Cleaning method, computer storage medium, and control apparatus

Abstract

To improve a convenience when cleaning a supply channel connected to a discharge part discharging a processing liquid to a substrate with a cleaning liquid.SOLUTION: A method of cleaning a supply channel connected to a discharge part discharging a processing liquid to a substrate, includes: a step (A) of discharging a cleaning liquid from the discharge part by supplying the cleaning liquid to the discharge part via the supply channel; and a step (B) of estimating whether or not a cleaning is completed on the basis of a detection result by a foreign matter detection device detecting a foreign matter in the cleaning liquid supplied to the supply channel. The (B) includes: a step (C) of estimating a cleaning completion point that the detection result is stable by the foreign matter detection device when a total discharging amount of the cleaning liquid is increased on the basis of a history of the detection result by the foreign matter detection device; and a step (D) of estimating whether or not the cleaning is completed on the basis of the cleaning completion point to be estimated.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a cleaning method, a computer storage medium, and a control device. [Background technology]

[0002] Patent Document 1 discloses that in order to eliminate defects caused by the presence of air bubbles in a resist supply pipe connected to a resist nozzle or particles in the resist, a dummy dispense of the resist nozzle is performed upon detecting the air bubbles or particles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-218022 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure improves convenience when cleaning, with a cleaning liquid, a supply flow path connected to a discharge part that discharges a processing liquid onto a substrate. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for cleaning a flow path connected to a discharge unit that discharges a processing liquid onto a substrate, the method including: (A) supplying a cleaning liquid to the discharge unit through the flow path and discharging the cleaning liquid from the discharge unit; and (B) estimating whether or not cleaning has been completed based on a detection result by a foreign matter detector that detects foreign matter in the cleaning liquid supplied to the flow path, (B) includes (C) estimating a cleaning completion point at which the detection result by the foreign matter detector becomes stable when the total discharge amount of the cleaning liquid increases based on a history of the detection results by the foreign matter detector, and (D) estimating whether the cleaning is completed or not based on the estimated cleaning completion point. Effect of the Invention

[0006] According to the present disclosure, it is possible to improve the convenience when cleaning, with a cleaning liquid, a supply flow path connected to a discharge part that discharges a treatment liquid onto a substrate. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an outline of the configuration of a coating and developing system as a substrate processing system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram showing an outline of the configuration of a treatment liquid supplying device. [Diagram 3] 5A and 5B are diagrams illustrating a state of the treatment liquid supplying device during a normal discharge operation. [Figure 4] 10 is a flowchart for explaining an example of cleaning of a supply flow path by the treatment liquid supply device. [Diagram 5] 11A and 11B are diagrams illustrating a state of the treatment liquid supplying device when the supply flow path is cleaned. [Figure 6] 13A and 13B are diagrams illustrating an example of a detection result of a foreign matter detector when a supply flow path is cleaned. [Figure 7] FIG. 13 is a diagram showing another example of the arrangement of the foreign object detector. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In photolithography processes in the manufacturing process of semiconductor devices and the like, processing liquids such as resist liquid and developer liquid are used to form coating films such as resist films on substrates such as semiconductor wafers (hereinafter referred to as "wafers") and to develop resist films after exposure. In liquid processing apparatuses that process substrates with processing liquids, the processing liquid is discharged onto the substrate from a discharge nozzle, which is a discharge section. The processing liquid is supplied to the discharge nozzle via a supply flow path.

[0009] The processing liquid from the discharge nozzle may contain foreign matter (particles). Even if the original processing liquid does not contain foreign matter, if foreign matter is attached to the supply flow path connected to the discharge nozzle, the foreign matter may be mixed into the processing liquid discharged from the discharge nozzle. For this reason, a filter is provided in the supply flow path to the discharge nozzle to remove the foreign matter.

[0010] However, even if a filter is provided, foreign matter generated in the supply flow path downstream of the filter cannot be removed. For this reason, a dummy dispense is performed before operating a liquid processing apparatus, in which a cleaning liquid is discharged from a discharge nozzle through a supply flow path to clean the supply flow path. However, the conventional technology related to the dummy dispense has room for improvement in terms of convenience. For example, in the past, after a dummy dispense is performed until a predetermined amount of cleaning liquid is passed through, the amount of foreign matter in the cleaning liquid discharged from the discharge nozzle is detected by a device provided outside the substrate processing system in which the liquid processing apparatus is mounted, and thereafter, the dummy dispense and the detection of the amount of foreign matter using a device outside the system are alternately performed until the amount of foreign matter becomes equal to or less than a predetermined value. In this method, a large amount of cleaning liquid and a long time are required to clean the supply flow path.

[0011] In view of this, the technology according to the present disclosure improves the convenience when cleaning, with a cleaning liquid, a supply flow path connected to a discharge part that discharges a processing liquid onto a substrate.

