SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING APPARATUS

Abstract

To provide a substrate processing method and a substrate processing apparatus capable of suitably cleaning a liquid supply portion.SOLUTION: A substrate processing apparatus 1 processes a substrate 5 using a liquid supply portion 11. The liquid supply portion includes a supply path 12, a first pump 21, a first valve 41, and a nozzle 31. A substrate processing method includes a processing step and a cleaning step. During the processing step, the first valve opens and closes. In the cleaning step, the first valve switches between a first large opening degree and a first small opening degree that is smaller than the first large opening degree. The first small opening degree is greater than the opening degree of the first valve when the first valve closes.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a substrate processing apparatus. The substrate processing apparatus includes a liquid supply unit and a cleaning liquid line. The liquid supply unit is connected to a processing liquid supply source. The liquid supply unit includes a supply path, a pump, a filter, a three-way valve, and a nozzle. The pump, the filter, the three-way valve, and the nozzle are each provided in the supply path. The filter is disposed downstream of the pump. The three-way valve is disposed downstream of the filter. The nozzle is connected to a downstream end of the supply path. The three-way valve switches between a first position and a second position. When the three-way valve is in the first position, the three-way valve connects the nozzle to the filter and blocks the nozzle from the cleaning line. When the three-way valve is in the second position, the three-way valve connects the nozzle to the cleaning line and blocks the nozzle from the filter.

[0003] To supply processing liquid to the substrate, the three-way valve is switched to a first position. Processing liquid flows from the pump to the nozzle. To clean the nozzle, the three-way valve is switched to a second position. Cleaning liquid flows from the cleaning liquid line through the three-way valve into the supply channel. Cleaning liquid flows from the three-way valve to the nozzle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-311408 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional example having such a configuration has the following problems. In the conventional example, the cleaning liquid flows only through a part of the liquid supply part (for example, the part of the liquid supply part located downstream of the three-way valve). Therefore, the conventional example does not clean the entire liquid supply part. For example, the conventional example does not clean the pump. Therefore, there are cases where the liquid supply part cannot be properly cleaned.

[0006] For example, in the case of AC, a user of the substrate processing apparatus manually attaches and detaches at least a part of the liquid supply unit.For example, in the case of AC, a user of the substrate processing apparatus manually detaches at least a part of the liquid supply unit. A. Start up the substrate processing equipment B. When the liquid supply unit is attached to and detached from at least one of the processing liquid supply source and the cleaning liquid supply source C. Replace the parts of the liquid supply unit Here, the components of the liquid supply unit include, for example, pipes, pumps, filters, valves, and nozzles.

[0007] For this reason, in the case of AC, there is a risk that particles may be present in the liquid supply part. In the case of AC, there is a risk that particles may enter the liquid supply part. Therefore, in the case of AC, it is preferable to clean the entire liquid supply part. In the case of AC, it is preferable to clean the pump. However, in the case of AC, the conventional example cannot properly clean the liquid supply part.

[0008] In recent years, semiconductor devices formed on substrates have become finer. For this reason, cleaning standards for liquid supply units have become higher. The cleaning standards are, for example, the allowable number of particles present in the cleaning liquid discharged from the liquid supply unit. The liquid supply unit is cleaned until it meets the cleaning standards. If it takes a long time to clean the liquid supply unit, the operating rate of the substrate processing apparatus decreases. The yield decreases.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of suitably cleaning a liquid supply unit. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above problems, and have come to the following findings. The liquid supply unit includes one or more valves. Foreign matter may adhere to the valves. If the foreign matter is metal, it is difficult to remove the foreign matter from the valve. This is because cleaning liquids have a hard time dissolving metal. When the foreign matter adheres to the valve, the foreign matter continues to generate particles. For this reason, when the foreign matter adheres to the valve, it is difficult for the liquid supply unit to meet the cleaning standards. When the foreign matter adheres to the valve, the liquid supply unit cannot be efficiently cleaned.

[0011] The inventors further obtained the following findings. One of the reasons why foreign matter adheres to a valve is that the valve catches the foreign matter. The valve opens and closes to control the flow of the cleaning liquid. When the valve closes, there is a risk that the valve will catch the foreign matter. When the foreign matter catches the valve, it is difficult for the foreign matter to be removed from the valve.

[0012] The present invention was achieved through further intensive research based on these findings, and has the following configuration.

[0013] That is, the present invention is a substrate processing method for processing a substrate using a liquid supply unit, the liquid supply unit comprising: a supply path having an upstream end and a downstream end, a first pump provided in the supply path, a first valve provided in the supply path and positioned upstream of the first pump, and a nozzle connected to the downstream end, the substrate processing method comprising: a processing step of supplying a processing liquid to the upstream end and supplying the processing liquid from the liquid supply unit to the substrate to process the substrate, and a cleaning step of supplying a cleaning liquid to the upstream end and flowing the cleaning liquid into the liquid supply unit to clean the liquid supply unit, wherein in the processing step, the first valve opens and closes, and in the cleaning step, the first valve switches between a first large opening and a first small opening smaller than the first large opening, and the first small opening is larger than the opening of the first valve when the first valve is closed.

[0014] The substrate processing method processes a substrate using a liquid supply unit. The liquid supply unit includes a supply path, a first pump, a first valve, and a nozzle. The supply path has an upstream end and a downstream end. The first pump and the first valve are each provided in the supply path. The first valve is disposed between the first pump and the upstream end. The nozzle is connected to the downstream end.

[0015] The substrate processing method includes a processing step, which performs processing on the substrate, and a processing liquid is supplied to the upstream end of the substrate, and a liquid supply unit supplies the processing liquid to the substrate.

[0016] In the processing step, the first valve opens and closes. Here, "close" means "fully closed." When the first valve opens, the first valve allows the flow of processing liquid upstream of the first pump. When the first valve closes, the first valve stops the flow of processing liquid upstream of the first pump. In this way, in the processing step, the first valve strictly controls the flow of processing liquid upstream of the first pump. Here, "upstream of the first pump" refers to, for example, a portion of the supply path between the first valve and the first pump. Therefore, in the processing step, the liquid supply unit can appropriately supply the processing liquid to the substrate. Therefore, in the processing step, the substrate can be appropriately processed.

[0017] The substrate processing method includes a cleaning step. In the cleaning step, the liquid supply unit is cleaned. In the cleaning step, a cleaning liquid is supplied to an upstream end. In the cleaning step, the cleaning liquid is caused to flow in the liquid supply unit. Thus, in the cleaning step, the liquid supply unit can be suitably cleaned. For example, in the cleaning step, the first pump can be suitably cleaned.

[0018] In the cleaning process, the first valve switches between a first large opening and a first small opening. The first small opening is smaller than the first large opening. Therefore, the first valve opening at the first small opening suppresses the flow of cleaning liquid more than the first valve opening at the first large opening. Thus, in the cleaning process, the first valve substantially controls the flow of cleaning liquid upstream of the first pump. Therefore, in the cleaning process, cleaning liquid can be appropriately flowed to the liquid supply section.

[0019] Here, when the first valve is opened to the first small opening, some cleaning liquid may flow upstream of the first pump. However, the cleaning process does not process the substrate. Therefore, even if the first valve does not strictly control the flow of the cleaning liquid, the quality of the process performed on the substrate is not degraded.

[0020] Furthermore, when the first valve is opened to the first small opening degree, the first valve does not close. Of course, when the first valve is opened to the first large opening degree, the first valve does not close. For this reason, foreign matter is less likely to adhere to the first valve during the cleaning process. Therefore, the cleaning process can efficiently clean the liquid supply unit.

[0021] In summary, according to the substrate processing method of the present invention, the cleaning step can suitably clean the liquid supply unit. Specifically, in the cleaning step, the first valve substantially controls the flow of the cleaning liquid upstream of the first pump while preventing foreign matter from adhering to the first valve. The processing step can suitably process the substrate.

[0022] In the above-mentioned substrate processing method, the first small opening is preferably slightly larger than the opening of the first valve when the first valve is closed. When the first valve opens at the first small opening, the first valve significantly suppresses the flow of the cleaning liquid upstream of the first pump. Therefore, in the cleaning process, the first valve can suitably control the flow of the cleaning liquid upstream of the first pump.

[0023] In the above-mentioned substrate processing method, it is preferable that when the first valve opens to the first large opening in the cleaning step, the first pump sucks in the cleaning liquid, and when the first valve opens to the first small opening in the cleaning step, the first pump discharges the cleaning liquid. When the first valve opens to the first large opening in the cleaning step, the first pump sucks in the cleaning liquid. Therefore, when the first pump sucks in the cleaning liquid, the first valve allows the cleaning liquid to flow from the first valve to the first pump. When the first valve opens to the first small opening in the cleaning step, the first pump discharges the cleaning liquid. Therefore, when the first pump discharges the cleaning liquid, the first valve suppresses the cleaning liquid from flowing back from the first pump to the first valve. In this way, the first valve can substantially control the flow of the cleaning liquid upstream of the first pump according to the operation of the first pump.

[0024] In the above-mentioned substrate processing method, it is preferable that when the first valve opens at the first large opening in the cleaning step, the first pump sucks in the cleaning liquid at a first flow rate and the first valve allows the cleaning liquid to pass through the first valve at the first flow rate, and when the first valve opens at the first small opening in the cleaning step, the first pump discharges the cleaning liquid at a second flow rate and the first valve limits the flow rate of the cleaning liquid passing through the first valve to less than the second flow rate. When the first valve opens at the first large opening in the cleaning step, the first pump sucks in the cleaning liquid at a first flow rate. When the first valve opens at the first large opening in the cleaning step, the first valve allows the cleaning liquid to pass through the first valve at the first flow rate. Therefore, when the first pump sucks in the cleaning liquid, the first valve allows the cleaning liquid to flow smoothly from the first valve to the first pump. When the first valve opens to the first small opening in the cleaning process, the first pump discharges the cleaning liquid at a second flow rate. When the first valve opens to the first small opening in the cleaning process, the first valve limits the flow rate of the cleaning liquid passing through the first valve to less than the second flow rate. Therefore, when the first pump discharges the cleaning liquid, the first valve prevents the cleaning liquid from flowing back from the first pump to the first valve.

[0025] In the above-described substrate processing method, when the first valve is opened to the first small opening in the cleaning step, the first valve preferably limits the flow rate of the cleaning liquid passing through the first valve to 20% or less of the second flow rate. When the first pump discharges the cleaning liquid, the first valve further suppresses the cleaning liquid from flowing back from the first pump to the first valve.

[0026] In the above-mentioned substrate processing method, it is preferable that the first valve includes a valve seat, a valve body capable of contacting the valve seat, and an electric motor that moves the valve body relative to the valve seat to adjust a separation distance between the valve seat and the valve body. The electric motor can finely adjust the separation distance. Here, the separation distance corresponds to an opening degree of the first valve. Thus, the electric motor can finely adjust the opening degree of the first valve.

[0027] In the above-mentioned substrate processing method, it is preferable that when the first valve opens at the first large opening, the separation distance is 400 μm or more, and when the first valve opens at the first small opening, the separation distance is greater than 5 μm and smaller than 100 μm. When the first valve opens at the first large opening, the separation distance is 400 μm or more. Therefore, when the first valve opens at the first large opening in the cleaning process, the cleaning liquid passes smoothly between the valve seat and the valve body. That is, when the first valve opens at the first large opening in the cleaning process, the first valve allows the cleaning liquid to pass smoothly through the first valve. When the first valve opens at the first small opening, the separation distance is smaller than 100 μm. Therefore, when the first valve opens at the first small opening in the cleaning process, the cleaning liquid does not easily pass between the valve seat and the valve body. That is, when the first valve opens at the first small opening in the cleaning process, the first valve prevents the cleaning liquid from passing through the first valve. When the first valve opens at the first small opening, the separation distance is greater than 5 μm. Therefore, when the first valve opens at the first small opening, foreign matter can easily pass through the gap formed between the valve seat and the valve body. Of course, when the first valve opens at the first large opening, foreign matter can also easily pass through the gap formed between the valve seat and the valve body. Therefore, foreign matter is less likely to adhere to at least one of the valve body and the valve seat.

[0028] In the above-mentioned substrate processing method, the processing step includes a first feed step of flowing a processing liquid from the first valve to the first pump through the supply path, and a second feed step of flowing a processing liquid from the first pump downstream of the first pump, and the cleaning step includes a first step of flowing a cleaning liquid from the first valve to the first pump through the supply path, and a second step of flowing a cleaning liquid from the first pump downstream of the first pump, and it is preferable that in the first feed step, the first valve is opened and the first pump sucks in the processing liquid, and in the second feed step, the first valve is closed and the first pump discharges the processing liquid, and in the first step, the first valve is opened at the first large opening, and the first pump sucks in the cleaning liquid, and in the second step, the first valve is opened at the first small opening, and the first pump discharges the cleaning liquid.

[0029] The processing step includes a first feed step and a second feed step. In the first feed step, the first valve opens and the first pump sucks in. Therefore, in the first feed step, the processing liquid flows smoothly from the first valve to the first pump through the supply path. In the second feed step, the first valve closes and the first pump expels. Therefore, in the second feed step, the first valve prohibits the processing liquid from flowing back from the first pump to the first valve. As a result, in the second feed step, the processing liquid flows from the first pump downstream of the first pump.

[0030] The cleaning process includes a first process and a second process. In the first process, the first valve opens to a first large opening, and the first pump sucks in the cleaning liquid. Therefore, in the first process, the cleaning liquid flows substantially from the first valve to the first pump through the supply path. In the second process, the first valve opens to a first small opening, and the first pump expels the cleaning liquid. Therefore, in the second process, the first valve prevents the cleaning liquid from flowing back from the first pump to the first valve. As a result, in the second process, the cleaning liquid flows substantially from the first pump to downstream of the first pump.

[0031] In the above-described substrate processing method, it is preferable that the liquid supply unit includes a second valve provided in the supply path and positioned downstream of the first pump, and that in the first feed process, the second valve is closed and in the second feed process, the second valve is opened, and that in the first process, the first valve is opened wider than the second valve and in the second process, the second valve is opened wider than the first valve.

[0032] The liquid supply includes a second valve disposed between the first pump and the downstream end.

[0033] In the first feed step, the second valve is closed. Therefore, in the first feed step, the second valve prohibits the processing liquid from flowing back from the second valve to the first pump. In the second feed step, the second valve is opened. Therefore, in the second feed step, the processing liquid flows smoothly from the first pump to the second valve through the supply path.

[0034] In the first step, the first valve opens wider than the second valve. Therefore, in the first step, the cleaning liquid flows substantially from the first valve to the first pump through the supply line. In the second step, the second valve opens wider than the first valve. Therefore, in the second step, the cleaning liquid flows substantially from the first pump to the second valve through the supply line.

[0035] In the above-described substrate processing method, it is preferable that in the first step, the second valve opens less than the first valve. In the first step, the second valve prevents the cleaning liquid from flowing back from the second valve to the first pump. Furthermore, in the first step, the second valve does not close. Of course, the second valve does not close in the second step either. Therefore, foreign matter is less likely to adhere to the second valve. Therefore, the cleaning step can clean the liquid supply unit more efficiently.

[0036] In the above-mentioned substrate processing method, the first valve is disposed in a first portion of the supply path between the upstream end and the first pump, and the liquid supply unit includes: a branch portion provided in the supply path and disposed downstream of the first pump; a second pump provided in the supply path and disposed downstream of the branch portion; a return path provided separately from the supply path and communicating the second pump with the first pump; a drain path connected to the branch portion and branching off from the supply path; a second valve provided in the second portion of the supply path between the first pump and the branch portion; a third valve provided in a third portion of the supply path between the branch portion and the second pump; a fourth valve provided in a fourth portion of the supply path between the second pump and the downstream end; a fifth valve provided in the return path; and a drain valve provided in the drain path, and the processing step includes a first sending step of flowing the processing liquid from the upstream end to the first pump through the first portion, the second pump to the nozzle through the second and third portions; a return path to reverse the processing liquid from the second pump to the first pump through the return path; and a third supply step to reverse the processing liquid from the second pump to the nozzle through the fourth portion, and the cleaning step preferably comprises a first cleaning step of flowing the cleaning liquid from the upstream end through the first and second portions to the branching portion and discharging the cleaning liquid from the branching portion to the discharge path, a second cleaning step of flowing the cleaning liquid from the upstream end through the first portion to the first pump, flowing the cleaning liquid from the first pump to the second pump through the return path, reverse the cleaning liquid from the second pump to the branching portion through the third portion and discharging the cleaning liquid from the branching portion to the discharge path, and a third cleaning step of flowing the cleaning liquid from the upstream end to the nozzle through the first, second, third and fourth portions.

[0037] The liquid supply unit includes a branching portion, a second pump, a return path, and a discharge path. The branching portion and the second pump are each provided in the supply path. The branching portion is disposed between the first pump and the downstream end. The second pump is disposed between the branching portion and the downstream end. The return path is provided separately from the supply path. The return path connects the second pump to the first pump. The discharge path is connected to the branch portion. The discharge path branches off from the supply path.

