mentioned treatment liquid, in step S1, for example, Figure 5 As shown, the on-off valves V1 to V5 are brought into an open state. Then, the processing liquid bottle 101 is pressurized by the pressure of the inert gas supplied from the gas supply source 110. As a result, the processing liquid (i.e., the cleaning liquid) is transported from the inside of the processing liquid bottle 101, and the supply flow path 150 from the processing liquid bottle 101 to the supply control valve V6 is filled with the cleaning liquid.

[0052] (Step S2)

[0053] Next, under the control of the control device 13, the cleaning liquid is supplied to the discharge nozzle 11b through the supply flow path 150, so that the cleaning liquid is discharged from the discharge nozzle 11b. In other words, preliminary discharge is performed.

[0054] Specifically, as in the above-mentioned normal discharge, the on-off valves V1 and V2 are closed, the on-off valves V3 to V5 and the supply control valve V6 are opened, and the pump 103 is driven by the control of the control device 13. Thus, a predetermined amount of the processing liquid filled in the downstream side of the pump 103 of the supply flow path 150 (and the processing liquid sent from the pump 103) is supplied toward the discharge nozzle 11b and discharged through the discharge nozzle 11b.

[0055] (Step S3)

[0056] Furthermore, the control device 13 estimates whether the cleaning of the supply flow path 150 has been completed based on the detection result of the foreign matter detector 120 on the foreign matter in the cleaning liquid supplied to the supply flow path 150 .

[0057] This step S3 includes steps S3a, S3b, and S3c. Figure 4 It can be clearly seen that step S2 (ie, pre-spraying) and step S3 can be repeatedly performed.

[0058] (Step S3a)

[0059] In this step, under the control of the control device 13 , the foreign matter detector 120 performs detection of foreign matter in the cleaning liquid supplied to the supply flow path 150 .

[0060] Specifically, in step S2 , when the cleaning liquid is discharged from the discharge nozzle 11 b , the foreign matter detector 120 detects foreign matter.

[0061] The detection result of the foreign matter detector 120 on the foreign matter is output to the control device 13. The detection result output to the control device 13 is stored in a storage device (not shown) together with the total discharge amount of the cleaning liquid until the time point when the detection result is obtained (information about it), specifically, together with the number of times of step S2 (information about it), that is, for example, the number of times the preliminary spraying is performed until the time point when the detection result is obtained. In other words, the detection result of the foreign matter detector 120 output to the control device 13 is stored in the storage device as a history.

[0062] (Step S3b)

[0063] After step S3a, the control device 13 estimates the cleaning completion point at which the detection result of the foreign object detector 120 becomes stable when the total discharge amount of the cleaning liquid increases, based on the history of the detection result of the foreign object detector 120.

[0064] like Figure 6 As shown, as the total discharge volume of the cleaning fluid increases, specifically, as the number of pre-sprays increases, when the number is small, the amount of foreign matter detected by the foreign matter detector 120 decreases significantly, while when the number is large and the cleanliness of the supply flow path 150 increases, the amount of foreign matter hardly decreases or does not decrease at all, that is, it is stable.

[0065] Therefore, the control device 13 estimates the purge completion point as described above, and as will be described later, estimates whether the purge of the supply flow path 150 has been completed based on the estimated purge completion point.

[0066] The control device 13 specifically performs the estimation of the cleaning completion point as follows.

[0067] More specifically, the control device 13 uses a predetermined mathematical model to approximate the history of the amount of foreign matter detected by the foreign matter detector 120 relative to the total discharge amount of the cleaning liquid to obtain an approximate curve. The predetermined mathematical model is a monotonically decreasing function f(x) with the total discharge amount of the cleaning liquid (specifically, the number of pre-sprays) as the variable x, and the function is a function whose differential value gradually approaches zero, that is, a function that converges to a certain value. The control device 13 obtains the value to which the amount of foreign matter detected by the foreign matter detector 120 converges in the approximate curve as the cleaning completion point, that is, the convergence value is estimated as the cleaning completion point.