[0012] Hereinafter, a cleaning method and a control device for a processing liquid supplying device according to the present embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0013] <Coating and developing system> FIG. 1 is a diagram illustrating a schematic configuration of a coating and developing system as a substrate processing system according to the present embodiment. The coating and developing system 1 in FIG. 1 is a semiconductor manufacturing device, and specifically, it forms a resist film on a wafer as a substrate, develops the resist film after exposure, heats the wafer before exposure, and heats the wafer after exposure.

[0014] For example, the coating and developing system 1 includes a liquid treatment device 11, a treatment liquid supply device 12, and a control device 13.

[0015] The liquid processing device 11 includes a resist film forming device that applies a resist as a processing liquid onto a wafer to form a resist film, and a developing device that supplies a developing liquid as a processing liquid to the exposed wafer and develops the resist film on the wafer.

[0016] Each liquid processing device 11 has a spin chuck (see reference numeral 11a in FIG. 2 described later) as a holding part for holding a wafer, and a discharge nozzle (see reference numeral 11b in FIG. 2 described later) as a discharge part for discharging a processing liquid onto the wafer. The spin chuck specifically holds the wafer so that it can rotate. The discharge nozzle specifically discharges a processing liquid onto the wafer held by the spin chuck.

[0017] Furthermore, each liquid processing device 11 applies the processing liquid to the wafer by a spin coating method, in which the processing liquid is discharged onto the wafer from a discharge nozzle and the wafer is rotated to spread the processing liquid over the surface of the wafer. Each liquid processing device may have a known configuration.

[0018] The processing liquid supplying device 12 supplies the processing liquid to the discharge nozzle of the liquid processing device 11. This causes the processing liquid to be discharged from the discharge nozzle. A specific configuration of the processing liquid supplying device 12 will be described later.

[0019] The control device 13 controls at least the processing liquid supply device 12. The control device 13 may also function as a control device that controls the entire coating and developing system 1. The control device 13 may also constitute a part of the processing liquid supply device 12. The control device 13 is a computer equipped with a processor such as a CPU and a memory, and has a program storage unit (not shown) for storing a program including instructions executed by the processor. The program storage unit stores a program including instructions for the processing liquid supply device 12 to supply the processing liquid to the discharge nozzle, and a program including instructions for the processing liquid supply device 12 to clean a supply flow path, which will be described later. When the control device 13 also serves as a control device for controlling the entire coating and developing system 1, the program storage unit also stores a program including instructions for wafer processing by the coating and developing system 1. The above program may be recorded in a computer-readable storage medium M and installed from the storage medium M to the control device 13. The storage medium M may be a medium for temporary storage or a medium for non-temporary storage.

[0020] The coating and developing system 1 is provided with a cassette station (not shown) and a wafer transport mechanism (not shown). The cassette station is used to load and unload cassettes containing multiple wafers. The wafer transport mechanism is used to transport wafers between the cassette station and various processing devices, and between various processing devices.

[0021] <Processing liquid supply device 12> FIG. 2 is an explanatory diagram showing an outline of the configuration of the treatment liquid supplying device 12. As shown in FIG. 2 supplies a processing liquid to the discharge nozzle 11b of the liquid processing apparatus 11 as described above. The processing liquid supplied by the processing liquid supply apparatus 12 and discharged from the discharge nozzle 11b may differ depending on the discharge nozzle 11b, and may be, for example, a resist liquid or a developing liquid.

[0022] The processing liquid supply device 12 includes a supply flow path 150 connected to the discharge nozzle 11b. For example, one end of the supply flow path 150 is connected to the discharge nozzle 11b, and the other end is connected to a processing liquid bottle 101 serving as a processing liquid supply source.

[0023] The processing liquid bottle 101 stores the processing liquid therein and is replaceable. A supply flow path 151 having an on-off valve V1 is also connected to the processing liquid bottle 101. The supply flow path 151 connects the processing liquid bottle 101 to a gas supply source 110, which is a supply source of an inert gas such as nitrogen gas, and the processing liquid bottle 101, and an electropneumatic regulator 111 for adjusting pressure is provided upstream of the on-off valve V1. In addition, instead of the processing liquid bottle 101, a storage source of the processing liquid constituting the equipment in the factory in which the coating and developing system 1 is installed may be used.

[0024] In the supply flow path 150, a buffer tank 102, a pump 103, and a filter 104 are provided in this order from the upstream side. An on-off valve V2 is provided between the processing liquid bottle 101 and the buffer tank 102 in the supply flow path 150. An on-off valve V3 is provided between the buffer tank 102 and the pump 103 in the supply flow path 150. An on-off valve V4 is provided between the pump 103 and the filter 104 in the supply flow path 150. An on-off valve V5 and a supply control valve V6 are provided in this order from the upstream side in the supply flow path 150 between the filter 104 and the discharge nozzle 11b.