[0038] The supply path includes a first portion, a second portion, a third portion, and a fourth portion. The first portion is a portion of the supply path between the upstream end and the first pump. The second portion is a portion of the supply path between the first pump and the branching portion. The third portion is a portion of the supply path between the branching portion and the second pump. The fourth portion is a portion of the supply path between the second pump and the downstream end.

[0039] The liquid supply unit includes a first valve, a second valve, a third valve, a fourth valve, a fifth valve, and a discharge valve. The first valve is provided in the first section. The second valve is provided in the second section. The third valve is provided in the third section. The fourth valve is provided in the fourth section. The fifth valve is provided in the return path. The discharge valve is provided in the discharge path.

[0040] The processing step includes a first sending step, a second sending step, a return step, and a third sending step. The first sending step causes the processing liquid to flow from the upstream end to the first pump through the first portion. The second sending step causes the processing liquid to flow from the first pump to the second pump through the second and third portions. The return step causes the processing liquid to flow backward from the second pump to the first pump through the return path. The third sending step causes the processing liquid to flow from the second pump to the nozzle through the fourth portion. If air gets mixed into the second pump, the return step returns the air together with the processing liquid from the second pump to the first pump. Therefore, the third sending step can send the processing liquid that does not contain air to the nozzle. Therefore, in the processing step, the liquid supply unit can suitably supply the processing liquid to the substrate.

[0041] The cleaning process includes a first cleaning process, a second cleaning process, and a third cleaning process. In the first cleaning process, the cleaning liquid is caused to flow through the first and second parts from the upstream end to the branching part. In the first cleaning process, the cleaning liquid is discharged from the branching part to the discharge path. Therefore, the first cleaning process cleans the first and second parts. In the second cleaning process, the cleaning liquid is caused to flow through the first part from the upstream end to the first pump. In the second cleaning process, the cleaning liquid is caused to flow from the first pump to the second pump through the return path. In the second cleaning process, the cleaning liquid is caused to flow back from the second pump to the branching part through the third part. In the second cleaning process, the cleaning liquid is discharged from the branching part to the discharge path. Therefore, the second cleaning process cleans the first part, the return path, and the third part. In the third cleaning process, the cleaning liquid is caused to flow through the first, second, third, and fourth parts from the upstream end to the nozzle. Therefore, the third cleaning process cleans the first, second, third, and fourth parts. Therefore, in the cleaning process, the cleaning liquid can be efficiently supplied to the entire liquid supply section.

[0042] The direction of the cleaning liquid flowing through the return path in the second cleaning step is opposite to the direction of the processing liquid flowing through the return path in the return step, so that the return path can be cleaned effectively in the second cleaning step.

[0043] The direction of the cleaning liquid flowing through the third portion in the second cleaning step is opposite to the direction of the cleaning liquid flowing through the third portion in the third cleaning step, so that the third portion can be cleaned appropriately.

[0044] In the above-mentioned substrate processing method, it is preferable that in the processing step, the second valve opens and closes, and in the cleaning step, the second valve switches between a second large opening and a second small opening smaller than the second large opening, and in the processing step, the third valve opens and closes, and in the cleaning step, the third valve switches between a third large opening and a third small opening smaller than the third large opening, and in the processing step, the fifth valve opens and closes, and in the cleaning step, the fifth valve switches between a fifth large opening and a fifth small opening smaller than the fifth large opening, the second small opening being larger than the opening of the second valve when the second valve is closed, the third small opening being larger than the opening of the third valve when the third valve is closed, and the fifth small opening being larger than the opening of the fifth valve when the fifth valve is closed.

[0045] In the processing step, the second valve opens and closes. When the second valve opens, the second valve allows the flow of the processing liquid in the second portion. When the second valve closes, the second valve stops the flow of the processing liquid in the second portion. In this way, in the processing step, the second valve strictly controls the flow of the processing liquid in the second portion. Similarly, in the processing step, the third valve opens and closes. Therefore, in the processing step, the third valve strictly controls the flow of the processing liquid in the third portion. In the processing step, the fifth valve opens and closes. Therefore, in the processing step, the fifth valve strictly controls the flow of the processing liquid in the return path. Therefore, in the processing step, the flow of the processing liquid in the liquid supply unit strictly controls. Therefore, the liquid supply unit can properly supply the processing liquid to the substrate. In the processing step, the substrate can be properly processed.

[0046] In the cleaning process, the second valve switches between a second large opening and a second small opening. The second small opening is smaller than the second large opening. Thus, in the cleaning process, the second valve substantially controls the flow of the cleaning liquid in the second portion. Similarly, in the cleaning process, the third valve switches between a third large opening and a third small opening. The third small opening is smaller than the third large opening. Thus, in the cleaning process, the third valve substantially controls the flow of the cleaning liquid in the third portion. In the cleaning process, the fifth valve switches between a fifth large opening and a fifth small opening. The fifth small opening is smaller than the fifth large opening. Thus, in the cleaning process, the fifth valve substantially controls the flow of the cleaning liquid in the return path. Thus, in the cleaning process, the cleaning liquid can be appropriately flowed to the liquid supply section.

[0047] Furthermore, when the second valve is opened at the second small opening degree, the second valve does not close. Of course, when the second valve is opened at the second large opening degree, the second valve does not close. Therefore, foreign matter is less likely to adhere to the second valve during the cleaning process. Similarly, foreign matter is less likely to adhere to the third valve during the cleaning process. Foreign matter is less likely to adhere to the fifth valve during the cleaning process. Therefore, the cleaning process can efficiently clean the liquid supply section.

[0048] In the above-described substrate processing method, it is preferable that in the first cleaning step, the third valve opens at the third small opening and the fifth valve opens at the fifth small opening, and in the second cleaning step, the second valve opens at the second small opening and in the third cleaning step, the fifth valve opens at the fifth small opening.

[0049] In the first cleaning step, the fifth valve opens to the fifth small opening. Therefore, in the first cleaning step, the fifth valve suppresses the flow of cleaning liquid in the return path. As a result, in the first cleaning step, the cleaning liquid flows substantially from the first portion to the second portion.

[0050] In the first cleaning step, the third valve opens to a third small opening. Therefore, in the first cleaning step, the third valve suppresses the flow of cleaning liquid in the third portion. In the first cleaning step, the third valve suppresses the flow of cleaning liquid from the second portion to the third portion. As a result, in the first cleaning step, the cleaning liquid substantially flows from the second portion to the discharge path.

[0051] In the second cleaning step, the second valve opens to the second small opening. Therefore, in the second cleaning step, the second valve suppresses the flow of cleaning liquid in the second portion. As a result, in the second cleaning step, the cleaning liquid flows substantially from the first portion to the return path. Furthermore, in the second cleaning step, the cleaning liquid flows substantially from the third portion to the discharge path.

[0052] In the third cleaning step, the fifth valve opens to the fifth small opening. Therefore, in the third cleaning step, the fifth valve suppresses the flow of cleaning liquid in the return path. As a result, in the third cleaning step, the cleaning liquid flows smoothly from the first portion to the second portion. Furthermore, in the third cleaning step, the cleaning liquid flows substantially from the third portion to the fourth portion.

[0053] In the above-mentioned substrate processing method, it is preferable that the branching portion includes a first connection port connected to the second portion, a second connection port connected to the third portion, and a third connection port connected to the discharge path, and in the first cleaning step, the cleaning liquid flows into the first connection port and flows out from the third connection port, and in the second cleaning step, the cleaning liquid flows into the second connection port and flows out from the third connection port, and in the third cleaning step, the cleaning liquid flows into the first connection port and flows out from the second connection port. The cleaning step can suitably clean the branching portion.

[0054] In the above-described substrate processing method, it is preferable that when the cleaning liquid flows from the second portion through the branch portion to the discharge path, the third valve opens less than the second valve and the discharge valve, and when the cleaning liquid flows from the third portion through the branch portion to the discharge path, the second valve opens less than the third valve and the discharge valve, and when the cleaning liquid flows from the second portion through the branch portion to the third portion, the second valve and the third valve open more than the discharge valve.

[0055] When the cleaning liquid flows from the second portion through the branch portion to the discharge passage, the third valve opens less than the second valve and the discharge valve, so that the cleaning liquid substantially flows from the second portion through the branch portion to the discharge passage.

[0056] When the cleaning liquid flows from the third portion through the branch portion to the discharge passage, the second valve opens less than the third valve and the discharge valve, so that the cleaning liquid substantially flows from the third portion through the branch portion to the discharge passage.

[0057] When the cleaning liquid flows from the second portion to the third portion via the branch, the second valve and the third valve open wider than the drain valve, so that the cleaning liquid flows substantially from the second portion to the third portion via the branch.

[0058] Furthermore, when the cleaning liquid flows from the second portion to the discharge path via the branch portion, the third valve does not close. Similarly, when the cleaning liquid flows from the third portion to the discharge path via the branch portion, the second valve does not close. When the cleaning liquid flows from the second portion to the third portion via the branch portion, the second valve and the third valve do not close. Therefore, in the cleaning process, foreign matter is less likely to adhere to at least one of the second valve and the third valve. Therefore, the cleaning process can efficiently clean the liquid supply section.

[0059] In the above-mentioned substrate processing method, the branching portion is preferably a filter, which effectively removes particles from the cleaning liquid.

[0060] In the above-mentioned substrate processing method, it is preferable that the fourth valve is closed in the first cleaning step, the fourth valve is closed in the second cleaning step, and the fourth valve is opened in the third cleaning step. In the first cleaning step, the fourth valve is closed. Therefore, in the first cleaning step, the cleaning liquid is discharged to the discharge path without passing through the fourth portion. Similarly, in the second cleaning step, the fourth valve is closed. Therefore, in the second cleaning step, the cleaning liquid is discharged to the discharge path without passing through the fourth portion. Therefore, in the first cleaning step and the second cleaning step, the cleaning liquid does not flow to the nozzle. In other words, in the first cleaning step and the second cleaning step, the cleaning liquid does not discharge particles through the nozzle. Therefore, the first cleaning step and the second cleaning step suppress contamination of the nozzle. In the third cleaning step, the fourth valve is opened. Therefore, in the third cleaning step, the cleaning liquid flows to the nozzle through the fourth portion. Therefore, the third cleaning step cleans the nozzle.

[0061] In the above-mentioned substrate processing method, the second cleaning step comprises: First cleaning process The third cleaning step is carried out after Second cleaning process It is preferable that the cleaning process is performed after the first cleaning process. The first cleaning process cleans the first and second portions. The second cleaning process cleans the third portion. The fourth cleaning process cleans the fourth portion. Here, the third portion is located downstream of the second portion. The fourth portion is located downstream of the third portion. Therefore, the cleaning process cleans the supply path in stages from the upstream end to the downstream end. Therefore, the cleaning process can efficiently clean the liquid supply section.

[0062] The present invention also provides a substrate processing apparatus comprising: a substrate holding section for holding a substrate; a liquid supply section for supplying a processing liquid to a substrate held by the substrate holding section; and a control section for controlling the liquid supply section, wherein the liquid supply section comprises a supply path having an upstream end and a downstream end, a first pump provided in the supply path, a first valve provided in the supply path and positioned upstream of the first pump, and a nozzle connected to the downstream end, wherein when supplying cleaning liquid for cleaning the liquid supply section to the upstream end, the control section switches an opening degree of the first valve between a first large opening degree and a first small opening degree smaller than the first large opening degree, and the first small opening degree is larger than the opening degree of the first valve when the first valve is closed.

[0063] The cleaning liquid is supplied to the upstream end, which allows the first pump to be cleaned effectively.

[0064] When supplying the cleaning liquid to the upstream end, the control unit switches the opening degree of the first valve between a first large opening degree and a first small opening degree. The first small opening degree is smaller than the first large opening degree. Therefore, when supplying the cleaning liquid to the upstream end, the first valve substantially controls the flow of the cleaning liquid upstream of the first pump. This allows the cleaning liquid to flow appropriately to the liquid supply unit.

[0065] Furthermore, the first small opening is larger than the opening of the first valve when it is closed. That is, when the first valve opens at the first small opening, the first valve does not close. The first large opening is larger than the first small opening. Therefore, even when the first valve opens at the first large opening, the first valve does not close. Therefore, when the cleaning liquid is supplied to the upstream end, foreign matter is less likely to adhere to the first valve. Therefore, the liquid supply unit can be efficiently cleaned.

[0066] In summary, the substrate processing apparatus according to the present invention can effectively clean the liquid supply unit. Specifically, the first pump can be effectively cleaned. The first valve effectively controls the flow of the cleaning liquid upstream of the first pump while preventing foreign matter from adhering to the first valve. Effect of the Invention

[0067] According to the present invention, the liquid supply section can be suitably cleaned. [Brief description of the drawings]

[0068] [Figure 1] 1 is a diagram showing a schematic configuration of a substrate processing apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a partial cross-sectional view illustrating a first pump. [Diagram 3] 3(a) and 3(b) are each a partial cross-sectional view illustrating the first valve. [Figure 4] 4 is a flowchart showing the procedure of an operation of a processing step according to the first embodiment. [Diagram 5] Figure 5(a) is a diagram showing the substrate processing apparatus in a first feeding step, and Figure 5(b) is a diagram showing the substrate processing apparatus in a second feeding step. [Figure 6] 5 is a flowchart showing the procedure of an operation of a cleaning process in the first embodiment. [Figure 7] Fig. 7(a) is a diagram showing the substrate processing apparatus in a first step, and Fig. 7(b) is a diagram showing the substrate processing apparatus in a second step. [Figure 8] FIG. 13 is a diagram showing a schematic configuration of a substrate processing apparatus according to a second embodiment. [Figure 9]10 is a flowchart showing the procedure of an operation of a processing step according to a second embodiment. [Figure 10] Fig. 10(a) is a diagram showing the substrate processing apparatus in a first forwarding step, Fig. 10(b) is a diagram showing the substrate processing apparatus in a second forwarding step, Fig. 10(c) is a diagram showing the substrate processing apparatus in a return step, and Fig. 10(d) is a diagram showing the substrate processing apparatus in a third forwarding step. [Figure 11] 10 is a flowchart showing the procedure of an operation of a cleaning process according to a second embodiment. [Figure 12] Fig. 12(a) is a diagram illustrating the substrate processing apparatus in a first cleaning step (first step), and Fig. 12(b) is a diagram illustrating the substrate processing apparatus in a first cleaning step (second step). [Figure 13] Fig. 13(a) is a diagram showing the substrate processing apparatus in the second cleaning step (third step), Fig. 13(b) is a diagram showing the substrate processing apparatus in the second cleaning step (fourth step), and Fig. 13(c) is a diagram showing the substrate processing apparatus in the second cleaning step (fifth step). [Figure 14] Fig. 14(a) is a diagram showing the substrate processing apparatus in the third cleaning step (sixth step), Fig. 14(b) is a diagram showing the substrate processing apparatus in the third cleaning step (seventh step), and Fig. 14(c) is a diagram showing the substrate processing apparatus in the third cleaning step (eighth step). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] First embodiment A first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a diagram showing a schematic configuration of a substrate processing apparatus according to the first embodiment. The substrate processing apparatus 1 according to the first embodiment is an apparatus for processing a substrate W.

[0070] The substrate W is, for example, a semiconductor wafer, a substrate for a liquid crystal display, a substrate for an organic EL (Electroluminescence), a substrate for an FPD (Flat Panel Display), a substrate for an optical display, a substrate for a magnetic disk, a substrate for an optical disk, a substrate for a magneto-optical disk, a substrate for a photomask, or a substrate for a solar cell.

[0071] 1. Overview of the substrate processing apparatus 1 The substrate processing apparatus 1 includes a substrate holding unit 5 and a rotation drive unit 6. The substrate holding unit 5 holds the substrate W. Specifically, the substrate holding unit 5 holds the substrate W in a substantially horizontal position. The substrate holding unit 5 holds, for example, the back surface (lower surface) of the substrate W. The rotation drive unit 6 is connected to the substrate holding unit 5. The rotation drive unit 6 rotates the substrate holding unit 5. When the substrate holding unit 5 rotates, the substrate W held by the substrate holding unit 5 rotates integrally with the substrate holding unit 5. The substrate W rotates around an axis parallel to the vertical direction.

[0072] The substrate processing apparatus 1 includes a cup 7. The cup 7 has a cylindrical shape. The cup 7 is disposed so as to surround the side of the substrate holder 5. The cup 7 receives the processing liquid splashed from the substrate W.

[0073] The substrate processing apparatus 1 includes a liquid supply unit 11. The liquid supply unit 11 supplies a processing liquid to the substrate W. Specifically, the liquid supply unit 11 supplies the processing liquid to the substrate W held by the substrate holding unit 5.