[0068] More specifically, the control device 13 uses the following formula (X) to approximate the history of the amount of foreign matter detected by the foreign matter detector 120 relative to the total discharge amount of the cleaning fluid (specifically, the number of pre-sprays) to obtain α in the following formula (X) as the cleaning completion point, that is, α is estimated as the cleaning completion point.

[0069] N=(N0-α)*(1 / 2)t / T+α...(X)

[0070] N: The amount of foreign matter detected by the foreign matter detector 120

[0071] N0 = initial value of the amount of foreign matter detected by the foreign matter detector 120

[0072] T = total discharge amount of cleaning fluid until the amount of foreign matter detected by the foreign matter detector 120 is halved

[0073] t = total discharge volume of cleaning fluid

[0074] Note that the above formula (X) Figure 6 The coefficient of determination (i.e., goodness of fit) of the approximate expression F obtained by approximating the data in 2 It is above 0.85.

[0075] (Step S3c)

[0076] After step S3b, the control device 13 estimates whether the cleaning of the supply flow path 150 has been completed based on the cleaning completion point estimated in step S3b.

[0077] Specifically, the control device 13 estimates whether the cleaning of the supply flow path 150 has been completed based on whether the amount of foreign matter detected by the foreign matter detector 120 in step S2 falls within a target range based on the cleaning completion point. The target range is, for example, α (cleaning completion point) ±1%.

[0078] Step S2 (i.e., preliminary spraying) and step S3 may be repeatedly performed, and when the amount of foreign matter detected at the most recent step S2 (i.e., preliminary spraying) falls within the target range based on the cleaning completion point, the control device 13 estimates that the cleaning of the supply flow path 150 has been completed. In addition, when the amount of foreign matter detected at the most recent n (n is a natural number greater than or equal to 2) preliminary spraying continuously falls within the target range, or when the average amount of foreign matter detected at the most recent n preliminary spraying falls within the target range, the control device 13 estimates that the cleaning of the supply flow path 150 has been completed.

[0079] If it is estimated that the cleaning is not yet completed (in the case of "No"), the control device 13 returns the process to step S2 to perform preliminary spraying. In this case, the control device 13 appropriately performs replenishment of the cleaning liquid from the processing liquid bottle 101 to the pump 103.

[0080] On the other hand, when it is estimated that the cleaning has been completed (in the case of “YES”), a series of steps of cleaning the supply channel 150 by the processing liquid supply device 12 is completed.

[0081] Note that, in the case where it is estimated that the cleaning has been completed, the cleaning liquid via the supply flow path 150 and the discharge nozzle 11b may be discharged onto the pseudo wafer under the control of the control device 13. The amount of foreign matter in the cleaning liquid discharged onto the pseudo wafer may be counted by a device external to the coating and developing system 1. This makes it possible to determine whether the cleaning of the supply flow path 150 has actually been completed based on the counting result of the external device.

[0082] In addition, when it is estimated in step S3c that the cleaning has not been completed for more than a predetermined number of times, a warning indicating that the cleaning has not been completed, etc. can be notified by the notification unit (not shown) of the control device 13 (for example, a display unit or a sound output unit).

[0083] Note that, in a case where the estimated cleaning completion point is equal to or greater than a predetermined value, a warning indicating that an abnormality or the like has occurred may be notified by the notification unit.