[0025] The buffer tank 102 is a storage unit that stores the processing liquid transferred from the processing liquid bottle 101 and sent to the pump 103. The buffer tank 102 is provided with a liquid level sensor (not shown) that detects the remaining amount of the processing liquid, and opening / closing valves V1 and V2 are opened and closed in response to the detection result of the liquid level sensor, and the supply of the processing liquid from the processing liquid bottle 101 to the buffer tank 102, i.e., replenishment, is started and stopped.

[0026] The pump 103 pumps the processing liquid. The pump 103 is, for example, a variable displacement pump, and more specifically, a diaphragm pump. The pump 103 may also be configured to suck the processing liquid from the buffer tank 102. The filter 104 filters the processing liquid to remove foreign matter. Specifically, the filter 104 filters the processing liquid sent out from the pump 103 to remove foreign matter from the processing liquid.

[0027] Furthermore, the processing liquid supplying 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, downstream 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.

[0028] A known configuration can be used for the foreign matter detector 120. For example, the foreign matter detector 120 has an irradiation unit (not shown) that irradiates light onto the processing liquid flowing through the supply flow path 150, a light receiving unit (not shown) that receives the light irradiated by the irradiation unit and reflected by foreign matter in the processing liquid flowing through the supply flow path 150, and a control unit (not shown) that detects foreign matter based on the light reception result at 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 mounted. In addition, the control unit of the foreign matter detector 120 specifically calculates, i.e., detects, the number of foreign matter based on the light reception result at the light receiving unit. The detection result by foreign object detector 120 (specifically, the measurement result of the amount of foreign object by foreign object detector 120) is output to control device 13. The detection result by foreign object detector 120 output to control device 13 is specifically a detection signal corresponding to the detection result, and more specifically, a detection signal with a strength corresponding to the amount of foreign object detected.

[0029] Each valve provided in the processing liquid supplying device 12 is an electromagnetic valve or an air-operated valve that can be controlled by the control device 13, and each valve is electrically connected to the control device 13. The control device 13 is also electrically connected to the pump 103. With this configuration, the discharge of the processing liquid by the processing liquid supplying device 12 and the cleaning of the supply flow path 150 can be automatically performed under the control of the control device 13.

[0030] <Normal Discharge Operation of the Treatment Liquid Supplying Device 12> Next, the normal discharge operation of the treatment liquid supplying device 12 will be described with reference to Fig. 3. Fig. 3 is a diagram showing the state of the treatment liquid supplying device 12 during the normal discharge operation. In Fig. 3, valves in an open state are painted white, valves in a closed state are painted black, and pipes through which the treatment liquid flows are shown by thick lines. The same applies to Fig. 5 described later. Note that, before the normal discharge operation described below, the supply flow path 150 is assumed to be filled with the treatment liquid in advance.

[0031] 3, during normal discharge of the processing liquid from the discharge nozzle 11b onto the product wafer W, the on-off valves V3 to V5 and the supply control valve V6 are opened and the pump 103 is driven under the control of the controller 13. As a result, a predetermined amount of the processing liquid filled downstream of the pump 103 in the supply flow path 150 (and the processing liquid delivered from the pump 103) is supplied toward the discharge nozzle 11b and discharged onto the product wafer W via the discharge nozzle 11b.

[0032] <Example of cleaning of supply flow path 150 by treatment liquid supply device 12> An example of cleaning of the supply flow path 150 by the processing liquid supply device 12 will be described with reference to FIGS. 4 to 6. FIG. 4 is a flow chart for explaining the above example. FIG. 5 is a diagram showing the state of the processing liquid supply device 12 when cleaning the supply flow path 150. FIG. 6 is a diagram showing an example of the detection result of the foreign matter detector 120 when cleaning the supply flow path 150, and is a diagram showing the result when PGMEA is used as the cleaning liquid. In FIG. 6, the horizontal axis indicates the number of steps S2 corresponding to the total amount of cleaning liquid discharged from the discharge nozzle 11b, that is, the number of dummy dispenses, and the vertical axis indicates the amount of foreign matter per ml (hereinafter, abbreviated as "amount of foreign matter"), which is the detection result of foreign matter by the foreign matter detector 120. Note that cleaning of the supply flow path 150 is performed, for example, when the processing liquid supply device 12 is started up or when the type of processing liquid discharged from the discharge nozzle 11b is changed.

[0033] (Step S1) For example, first, under the control of the control device 13, the supply flow passage 150 is filled with the cleaning liquid as shown in FIG. The cleaning liquid is a processing liquid that is supplied to the discharge nozzle 11b through the supply flow passage 150 after the supply flow passage 150 has been cleaned, or a chemical liquid other than the above processing liquid that is suitable for cleaning. When the cleaning liquid is the above-mentioned processing liquid, in this step S1, for example, the on-off valves V1 to V5 are opened as shown in Fig. 5. 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 sent out from the processing liquid bottle 101, and the supply flow path 150 is filled with the cleaning liquid from the processing liquid bottle 101 to the supply control valve V6.