[0074] The liquid supply unit 11 includes a supply path 12. The supply path 12 includes an upstream end 13 and a downstream end .

[0075] In this specification, the direction from upstream end 13 toward downstream end 14 along supply path 12 will be referred to as the downstream side as appropriate. The direction from downstream end 14 toward upstream end 13 along supply path 12 will be referred to as the upstream side as appropriate. Flowing upstream through supply path 12 will be referred to as "flowing backward" as appropriate.

[0076] The liquid supply unit 11 includes a first pump 21 and a nozzle 31. The first pump 21 is provided in the supply path 12. That is, the first pump 21 is provided between the upstream end 13 and the downstream end 14. The nozzle 31 is connected to the downstream end 14 of the supply path 12.

[0077] The supply path 12 includes pipes 15 and 16. The pipe 15 has a first end and a second end. The first end of the pipe 15 corresponds to the upstream end 13. The second end of the pipe 15 is connected to the first pump 21. The pipe 15 corresponds to a portion of the supply path 12 located upstream of the first pump 21. The pipe 16 has a first end and a second end. The first end of the pipe 16 is connected to the first pump 21. The second end of the pipe 16 corresponds to the downstream end 14. The second end of the pipe 16 is connected to the nozzle 31. The pipe 16 corresponds to a portion of the supply path 12 located downstream of the first pump 21.

[0078] The liquid supply unit 11 includes a first valve 41 and a second valve 42. The first valve 41 and the second valve 42 are each provided in the supply path 12. The first valve 41 is provided in the pipe 15. The first valve 41 is disposed upstream of the first pump 21. The second valve 42 is provided in the pipe 16. The second valve 42 is disposed downstream of the first pump 21.

[0079] The substrate processing apparatus 1 includes a nozzle moving mechanism 33. The nozzle moving mechanism 33 moves the nozzle 31. The nozzle moving mechanism 33 moves the nozzle 31 to a processing position and a standby position. In Fig. 1, the nozzle 31 disposed at the processing position is shown by a dashed line. In Fig. 1, the nozzle 31 disposed at the standby position is shown by a solid line.

[0080] When the nozzle 31 is located at the processing position, the nozzle 31 is located, for example, above the substrate holding part 5. When the nozzle 31 is located at the processing position, the nozzle 31 ejects the processing liquid, for example, onto the upper surface of the substrate W held by the substrate holding part 5. When the nozzle 31 is located at the processing position, the nozzle 31 overlaps with the substrate W held by the substrate holding part 5, for example, in a plan view. When the nozzle 31 is located at the standby position, the nozzle 31 cannot eject the processing liquid onto the substrate W held by the substrate holding part 5. When the nozzle 31 is located at the standby position, the nozzle 31 does not overlap with the substrate W held by the substrate holding part 5, for example, in a plan view.

[0081] The substrate processing apparatus 1 includes a nozzle standby section 35. The nozzle standby section 35 is, for example, a standby pot. The nozzle standby section 35 is disposed outside the cup 7. The nozzle standby section 35 is disposed at a standby position for the nozzle 31. When the nozzle 31 is disposed at the standby position, the nozzle standby section 35 accommodates, for example, at least a portion of the nozzle 31. The nozzle standby section 35 receives, for example, the processing liquid ejected from the nozzle 31. When the nozzle 31 is disposed at the nozzle standby section 35, the nozzle 31 is capable of performing a dummy dispense.

[0082] The upstream end 13 is connected to a processing liquid supply source 61. The processing liquid supply source 61 supplies a processing liquid to the upstream end 13. The processing liquid supply source 61 includes, for example, at least one of a tank and a trap tank. The processing liquid supply source 61 may or may not be an element of the substrate processing apparatus 1.

[0083] The processing liquid is a liquid supplied to the substrate W. The processing liquid is a liquid used to process the substrate. Specifically, the processing liquid is a liquid used to form a semiconductor device on the substrate W. The processing liquid is, for example, a coating liquid. The coating liquid is a coating material for forming a coating film on the substrate W. The coating liquid is, for example, a resist film material.

[0084] The upstream end 13 is connectable to a cleaning liquid supply source 63. The cleaning liquid supply source 63 supplies a cleaning liquid to the upstream end 13. The cleaning liquid supply source 63 includes, for example, a tank and / or a trap tank. Furthermore, the cleaning liquid supply source 63 may include at least one of a pump and / or a filter. The cleaning liquid supply source 63 may or may not be an element of the substrate processing apparatus 1.

[0085] The cleaning liquid is a liquid that cleans the liquid supply unit 11. Specifically, the cleaning liquid is a liquid used to remove particles from the liquid supply unit 11. The cleaning liquid is not a liquid that is supplied to the substrate W. The cleaning liquid is not a liquid that is used to process the substrate W. Specifically, the cleaning liquid is not a liquid that is used to form a semiconductor device on the substrate W. The cleaning liquid is, for example, an organic solvent. The organic solvent is, for example, a thinner.

[0086] In the following, when there is no distinction between the processing liquid and the cleaning liquid, they are referred to as "liquids."

[0087] A part of the liquid supply unit 11 is manually attached or detached by a user of the substrate processing apparatus 1. For example, the parts of liquid supply unit 11 are attached and detached by the user manually. Here, the parts of liquid supply unit 11 are pipes 15, 16, first pump 21, nozzle 31, first valve 41, and second valve 42. For example, first pump 21 is attached and detached to and from pipes 15, 16 by the user manually. This allows the user to replace first pump 21.

[0088] The entire liquid supply unit 11 is attached or detached by the user manually. For example, the liquid supply unit 11 is attached or detached to the processing liquid supply source 61 by the user manually. Specifically, the upstream end 13 is attached or detached to the processing liquid supply source 61. For example, the liquid supply unit 11 is attached or detached to the cleaning liquid supply source 63 by the user manually. Specifically, the upstream end 13 is attached or detached to the cleaning liquid supply source 63.

[0089] The upstream end 13 cannot be connected to both the processing liquid source 61 and the cleaning liquid source 63 simultaneously. Therefore, when switching between the processing liquid supply source 61 and the cleaning liquid supply source 63, the user must perform the operation of attaching and detaching between the upstream end 13 and the processing liquid supply source 61 and the operation of attaching and detaching between the upstream end 13 and the cleaning liquid supply source 63.

[0090] The substrate processing apparatus 1 includes a control unit 65. The control unit 65 controls the rotation drive unit 6. The control unit 65 controls the liquid supply unit 11. Specifically, the control unit 65 controls the first pump 21, the first valve 41, the second valve 42, and the nozzle moving mechanism 33.

[0091] The control unit 65 is realized, for example, by a processor (e.g., a central processing unit (CPU)) that executes various processes, a random-access memory (RAM) that serves as a working area for the calculation processes, and a storage medium such as a fixed disk that stores various information. The information stored in the storage medium is, for example, a processing recipe (processing program) that defines the processing conditions for the substrate W. The information stored in the storage medium is, for example, a cleaning recipe (cleaning program) that defines the cleaning conditions for the liquid supply unit 11.

[0092] 2. First pump 21 2 is a partial cross-sectional view illustrating the first pump 21. The first pump 21 is classified as a reciprocating pump. The first pump 21 alternates between suction and discharge in time.

[0093] The first pump 21 has a pump chamber 24. The pump chamber 24 is a space. The pump chamber 24 contains liquid (i.e., the processing liquid and the cleaning liquid). The pump chamber 24 is filled with liquid. The volume of the pump chamber 24 is variable. When the volume of the pump chamber 24 increases, the first pump 21 sucks liquid into the pump chamber 24. When the volume of the pump chamber 24 decreases, the first pump 21 expels liquid from the pump chamber 24.

[0094] The first pump 21 includes a housing 25 and a diaphragm 26. The diaphragm 26 is attached to the housing 25. The housing 25 fixes the peripheral portion of the diaphragm 26. The housing 25 and the diaphragm 26 define the pump chamber 24. The diaphragm 26 is flexible. The diaphragm 26 is, for example, a rolling diaphragm. The material of the diaphragm 26 is, for example, a synthetic resin.

[0095] The pump chamber 24 communicates with the supply passage 12. The first pump 21 has connection ports 27a, 27b. The connection ports 27a, 27b are each formed in the housing 25. The connection ports 27a, 27b each connect the pump chamber 24 to the supply passage 12. The connection port 27a is connected to the pipe 15. The connection port 27b is connected to the pipe 16.

[0096] The first pump 21 includes a pump drive unit 29. The pump drive unit 29 changes the volume of the pump chamber 24.

[0097] The pump driving unit 29 includes a piston 29a and an actuator 29b. The piston 29a is attached to the diaphragm 26. The piston 29a is attached to, for example, a central portion of the diaphragm 26. The actuator 29b moves the piston 29a. The actuator 29b is, for example, an electric motor. The actuator 29b is, for example, a stepping motor.

[0098] The pump driving unit 29 may further include a conversion mechanism (not shown). The conversion mechanism connects the actuator 29b and the piston 29a. The conversion mechanism converts the rotational power of the actuator 29b into the linear motion of the piston 29a.

[0099] The piston 29a performs a reciprocating linear motion relative to the pump chamber 24. Specifically, the piston 29a moves in a positive direction Ep and a negative direction En. The negative direction En is the opposite direction to the positive direction Ep.

[0100] When the piston 29a moves in the positive direction Ep, the pump drive unit 29 decreases the volume of the pump chamber 24. When the piston 29a moves in the negative direction En, the pump drive unit 29 increases the volume of the pump chamber 24.

[0101] The flow rate of liquid discharged from the first pump 21 depends on the speed of the piston 29a moving in the positive direction Ep. The flow rate of liquid sucked into the first pump 21 depends on the speed of the piston 29a moving in the negative direction En.

[0102] The control unit 65 controls the pump driving unit 29. Specifically, the control unit 65 controls the actuator 29b. The control unit 65 controls the pump driving unit 29, whereby the control unit 65 drives the first pump. For example, the control unit 65 causes the first pump 21 to suck and discharge. For example, the control unit 65 controls the flow rate of liquid sucked into the first pump and the flow rate of liquid discharged from the first pump.

[0103] 3. First valve 41 3(a) and 3(b) are partial cross-sectional views illustrating the first valve 41. Fig. 3(a) shows the first valve 41 in an open state. Fig. 3(b) shows the first valve 41 in a closed state. In this specification, "closed" means fully closed.

[0104] The first valve 41 is classified as a motor-operated valve.

[0105] The first valve 41 includes a valve seat 51, a valve element 52, and an electric motor 53. The valve element 52 is capable of coming into contact with the valve seat 51. The electric motor 53 moves the valve element 52 relative to the valve seat 51.

[0106] When the first valve 41 is open, the valve disc 52 does not contact the valve seat 51. When the first valve 41 is open, the valve disc 52 is separated from the valve seat 51. When the first valve 41 is closed, the valve disc 52 contacts the valve seat 51.

[0107] The distance of the gap between the valve seat 51 and the valve body 52 is called the separation distance D. When the first valve 41 is open, the separation distance D is greater than 0. When the first valve 41 is closed, the separation distance D is 0.

[0108] The electric motor 53 adjusts the separation distance D. The electric motor 53 finely adjusts the separation distance D. The electric motor 53 finely adjusts the separation distance D in units of several micrometers, for example.

[0109] The separation distance D corresponds to the opening degree of the first valve 41. The opening degree of the first valve 41 increases as the separation distance D increases. Therefore, the electric motor 53 finely adjusts the opening degree of the first valve 41.

[0110] More specifically, the first valve 41 includes a valve body 54 and a diaphragm 55. The diaphragm 55 is attached to the valve body 54. The valve body 54 fixes the peripheral edge of the diaphragm 55. The diaphragm 55 has flexibility. The diaphragm 55 is, for example, a rolling diaphragm. The material of the diaphragm 55 is, for example, a synthetic resin.

[0111] The valve body 54 and the diaphragm 55 define an internal flow passage 56. The internal flow passage 56 is a space.

[0112] The valve body 52 is formed, for example, in the center of the diaphragm 55. The valve seat 51 is formed in the valve box 54. The valve seat 51 is disposed in the internal flow path 56. The valve seat 51 faces the valve body 52. ​​The valve seat 51 has a substantially ring shape.

[0113] The valve disc 52 and the valve seat 51 divide the internal flow path 56 into a first internal flow path 56a and a second internal flow path 56b. When the valve disc 52 contacts the valve seat 51, the valve seat 51 and the valve disc 52 separate the first internal flow path 56a from the second internal flow path 56b. When the valve disc 52 is not in contact with the valve seat 51, the first internal flow path 56a and the second internal flow path 56b communicate with each other through the gap between the valve disc 52 and the valve seat 51.

[0114] The first valve 41 includes connection ports 57a and 57b. The connection ports 57a and 57b are formed in the valve body 54. The connection port 57a communicates with the first internal flow path 56a. The connection port 57b communicates with the second internal flow path 56b.

[0115] The internal flow path 56 communicates with the supply path 12. The connection ports 57a and 57b are each connected to a pipe 15. The first internal flow path 56a communicates with the pipe 15 through the connection port 57a. The second internal flow path 56b communicates with the pipe 15 through the connection port 57b.

[0116] The first valve 41 includes a rod 58. The rod 58 is attached to the valve body 52. ​​The rod 58 is attached to the center of the diaphragm 55, for example.

[0117] The electric motor 53 moves the rod 58. The electric motor 53 moves the valve body 52 via the rod 58. The electric motor 53 is, for example, a stepping motor.

[0118] The first valve 41 includes a conversion mechanism (not shown). The conversion mechanism connects the electric motor 53 and the rod 58. The conversion mechanism converts the rotational power of the electric motor 53 into the linear motion of the rod 58.

[0119] The rod 58 performs a reciprocating linear motion relative to the valve seat 51. Specifically, the rod 58 moves in a positive direction Fp and a negative direction Fn. The negative direction Fn is the opposite direction to the positive direction Fp.

[0120] When the electric motor 53 rotates in the forward direction, the rod 58 moves in the forward direction Fp. When the rod 58 moves in the forward direction Fp, the separation distance D decreases. That is, when the electric motor 53 rotates in the forward direction, the opening degree of the first valve 41 decreases. When the electric motor 53 rotates in the reverse direction, the rod 58 moves in the negative direction Fn. When the rod 58 moves in the negative direction Fn, the separation distance D increases. That is, when the electric motor 53 rotates in the reverse direction, the opening degree of the first valve 41 increases.

[0121] The amount of movement of the rod 58 depends on the amount of rotation of the electric motor 53. The amount of movement of the rod 58 is also called the stroke amount of the rod 58. The position of the rod 58 depends on the rotation angle of the electric motor 53. Therefore, the separation distance D depends on the rotation angle of the electric motor 53.

[0122] The electric motor 53 can finely adjust the position of the rod 58. The electric motor 53 finely adjusts the position of the rod 58, thereby finely adjusting the separation distance D.

[0123] The first valve 41 includes a position sensor 59. The position sensor 59 detects the position of the valve body 52. ​​The position sensor 59 detects, for example, the amount of rotation of the electric motor 53 or the rotation angle of the electric motor 53. The position sensor 59 is, for example, an encoder.

[0124] The control unit 65 controls the electric motor 53. The control unit 65 acquires the detection result of the position sensor 59. The control unit 65 monitors, for example, the detection result of the position sensor 59. The control unit 65 controls, for example, the electric motor 53 based on the detection result of the position sensor 59. The control unit 65 controls the electric motor 53, thereby opening and closing the first valve 41. Furthermore, the control unit 65 controls the opening degree of the first valve 41.

[0125] 4. Second valve 42 The second valve 42 is classified as, for example, an air operated valve. Although not shown, the second valve 42 includes a valve seat and a valve body. The second valve 42 includes an air drive unit instead of the electric motor 53 described above. The air drive unit moves the valve body relative to the valve seat. The air drive unit opens and closes the second valve 42. However, it is difficult to finely adjust the opening degree of the second valve using the air drive unit.

[0126] The control unit 65 controls the air driver, whereby the control unit 65 opens and closes the second valve .

[0127] 5. Example of processing operation The operation of the substrate processing apparatus 1 of the first embodiment (i.e., the substrate processing method of the first embodiment) will be described. The substrate processing method processes the substrate W using the liquid supply unit 11. Specifically, the substrate processing method includes a processing step. The processing step processes the substrate W. Specifically, the processing step performs a process of forming a semiconductor device on the substrate W. In the following description, it is assumed that the rotation drive unit 6 and the liquid supply unit 11 operate in accordance with the control unit 65.

[0128] 4 is a flow chart showing the procedure of the operation of the processing step of the first embodiment. The processing step includes a first feed step and a second feed step. The second feed step is performed after the first feed step.

[0129] Fig. 5(a) is a diagram showing the substrate processing apparatus 1 in a first transfer step. Fig. 5(b) is a diagram showing the substrate processing apparatus 1 in a second transfer step. Figs. 5(a) and 5(b) each show a simplified view of the substrate processing apparatus 1. In the processing step, the upstream end 13 is connected to a processing liquid supply source 61.