[0084] <Main Effects of This Embodiment>

[0085] As described above, the cleaning method of the supply flow path 150 according to the present embodiment includes: supplying the cleaning liquid to the discharge nozzle 11b via the supply flow path 50, and discharging the cleaning liquid from the discharge nozzle 11b; and estimating whether the cleaning of the supply flow path has been completed based on the detection result of the foreign matter detector 120 on the foreign matter in the cleaning liquid supplied to the supply flow path 150. In addition, when estimating, the cleaning completion point at which the detection result of the foreign matter detector 120 is stable when the total discharge amount of the cleaning liquid increases is estimated based on the history of the detection result of the foreign matter detector 120, and whether the cleaning of the supply flow path 150 has been completed is estimated based on the cleaning completion point. Therefore, the cleanliness of the supply flow path 150 that can be achieved by the liquid flow (i.e., pre-spraying) of the cleaning liquid can be achieved with a small amount of cleaning liquid. In addition, since the amount of cleaning liquid used is small, the time for the cleaning liquid to pass can be shortened, thereby shortening the time required to clean the supply flow path 150. In addition, since it is not necessary to detect the amount of foreign matter using a device external to the coating and developing system 1, or the number of detections using an external device can be reduced, from this point of view, it is also possible to shorten the time required to clean the supply flow path 150. Therefore, according to this embodiment, it is possible to reduce the amount of cleaning liquid and the time when the supply flow path 150 is cleaned with the cleaning liquid, and improve the convenience during cleaning.

[0086] <Another Example of Cleaning Completion Point Estimation>

[0087] When estimating the cleaning completion point, the control device 13 may exclude the amount of foreign matter exceeding a predetermined value from the history of foreign matter detection by the foreign matter detector 120 and approximate the history after the exclusion using the above-mentioned predetermined mathematical model.

[0088] The predetermined value is determined, for example, based on the amount of foreign matter detected by the foreign matter detector 120, specifically, based on the amount of foreign matter detected in step S2 (ie, the first preliminary spray).

[0089] In the case where there are no foreign matter but bubbles in the cleaning fluid flowing through the supply flow path 150, the amount of light received by the light receiving portion of the foreign matter detector 120 is large, and it appears as if many foreign matter are detected by the foreign matter detector 120. In other words, the bubbles are misdetected as foreign matter. In contrast, by excluding the amount of foreign matter exceeding a predetermined value from the history of the amount of foreign matter used for approximation as described above, it is possible to prevent the estimated result of the cleaning completion point from being affected by the bubbles in the cleaning fluid. Thus, it is possible to prevent the estimated result of whether the cleaning of the supply flow path 150 has been completed from being incorrect due to the influence of the bubbles in the cleaning fluid.

[0090] Note that not only the foreign matter amount exceeding the initial value can be excluded from the history used for approximation, but also the foreign matter amount detected in the detections performed before and after the detection in which the foreign matter amount exceeding the initial value is obtained can be excluded from the history used for approximation.

[0091] <Operation example when the amount of foreign matter exceeds the predetermined value multiple times>

[0092] Before it is estimated that the cleaning of the supply flow path 150 has been completed, the amount of foreign matter exceeding the predetermined value may be detected multiple times.

[0093] In this case, if the frequency with which the foreign matter detector 120 detects an amount of foreign matter exceeding a predetermined value does not decrease, that is, if the frequency of occurrence of bubbles does not decrease, the operation of the processing liquid supply device 12 of step S2 to discharge the cleaning liquid may be changed. Specifically, the operation of discharging the cleaning liquid may be stopped, or the flow rate of the cleaning liquid may be reduced so that bubbles are less likely to be generated. In this case, a warning indicating the fact that bubbles are continuously generated may be notified by the above-mentioned notification unit, etc. In addition, in the case where the pump 103 is configured to be able to perform a degassing process on the liquid in the pump 103, a degassing process of the cleaning liquid in the pump 103 may be performed after the operation of discharging the cleaning liquid is once stopped, and the degassed cleaning liquid may be passed through the supply flow path 150. Note that in the degassing process, decompression of the storage chamber of the cleaning liquid in the pump 103 and removal of bubbles from the storage chamber are performed.