[0034] (Step S2) Next, under the control of the control device 13, the cleaning liquid is supplied to the discharge nozzle 11b via the supply flow path 150, and the cleaning liquid is discharged from the discharge nozzle 11b. That is, a dummy dispense is performed. Specifically, similarly to the normal discharge described above, the on-off valves V1 and V2 are closed, and the on-off valves V3 to V5 and the supply control valve V6 are opened under the control of the control device 13, and the pump 103 is driven. As a result, a predetermined amount of the cleaning liquid filled in the supply flow path 150 downstream of the pump 103 (and the cleaning liquid delivered from the pump 103) is supplied toward the discharge nozzle 11b and discharged through the discharge nozzle 11b.

[0035] (Step S3) Furthermore, the control device 13 estimates whether or not cleaning of the supply flow passage 150 has been completed based on the result of detection of foreign matter in the cleaning liquid supplied to the supply flow passage 150 by the foreign matter detector 120. This step S3 includes steps S3a, S3b, and S3c. As is clear from Fig. 4, step S2, i.e., the pre-dispense, and step S3 can be repeated.

[0036] (Step S3a) In this step, under the control of the controller 13, the foreign matter detector 120 detects foreign matter in the cleaning liquid supplied to the supply flow passage 150. Specifically, when the cleaning liquid is discharged from the discharge nozzle 11b in step S2, the foreign matter detector 120 detects foreign matter. The result of detection of foreign matter by foreign matter detector 120 is output to control device 13. The detection result output to control device 13 is stored in a memory unit (not shown) together with (information about) the total amount of cleaning liquid dispensed up to the time when the detection result was obtained, specifically, for example, together with (information about) the number of times step S2, i.e., the number of dummy dispenses, performed up to the time when the detection result was obtained. That is, the detection result by foreign matter detector 120 output to control device 13 is stored in the memory unit as history.

[0037] (Step S3b) After step S3a, the control device 13 estimates the cleaning completion point at which the detection result by the foreign matter detector 120 becomes stable when the total discharge amount of the cleaning liquid increases, based on the history of the detection result by the foreign matter detector 120. As shown in FIG. 6, when the total amount of cleaning liquid discharged increases, specifically when the number of dummy dispenses increases, the number of foreign matter detected by foreign matter detector 120 decreases significantly while the number of dummy dispenses is low. However, as the number of dummy dispenses increases and the cleanliness of supply flow path 150 increases, the number of foreign matter decreases little or not at all, i.e., stabilizes. Therefore, the control device 13 estimates the cleaning completion point as described above, and also estimates whether or not cleaning of the supply flow passage 150 has been completed based on the estimated cleaning completion point, as will be described later.

[0038] Specifically, the control device 13 estimates the cleaning completion point as follows. That is, the control device 13 approximates the history of the amount of foreign matter detected by the foreign matter detector 120 relative to the total amount of cleaning liquid discharged with a predetermined mathematical model, and obtains an approximation curve. The predetermined mathematical model is a monotonically decreasing function f(x) with the total amount of cleaning liquid discharged (specifically, the number of dummy dispenses) as the variable x, and is a function whose differential value gradually approaches zero, i.e., a function that converges to a certain value. Then, the control device 13 obtains the value at which the amount of foreign matter detected by the foreign matter detector 120 converges on the approximation curve as the cleaning completion point, that is, it estimates the converged value as the cleaning completion point. More specifically, the control device 13 approximates the history of the amount of foreign matter detected by the foreign matter detector 120 relative to the total amount of cleaning liquid discharged (specifically, the number of dummy dispenses) using the following formula (X), and obtains α in the following formula (X) as the cleaning completion point, i.e., estimates α as the cleaning completion point. N = (N0-α) * (1 / 2) t / T +α …(X) N: Amount of foreign matter detected by the foreign matter detector 120 N0: Initial value of the amount of foreign matter detected by the foreign matter detector 120 T: The total amount of cleaning liquid discharged until the amount of foreign matter detected by the foreign matter detector 120 is reduced by half t: Total amount of cleaning solution dispensed

[0039] The coefficient of determination (i.e., goodness of fit) R of the approximation formula F obtained by approximating the data in Figure 6 using the above formula (X) 2 was above 0.85.

[0040] (Step S3c) After step S3b, the control device 13 estimates whether or not cleaning of the supply flow passage 150 has been completed based on the cleaning completion point estimated in step S3b. Specifically, the control device 13 estimates whether cleaning of the supply flow path 150 is completed based on whether the number of particles detected by the particle detector 120 in step S2 is within a target range based on the cleaning completion point. The target range is, for example, the above-mentioned α (cleaning completion point) ±1%. Step S2, i.e., dummy dispensing, and step S3 may be performed repeatedly, and for example, when the amount of foreign matter detected in the most recent step S2, i.e., dummy dispensing, falls within a target range based on the cleaning completion point, the control device 13 estimates that cleaning of the supply flow path 150 has been completed. Also, when the amount of foreign matter detected in the most recent n dummy dispensings (n is a natural number of 2 or more) consecutively falls within the target range, or when the average amount of foreign matter detected in the most recent n dummy dispensings falls within the target range, the control device 13 estimates that cleaning of the supply flow path 150 has been completed.