[0130] 5(a) and 5(b) each show a schematic flow of the processing liquid. In the cleaning process, the processing liquid is supplied to the upstream end 13. In the cleaning process, the processing liquid is supplied to the liquid supply unit 11 through the upstream end 13. In the processing process, the liquid supply unit 11 supplies the processing liquid to the substrate W.

[0131] [Step S1: First feeding process] Referring to FIG. 5(a), the first valve 41 is open. The first valve 41 allows the flow of the treatment liquid in the pipe 15. The second valve 42 is closed. The second valve 42 prohibits the flow of the treatment liquid in the pipe 16. The first pump 21 sucks the treatment liquid. Therefore, the treatment liquid flows from the upstream end 13 to the first pump 21 through the pipe 15. The first pump 21 sucks the treatment liquid from the pipe 15.

[0132] The processing liquid does not flow through the pipe 16. The first pump 21 does not suck the processing liquid from the pipe 16. This is because the second valve prevents the processing liquid from flowing back from the pipe 16 to the first pump 21.

[0133] [Step S2: Second feeding process] Referring to FIG. 5(b), the first valve 41 is closed. The first valve 41 prohibits the flow of the treatment liquid in the pipe 15. The second valve 42 is opened. The second valve 42 allows the flow of the treatment liquid in the pipe 16. The first pump 21 discharges the treatment liquid. Therefore, the first pump 21 discharges the treatment liquid into the pipe 16. The treatment liquid flows from the first pump 21 to the nozzle 31 through the pipe 16. The nozzle 31 discharges the treatment liquid.

[0134] The substrate holding unit 5 holds the substrate W. The rotation drive unit 6 rotates the substrate W held by the substrate holding unit 5. The nozzle 31 is located at a processing position. The nozzle 31 ejects a processing liquid onto the substrate W held by the substrate holding unit 5. The cup 7 receives the processing liquid splashed from the substrate W.

[0135] The treatment liquid does not flow through the pipe 15. The first pump 21 does not discharge the treatment liquid into the pipe 15. This is because the first valve 41 prevents the treatment liquid from flowing back from the first pump 21 to the pipe 15.

[0136] The operations of the first valve 41 and the second valve 42 in the above-mentioned process are summarized below. The first valve 41 opens and closes. The second valve 42 opens and closes. When the first valve 41 opens, the second valve 42 closes. When the first valve 41 closes, the second valve 42 opens.

[0137] 6. Example of cleaning process The substrate processing method includes a cleaning process. In the cleaning process, the liquid supply unit 11 is cleaned. In the cleaning process, no processing is performed on the substrate W. Specifically, in the cleaning process, no processing of forming a semiconductor device is performed on the substrate W. In the cleaning process, the liquid supply unit 11 does not supply a processing liquid to the substrate W. In the cleaning process, the liquid supply unit 11 does not supply a cleaning liquid to the substrate W. In the following description, the rotation drive unit 6 and the liquid supply unit 11 are assumed to operate in accordance with the control unit 65.

[0138] 6 is a flow chart showing the procedure of the operation of the cleaning process of the first embodiment. The cleaning process includes a first step and a second step. The cleaning process further includes an inspection step. The second step is performed after the first step. The inspection step is performed after the second step. The first step and the second step may be repeatedly performed before the inspection step.

[0139] Fig. 7(a) is a diagram showing the substrate processing apparatus 1 in a first step. Fig. 7(b) is a diagram showing the substrate processing apparatus 1 in a second step. Figs. 7(a) and 7(b) each show a simplified view of the substrate processing apparatus 1. In the cleaning step, the upstream end 13 is connected to a cleaning liquid supply source 63.

[0140] 7(a) and 7(b) each show a schematic diagram of the flow of the cleaning liquid. In the cleaning process, the cleaning liquid is supplied to the upstream end 13. In the cleaning process, the cleaning liquid is supplied to the liquid supply unit 11 through the upstream end 13. In the cleaning process, the cleaning liquid is caused to flow in the liquid supply unit 11.

[0141] [Step S3: First Process] Refer to Fig. 7(a). The first valve 41 opens at a first large opening degree A1. The second valve 42 closes. Therefore, the first valve 41 opens larger than the second valve 42. Specifically, the first valve 41 opens at a larger opening degree than the opening degree of the second valve 42. The first pump 21 sucks in the cleaning liquid. Specifically, the first pump 21 sucks in the cleaning liquid at a first flow rate Q1.

[0142] The first large opening degree A1 will be described. When the first valve 41 opens at the first large opening degree A1, the separation distance D is 400 μm or more.

[0143] When the first valve 41 is opened at the first large opening degree A1, the first valve 41 allows the cleaning liquid to pass through the first valve 41 at a first flow rate Q1.

[0144] The first flow rate Q1 is, for example, 1 cc / sec. In this case, when the first valve 41 opens at the first large opening degree A1, the first valve 41 allows the cleaning liquid to pass through the first valve 41 at 1 cc / sec.

[0145] Thus, the cleaning liquid flows from the upstream end 13 through the pipe 15 to the first pump 21 . The first pump 21 sucks the treatment liquid from the pipe 15. The treatment liquid does not flow through the pipe 16. The first pump 21 does not suck the treatment liquid from the pipe 16.

[0146] In the first step, the first valve 41 is cleaned. In the first step, the pipe 15 is cleaned.

[0147] [Step S4: Second process] Refer to Fig. 7(b). The first valve 41 opens at a first small opening B1. The second valve 42 opens. Specifically, the second valve 42 opens larger than the first valve 41. The first pump 21 discharges the cleaning liquid. Specifically, the first pump 21 discharges the cleaning liquid at a second flow rate Q2.

[0148] The first small opening degree B1 will be described. The first small opening degree B1 is smaller than the first large opening degree A1. The first small opening degree B1 is slightly larger than the opening degree of the first valve 41 when the first valve is closed.

[0149] When the first valve 41 opens at the first small opening degree B1, the separation distance D is smaller than 100 μm When the first valve 41 opens at the first small opening degree B1, the separation distance D is greater than 5 μm.

[0150] When the first valve 41 opens at the first small opening degree B1, the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to less than the second flow rate Q2. When the first valve 41 opens at the first small opening degree B1, it is preferable that the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to 20% or less of the second flow rate Q2.

[0151] The second flow rate is, for example, 1 cc / sec. In this case, when the first valve 41 opens at the first small opening B1, the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to less than 1 cc / sec. In other words, when the first valve 41 opens at the first small opening B1, the first valve 41 limits the amount of leakage from the first valve 41 to less than 1 cc / sec. When the first valve 41 opens at the first small opening B1, it is preferable that the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to 0.2 cc / sec or less. 0.2 cc / sec corresponds to 12 cc / min. When the first valve 41 opens at the first small opening B1, it is preferable that the first valve 41 limits the amount of leakage from the first valve 41 to less than 12 cc / min.

[0152] Therefore, when the first valve 41 is opened at the first small opening degree B1, the first valve 41 restricts the flow of the treatment liquid in the pipe 15.

[0153] On the other hand, the second valve 42 opens to an opening degree larger than the first small opening degree B1. Therefore, the second valve 42 allows the cleaning liquid to pass through the second valve 42 at the second flow rate Q2.

[0154] As a result, the first pump 21 essentially discharges the processing liquid into the pipe 16. The cleaning liquid flows substantially from the first pump 21 to the nozzle 31 through the pipe 16. The nozzle 31 discharges the cleaning liquid. The nozzle 31 is located at a standby position. The nozzle standby section 35 receives the cleaning liquid. As a result, the particles are discharged from the inside of the liquid supply section 11 to the outside of the liquid supply section 11 together with the cleaning liquid.

[0155] Here, the first valve 41 opens at the first small opening degree B1. That is, the first valve 41 does not close. Therefore, the first valve 41 does not prohibit the flow of the cleaning liquid in the pipe 15. Therefore, the cleaning liquid may flow back from the first pump 21 to the pipe 15. Even in this case, the flow rate of the cleaning liquid flowing from the first pump 21 to the pipe 16 is greater than the flow rate of the cleaning liquid flowing from the first pump 21 to the pipe 15. This is because, in the second step, the second valve 42 opens more than the first valve 41. Therefore, in the second step, the cleaning liquid substantially flows from the first pump 21 to the pipe 16.

[0156] In the second step, the first pump 21, the second valve 42, and the nozzle 31 are cleaned. In the second step, the pipe 16 is cleaned.

[0157] [Step S5: Inspection process] Although not shown in the drawing, the inspection step inspects the cleanliness of the liquid supply unit 11.

[0158] In the inspection process, the amount of particles present in the cleaning liquid extracted from the liquid supply unit 11 is measured. For example, the amount of particles present in the cleaning liquid discharged from the nozzle 31 is measured. For example, the substrate holding unit 5 holds an inspection plate (not shown), the nozzle 31 is positioned at the processing position, and the nozzle 31 discharges the cleaning liquid onto the inspection plate held by the substrate holding unit 5. Thereafter, the amount of particles present on the inspection plate is measured. For example, the nozzle 31 is positioned at the standby position, and the nozzle 31 discharges the cleaning liquid into the nozzle standby unit 35. Thereafter, the amount of particles present in the cleaning liquid received by the nozzle standby unit 35 is measured. Here, the measured amount of particles is called a measurement value.

[0159] In the inspection step, the user determines whether to continue or end the cleaning step based on the measured value. If the user determines to resume the cleaning step, the first and second steps described above are executed again.

[0160] The operations of the first valve 41 and the second valve 42 in the above-mentioned cleaning process are summarized below. The first valve 41 switches between a first large opening degree A1 and a first small opening degree B1. The second valve 42 opens and closes. When the first valve 41 opens at the first large opening degree A1, the second valve 42 closes. When the first valve 41 opens at the first small opening degree B1, the second valve 42 opens wider than the first valve 41.

[0161] 5.Effects The substrate processing method of the first embodiment processes a substrate W using a liquid supply unit 11. The liquid supply unit 11 includes a supply path 12, a first pump 21, a first valve 41, and a nozzle 31. The supply path 12 has an upstream end 13 and a downstream end 14. The first pump 21 and the first valve 41 are each provided on the supply path 12. The first valve 41 is disposed upstream of the first pump 21. The nozzle 31 is connected to the downstream end 14 of the first pump 21. The substrate processing method includes a processing step. The processing step supplies a processing liquid to the upstream end 13. In the processing step, the first valve 41 opens and closes. When the first valve 41 opens, the first valve 41 allows the processing liquid to flow in the pipe 15. When the first valve 41 closes, the first valve 41 stops the flow of the processing liquid in the pipe 15. In this manner, in the processing step, the first valve 41 strictly controls the flow of the processing liquid upstream of the first pump 21. Therefore, in the processing step, the liquid supply unit 11 can appropriately supply the processing liquid to the substrate W. In the processing step, the substrate W can be appropriately processed using the liquid supply unit 11.

[0162] The substrate processing method includes a cleaning process. In the cleaning process, a cleaning liquid is supplied to the upstream end 13. In the cleaning process, the cleaning liquid is caused to flow through the liquid supply unit 11. Thus, the cleaning process can suitably clean the liquid supply unit 11. In the cleaning process, for example, the first pump 21 can be suitably cleaned. Therefore, when a user performs an operation of attaching or detaching at least a part of the liquid supply unit 11, the cleaning process can suitably clean the liquid supply unit 11. For example, in the case of the following AC, the cleaning process can suitably clean the liquid supply unit 11. A. Start up the substrate processing apparatus 1 B. The liquid supply unit 11 is attached to and detached from at least one of the processing liquid supply source 61 and the cleaning liquid supply source 63. C. Replace the parts of the liquid supply unit 11

[0163] In the cleaning process, the first valve 41 switches between the first large opening degree A1 and the first small opening degree B1. The first small opening degree B1 is smaller than the first large opening degree A1. Therefore, the first valve 41 opening at the first small opening degree B1 suppresses the flow of the cleaning liquid more than the first valve 41 opening at the first large opening degree A1. In other words, the cleaning liquid passes through the first valve 41 opening at the first large opening degree A1 relatively easily and passes through the first valve 41 opening at the first small opening degree B1 relatively less easily. Thus, in the cleaning process, the first valve 41 substantially controls the flow of the cleaning liquid upstream of the first pump 21. Therefore, in the cleaning process, the cleaning liquid can be appropriately flowed to the liquid supply unit 11.

[0164] Here, when the first valve 41 is opened at the first small opening degree B1, some amount of cleaning liquid may flow upstream of the first pump 21. However, the cleaning process does not process the substrate W. Therefore, even if the first valve 41 does not strictly control the flow of the cleaning liquid, the quality of the process performed on the substrate W is not degraded.

[0165] When the first valve 41 opens at the first small opening degree B1, the first valve 41 does not close. Of course, when the first valve 41 opens at the first large opening degree A1, the first valve 41 does not close. For this reason, foreign matter is less likely to adhere to the first valve 41. In other words, the first valve 41 is less likely to be contaminated in the cleaning process. Therefore, the cleaning process can efficiently clean the liquid supply unit 11. For example, an increase in the time spent in the cleaning process can be preferably prevented. For example, an increase in the amount of cleaning liquid used in the cleaning process can be preferably prevented.

[0166] In summary, according to the substrate processing method of the first embodiment, the cleaning step can suitably clean the liquid supply unit 11. In the cleaning step, the first valve 41 substantially controls the flow of the cleaning liquid upstream of the first pump 21, while suppressing adhesion of foreign matter to the first valve 41. In the processing step, the substrate W can be suitably processed.

[0167] The first small opening B1 is slightly larger than the opening of the first valve 41 when the first valve 41 is closed. Therefore, when the first valve 41 opens at the first small opening B1, the first valve 41 significantly suppresses the flow of the cleaning liquid upstream of the first pump 21. Therefore, in the cleaning process, the first valve 41 can suitably control the flow of the cleaning liquid upstream of the first pump 21.

[0168] When the first valve 41 opens at the first large opening degree A1 in the cleaning process, the first pump 21 sucks in the cleaning liquid. Therefore, the first valve 41 allows the cleaning liquid to flow from the first valve 41 to the first pump 21 when the first pump 21 sucks in the cleaning liquid. When the first valve 41 opens at the first small opening degree B1 in the cleaning process, the first pump 21 expels the cleaning liquid. Therefore, the first valve 41 prevents the cleaning liquid from flowing back from the first pump 21 to the first valve 41 when the first pump 21 expels it. In this way, the first valve 41 can substantially control the flow of the cleaning liquid upstream of the first pump 21 in accordance with the operation of the first pump 21.

[0169] When the first valve 41 opens at the first large opening degree A1 in the cleaning process, the first pump 21 draws in the cleaning liquid at a first flow rate Q1. When the first valve 41 opens at the first large opening degree A1 in the cleaning process, the first valve 41 allows the cleaning liquid to pass through the first valve 41 at the first flow rate Q1. Therefore, when the first pump 21 draws in the cleaning liquid, the first valve 41 allows the cleaning liquid to flow smoothly from the first valve 41 to the first pump 21.

[0170] When the first valve 41 opens at the first small opening B1 in the cleaning process, the first pump 21 discharges the cleaning liquid at the second flow rate Q2. When the first valve 41 opens at the first small opening B1 in the cleaning process, the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to less than the second flow rate Q2. Therefore, the first valve 41 prevents the cleaning liquid from flowing back from the first pump 21 to the first valve 41 when the first pump 21 discharges the cleaning liquid.

[0171] When the first valve 41 opens to the first small opening B1 in the cleaning process, the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to 20% or less of the second flow rate Q2. Therefore, the first valve 41 further prevents the cleaning liquid from flowing back from the first pump 21 to the first valve 41 when the first pump 21 discharges the cleaning liquid.

[0172] The first valve 41 includes a valve seat 51, a valve body 52, and an electric motor 53. The valve body 52 is capable of coming into contact with the valve seat 51. The electric motor 53 moves the valve body 52 relative to the valve seat 51. The electric motor 53 adjusts the separation distance D. Thus, the electric motor 53 can finely adjust the separation distance D. That is, the electric motor 53 can finely adjust the opening degree of the first valve 41.

[0173] When the first valve 41 opens at the first large opening degree A1, the separation distance D is 400 μm or more. Therefore, when the first valve 41 opens at the first large opening degree A1 in the cleaning process, the cleaning liquid passes smoothly between the valve seat 51 and the valve body 52. ​​In other words, when the first valve 41 opens at the first large opening degree A1 in the cleaning process, the first valve 41 allows the cleaning liquid to pass smoothly through the first valve 41.