[0094] <Modification of Cleaning Supply Flow Path 150 by Processing Liquid Supply Device 12>

[0095] In the above example, the control device 13 obtains the approximate curve and estimates the cleaning completion point at each step S2 (ie, preliminary spraying). Alternatively, the control device 13 may obtain the approximate curve and estimate the cleaning completion point every time the preliminary spraying is performed m times (m is a natural number greater than 2).

[0096] In addition, the control device 13 can obtain an approximate curve and estimate the cleaning completion point based on the history of the amount of foreign matter detected until an initial predetermined number of pre-sprays (for example, 100 times), and can use the estimated cleaning completion point to estimate whether the cleaning has been completed during the pre-sprays after the predetermined number of times.

[0097] In the above example, the discharge of the cleaning liquid from the discharge nozzle 11b of step S2 is performed continuously, that is, the pre-spray is repeatedly performed until it is estimated that the cleaning of the supply flow path 150 has been completed. Alternatively, the pre-spray can be interrupted for more than 30 minutes before it is estimated that the cleaning of the supply flow path 150 has been completed. The time period for interrupting the pre-spray is, for example, more than 30 minutes and less than 10 hours, but can exceed 10 hours. Through this interruption, the cleaning liquid can be retained in the supply flow path 150 to produce foreign matter (specifically, organic foreign matter, etc.) peculiar to the retention from the filter 104 provided in the supply flow path. The foreign matter peculiar to the retention can be removed by restarting the pre-spray of the cleaning liquid. The time period for interrupting the pre-spray can be, for example, longer than the time required for each processing liquid supply device in the coating and developing system to perform a treatment.

[0098] The preliminary spray is intermittently performed for more than 30 minutes. In other words, the preliminary spray and the preliminary spray are alternately performed and interrupted for more than 30 minutes a plurality of times.

[0099] In addition, whether to perform the interruption again is determined, for example, based on the detection result of the foreign matter detector 120, specifically, based on the detection results of the foreign matter detector 120 before and after the most recent interruption. More specifically, when the amount of foreign matter detected by the foreign matter detector 120 just after the interruption (i.e., just after the restart of the pre-spray) exceeds the amount of foreign matter detected by the foreign matter detector 120 immediately before the interruption, it is determined to perform the interruption again, otherwise, it is determined not to perform the interruption again.

[0100] It should be noted that the timing of restarting the pilot spraying interrupted for more than 30 minutes is, for example, as follows. Specifically, after the pilot spraying is restarted, when the amount of foreign matter detected by the foreign matter detector 120 at the time of the pilot spraying falls within a predetermined range based on the most recently acquired approximate curve, the interruption is restarted. Specifically, after the pilot spraying is restarted, when the amount of foreign matter detected by the foreign matter detector 120 at the p-th pilot spraying (including the pilot spraying before the interruption) falls within ±1% of the amount of foreign matter at the p-th time in the most recently acquired approximate curve, the interruption is restarted.

[0101] The interruption time can be different each time, or can be increased gradually.

[0102] By interrupting the preliminary spraying for more than 30 minutes (specifically, restarting the preliminary spraying afterwards), when the processing liquid is retained in the supply flow path after the cleaning of the supply flow path 150 is completed, the generation of foreign matter that is specific to the retention can be suppressed. Also in this case, whether the cleaning of the supply flow path 150 has been completed is estimated based on the cleaning completion point, so that when foreign matter that is specific to the retention is generated due to the preliminary spraying, the cleanliness of the supply flow path that can be achieved by the preliminary spraying can be achieved in a short time with a small amount of cleaning liquid.

[0103] Furthermore, by repeatedly performing the preliminary spray and interrupting the preliminary spray for more than 30 minutes, the filter or the like that generates foreign matter unique to the stagnation is brought into a state where the foreign matter is unlikely to be generated, that is, the filter or the like is brought into a state that is not affected by the stagnation. Furthermore, by determining whether to perform the interruption again based on the detection result of the foreign matter detector 120, the number of interruptions required to bring the filter or the like into a state that is not affected by the stagnation can be suppressed. Therefore, the filter or the like that is in a state that is not affected by the stagnation can be obtained in a relatively short time.