[0041] If it is estimated that the cleaning is not completed (if NO), the control device 13 returns the process to step S2 and executes a dummy dispense. At that time, the control device 13 appropriately causes the pump 103 to replenish with the cleaning liquid from the processing liquid bottle 101. On the other hand, if it is estimated that the cleaning is completed (if YES), the series of steps for cleaning the supply flow passage 150 by the processing liquid supplying device 12 is completed.

[0042] When it is estimated that the cleaning is completed, the cleaning liquid may be discharged onto the dummy wafer via the supply flow path 150 and the discharge nozzle 11b under the control of the control device 13. Then, the number of foreign matter particles in the cleaning liquid discharged onto the dummy wafer may be measured by a device external to the coating and developing system 1. This makes it possible to determine whether or not the cleaning of the supply flow path 150 has actually been completed based on the measurement result by the external device.

[0043] In addition, if it is determined in step S3c that the cleaning is not complete a predetermined number of times, a warning indicating that the cleaning cannot be completed may be issued by an alarm means (not shown) such as a display means or audio output means provided in the control device 13. If the estimated cleaning completion point is equal to or greater than a predetermined value, a warning indicating that an abnormality has occurred may be issued by the notification means.

[0044] <Main Effects of This Embodiment> As described above, the method for cleaning the supply flow path 150 according to the present embodiment includes a step of supplying the cleaning liquid to the discharge nozzle 11b via the supply flow path 150 and discharging the cleaning liquid from the discharge nozzle 11b, and a step of estimating whether or not cleaning of the supply flow path 150 has been completed based on the detection result by the foreign matter detector 120 of the foreign matter in the cleaning liquid supplied to the supply flow path 150. In addition, in the estimation step, a cleaning completion point at which the detection result by the foreign matter detector 120 becomes stable when the total discharge amount of the cleaning liquid increases is estimated based on the history of the detection result by the foreign matter detector 120, and whether or not cleaning of the supply flow path 150 has been completed is estimated based on the cleaning completion point. Therefore, it is possible to achieve the cleanliness of the supply flow path 150 that can be achieved by passing the cleaning liquid, i.e., by dummy dispensing, with a small amount of cleaning liquid. In addition, since the amount of cleaning liquid used is small, the time for passing the cleaning liquid can be shortened, and the time required for cleaning the supply flow path 150 can be shortened. Furthermore, since it is not necessary to detect the number of foreign matters using an external device of the coating and developing system 1, or the number of times the detection is required can be reduced, also from this viewpoint, it is 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 required to clean the supply flow path 150 with the cleaning liquid, and it is possible to improve the convenience during the cleaning.

[0045] <Another example of estimating the cleaning completion point> When estimating the cleaning completion point, the control device 13 may exclude amounts of foreign matter exceeding a predetermined value from the history of the amounts of foreign matter detected by the foreign matter detector 120, and approximate the above history after exclusion using the aforementioned specified mathematical model. The above-mentioned predetermined value is, for example, the amount of foreign matter detected by the foreign matter detector 120, specifically, the amount of foreign matter detected at the first time of step S2, that is, at the time of pre-dispense.

[0046] When bubbles, rather than foreign matter, are present in the cleaning liquid flowing through the supply flow path 150, the amount of light received by the light receiving section of the foreign matter detector 120 increases, and it appears as if the foreign matter detector 120 has detected a large number of foreign matters. In other words, the bubbles are erroneously detected as foreign matters. In response to this, as described above, by excluding the amount of foreign matter exceeding a predetermined value from the history of the amount of foreign matter used for approximation, it is possible to prevent the estimation result of the cleaning completion point from being influenced by bubbles in the cleaning liquid. As a result, it is possible to prevent the estimation result of whether or not cleaning of the supply flow path 150 has been completed from being inaccurate due to the influence of bubbles in the cleaning liquid.

[0047] In addition, not only the amount of foreign matter exceeding the initial value, but also the amount of foreign matter detected in detections performed before and after the detection in which the amount of foreign matter exceeding the initial value was obtained may be excluded from the history used for approximation.