[0174] When the first valve 41 opens at the first small opening B1, the separation distance D is smaller than 100 μm. Therefore, when the first valve 41 opens at the first small opening B1 in the cleaning process, the cleaning liquid is unlikely to pass between the valve seat 51 and the valve body 52. ​​In other words, when the first valve 41 opens at the first small opening B1 in the cleaning process, the first valve 41 prevents the cleaning liquid from passing through it.

[0175] When the first valve 41 opens at the first small opening degree B1, the separation distance D is greater than 5 μm. Therefore, when the first valve 41 opens at the first small opening degree B1, the foreign matter can easily pass through the gap formed between the valve seat 51 and the valve body 52. ​​Of course, when the first valve 41 opens at the first large opening degree A1, the foreign matter can easily pass through the gap formed between the valve seat 51 and the valve body 52. ​​Therefore, the foreign matter is less likely to adhere to at least one of the valve body 52 and the valve seat 51. For example, the valve seat 51 and the valve body 52 can be suitably prevented from pinching the foreign matter between the valve seat 51 and the valve body 52. ​​For example, the valve body 52 can be suitably prevented from pressing the foreign matter against the valve seat 51. For example, the valve seat 51 can be suitably prevented from pressing the foreign matter against the valve body 52.

[0176] The treatment process includes a first feed process and a second feed process. In the first feed process, the first valve 41 opens and the first pump 21 sucks in. Therefore, in the first feed process, the treatment liquid flows smoothly from the first valve 41 to the first pump 21 through the piping 15. More specifically, in the first feed process, the treatment liquid flows smoothly from the upstream end 13 to the first pump 21 through the piping 15. In the second feed process, the first valve 41 closes and the first pump 21 discharges. Therefore, in the second feed process, the first valve 41 prohibits the treatment liquid from flowing back from the first pump 21 to the first valve 41. As a result, in the second feed process, the treatment liquid flows from the first pump 21 to the piping 16.

[0177] The cleaning process includes a first process and a second process. In the first process, the first valve 41 opens at a first large opening A1, and the first pump 21 sucks in the cleaning liquid. Therefore, in the first process, the cleaning liquid flows substantially from the first valve 41 to the first pump 21 through the piping 15. More specifically, in the first process, the cleaning liquid flows substantially from the upstream end 13 to the first pump 21 through the piping 15. In the second process, the first valve 41 opens at a first small opening B1, and the first pump 21 discharges the cleaning liquid. Therefore, in the second process, the first valve 41 suppresses the cleaning liquid from flowing back from the first pump 21 to the first valve 41. As a result, in the second process, the cleaning liquid flows substantially from the first pump 21 to the downstream of the first pump.

[0178] The liquid supply unit 11 includes a second valve 42. The second valve 42 is provided in the supply path 12. The second valve 42 is disposed downstream of the first pump 21. In the processing step, the second valve 42 opens and closes. When the second valve 42 opens, the second valve 42 allows the processing liquid to flow in the pipe 16. When the second valve 42 closes, the second valve 42 stops the processing liquid from flowing in the pipe 16. In this manner, in the processing step, the second valve 42 strictly controls the flow of the processing liquid downstream of the first pump 21. Therefore, in the processing step, the liquid supply unit 11 can more appropriately supply the processing liquid to the substrate W. Therefore, in the processing step, the processing can be more appropriately performed on the substrate W.

[0179] In the first feed step, the second valve 42 is closed. Therefore, in the first feed step, the second valve 42 prohibits the treatment liquid from flowing back from the second valve 42 to the first pump 21. In the second feed step, the second valve 42 is opened. Therefore, in the second feed step, the treatment liquid flows smoothly from the first pump 21 to the second valve 42 through the pipe 16.

[0180] In the first step, the first valve 41 opens wider than the second valve 42. In the first step, the cleaning liquid passes through the first valve 41 more smoothly than the second valve 42. Therefore, in the first step, the cleaning liquid flows substantially from the first valve 41 to the first pump 21 through the pipe 15. In the second step, the second valve 42 opens wider than the first valve 41. In the second step, the cleaning liquid passes through the second valve 42 more smoothly than the first valve 41. Therefore, in the second step, the cleaning liquid flows substantially from the first pump 21 to the second valve 42 through the pipe 16.

[0181] The substrate processing apparatus 1 includes a substrate holding unit 5, a liquid supply unit 11, and a control unit 65. The liquid supply unit 11 includes a supply path 12, a first pump 21, a first valve 41, and a nozzle 31. The supply path 12 has an upstream end 13. A cleaning liquid for cleaning the liquid supply unit 11 is supplied to the upstream end 13. This allows the first pump 21 to be cleaned appropriately.

[0182] When supplying the cleaning liquid to the upstream end 13, the control unit 65 switches the opening degree of the first valve 41 between a first large opening degree A1 and a first small opening degree B1. The first small opening degree B1 is smaller than the first large opening degree A1. Therefore, when supplying the cleaning liquid to the upstream end 13, the first valve 41 substantially controls the flow of the cleaning liquid upstream of the first pump 21. This allows the cleaning liquid to flow appropriately in the liquid supply unit 11.

[0183] Furthermore, the first small opening degree B1 is larger than the opening degree of the first valve 41 when the first valve 41 is closed. That is, when the first valve 41 opens at the first small opening degree B1, the first valve 41 does not close. The first large opening degree A1 is larger than the first small opening degree B1. Therefore, even when the first valve 41 opens at the first large opening degree A1, the first valve 41 does not close. Therefore, when the cleaning liquid is supplied to the upstream end 13, foreign matter is unlikely to adhere to the first valve 41. Therefore, the liquid supply unit 11 can be efficiently cleaned.

[0184] In summary, the substrate processing apparatus according to the first embodiment can suitably clean the liquid supply unit 11. Specifically, the first pump 21 can be suitably cleaned. The first valve 41 substantially controls the flow of the cleaning liquid upstream of the first pump 21, while preventing foreign matter from adhering to the first valve 41.

[0185] Second embodiment Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. Note that the same components as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

[0186] 8 is a diagram showing a schematic configuration of a substrate processing apparatus 1 according to a second embodiment. Except for a liquid supply unit 11, the substrate processing apparatus 1 according to the second embodiment has substantially the same configuration as that of the first embodiment.

[0187] 1.Liquid supply section 11 The liquid supply unit 11 includes a second pump 22 in addition to a first pump 21. The first pump 21 and the second pump 22 are each provided in the supply path 12. The second pump 22 is disposed downstream of the first pump 21.

[0188] The liquid supply unit 11 includes a filter 71. The filter 71 is provided in the supply path 12. The filter 71 is disposed downstream of the first pump 21 and upstream of the second pump 22.

[0189] The liquid supply unit 11 includes pipes 17 and 18 in addition to pipes 15 and 16. Pipe 15 has a first end and a second end. The first end of pipe 15 corresponds to the upstream end 13. The second end of pipe 15 is connected to a first pump 21. Pipe 16 is connected to the first pump 21 and a filter 71. Pipe 17 is connected to a filter 71 and a second pump 22. Pipe 18 has a first end and a second end. The first end of pipe 18 is connected to the second pump 22. The second end of pipe 18 corresponds to the downstream end 14. The second end of pipe 18 is connected to a nozzle 31.

[0190] Pipe 15 is an example of a first portion of supply path 12 of the present invention. Pipe 16 is an example of a second portion of supply path 12 of the present invention. Pipe 17 is an example of a third portion of supply path 12 of the present invention. Pipe 18 is an example of a fourth portion of supply path 12 of the present invention.

[0191] The liquid supply unit 11 includes a return path 75. The return path 75 communicates between the first pump 21 and the second pump 22. The return path 75 is provided separately from the supply path 12.

[0192] In this specification, the flow from the second pump 22 to the first pump 21 through the return path 75 is appropriately described as "backflow."

[0193] The liquid supply unit 11 includes a discharge path 77. The discharge path 77 is connected to a filter 71. The filter 71 connects the supply path 12 and the discharge path 77. The discharge path 77 branches off from the supply unit 12.

[0194] The discharge path 77 communicates with a liquid drainage facility (not shown). The liquid discharged from the supply path 12 to the discharge path 77 does not return to the liquid supply unit 11.

[0195] The liquid supply unit 11 includes a third valve 43, a fourth valve 44, a fifth valve 45, and a discharge valve 46 in addition to the first valve 41 and the second valve 42. The first valve 41, the second valve 42, the third valve 43, and the fourth valve 44 are each provided in the supply passage 12. The first valve 41 is provided in the pipe 15. The first valve 41 is disposed upstream of the first pump 21. The second valve 42 is provided in the pipe 16. The second valve 42 is disposed downstream of the first pump 21 and upstream of the filter 71. The third valve 43 is provided in the pipe 17. The third valve 43 is disposed downstream of the filter 71 and upstream of the second pump 22. The fourth valve 44 is provided in the pipe 18. The fourth valve 44 is disposed downstream of the second pump 22. The fifth valve 45 is provided in the return passage 75. The discharge valve 46 is provided in the discharge passage 77 .

[0196] The first pump 21 of the second embodiment has a similar structure to the first pump 21 of the first embodiment. The first pump 21 of the second embodiment has a connection port 27c in addition to the connection ports 27a and 27b. The connection port 27a is connected to the pipe 15. The connection port 27b is connected to the pipe 16. The connection ports 27a and 27b each connect the pump chamber 24 to the supply path 12. The connection port 27c is connected to the return path 75. The connection port 27c connects the pump chamber 24 to the return path 75.

[0197] The second pump 22 has the same structure as the first pump 21. The second pump 22 has connection ports 28a, 28b, and 28c. The connection port 28a is connected to the pipe 17. The connection port 28b is connected to the pipe 18. The connection ports 28a and 28b each connect a pump chamber (not shown) of the second pump 22 to the supply path 12. The connection port 28c is connected to the return path 75. The connection port 28c connects the pump chamber of the second pump 22 to the return path 75.

[0198] In the second embodiment, the second valve 42 has the same structure as the first valve 41 in the first embodiment. Furthermore, the third valve 43 and the fifth valve 45 also have the same structure as the first valve 41 in the first embodiment. That is, the first valve 41, the second valve 42, the third valve 43 and the fifth valve 45 each include a valve seat 51, a valve body 52 and an electric motor 53. The first valve 41, the second valve 42, the third valve 43 and the fifth valve 45 are each classified as a motor-operated valve.

[0199] The fourth valve 44 and the discharge valve 46 each have the same structure as the second valve 42 in the first embodiment. That is, the fourth valve 44 and the discharge valve 46 each include a valve seat, a valve body, and an air drive unit. The fourth valve 44 and the discharge valve 46 each are classified as air operated valves.

[0200] The filter 71 includes a filter body 72, a first connection port 73a, a second connection port 73b, and a third connection port 73c. ​​The filter body 72 has an internal flow path and a filtering material (not shown). The internal flow path is a space. The filtering material is disposed in the internal flow path. The filtering material is, for example, a porous membrane. The first connection port 73a, the second connection port 73b, and the third connection port 73c each communicate with the internal flow path of the filter 71. The first connection port 73a is connected to the pipe 16. The second connection port 73b is connected to the pipe 17. The first connection port 73a and the second connection port 73b each communicate the internal flow path of the filter 71 with the supply path 12. The third connection port 73c is connected to the discharge path 77. The third connection port 73c communicates the internal flow path of the filter 71 with the discharge path 77.

[0201] The filter 71 is an example of a branching portion according to the present invention.

[0202] The control unit 65 controls the rotation drive unit 6. The control unit 65 controls the liquid supply unit 11. Specifically, the control unit 65 drives the first pump 21 and the second pump 22. The control unit 65 opens and closes the first valve 41, the second valve 42, the third valve 43, the fourth valve 44, the fifth valve 45, and the discharge valve 46. Furthermore, the control unit 65 controls the opening degrees of the first valve 41, the second valve 42, the third valve 43, and the fifth valve 45. The control unit 65 drives the nozzle movement mechanism 33.

[0203] 2. Example of processing operation The operation of the substrate processing apparatus 1 of the second embodiment (i.e., the substrate processing method of the second embodiment) will be described. The substrate processing method processes the substrate W using the liquid supply unit 11. Specifically, the substrate processing method includes a processing step. The processing step processes the substrate W. In the following description, the rotation drive unit 6 and the liquid supply unit 11 are assumed to operate in accordance with the control unit 65.

[0204] 9 is a flow chart showing the procedure of the operation of the processing step of the second embodiment. The processing step includes a first feed step, a second feed step, a pressure release step, a return step, and a third feed step. After the first feed step, the second feed step is performed. After the second feed step, the pressure release step is performed. After the pressure release step, the return step is performed. After the return step, the third feed step is performed.

[0205] Fig. 10(a) is a diagram showing the substrate processing apparatus 1 in a first forwarding process. Fig. 10(b) is a diagram showing the substrate processing apparatus 1 in a second forwarding process. Fig. 10(c) is a diagram showing the substrate processing apparatus 1 in a return process. Fig. 10(d) is a diagram showing the substrate processing apparatus 1 in a third forwarding process. Figs. 10(a)-10(d) each show a simplified view of the substrate processing apparatus 1. In the processing process, the upstream end 13 is connected to a processing liquid supply source 61.

[0206] 10(a) to 10(d) each show a schematic flow of a processing liquid. In the processing step, the processing liquid is supplied to the upstream end 13. In the processing step, the liquid supply unit 11 supplies the processing liquid to the substrate W.

[0207] [Step S11: First feeding process] Referring to FIG. 10(a). The first valve 41 is open. The second valve 42 is closed. The fifth valve 45 is closed. The first pump 21 sucks in the treatment liquid. Therefore, the treatment liquid flows from the upstream end 13 to the first pump 21 through the pipe 15. The first pump 21 sucks in the treatment liquid from the pipe 15. The treatment liquid does not flow through the pipe 16. The treatment liquid does not flow through the return path 75.

[0208] Furthermore, the third valve 43, the fourth valve 44 and the discharge valve 46 are each closed. The second pump 22 does not operate. That is, the second pump 22 neither sucks nor discharges. Therefore, the treatment liquid does not flow through the pipes 17 and 18 and the discharge path 77.

[0209] [Step S12: Second feeding process] Referring to FIG. 10(b), the first valve 41 is closed. The second valve 42 and the third valve 43 are each open. The fourth valve 44, the fifth valve 45, and the drain valve 46 are each closed. The first pump 21 discharges the treatment liquid. The second pump 22 sucks in the treatment liquid. Therefore, the treatment liquid flows from the first pump 21 to the second pump 22 through the pipes 16 and 17. The treatment liquid does not flow through the pipe 15. The treatment liquid does not flow through the pipe 18. The treatment liquid does not flow through the drain path 77.

[0210] [Step S13: Pressure release process] Although not shown, the first valve 41, the second valve 42, the third valve 4, and the fifth valve 45 are each open. The fourth valve 44 and the discharge valve 46 are each closed. The first pump 21 and the second pump 22 are each inoperative. As a result, the pressure of the treatment liquid in the supply path 12 becomes equal to the pressure of the treatment liquid in the return path 75. The pressure of the treatment liquid in the first pump 21 becomes equal to the pressure of the treatment liquid in the second pump 22.

[0211] [Step S14: Return process] Refer to FIG. 10(c). The first valve 41 is open. The second valve 42, the third valve 43, and the fourth valve 44 are each closed. The fifth valve 45 is open. The first pump 21 is not operating. The second pump 22 discharges the treatment liquid. As a result, the treatment liquid flows back from the second pump 22 to the first pump 21 through the return line 75. The treatment liquid flows back from the first pump 21 to the upstream end 13 through the pipe 15. The treatment liquid does not flow through the pipe 16. The treatment liquid does not flow through the pipe 17. The treatment liquid does not flow through the pipe 18.

[0212] Furthermore, on the return stroke, the drain valve 46 is closed and no processing liquid flows through the drain 77.

[0213] If the second pump 22 contains air, the return process returns the air together with the treatment liquid from the second pump 22 to the first pump 21.

[0214] [Step S15: Third feeding process] Refer to FIG. 10(d). The third valve 43 is closed. The fourth valve 44 is open. The fifth valve 45 is closed. The second pump 22 discharges the treatment liquid. Therefore, the treatment liquid flows from the second pump 22 to the nozzle 31 through the pipe 18. The nozzle 31 discharges the treatment liquid. The treatment liquid does not flow through the pipe 17. The treatment liquid does not flow through the return path 75.

[0215] Furthermore, the first valve 41, the second valve 42, and the drain valve 46 are each closed. The first pump 21 is not operated. The treatment liquid does not flow through the pipe 15. The treatment liquid does not flow through the pipe 16. The treatment liquid does not flow through the drain path 77.

[0216] The operations of the first to fifth valves 41-45 and the exhaust valve 46 in the above-mentioned process are summarized below. The first valve 41 opens and closes. Similarly, the second to fifth valves 42-45 open and close, respectively. The exhaust valve 46 closes.