[0104] <Another Arrangement Example of Foreign Object Detector>

[0105] Figure 7 is a diagram showing another arrangement example of the foreign matter detector 120 .

[0106] Although one foreign matter detector 120 is provided for one supply flow path 150 (i.e., one discharge nozzle 11b) in the above example, Figure 7 As shown, the foreign matter detector 120 may be provided in common among the plurality of supply channels 150 (ie, the plurality of ejection nozzles 11 b ). In this case, for example, the irradiation portion and the light receiving portion of the foreign matter detector 120 are configured to be movable in the arrangement direction of the plurality of supply channels 150 .

[0107] In the case where the foreign matter detector 120 is commonly provided as described above and in the case where a plurality of supply flow paths 150 are cleaned simultaneously, for example, detection by the foreign matter detector 120 is performed so that the detection frequency is equal among the plurality of supply flow paths 150 .

[0108] In the case where the foreign matter detector 120 is collectively provided as described above and in the case where a plurality of supply flow paths 150 are cleaned simultaneously but the start times of their cleaning are different, for example, the detection performed by the foreign matter detector 120 is performed so that the detection frequency is high for the supply flow path 150 which is in the initial stage of cleaning and has a larger amount of detectable foreign matter.

[0109] It should be noted that the estimation based on the history of the detection results of the foreign matter detector 120 in the case where the foreign matter detector 120 is commonly provided as described above is the same as the case where the foreign matter detector 120 is provided for each supply flow path 150 .

[0110] <Other Modifications>

[0111] In the above example, the foreign matter detector 120 is provided on the supply flow path 150, but may be provided in a branch flow path (not shown) branched from the supply flow path 150. The branch flow path specifically branches from a portion on the downstream side of the pump 103 and the filter 104 in the supply flow path 150. In addition, both ends of the branch flow path may be connected to the supply flow path 150 to constitute a circulation flow path together with a portion of the supply flow path, or to constitute a bypass flow path relative to the supply flow path 150.

[0112] The embodiments disclosed herein are examples in all respects and should not be considered as limiting. Various omissions, substitutions, and changes may be made to the embodiments without departing from the scope and spirit of the appended claims. For example, the constituent requirements of the above embodiments may be arbitrarily combined. Of course, operations and effects of the constituent requirements related to the combination may be obtained from any combination, and those skilled in the art may obtain clear other operations and effects from the description herein.

[0113] The effects described herein are only explanatory or illustrative in all aspects, and are not restrictive. According to the description herein, in addition to or in place of the above effects, the technology related to the present disclosure can provide other clear effects to those skilled in the art.

[0114] It should be noted that the following configuration examples also belong to the technical scope of the present disclosure.

[0115] (1) A method for cleaning a supply flow path connected to a discharge portion that discharges a processing liquid onto a substrate, the method comprising:

[0116] Step (A), supplying the cleaning liquid to the discharge portion via the supply flow path, and discharging the cleaning liquid from the discharge portion; and

[0117] Step (B), estimating whether cleaning has been completed based on a detection result of a foreign matter detector, the foreign matter detector being configured to detect foreign matter in the cleaning fluid supplied to the supply flow path, wherein

[0118] The step (B) comprises:

[0119] Step (C), estimating a cleaning completion point at which the detection result of the foreign object detector becomes stable when the total discharge amount of the cleaning liquid increases based on the history of the detection result of the foreign object detector; and

[0120] Step (D), estimating whether cleaning has been completed based on the estimated cleaning completion point.

[0121] (2) The cleaning method according to (1), wherein:

[0122] The step (C) approximates the history of the amount of foreign matter detected by the foreign matter detector using a predetermined mathematical model to obtain an approximate curve, and estimates the value at which the amount of foreign matter converges in the approximate curve as a cleaning completion point; and

[0123] The step (D) determines whether the cleaning has been completed based on whether the amount of foreign matter detected by the foreign matter detector falls within a target range based on the cleaning completion point.