[0048] <Example of operation when the amount of foreign matter exceeding the specified value is detected multiple times> There may be cases where the amount of foreign matter exceeding the predetermined value is detected multiple times until it is estimated that cleaning of the supply flow passage 150 is completed. In this case, if the frequency at which the amount of foreign matter exceeding the predetermined value is detected by the foreign matter detector 120 does not decrease, that is, if the frequency at which bubbles are generated does not decrease, the discharge operation of the cleaning liquid by the processing liquid supply device 12 in step S2 may be changed. Specifically, the discharge operation of the cleaning liquid may be stopped, or the flow rate of the cleaning liquid may be slowed down so that bubbles are less likely to be generated. In this case, a warning indicating that bubbles are being generated continuously may be issued by the above-mentioned notification means. In addition, if the pump 103 is configured to be capable of degassing the liquid in the pump 103, the discharge operation of the cleaning liquid may be stopped once, and then the cleaning liquid in the pump 103 may be degassed, and the degassed cleaning liquid may be passed through the supply flow path 150. In addition, in the degassing process, the pressure in the storage chamber of the cleaning liquid in the pump 103 is reduced, and bubbles are removed from the storage chamber.

[0049] <Modification of cleaning of supply flow path 150 by treatment liquid supply device 12> In the above example, the control device 13 obtains an approximation curve and estimates the cleaning completion point every time step S2 is performed, i.e., every time a dummy dispense is performed. Alternatively, the control device 13 may obtain an approximation curve and estimate the cleaning completion point every time a dummy dispense is performed m times (m is a natural number of 2 or more). In addition, the control device 13 may obtain an approximation curve and estimate the cleaning completion point based on the history of the number of foreign matter detected up to the first predetermined number of dummy dispenses (e.g., 100 times), and use this estimated cleaning completion point to estimate whether cleaning is completed when dummy dispenses are performed after the predetermined number of times.

[0050] In the above example, the cleaning liquid is continuously discharged from the discharge nozzle 11b in step S2 until it is estimated that the cleaning of the supply flow path 150 is completed, that is, the dummy dispensing is repeatedly performed. Alternatively, the dummy dispensing may be interrupted for 30 minutes or more before it is estimated that the cleaning of the supply flow path 150 is completed. The time for interrupting the dummy dispensing is, for example, 30 minutes or more and 10 hours or less, but may be longer than 10 hours. This interruption may cause the cleaning liquid to remain in the supply flow path 150, and may cause foreign matter (specifically, organic foreign matter, etc.) specific to the retention of the cleaning liquid to be generated from the filter 104, etc., interposed in the supply flow path 150. This foreign matter specific to the retention of the cleaning liquid can be removed by resuming the dummy dispensing of the cleaning liquid. The time for interrupting the dummy dispensing may be set to be longer than the processing time of one process by each liquid processing device in the coating and developing system 1, for example.

[0051] The interruption of dummy dispensing for 30 minutes or more is performed intermittently, i.e., dummy dispensing and interruption of dummy dispensing for 30 minutes or more are each repeated alternately multiple times. Furthermore, whether or not to perform the interruption again is determined based on, for example, the detection result by foreign object detector 120, specifically, based on the detection results by foreign object detector 120 before and after the most recent interruption. More specifically, if the amount of foreign objects detected by foreign object detector 120 immediately after the interruption, i.e., immediately after the resumption of the pre-dispense, exceeds the amount of foreign objects detected by foreign object detector 120 immediately before the interruption, it is determined that the interruption is to be performed again, and in other cases, it is determined that the interruption is not to be performed again.

[0052] The timing for resuming pre-dispense after an interruption of 30 minutes or more is, for example, as follows: That is, after pre-dispense is resumed, when the amount of foreign matter detected by foreign matter detector 120 during pre-dispense falls within a predetermined range based on the most recently acquired approximation line, the interruption is resumed. Specifically, after pre-dispense is resumed, when the amount of foreign matter detected by foreign matter detector 120 during the pth pre-dispense (including the pre-dispense before the interruption) falls within ±1% of the amount of foreign matter at the pth pre-dispense on the most recently acquired approximation line, the interruption is resumed. The duration of the interruption may vary from one session to the next, and may be gradually increased.

[0053] As in this example, by interrupting the dummy dispense for 30 minutes or more (specifically, by resuming the dummy dispense thereafter), it is possible to suppress the generation of foreign matter specific to the above-mentioned stagnation when the processing liquid stagnates in the supply flow path 150 after the cleaning of the supply flow path 150 is completed. In this example as well, since it is estimated whether or not the cleaning of the supply flow path 150 is completed based on the cleaning completion point, it is possible to reach the cleanliness of the supply flow path 150 that can be achieved by the dummy dispense in a short time with a small amount of cleaning liquid when foreign matter specific to stagnation occurs due to the dummy dispense.

[0054] Furthermore, by repeatedly performing dummy dispensing and interrupting the dummy dispensing for 30 minutes or more, filters that generate foreign matter specific to retention can be brought into a state in which the same foreign matter is unlikely to occur, that is, the filters are free from the influence of retention. Furthermore, since whether or not to repeat the interruption is determined based on the detection result by the foreign matter detector 120, the number of interruptions required to make the filters free from the influence of retention can be reduced. Therefore, filters free from the influence of retention can be obtained in a relatively short time.