[0217] 3. Example of the cleaning process The substrate processing method includes a cleaning step. In the cleaning step, the liquid supply unit 11 is cleaned. In the cleaning step, no processing is performed on the substrate W. In the following description, the rotation driver 6 and the liquid supply unit 11 are assumed to operate under the control of a control unit 65.

[0218] 11 is a flow chart showing the procedure of the operation of the cleaning process of the second embodiment. The cleaning process includes a first cleaning process, a second cleaning process, and a third cleaning process. The second cleaning process is performed after the first cleaning process. The third cleaning process is performed after the second cleaning process.

[0219] The first washing step may be performed two or more times before the second washing step. The second washing step may be performed two or more times before the third washing step. The third washing step may be performed two or more times after the second washing step.

[0220] The first cleaning process includes steps 1 and 2. After step 1, step 2 is performed. The second cleaning process includes steps 3, 4, and 5. After step 3, step 4 is performed. After step 4, step 5 is performed. The third cleaning process includes steps 6, 7, and 8. After step 6, step 7 is performed. After step 7, step 8 is performed. Here, the operation of step 3 is the same as the operation of step 1. The operation of step 6 is also the same as the operation of step 1.

[0221] 12(a) and 12(b) are views showing the substrate processing apparatus 1 in a first cleaning step. FIGS. 13(a)-13(c) are views showing the substrate processing apparatus 1 in a second cleaning step. FIGS. 14(a)-14(c) are views showing the substrate processing apparatus 1 in a third cleaning step. FIGS. 12(a)-12(b), 13(a)-13(c) and 14(a)-14(c) are schematic views showing the substrate processing apparatus 1. In the cleaning step, the upstream end 13 is connected to a cleaning liquid supply source 63.

[0222] 12(a)-12(b), 13(a)-13(c), and 14(a)-14(c) each show a schematic diagram of the flow of the cleaning liquid. In the cleaning process, the cleaning liquid is supplied to the upstream end 13. In the cleaning process, the cleaning liquid is caused to flow in the liquid supply unit 11.

[0223] 3-1. Step S21: First cleaning process 12(a) and 12(b), in the first cleaning step, a cleaning liquid is caused to flow from the upstream end 13 to the filter 71 through the pipes 15 and 16, and the cleaning liquid is discharged from the filter 71 to the discharge path 77.

[0224] 3-1-1. Step T1: First process Refer to Fig. 12(a). The first valve 41 opens at a first large opening A1. The second valve 42 opens at a second small opening B2. The fifth valve 45 opens at a fifth small opening B5. The first pump 21 sucks in the cleaning liquid. Specifically, the first pump 21 sucks in the cleaning liquid at a first flow rate Q1.

[0225] Here, the first large opening degree A1 is larger than the second small opening degree B2 and the fifth small opening degree B5. Therefore, the first valve 41 opens larger than the second valve 42 and the fifth valve 45. The second valve 42 and the fifth valve 45 each open smaller than the first valve 41.

[0226] The second small opening B2 is larger than the opening of the second valve 42 when the second valve 42 is closed. The second small opening B2 is equal to, for example, the first small opening B1 described in the first embodiment. Similarly, the fifth small opening B5 is larger than the opening of the fifth valve 45 when the fifth valve 45 is closed. The fifth small opening B5 is equal to, for example, the first small opening B1 described in the first embodiment.

[0227] When the first valve 41 is opened at the first large opening degree A1, the first valve 41 allows the cleaning liquid to pass through the first valve 41 at a first flow rate Q1.

[0228] When the second valve 42 opens at the second small opening B2, the second valve 42 limits the flow rate of the cleaning liquid passing through the second valve 42 to less than the first flow rate Q1. When the second valve 42 opens at the second small opening B2, the second valve 42 preferably limits the flow rate of the cleaning liquid passing through the second valve 42 to 20% or less of the first flow rate Q1. When the fifth valve 45 opens at the fifth small opening B5, the second valve 42 limits the flow rate of the cleaning liquid passing through the fifth valve 45 to less than the first flow rate Q1. When the fifth valve 45 opens at the fifth small opening B5, the fifth valve 45 preferably limits the flow rate of the cleaning liquid passing through the fifth valve 45 to 20% or less of the first flow rate Q1.

[0229] Thus, the cleaning liquid flows substantially from the upstream end 13 through the line 15 to the first pump 21 .

[0230] Here, the cleaning liquid may flow from the pipe 16 to the first pump 21. Even in this case, the flow rate of the cleaning liquid flowing from the pipe 15 to the first pump 21 is greater than the flow rate of the cleaning liquid flowing from the pipe 16 to the first pump 21. The cleaning liquid may flow from the return path 75 to the first pump 21. Even in this case, the flow rate of the cleaning liquid flowing from the pipe 15 to the first pump 21 is greater than the flow rate of the cleaning liquid flowing from the return path 75 to the first pump 21. Therefore, the cleaning liquid substantially flows from the pipe 15 to the first pump 21.

[0231] Furthermore, the third valve 43 opens at a third small opening degree B3. The third small opening degree B3 is greater than the opening degree of the third valve 43 when the third valve 43 is closed. The third small opening degree B3 is equal to, for example, the first small opening degree B1 described in the first embodiment.

[0232] The fourth valve 44 and the drain valve 46 are both closed, so that the cleaning liquid does not flow through the pipe 18. The cleaning liquid does not flow through the drain path 77.

[0233] 3-1-2. Step T2: Second process Refer to Fig. 12(b). The first valve 41 opens at a first small opening B1. The second valve 42 opens at a second large opening A2. The third valve 43 opens at a third small opening B3. The fifth valve 45 opens at a fifth small opening B5. The discharge valve 46 opens. The first pump 21 discharges the cleaning liquid. Specifically, the first pump 21 discharges the cleaning liquid at a second flow rate Q2.

[0234] Here, the second large opening degree A2 is larger than the first small opening degree B1, the third small opening degree B3, and the fifth small opening degree B5. Therefore, the second valve 42 opens larger than the first valve 41, the third valve 43, and the fifth valve 45. The first valve 41, the third valve 43, and the fifth valve 45 each open smaller than the second valve 42. Furthermore, the third valve 43 opens smaller than the exhaust valve 46.

[0235] The second large opening degree A2 is larger than the second small opening degree B2. The second large opening degree A2 is equal to, for example, the first large opening degree A1 described in the first embodiment.

[0236] When the second valve 42 is opened to the second large opening degree A2, the second valve 42 allows the cleaning liquid to pass through the second valve 42 at a second flow rate Q2.

[0237] When the first valve 41 opens at the first small opening B1, the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to less than the second flow rate Q2. When the first valve 41 opens at the first small opening B1, the first valve 41 preferably limits the flow rate of the cleaning liquid passing through the first valve 41 to 20% or less of the second flow rate Q2. When the third valve 43 opens at the third small opening B3, the third valve 43 limits the flow rate of the cleaning liquid passing through the third valve 43 to less than the second flow rate Q2. When the third valve 43 opens at the third small opening B3, the third valve 43 preferably limits the flow rate of the cleaning liquid passing through the third valve 43 to 20% or less of the second flow rate Q2. When the fifth valve 45 opens at the fifth small opening B5, the fifth valve 45 limits the flow rate of the cleaning liquid passing through the fifth valve 45 to less than the second flow rate Q2. When the fifth valve 45 is opened at the fifth small opening B5, it is preferable that the fifth valve 45 limits the flow rate of the cleaning liquid passing through the fifth valve 45 to 20% or less of the second flow rate Q2.

[0238] Therefore, the cleaning liquid flows substantially from the first pump 21 to the filter 71 through the pipe 16. The cleaning liquid flows into the first connection port 73a and flows out from the third connection port 73c. ​​The cleaning liquid is discharged from the filter 71 to the discharge path 77. The cleaning liquid discharges particles to the outside of the liquid supply unit 11 through the discharge path 77.

[0239] Here, some of the cleaning liquid may flow from the first pump 21 to the return path 75. Even in this case, the flow rate of the cleaning liquid flowing from the first pump 21 to the piping 16 is greater than the flow rate of the cleaning liquid flowing from the first pump 21 to the return path 75. Therefore, the cleaning liquid substantially flows from the first pump 21 to the piping 16. Some of the cleaning liquid may flow from the filter 71 to the piping 17. Even in this case, the flow rate of the cleaning liquid flowing from the filter 71 to the discharge path 77 is greater than the flow rate of the cleaning liquid flowing from the filter 71 to the piping 17. Therefore, the cleaning liquid substantially flows from the filter 71 to the discharge path 77.

[0240] Furthermore, the fourth valve 44 is closed, so that the cleaning liquid does not flow through the pipe 18.

[0241] As stated above, First cleaning process cleans the first valve 41, the second valve 42, the first pump 21, and the filter 71. First cleaning process Clean the pipes 15 and 16.

[0242] First cleaning process The operations of the first to fifth valves 41-45 and the exhaust valve 46 in the above are summarized below. The first valve 41 switches between a first large opening degree A1 and a first small opening degree B1. The second valve 42 switches between a second large opening degree A2 and a second small opening degree B2. The third valve 43 opens at a third small opening degree B3. The fourth valve 44 closes. The fifth valve 45 opens at a fifth small opening degree B5. The exhaust valve 46 opens and closes.

[0243] In the first cleaning step, the third valve 43 restricts the flow of the cleaning liquid in the pipe 17. In the first cleaning step, the fifth valve 45 restricts the flow of the cleaning liquid in the return line 75.

[0244] When the cleaning liquid flows from the pipe 16 through the filter 71 to the drain passage 77, the third valve 43 opens less than the second valve 42 and the drain valve 46.

[0245] In the first cleaning step, the cleaning liquid is discharged to the outside of the liquid supply unit 11 without passing through the pipe 18 and the nozzle 31.

[0246] 3-2. Step S22: Second cleaning process 13(a), 13(b), and 13(c), in the second cleaning step, the cleaning liquid is caused to flow from the upstream end 13 to the first pump 21 through the piping 15, the cleaning liquid is caused to flow from the first pump 21 to the second pump 22 through the return path 75, the cleaning liquid is caused to flow back from the second pump 22 to the filter 71 through the piping 17, and the cleaning liquid is discharged from the filter 71 to the discharge path 77.

[0247] 3-2-1. Step T3: Third Process Refer to FIG. 13(a). The operation of the third step is the same as that of the first step. That is, the first valve 41 opens at the first large opening A1. The second valve 42 opens at the second small opening B2. The third valve 43 opens at the third small opening B3. The fourth valve 44 closes. The fifth valve 45 opens at the fifth small opening B5. The discharge valve 46 closes. The first pump 21 sucks in the cleaning liquid. Therefore, the cleaning liquid substantially flows from the upstream end 13 to the first pump 21 through the pipe 15. The cleaning liquid does not flow through the pipe 18. The cleaning liquid does not flow through the discharge path 77.

[0248] 3-2-2. Step T4: Fourth process Refer to FIG. 13(b). The first valve 41 opens at a first small opening B1. The second valve 42 opens at a second small opening B2. The third valve 43 opens at a third small opening B3. The fourth valve 44 closes. The fifth valve 45 opens at a fifth large opening A5. The discharge valve 46 closes. The first pump 21 discharges the cleaning liquid. Specifically, the first pump 21 discharges the cleaning liquid at a second flow rate Q2. The second pump 22 sucks in the cleaning liquid. Specifically, the second pump 22 sucks in the cleaning liquid at a third flow rate Q3.

[0249] Here, the fifth large opening degree A5 is larger than the first small opening degree B1, the second small opening degree B2, and the third small opening degree B3. Therefore, the fifth valve 45 opens larger than the first valve 41, the second valve 42, and the third valve 43. The first valve 41, the second valve 42, and the third valve 43 each open smaller than the fifth valve 45.

[0250] The fifth large opening degree A5 is larger than the fifth small opening degree B5. The fifth large opening degree A5 is equal to, for example, the first small opening degree B1 described in the first embodiment.

[0251] When the fifth valve 45 opens at the fifth large opening degree A5, the fifth valve 45 allows the cleaning liquid to pass through the fifth valve 45 at the second flow rate Q2. When the fifth valve 45 opens at the fifth large opening degree A5, the fifth valve 45 allows the cleaning liquid to pass through the fifth valve 45 at the third flow rate Q3.

[0252] When the first valve 41 opens at the first small opening B1, the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to less than the second flow rate Q2. When the second valve 42 opens at the second small opening B2, the second valve 42 limits the flow rate of the cleaning liquid passing through the second valve 42 to less than the second flow rate Q2. When the third valve 43 opens at the third small opening B3, the third valve 43 limits the flow rate of the cleaning liquid passing through the third valve 43 to less than the third flow rate Q3.

[0253] The third flow rate Q3 is, for example, equal to the second flow rate Q2.

[0254] Thus, the cleaning liquid flows substantially from the first pump 21 to the second pump 22 via the return path 75 .

[0255] Here, some cleaning liquid may flow from the first pump 21 to the pipe 15. Some cleaning liquid may flow from the first pump 21 to the pipe 16. Even in these cases, the cleaning liquid mainly flows from the first pump 21 to the return path 75. Some cleaning liquid may flow from the pipe 17 to the second pump 22. Even in this case, the cleaning liquid mainly flows from the return path 75 to the second pump 22.

[0256] 3-2-3. Step T5: Fifth process Refer to Figure 13 (c). The second valve 42 opens at the second small opening B2. The third valve 43 opens at the third large opening A3. The fourth valve 44 closes. The fifth valve 45 opens at the fifth small opening B5. The discharge valve 46 opens. The second pump 22 discharges the cleaning liquid. Specifically, the second pump 22 discharges the cleaning liquid at a fourth flow rate Q4.

[0257] Here, the third large opening degree A3 is larger than the second small opening degree B2 and the fifth small opening degree B3. Therefore, the third valve 43 opens larger than the second valve 42 and the fifth valve 45. The second valve 42 and the fifth valve 45 each open smaller than the third valve 43. Furthermore, the third valve 43 opens larger than the fourth valve 44. The second valve 42 opens smaller than the exhaust valve 46.

[0258] The third large opening degree A3 is larger than the third small opening degree B3. The third large opening degree A3 is equal to, for example, the first small opening degree B1 described in the first embodiment.

[0259] When the third valve 43 is opened at the third large opening degree A3, the third valve 43 allows the cleaning liquid to pass through the third valve 43 at a fourth flow rate Q4.

[0260] When the second valve 42 opens at the second small opening B2, the second valve 42 limits the flow rate of the cleaning liquid passing through the second valve 42 to less than the fourth flow rate Q4. When the fifth valve 45 opens at the fifth small opening B5, the fifth valve 45 limits the flow rate of the cleaning liquid passing through the fifth valve 45 to less than the fourth flow rate Q4.

[0261] The fourth flow rate Q4 is, for example, equal to the second flow rate Q2.

[0262] Therefore, the cleaning liquid flows substantially from the second pump 22 to the filter 71 through the pipe 17. The cleaning liquid flows into the second connection port 73b and flows out from the third connection port 73c. ​​The cleaning liquid is discharged from the filter 71 to the discharge path 77. The cleaning liquid discharges particles to the outside of the liquid supply unit 11 through the discharge path 77.

[0263] Here, some of the cleaning liquid may flow from the second pump 22 to the return path 75. Even in this case, the cleaning liquid mainly flows from the second pump 22 to the piping 17. Some of the cleaning liquid may flow from the filter 71 to the piping 16. Even in this case, the cleaning liquid mainly flows from the filter 71 to the discharge path 77.

[0264] Furthermore, the first valve 41 opens at a first small opening B1. The first valve 41 opens less than the third valve 43. The first pump 21 does not operate.

[0265] As stated above, Second cleaning process cleans the first valve 41, the third valve 43, the fifth valve 45, the first pump 21, the second pump 22, and the filter 71. Second cleaning process Clean the pipes 15, 17 and the return passage 75. Second cleaning process causes the cleaning liquid to flow back into the pipe 17. Second cleaning process causes the cleaning liquid to flow back into the return path 75.

[0266] Second cleaning process The operations of the first to fifth valves 41-45 and the exhaust valve 46 in the above are summarized below. The first valve 41 switches between a first large opening degree A1 and a first small opening degree B1. The second valve 42 opens at a second small opening degree B2. The third valve 43 switches between a third large opening degree A3 and a third small opening degree B3. The fourth valve 44 closes. The fifth valve 45 switches between a fifth large opening degree A1 and a fifth small opening degree B5. The exhaust valve 46 opens and closes.

[0267] In the second cleaning step, the second valve 42 restricts the flow of cleaning liquid in the line 16 .

[0268] When the cleaning liquid flows from the pipe 17 through the filter 71 to the drain passage 77, the second valve 42 opens less than the third valve 43 and the drain valve 46.

[0269] In the second cleaning step, the cleaning liquid is discharged outside the liquid supply unit 11 without passing through the pipe 18 and the nozzle 31.

[0270] 3-3. Step S23: Third cleaning process 14(a), 14(b) and 14(c), in the third cleaning step, a cleaning liquid is caused to flow from the upstream end 13 to the nozzle 31 through the pipes 15-18.