[0124] (3) The cleaning method according to (2), wherein

[0125] The predetermined mathematical model is represented by the following formula (X):

[0126] N=(N0-α)*(1 / 2)t / T+α...(X)

[0127] N: The amount of foreign matter detected by the foreign matter detector

[0128] N0 = initial value of the amount of foreign matter detected by the foreign matter detector

[0129] T = total discharge volume of cleaning fluid until the amount of foreign matter detected by the foreign matter detector is halved

[0130] t = total discharge volume of cleaning fluid

[0131] α = cleaning completion point.

[0132] (4) The cleaning method according to (2) or (3), wherein

[0133] In the approximation in (C), the foreign matter amount exceeding a predetermined value is excluded from the history of the foreign matter amount detected by the foreign matter detector, and the history after the exclusion is approximated using the predetermined mathematical model.

[0134] (5) The cleaning method according to (4), wherein

[0135] If the frequency of detecting the amount of foreign matter exceeding the predetermined value does not decrease, the discharge operation of discharging the cleaning liquid is changed.

[0136] (6) The cleaning method according to any one of (1) to (5), further comprising:

[0137] The step (A) is interrupted for more than 30 minutes before the cleaning is estimated to be completed in the step (B).

[0138] (7) The cleaning method according to (6), wherein the step (A) and interruption of the step (A) for 30 minutes or more are performed alternately a plurality of times.

[0139] (8) A non-transitory computer-readable storage medium storing a program running on a computer of a control device, the control device being configured to control a processing liquid supply device so that the processing liquid supply device executes a method for cleaning a supply flow path connected to a discharge portion that discharges a processing liquid onto a substrate,

[0140] The processing liquid supply device has the supply flow path,

[0141] The method comprises the following steps:

[0142] Step (A), supplying the cleaning liquid to the discharge portion via the supply flow path, and discharging the cleaning liquid from the discharge portion; and

[0143] Step (B), estimating whether cleaning has been completed based on a detection result of a foreign matter detector, the foreign matter detector being configured to detect foreign matter in the cleaning fluid supplied to the supply flow path, wherein

[0144] The step (B) comprises:

[0145] Step (C), estimating a cleaning completion point at which the detection result of the foreign object detector becomes stable when the total discharge amount of the cleaning liquid increases based on the history of the detection result of the foreign object detector; and

[0146] Step (D), estimating whether cleaning has been completed based on the estimated cleaning completion point.

[0147] (9) A control device for supplying a processing liquid to a discharging portion for discharging the processing liquid onto a substrate,

[0148] The processing liquid supply device has a supply flow path connected to the discharge portion,

[0149] The control device controls the treatment liquid supply device to perform:

[0150] Step (A), supplying the cleaning liquid to the discharge portion via the supply flow path, and discharging the cleaning liquid from the discharge portion; and

[0151] Step (B), estimating whether cleaning has been completed based on a detection result of a foreign matter detector, the foreign matter detector being configured to detect foreign matter in the cleaning fluid supplied to the supply flow path, wherein

[0152] The step (B) comprises:

[0153] Step (C), estimating a cleaning completion point at which the detection result of the foreign object detector becomes stable when the total discharge amount of the cleaning liquid increases based on the history of the detection result of the foreign object detector; and

[0154] Step (D), estimating whether cleaning has been completed based on the estimated cleaning completion point.

[0155] According to the present disclosure, when the supply flow path connected to the discharge portion that discharges the processing liquid to the substrate is cleaned with the cleaning liquid, the convenience can be improved.