[0055] <Other examples of placement of foreign object detectors> FIG. 7 is a diagram showing another example of the arrangement of the foreign object detector 120. In FIG. In the above example, one foreign object detector 120 is provided for one supply flow path 150, i.e., one discharge nozzle 11b, but as shown in Fig. 7, the foreign object detector 120 may be provided in common between a plurality of supply flow paths 150, i.e., between a plurality of discharge nozzles 11b. In this case, for example, the above-mentioned irradiation unit and light receiving unit of the foreign object detector 120 are configured to be movable in the arrangement direction of the plurality of supply flow paths 150.

[0056] When the foreign matter detector 120 is provided in common as described above and cleaning of multiple supply flow paths 150 is performed simultaneously, for example, detection by the foreign matter detector 120 is performed so that the detection frequency is equal among the supply flow paths 150.

[0057] In the case where the foreign object detector 120 is provided in common as described above, and cleaning of multiple supply flow paths 150 is performed simultaneously but at different cleaning start times, for example, detection by the foreign object detector 120 is performed so as to have a higher detection frequency for the supply flow path 150 which is in the early stages of cleaning and has a large number of detectable foreign objects.

[0058] In addition, in the case where the foreign object detector 120 is provided in common as described above, the estimation based on the history of the detection results of the foreign object detector 120 is similar to the case where the foreign object detector 120 is provided for each supply flow path 150.

[0059] <Other Modifications> In the above example, the foreign object detector 120 is provided in the supply flow path 150, but it may be provided in a branch flow path (not shown) branched off from the supply flow path 150. Specifically, the branch flow path branches off from a portion of the supply flow path 150 downstream of the pump 103 and the filter 104. In addition, the branch flow path may have both ends connected to the supply flow path 150, and may form a circulation path together with a part of the supply flow path 150, or may form a bypass path for the supply flow path 150.

[0060] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. From such an arbitrary combination, the actions and effects of each of the components in the combination can be obtained as a matter of course, and other actions and effects that are obvious to a person skilled in the art from the description of this specification can be obtained.

[0061] In addition, the effects described in this specification are merely explanatory or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification in addition to or in place of the above effects.

[0062] Note that the following configuration examples also fall within the technical scope of the present disclosure. (1) A method for cleaning a supply flow path connected to a discharge unit that discharges a treatment liquid onto a substrate, comprising the steps of: (A) supplying a cleaning liquid to the discharge portion through the supply flow path and discharging the cleaning liquid from the discharge portion; (B) estimating whether or not cleaning has been completed based on a detection result by a foreign matter detector that detects foreign matter in the cleaning liquid supplied to the supply flow path, The above (B) is (C) estimating a cleaning completion point at which the detection result by the foreign matter detector becomes stable when the total discharge amount of the cleaning liquid increases, based on a history of the detection result by the foreign matter detector; and (D) estimating whether the cleaning is completed based on the estimated cleaning completion point. (2) In the cleaning method according to (1), (C) approximating a history of the amount of foreign matter detected by the foreign matter detector with a predetermined mathematical model to obtain an approximation curve, and estimating a value at which the amount of foreign matter converges on the approximation curve as the cleaning completion point; The step (D) determines whether the cleaning is completed based on whether the amount of the foreign matter detected by the foreign matter detector falls within a target range based on the cleaning completion point. (3) In the cleaning method according to (2), The predetermined mathematical model is represented by the following formula (X). N = (N0-α) * (1 / 2) t / T +α …(X) N: the amount of the foreign matter detected by the foreign matter detector N0: Initial value of the amount of the foreign object detected by the foreign object detector T: The total amount of cleaning liquid discharged until the amount of the foreign matter detected by the foreign matter detector is reduced by half t: total discharge amount of the cleaning liquid α: Said cleaning completion point (4) In the cleaning method according to (2) or (3), During the approximation in (C), the amount of the foreign matter that exceeds a predetermined value is excluded from the history of the amount of the foreign matter detected by the foreign matter detector, and the history after the exclusion is approximated by the predetermined mathematical model. (5) In the cleaning method according to (4), If the frequency with which the amount of the foreign matter exceeding the predetermined value is detected does not decrease, the discharge operation of the cleaning liquid in the discharge is changed. (6) In the cleaning method according to any one of (1) to (5), The method includes interrupting the step (A) for 30 minutes or more before the cleaning in the step (B) is deemed to be completed. (7) In the cleaning method according to (6) above, The above-mentioned (A) and an interruption of 30 minutes or more of the above-mentioned (A) are alternately performed multiple times. (8) A readable non-transitory computer storage medium storing a program that operates on a computer of a control device that controls a processing liquid supplying device so as to cause the processing liquid supplying device to execute a method for cleaning a supply flow path connected to a discharge unit that discharges a processing liquid onto a substrate, the processing liquid supply device has the supply flow path, The method (A) supplying a cleaning liquid to the discharge portion through the supply flow path and discharging the cleaning liquid from the discharge portion; (B) estimating whether or not cleaning has been completed based on a detection result by a foreign matter detector that detects foreign matter in the cleaning liquid supplied to the supply flow path, The above (B) is (C) estimating a cleaning completion point at which the detection result by the foreign matter detector becomes stable when the total discharge amount of the cleaning liquid increases, based on a history of the detection result by the foreign matter detector; and (D) estimating whether the cleaning is completed based on the estimated cleaning completion point. (9) A control device for a processing liquid supplying device that supplies a processing liquid to a discharge section that discharges the processing liquid onto a substrate, the treatment liquid supply device has a supply flow path connected to the discharge portion, The control device controls the processing liquid supply device. (A) supplying a cleaning liquid to the discharge portion through the supply flow path and discharging the cleaning liquid from the discharge portion; (B) estimating whether or not cleaning has been completed based on a detection result by a foreign matter detector that detects foreign matter in the cleaning liquid supplied to the supply flow path; The above (B) is (C) estimating a cleaning completion point at which the detection result by the foreign matter detector becomes stable when the total discharge amount of the cleaning liquid increases, based on a history of the detection result by the foreign matter detector; and (D) estimating whether the cleaning has been completed based on the estimated cleaning completion point. [Explanation of symbols]