[0271] 3-3-1. Step T6: 6th process Refer to FIG. 14(a). The operation of the sixth step is the same as that of the first step. That is, the first valve 41 opens at the first large opening A1. The second valve 42 opens at the second small opening B2. The third valve 43 opens at the third small opening B3. The fourth valve 44 closes. The fifth valve 45 opens at the fifth small opening B5. The discharge valve 46 closes. The first pump 21 sucks in the cleaning liquid. Therefore, the cleaning liquid substantially flows from the upstream end 13 to the first pump 21 through the pipe 15. The cleaning liquid does not flow through the pipe 18. The cleaning liquid does not flow through the discharge path 77.

[0272] 3-3-2. Step T7: 7th process Refer to FIG. 14(b). The first valve 41 opens at a first small opening B1. The second valve 42 opens at a second large opening A2. The third valve 43 opens at a third large opening A3. The fourth valve 44 closes. The fifth valve 45 opens at a fifth small opening B5. The discharge valve 46 closes. The first pump 21 discharges the cleaning liquid. Specifically, the first pump 21 discharges the cleaning liquid at a second flow rate Q2. The second pump 22 sucks in the cleaning liquid. Specifically, the second pump 22 sucks in the cleaning liquid at a third flow rate Q3.

[0273] Here, the second large opening degree A2 is larger than the first small opening degree B1 and the fifth small opening degree B5. Therefore, the second valve 42 opens larger than the first valve 41 and the fifth valve 45. The first valve 41 and the fifth valve 45 each open smaller than the second valve 42. Furthermore, the second valve 42 opens larger than the exhaust valve 46.

[0274] The third large opening degree A3 is larger than the first small opening degree B1 and the fifth small opening degree B5. Therefore, the third valve 43 opens larger than the first valve 41 and the fifth valve 45. The first valve 41 and the fifth valve 45 each open smaller than the third valve 43. Furthermore, the third valve 43 opens larger than the fourth valve 44 and the exhaust valve 46.

[0275] When the second valve 42 opens at the second large opening degree A2, the second valve 42 allows the cleaning liquid to pass through the second valve 42 at the second flow rate Q2. When the second valve 42 opens at the second large opening degree A2, the second valve 42 allows the cleaning liquid to pass through the second valve 42 at a third flow rate Q3. When the third valve 43 opens at the second large opening degree A2, the third valve 43 allows the cleaning liquid to pass through the third valve 43 at the second flow rate Q2. When the third valve 43 opens at the second large opening degree A2, the third valve 43 allows the cleaning liquid to pass through the third valve 43 at the third flow rate Q3.

[0276] When the first valve 41 opens at the first small opening B1, the first valve 41 limits the flow rate of the cleaning liquid passing through the first valve 41 to less than the second flow rate Q2. When the fifth valve 45 opens at the fifth small opening B5, the fifth valve 45 limits the flow rate of the cleaning liquid passing through the fifth valve 45 to less than the second flow rate Q2. When the fifth valve 45 opens at the fifth small opening B5, the fifth valve 45 limits the flow rate of the cleaning liquid passing through the fifth valve 45 to less than the third flow rate Q3.

[0277] Therefore, the cleaning liquid flows substantially from the first pump 21 to the second pump 22 through the pipes 16 and 17. More specifically, the cleaning liquid flows from the first pump 21 to the filter 71 through the pipe 16. The cleaning liquid flows into the first connection port 73a and out of the second connection port 73b. The cleaning liquid flows from the filter 71 to the second pump 22 through the pipe 17.

[0278] Here, some cleaning liquid may flow from the first pump 21 to the pipe 15. Some cleaning liquid may flow from the first pump 21 to the return path 75. Even in these cases, the cleaning liquid mainly flows from the first pump 21 to the pipe 16. Some cleaning liquid may flow from the return path 75 to the second pump 22. Even in this case, the cleaning liquid mainly flows from the pipe 17 to the second pump 22.

[0279] 3-3-3. Step T8: 8th process Refer to Fig. 14(c). The third valve 43 opens at a third small opening B3. The fourth valve 44 opens. The fifth valve 45 opens at a fifth small opening B5. The second pump 22 discharges the cleaning liquid. Specifically, the second pump 22 discharges the cleaning liquid at a fourth flow rate Q4.

[0280] Here, the fourth valve opens more than the third valve 43 and the fifth valve 45. The third valve 43 and the fifth valve 45 each open less than the fourth valve 44.

[0281] When the fourth valve 44 is open, the fourth valve 44 allows cleaning fluid to pass through the fourth valve 44 at a fourth flow rate Q4.

[0282] When the third valve 43 opens at the third small opening degree B3, the third valve 43 limits the flow rate of the cleaning liquid passing through the third valve 43 to less than the fourth flow rate Q4. When the fifth valve 45 opens at the fifth small opening degree B5, the fifth valve 45 limits the flow rate of the cleaning liquid passing through the fifth valve 45 to less than the fourth flow rate Q4.

[0283] Therefore, the cleaning liquid flows substantially from the second pump 22 to the nozzle 31 through the pipe 18. The nozzle 31 discharges the cleaning liquid. The cleaning liquid discharges particles to the outside of the liquid supply unit 11 through the nozzle 31.

[0284] Here, some cleaning liquid may flow from the second pump 22 to the pipe 17. Some cleaning liquid may flow from the second pump 22 to the return line 75. Even in these cases, the cleaning liquid mainly flows from the second pump 22 to the pipe 18.

[0285] Furthermore, the first valve 41 opens at a first small opening B1. The second valve 42 opens at a second small opening B2. The drain valve 46 closes. The first pump 21 does not operate. As a result, the treatment liquid does not flow through the drain path 77.

[0286] As stated above, Third cleaning process cleans the first valve 41, the second valve 42, the third valve 43, the fourth valve 44, the first pump 21, the second pump 22, and the filter 71. Third cleaning process Clean pipes 15-18.

[0287] Third cleaning process The operations of the first to fifth valves 41-45 and the exhaust valve 46 in the above are summarized below. The first valve 41 switches between a first large opening degree A1 and a first small opening degree B1. The second valve 42 switches between a second large opening degree A2 and a second small opening degree B2. The third valve 43 switches between a third large opening degree A3 and a third small opening degree B3. The fourth valve 44 opens and closes. The fifth valve 45 opens at a fifth small opening degree B5. The exhaust valve 46 closes.

[0288] In the third flushing step, the fifth valve 45 inhibits the flow of flushing liquid in the return line 75 .

[0289] When the cleaning liquid flows from the pipe 16 through the filter 71 to the pipe 17 , the second valve 42 and the third valve 43 each open wider than the drain valve 46 .

[0290] In the third cleaning step, the cleaning liquid flows through the pipe 18 and the nozzle 31 . In the third cleaning step, the cleaning liquid is discharged to the outside of the liquid supply unit 11 through the nozzle 31.

[0291] 4.Effects According to the second embodiment, the same effects as those of the first embodiment are achieved. Furthermore, according to the second embodiment, the following effects are achieved.

[0292] The liquid supply unit 11 includes a supply path 12, a first pump 21, a second pump 22, and a filter 71. The liquid supply unit 11 includes a return path 75 and a drain path 77. The supply path 12 includes pipes 15-18. The liquid supply unit 11 includes first to fifth valves 41-45 and a drain valve 46.

[0293] The processing step includes a first sending step, a second sending step, a return step, and a third sending step. In the first sending step, the processing liquid is fed from the upstream end 13 to the first pump 21 through the pipe 15. In the second sending step, the processing liquid is fed from the first pump 21 to the second pump 22 through the pipes 16 and 17. In the return step, the processing liquid is reversed from the second pump 22 to the first pump 21 through the return path 75. In the third sending step, the processing liquid is fed from the second pump 22 to the nozzle 31 through the pipe 18. If air is mixed into the second pump 22, in the return step, the air is returned from the second pump 22 to the first pump 21 together with the processing liquid. Therefore, in the third sending step, the processing liquid not containing air can be fed to the nozzle 31. Therefore, in the processing step, the liquid supply unit 11 can suitably supply the processing liquid to the substrate W.

[0294] The cleaning process includes a first cleaning process, a second cleaning process, and a third cleaning process. In the first cleaning process, the cleaning liquid is caused to flow from the upstream end 13 to the filter 71 through the pipes 15 and 16. In the first cleaning process, the cleaning liquid is discharged from the filter 71 to the discharge path 77. Therefore, the first cleaning process cleans the pipes 15 and 16. In the second cleaning process, the cleaning liquid is caused to flow from the upstream end 13 to the first pump 21 through the pipe 15. In the second cleaning process, the cleaning liquid is caused to flow from the first pump 21 to the second pump 22 through the return path 75. In the second cleaning process, the cleaning liquid is caused to flow backward from the second pump 22 to the filter 71 through the pipe 17. In the second cleaning process, the cleaning liquid is discharged from the filter 71 to the discharge path 77. Therefore, the second cleaning process cleans the pipe 15, the return path 75, and the pipe 17. In the third cleaning process, the cleaning liquid is caused to flow from the upstream end 13 to the nozzle 31 through the pipes 15-18. Therefore, the third cleaning step cleans the pipes 15-18. Here, the pipe 15 is the only overlapping portion between the range cleaned by the first cleaning step and the range cleaned by the second cleaning step. Therefore, the first and second cleaning steps can efficiently flow the cleaning liquid through the pipes 15-17 and the return path 75. Therefore, the cleaning step can efficiently flow the cleaning liquid throughout the entire liquid supply section.

[0295] The direction of the cleaning liquid flowing through the return path 75 in the second cleaning step is opposite to the direction of the processing liquid flowing through the return path 75 in the return step. Therefore, in the second cleaning step, the return path 75 can be cleaned appropriately.

[0296] The direction of the cleaning liquid flowing through the pipe 17 in the second cleaning step is opposite to the direction of the cleaning liquid flowing through the pipe 17 in the third cleaning step. Therefore, the pipe 17 can be cleaned appropriately. The third valve 43 can be cleaned appropriately. Here, the pipe 17 and the third valve 43 are each disposed downstream of the filter 71. That is, the filter 71 is not disposed downstream of the pipe 17 and the third valve 43. Therefore, in cleaning the liquid supply unit 11, it is important to increase the cleanliness of the pipe 17 and the third valve 43.

[0297] In the processing step, the second valve 42 opens and closes. When the second valve 42 opens, the second valve 42 allows the processing liquid to flow in the pipe 16. When the second valve 42 closes, the second valve 42 stops the processing liquid from flowing in the pipe 16. In this way, in the processing step, the second valve 42 strictly controls the flow of the processing liquid in the pipe 16. Similarly, in the processing step, the third valve 43 opens and closes. Therefore, in the processing step, the third valve 43 strictly controls the flow of the processing liquid in the pipe 17. In the processing step, the fifth valve 45 opens and closes. Therefore, in the processing step, the fifth valve 45 strictly controls the flow of the processing liquid in the return path 75. Therefore, in the processing step, the flow of the processing liquid in the liquid supply unit 11 is strictly controlled. For example, in the first sending step, the range in which the processing liquid flows, the direction in which the processing liquid flows, and the amount of the processing liquid flowing are strictly controlled. The same is true in the second feed step, the return step, and the third feed step. Therefore, the liquid supply unit 11 can appropriately supply the processing liquid to the substrate W. In the processing step, the substrate W can be appropriately processed.

[0298] In the cleaning process, the second valve 42 switches between the second large opening degree A2 and the second small opening degree B2. The second small opening degree B2 is smaller than the second large opening degree A2. Therefore, in the cleaning process, the second valve 42 substantially controls the flow of the cleaning liquid in the pipe 16. Similarly, in the cleaning process, the third valve 43 switches between the third large opening degree A3 and the third small opening degree B3. The third small opening degree B3 is smaller than the third large opening degree A3. Therefore, in the cleaning process, the third valve 43 substantially controls the flow of the cleaning liquid in the pipe 17. In the cleaning process, the fifth valve 45 switches between the fifth large opening degree A5 and the fifth small opening degree B5. The fifth small opening degree B5 is smaller than the fifth large opening degree A5. Therefore, in the cleaning process, the fifth valve 45 substantially controls the flow of the cleaning liquid in the return path 75. Therefore, in the cleaning process, the cleaning liquid can be appropriately supplied to the liquid supply unit 11.

[0299] Furthermore, when the second valve 42 opens at the second small opening degree B2, the second valve 42 does not close. Of course, when the second valve 42 opens at the second large opening degree A2, the second valve 42 does not close. Therefore, foreign matter is less likely to adhere to the second valve 42 in the cleaning process. In other words, the second valve 42 is less likely to be contaminated in the cleaning process. Similarly, even when the third valve 43 switches between the third large opening degree A3 and the third small opening degree B3, the third valve 43 does not close. Therefore, foreign matter is less likely to adhere to the third valve 43 in the cleaning process. Even when the fifth valve 45 switches between the fifth large opening degree A5 and the fifth small opening degree B5, the fifth valve 45 does not close. Therefore, foreign matter is less likely to adhere to the fifth valve 45 in the cleaning process. Therefore, the cleaning process can efficiently clean the liquid supply unit 11.

[0300] The first cleaning step includes a first step and a second step. In the first step, the first valve 41 opens at a first large opening degree A1, and the second valve 42 opens at a second small opening degree B2. That is, in the first step, the second valve 42 opens less than the first valve 41. Therefore, in the first step, the second valve prevents the cleaning liquid from flowing back from the second valve to the first pump. Therefore, in the first step, the first pump 21 essentially sucks the cleaning liquid from the pipe 15. In the second step, the first valve 41 opens at a first small opening degree B1, and the second valve 42 opens at a second large opening degree A2. That is, in the second step, the second valve 42 opens more than the first valve 41. Therefore, in the second step, the first pump 21 essentially discharges the cleaning liquid into the pipe 16. In this manner, the first valve 41 and the second valve 42 substantially control the flow of the treatment liquid upstream and downstream of the first pump 21 .

[0301] In the first cleaning step, the fifth valve 45 opens at a fifth small opening B5. Therefore, in the first cleaning step, the fifth valve 45 suppresses the flow of cleaning liquid in the return path 75. In the first cleaning step, the fifth valve 45 suppresses the cleaning liquid from flowing from the pipe 15 to the return path 75. As a result, in the first cleaning step, the cleaning liquid substantially flows from the pipe 15 to the pipe 16.

[0302] In the first cleaning step, the third valve 43 opens at the third small opening B3. Therefore, in the first cleaning step, the third valve 43 suppresses the flow of the cleaning liquid in the pipe 17. In the first cleaning step, the third valve 43 suppresses the cleaning liquid from flowing from the pipe 16 to the pipe 17. As a result, in the first cleaning step, the cleaning liquid substantially flows from the pipe 16 to the discharge path 77.

[0303] In the second cleaning step, the second valve 42 opens at the second small opening B2. Therefore, in the second cleaning step, the second valve 42 suppresses the flow of the cleaning liquid in the pipe 16. In the second cleaning step, the second valve 42 suppresses the flow of the cleaning liquid from the pipe 15 to the pipe 16. As a result, in the second cleaning step, the cleaning liquid substantially flows from the pipe 15 to the return path 75. Furthermore, in the second cleaning step, the second valve 42 suppresses the flow of the cleaning liquid from the pipe 17 to the pipe 16. As a result, in the second cleaning step, the cleaning liquid substantially flows from the pipe 17 to the discharge path 77.

[0304] In the third cleaning step, the fifth valve 45 opens at a fifth small opening B5. Therefore, in the third cleaning step, the fifth valve 45 suppresses the flow of cleaning liquid in the return path 75. In the third cleaning step, the fifth valve 45 suppresses the cleaning liquid from flowing from the pipe 15 to the return path 75. As a result, in the third cleaning step, the cleaning liquid flows smoothly from the pipe 15 to the pipe 16. Furthermore, in the third cleaning step, the fifth valve 45 suppresses the cleaning liquid from flowing from the pipe 17 to the return path 75. As a result, in the third cleaning step, the cleaning liquid substantially flows from the pipe 17 to the pipe 18.

[0305] The filter 71 has a first connection port 73a, a second connection port 73b, and a third connection port 73c. ​​The first connection port 73a is connected to the pipe 16. The second connection port 73b is connected to the pipe 17. The third connection port 73c is connected to the discharge path 77. In the first cleaning step, the cleaning liquid flows into the first connection port 73a and flows out from the third connection port 73c. ​​In the second cleaning step, the cleaning liquid flows into the second connection port 73b and flows out from the third connection port 73c. ​​In the third cleaning step, the cleaning liquid flows into the first connection port 73a and flows out from the second connection port 73b. Therefore, the cleaning step can suitably clean the filter 71.