Claims

1. A cleaning method for a supply flow path, the supply flow path being connected to a discharge portion for discharging a processing liquid toward a substrate, the cleaning method comprising: Step (A), supplying the cleaning liquid to the discharge portion via the supply flow path, and discharging the cleaning liquid from the discharge portion; as well as Step (B), estimating whether cleaning has been completed based on a detection result of a foreign matter detector, the foreign matter detector being configured to detect foreign matter in the cleaning fluid supplied to the supply flow path, wherein The step (B) comprises: Step (C), estimating, based on the history of the detection results of the foreign object detector, that the detection results of the foreign object detector reach a stable cleaning completion point when the total discharge amount of the cleaning liquid increases; and Step (D), estimating whether cleaning has been completed based on the estimated cleaning completion point.

2. The cleaning method according to claim 1, wherein: The step (C) approximates the history of the amount of foreign matter detected by the foreign matter detector using a predetermined mathematical model to obtain an approximate curve, and estimates the value at which the amount of foreign matter converges in the approximate curve as a cleaning completion point; and The step (D) determines whether the cleaning has been completed based on whether the amount of foreign matter detected by the foreign matter detector falls within a target range based on the cleaning completion point.

3. The cleaning method according to claim 2, wherein The predetermined mathematical model is represented by the following formula (X): N=(N0-α)*(1 / 2)t / T+α...(X) N: The amount of foreign matter detected by the foreign matter detector N0: The initial value of the amount of foreign matter detected by the foreign matter detector T: The total discharge volume of the cleaning fluid until the amount of foreign matter detected by the foreign matter detector is halved t: Total discharge volume of cleaning fluid α: Cleaning completion point.

4. The cleaning method according to claim 2, wherein In the approximation in the step (C), the foreign matter amount exceeding a predetermined value is excluded from the history of the foreign matter amount detected by the foreign matter detector, and the history after the exclusion is approximated using the predetermined mathematical model.

5. The cleaning method according to claim 4, wherein If the frequency of detecting the amount of foreign matter exceeding the predetermined value does not decrease, the discharge operation of discharging the cleaning liquid is changed.

6. The cleaning method according to claim 1, further comprising: The step (A) is interrupted for more than 30 minutes before the cleaning is estimated to be completed in the step (B).

7. The cleaning method according to claim 6, wherein The step (A) and interruption of the step (A) for more than 30 minutes are performed alternately multiple times.

8. A non-transitory computer-readable storage medium storing a program running on a computer of a control device, the program being used to control a processing liquid supply device so that the processing liquid supply device executes a method for cleaning a supply flow path connected to a discharge portion that discharges a processing liquid to a substrate, The processing liquid supply device has the supply flow path, and the method includes: Step (A), supplying the cleaning liquid to the discharge portion via the supply flow path, and discharging the cleaning liquid from the discharge portion; as well as Step (B), estimating whether cleaning has been completed based on a detection result of a foreign matter detector, the foreign matter detector being configured to detect foreign matter in the cleaning fluid supplied to the supply flow path, wherein the step (B) comprises: Step (C), based on the history of the detection results of the foreign object detector, estimating that the detection results of the foreign object detector reach a stable cleaning completion point when the total discharge amount of the cleaning liquid increases; as well as Step (D), estimating whether cleaning has been completed based on the estimated cleaning completion point.

9. A control device for supplying a processing liquid to a discharging portion for discharging the processing liquid to a substrate, The processing liquid supply device has a supply flow path connected to the discharge portion, The control device controls the treatment liquid supply device to perform: Step (A), supplying the cleaning liquid to the discharge portion via the supply flow path, and discharging the cleaning liquid from the discharge portion; as well as Step (B), estimating whether cleaning has been completed based on a detection result of a foreign matter detector, wherein the foreign matter detector is configured to detect foreign matter in the cleaning fluid supplied to the supply flow path, wherein The step (B) comprises: Step (C), estimating, based on the history of the detection results of the foreign object detector, that the detection results of the foreign object detector reach a stable cleaning completion point when the total discharge amount of the cleaning liquid increases; as well as Step (D), estimating whether cleaning has been completed based on the estimated cleaning completion point.

Images