[0063] 11b Discharge nozzle 12 Processing liquid supply device 13 Control device 120 Foreign object detector 150 Supply Channel M storage medium W Product Wafer

Claims

1. A method for cleaning a supply flow path connected to a discharge unit that discharges a processing liquid onto a substrate, comprising the steps of: (A) supplying a cleaning liquid to the discharge portion through the supply flow path and discharging the cleaning liquid from the discharge portion; (B) estimating whether or not cleaning has been completed based on a detection result by a foreign matter detector that detects foreign matter in the cleaning liquid supplied to the supply flow path, The (B) is (C) estimating a cleaning completion point at which the detection result by the foreign matter detector becomes stable when the total discharge amount of the cleaning liquid increases, based on a history of the detection result by the foreign matter detector; and (D) estimating whether the cleaning is completed based on the estimated cleaning completion point.

2. (C) approximating a history of the amount of foreign matter detected by the foreign matter detector with a predetermined mathematical model to obtain an approximation curve, and estimating a value at which the amount of foreign matter converges on the approximation curve as the cleaning completion point; 2. The cleaning method according to claim 1, wherein (D) determines whether the cleaning is completed based on whether an amount of the 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=(N) ０ -a)*(1 / 2) ｔ／Ｔ +a …(X) N: the amount of the foreign matter detected by the foreign matter detector N ０ : an initial value of the amount of the foreign matter detected by the foreign matter detector T: total amount of cleaning liquid discharged until the amount of the foreign matter detected by the foreign matter detector is reduced by half t: total discharge amount of the cleaning liquid α: Said cleaning completion point

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

5. 5. The cleaning method according to claim 4, further comprising changing a discharge operation of the cleaning liquid in the discharge when a frequency at which the amount of the foreign matter exceeding the predetermined value is detected does not decrease.

6. The cleaning method according to any one of claims 1 to 3, further comprising interrupting said (A) for 30 minutes or more before it is estimated that cleaning is completed in said (B).

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

8. A readable non-transitory computer storage medium storing a program that operates on a computer of a control device that controls a processing liquid supplying device so as to cause the processing liquid supplying device to execute a method for cleaning a supply flow path connected to a discharge unit that discharges a processing liquid onto a substrate, the processing liquid supply device has the supply flow path, The method (A) supplying a cleaning liquid to the discharge portion through the supply flow path and discharging the cleaning liquid from the discharge portion; (B) estimating whether or not cleaning has been completed based on a detection result by a foreign matter detector that detects foreign matter in the cleaning liquid supplied to the supply flow path, The (B) is (C) estimating a cleaning completion point at which the detection result by the foreign matter detector becomes stable when the total discharge amount of the cleaning liquid increases, based on a history of the detection result by the foreign matter detector; and and (D) estimating whether the cleaning is complete based on the estimated cleaning completion point.

9. A control device for a processing liquid supplying device that supplies a processing liquid to a discharge section that discharges the processing liquid onto a substrate, the treatment liquid supply device has a supply flow path connected to the discharge portion, The control device controls the processing liquid supply device. (A) supplying a cleaning liquid to the discharge portion through the supply flow path and discharging the cleaning liquid from the discharge portion; (B) estimating whether or not cleaning has been completed based on a detection result by a foreign matter detector that detects foreign matter in the cleaning liquid supplied to the supply flow path; The (B) is (C) estimating a cleaning completion point at which the detection result by the foreign matter detector becomes stable when the total discharge amount of the cleaning liquid increases, based on a history of the detection result by the foreign matter detector; and (D) estimating whether or not the cleaning has been completed based on the estimated cleaning completion point.

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