[0306] When the cleaning liquid flows from the pipe 16 to the drain passage 77 via the filter 71, the third valve 43 opens less than the second valve 42 and the drain valve 46. Therefore, the cleaning liquid is less likely to flow through the pipe 17 than through the pipe 16 and the drain passage 77. Therefore, the cleaning liquid substantially flows from the pipe 16 to the drain passage 77 via the filter 71.

[0307] When the cleaning liquid flows from the pipe 17 to the drain passage 77 via the filter 71, the second valve 42 opens less than the third valve 43 and the drain valve 46. Therefore, the cleaning liquid is less likely to flow through the pipe 16 than through the pipe 17 and the drain passage 77. Therefore, in the second cleaning step, the cleaning liquid substantially flows from the pipe 17 to the drain passage 77 via the filter 71.

[0308] When the cleaning liquid flows from the pipe 16 to the pipe 17 via the filter 71, the second valve 42 and the third valve 43 open wider than the drain valve 46. Therefore, the cleaning liquid is less likely to flow through the drain path 77 than through the pipes 16 and 17. Therefore, in the third cleaning step, the cleaning liquid substantially flows from the pipe 16 to the pipe 17 via the filter 71.

[0309] Furthermore, when the cleaning liquid flows from pipe 16 to drain passage 77 via filter 71, third valve 43 does not close. Similarly, when the cleaning liquid flows from pipe 17 to drain passage 77 via filter 71, second valve 42 does not close. When the cleaning liquid flows from pipe 17 to pipe 17 via filter 71, second valve 42 and third valve 43 do not close. Therefore, in the cleaning process, foreign matter is less likely to adhere to second valve 42. In the cleaning process, foreign matter is less likely to adhere to third valve 43. Therefore, the cleaning process can efficiently clean liquid supply unit 11.

[0310] In the first cleaning step, the fourth valve 44 is closed. Therefore, in the first cleaning step, the cleaning liquid is discharged to the discharge path 77 without passing through the pipe 18. Similarly, in the second cleaning step, the fourth valve 44 is closed. Therefore, in the second cleaning step, the cleaning liquid is discharged to the discharge path 77 without passing through the pipe 18. Therefore, in the first cleaning step and the second cleaning step, the cleaning liquid does not flow into the nozzle 31. In other words, in the first cleaning step and the second cleaning step, the cleaning liquid does not discharge particles through the nozzle 31. Therefore, the first cleaning step and the second cleaning step suppress contamination of the nozzle 31.

[0311] In the third cleaning step, the fourth valve 44 is opened. Therefore, in the third cleaning step, the cleaning liquid flows through the pipe 18 to the nozzle 31. Thus, the nozzle 31 is cleaned in the third cleaning step.

[0312] First cleaning process After that, a second washing step is carried out. Second cleaning process After that, the third cleaning process is performed. In the first cleaning process, pipes 15 and 16 are cleaned. In the second cleaning process, pipe 17 is cleaned. In the fourth cleaning process, pipe 18 is cleaned. Here, pipe 17 is located downstream of pipe 16. Pipe 18 is located downstream of pipe 17. Therefore, in the cleaning process, supply path 12 is cleaned in stages from upstream end 13 to downstream end 14. Therefore, the cleaning process can clean liquid supply section 11 efficiently.

[0313] The present invention is not limited to the first and second embodiments, and can be modified as follows.

[0314] (1) In the first step (S1) of the first embodiment, the second valve 42 is closed. However, this is not limited to this. For example, in the first step (S1), the second valve 42 may be opened less than the first valve 41. According to this modified embodiment, foreign matter is less likely to adhere to the second valve 42. Therefore, the cleaning step of the first embodiment can clean the liquid supply unit 11 more efficiently.

[0315] (2) In the second valve of the first embodiment, the second valve 42 is classified as an air-operated valve. However, this is not limited to this. For example, the second valve 42 of the first embodiment may be classified as an electric valve. For example, the second valve 42 of the first embodiment may have the same structure as the first valve 41. According to this modified embodiment, the opening degree of the second valve 42 can be finely adjusted.

[0316] (3) In the first to third cleaning steps (S21-S23) of the second embodiment, the fourth valve 44 opens and closes. However, this is not limited to this. For example, in the first to third cleaning steps (S21-S23), the fourth valve 44 may switch between the fourth large opening degree and the fourth small opening degree. The fourth large opening degree is, for example, equivalent to at least one of the third large opening degree A3 and the fifth large opening degree A5. The fourth small opening degree is, for example, equivalent to at least one of the third small opening degree B3 and the fifth small opening degree B5. According to this modified embodiment, foreign matter is less likely to adhere to the fourth valve 44. Therefore, the cleaning step can clean the liquid supply unit 11 more efficiently.

[0317] (4) In the second embodiment, the fourth valve 44 is classified as an air-operated valve. However, this is not limited to this. For example, the fourth valve 44 may be classified as an electric valve. For example, the fourth valve 44 may have the same structure as the first valve 41. According to this modified embodiment, the opening degree of the fourth valve 44 can be finely adjusted.

[0318] (5) In the first to third cleaning steps (S21-S23) of the second embodiment, the discharge valve 46 opens and closes. However, this is not limited to this. For example, in the first to third cleaning steps (S21-S23), the discharge valve 46 may switch between a sixth large opening degree and a sixth small opening degree. The sixth large opening degree is, for example, equivalent to at least one of the second large opening degree A2 and the third large opening degree A3. The sixth small opening degree is, for example, equivalent to at least one of the second small opening degree B2 and the third small opening degree B3. According to this modified embodiment, foreign matter is less likely to adhere to the discharge valve 46. Therefore, the cleaning step can clean the liquid supply unit 11 more efficiently.

[0319] (6) In the second embodiment, the discharge valve 46 is classified as an air-operated valve. However, this is not limited to this. For example, the discharge valve 46 may be classified as an electric valve. For example, the discharge valve 46 may have the same structure as the first valve 41. According to this modified embodiment, the opening degree of the discharge valve 46 can be finely adjusted.

[0320] (7) In the second embodiment, liquid supply unit 11 includes filter 71. However, this is not limited to this. Liquid supply unit 11 may include a branch joint instead of filter 71. The branch joint is connected to pipes 16, 17 and discharge pipe 77. The branch joint interconnects pipes 16, 17 and discharge pipe 77. The branch joint is an example of a branch portion of the present invention.

[0321] (8) In the first and second embodiments described above, a resist film material is exemplified as the coating liquid. However, the present invention is not limited to this. The coating liquid may be, for example, an anti-reflective film material, a protective film material, a SOG (Spin On Glass) film material, or a SOD (Spin on Dielectric) film material.

[0322] (9) In the first and second embodiments described above, an organic solvent is used as the cleaning liquid. However, the cleaning liquid is not limited to this. The cleaning liquid may be pure water.

[0323] (10) In the first and second embodiments described above, the cleaning liquid is a different type of liquid from the processing liquid. However, this is not limited to this. The cleaning liquid may be the same type of liquid as the processing liquid. For example, the cleaning liquid may be the liquid of the processing liquid supply source 61. If the cleaning liquid is the same type of liquid as the processing liquid, the same type of liquid as the processing liquid is not supplied to the substrate W. According to this modified embodiment, the cleaning process can more effectively clean the liquid supply unit 11.

[0324] (11) In the first and second embodiments described above, a single type of cleaning liquid is used in the cleaning process. However, this is not limited to this. A plurality of types of cleaning liquid may be used in the cleaning process. For example, the cleaning process may use the liquid from the processing liquid supply source 61 and the liquid from the processing liquid supply source 61.

[0325] (12) In the second embodiment described above, the cleaning process does not include an inspection process. However, this is not limited to this. The cleaning process of the second embodiment may further include an inspection process. For example, the inspection process of the second embodiment may be the same as the inspection process of the first embodiment.

[0326] (13) The first and second embodiments and the modified embodiments described in (1) to (12) above may be further modified as appropriate by replacing or combining each configuration with the configuration of another modified embodiment. [Explanation of symbols]

[0327] 1 ... Substrate processing equipment 11…Liquid supply section 12 … Supply route 13 … Upstream end 14 … Downstream end 15 … Piping (1st part) 16 … Piping (second part) 17 … Piping (3rd part) 18 … Piping (4th part) 21 … First pump 22 … Second pump 31 ... Nozzle 41 … First valve 42 … 2nd valve 43 ... 3rd valve 44 … 4th valve 45 … 5th valve 46 … Exhaust valve 51 ... Valve seat 52 ... Valve body 53 … Electric motor 65 ... Control section 71 … Filter (branch) 73a … First connection part 73b … Second connection part 73c … 3rd connection 75 … Return 77 … Discharge path A1 … 1st wide opening A2 … 2nd wide opening A3 … The third largest opening A5 … The fifth largest opening B1 … The first largest opening B2 … The second smallest opening B3 … The third smallest opening B5 … The fifth smallest opening D … Separation distance Q1 … The first flow rate Q2 … The second flow rate W … Substrate

Claims

1. A substrate processing method for processing a substrate using a liquid supply unit, comprising: The liquid supply unit includes: a supply channel having an upstream end and a downstream end; A first pump provided in the supply path; a first valve provided in the supply passage and arranged upstream of the first pump; A nozzle connected to the downstream end; Equipped with The substrate processing method includes: a processing step of supplying a processing liquid to the upstream end and supplying the processing liquid from the liquid supply unit to a substrate to process the substrate; a cleaning step of supplying a cleaning liquid to the upstream end and causing the cleaning liquid to flow through the liquid supply section to clean the liquid supply section; Equipped with In the cleaning step, the first valve is switched between a first large opening degree and a first small opening degree smaller than the first large opening degree, The first small opening is larger than the opening of the first valve when the first valve is closed. A method for processing a substrate.

2. The substrate processing method according to claim 1, When the first valve is opened to the first large opening in the cleaning step, the first pump sucks in the cleaning liquid, When the first valve is opened to the first small opening in the cleaning step, the first pump discharges the cleaning liquid. A method for processing a substrate.

3. The substrate processing method according to claim 2, When the first valve is opened to the first large opening degree in the cleaning step, the first pump sucks in the cleaning liquid at a first flow rate, and the first valve allows the cleaning liquid to pass through the first valve at the first flow rate; When the first valve is opened to the first small opening in the cleaning step, the first pump discharges the cleaning liquid at a second flow rate, and the first valve limits the flow rate of the cleaning liquid passing through the first valve to less than the second flow rate. A method for processing a substrate.

4. The substrate processing method according to claim 3, When the first valve is opened to the first small opening in the cleaning step, the first valve limits the flow rate of the cleaning liquid passing through the first valve to 20% or less of the second flow rate. A method for processing a substrate.

5. A substrate processing method according to any one of claims 1 to 4, The first valve is A valve seat; a valve body capable of contacting the valve seat; an electric motor that moves the valve body relative to the valve seat to adjust a distance between the valve seat and the valve body; Equipped A method for processing a substrate.

6. The substrate processing method according to claim 5, When the first valve is opened to the first large opening degree, the separation distance is 400 μm or more; When the first valve is opened to the first small opening, the separation distance is greater than 5 μm and less than 100 μm. A method for processing a substrate.

7. The substrate processing method according to claim 1, The processing step comprises: a first feeding step of feeding a treatment liquid from the first valve to the first pump through the supply path; a second sending step of sending a treatment liquid from the first pump to a downstream side of the first pump; Equipped with The washing step comprises: a first step of supplying a cleaning liquid from the first valve to the first pump through the supply path; a second step of flowing a cleaning liquid from the first pump downstream of the first pump; Equipped with In the first feeding step, the first valve is opened and the first pump sucks the processing liquid, In the second feeding step, the first valve is closed and the first pump discharges the treatment liquid; In the first step, the first valve is opened to the first large opening degree, and the first pump sucks in the cleaning liquid, In the second step, the first valve is opened to the first small opening, and the first pump discharges the cleaning liquid. A method for processing a substrate.

8. The substrate processing method according to claim 7, The liquid supply unit includes: a second valve provided in the supply passage and disposed downstream of the first pump; Equipped with In the first feeding step, the second valve is closed, In the second feeding step, the second valve is opened, In the first step, the first valve is opened wider than the second valve, In the second step, the second valve opens wider than the first valve. A method for processing a substrate.

9. The substrate processing method according to claim 8, In the first step, the second valve opens less than the first valve. A method for processing a substrate.

10. The substrate processing method according to claim 1, the first valve is disposed in a first portion of the supply line between the upstream end and the first pump; The liquid supply unit includes: a branch portion provided in the supply path and arranged downstream of the first pump; a second pump provided in the supply path and disposed downstream of the branching portion; a return path provided separately from the supply path and communicating between the second pump and the first pump; a discharge passage connected to the branching portion and branching off from the supply passage; a second valve disposed in a second portion of the supply line between the first pump and the branch; a third valve provided in a third portion of the supply line between the branch portion and the second pump; a fourth valve disposed in a fourth portion of the supply line between the second pump and the downstream end; A fifth valve provided in the return path; A discharge valve provided in the discharge path; Equipped with The processing step comprises: a first feeding step of flowing a treatment liquid from the upstream end to the first pump through the first portion; a second sending step of flowing a treatment liquid from the first pump to the second pump through the second portion and the third portion; a return step of causing the treatment liquid to flow back from the second pump to the first pump through the return path; a third sending step of flowing a treatment liquid from the second pump to the nozzle through a fourth portion; Equipped with The washing step comprises: a first cleaning step of flowing a cleaning liquid through the first portion and the second portion from the upstream end to the branching portion and discharging the cleaning liquid from the branching portion to the discharge path; a second cleaning step of flowing a cleaning liquid from the upstream end to the first pump through the first portion, flowing the cleaning liquid from the first pump to the second pump through the return path, backflowing the cleaning liquid from the second pump to the branching portion through the third portion, and discharging the cleaning liquid from the branching portion to the discharge path; a third cleaning step of flowing a cleaning liquid from the upstream end to the nozzle through the first portion, the second portion, the third portion and the fourth portion; Equipped A method for processing a substrate.

11. The substrate processing method according to claim 10, In the cleaning step, the second valve is switched between a second large opening degree and a second small opening degree smaller than the second large opening degree, In the cleaning step, the third valve is switched between a third large opening degree and a third small opening degree smaller than the third large opening degree, In the cleaning step, the fifth valve is switched between a fifth large opening degree and a fifth small opening degree smaller than the fifth large opening degree, The second small opening is larger than the opening of the second valve when the second valve is closed, the third small opening is greater than the opening of the third valve when the third valve is closed; The fifth small opening is larger than the opening of the fifth valve when the fifth valve is closed. A method for processing a substrate.

12. The substrate processing method according to claim 11, In the first cleaning step, the third valve is opened at the third small opening degree, and the fifth valve is opened at the fifth small opening degree, In the second cleaning step, the second valve is opened at the second small opening degree, In the third cleaning step, the fifth valve is opened at the fifth small opening. A method for processing a substrate.

13. The substrate processing method according to claim 10, further comprising: The branch portion is A first connection port connected to the second portion; A second connection port connected to the third portion; A third connection port connected to the discharge path; Equipped with In the first cleaning step, a cleaning liquid flows into the first connection port and flows out from the third connection port, In the second cleaning step, a cleaning liquid flows into the second connection port and flows out from the third connection port, In the third cleaning step, a cleaning liquid flows into the first connection port and flows out from the second connection port. A method for processing a substrate.

14. The substrate processing method according to claim 10, further comprising: When the cleaning liquid flows from the second portion through the branch portion to the discharge path, the third valve opens less than the second valve and the discharge valve; When the cleaning liquid flows from the third portion through the branch portion to the discharge path, the second valve opens less than the third valve and the discharge valve; When the cleaning liquid flows from the second portion to the third portion via the branch portion, the second valve and the third valve open wider than the drain valve. A method for processing a substrate.

15. The substrate processing method according to claim 10, further comprising: The branch is a filter. A method for processing a substrate.

16. The substrate processing method according to claim 10, further comprising: In the first cleaning step, the fourth valve is closed, In the second cleaning step, the fourth valve is closed, In the third cleaning step, the fourth valve is opened. A method for processing a substrate.

17. The substrate processing method according to claim 10, further comprising: The second cleaning step is carried out after the first cleaning step; The third cleaning step is carried out after the second cleaning step. A method for processing a substrate.

18. A substrate processing apparatus, comprising: A substrate holder for holding a substrate; a liquid supply unit that supplies a processing liquid to the substrate held by the substrate holder; A control unit that controls the liquid supply unit; Equipped with The liquid supply unit includes: a supply channel having an upstream end and a downstream end; A first pump provided in the supply path; a first valve provided in the supply passage and arranged upstream of the first pump; A nozzle connected to the downstream end; Equipped with when supplying a cleaning liquid for cleaning the liquid supply unit to the upstream end, the control unit switches the opening degree of the first valve between a first large opening degree and a first small opening degree smaller than the first large opening degree; The first small opening is larger than the opening of the first valve when the first valve is closed. Substrate processing equipment.

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