Substrate processing apparatus and method for replacing processing liquid

Abstract

To provide a technique capable of exchanging a process liquid in a tank and in a pipe while suppressing mixture of impurity into the pipe.SOLUTION: In a substrate processing device 100, a process liquid is stored in a first tank 21a. An upper end 30a of a connection pipe is connected to the first tank 21a. A first filter 33 and a first valve 404 are inserted in the connection pipe. A first filter return pipe 421 has: an upstream end connected to a drain port 33c of the first filter 33 or a portion between the first filter 33 and the first valve 404 in the connection pipe; and a downstream end connected to the first tank 21a. A first filter circulation valve 422 is inserted in the first filter return pipe 421. A first filter drain pipe 82 has an upstream end connected to the drain port 33c, a corresponding portion of the connection pipe or a portion between the connection pipe and the first filter circulation valve 422 in the first filter return pipe 421.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus and a method for replacing a processing liquid. [Background technology]

[0002] Substrate processing apparatuses that process substrates using a processing liquid have been proposed (for example, Patent Documents 1 and 2). The substrate processing apparatus includes a processing chamber. The processing chamber is provided with a spin chuck that holds the substrate and a nozzle that discharges the processing liquid onto the substrate. The substrate processing apparatus also includes a tank that stores the processing liquid. The processing liquid in the tank is supplied to the processing chamber through a liquid supply pipe. This liquid supply pipe is provided with a heater and an on-off valve. The on-off valve is provided in a position closer to the processing chamber than the heater, and when the on-off valve is opened, the processing liquid from the tank is supplied to the processing chamber. The heater heats the processing liquid to a temperature suitable for processing.

[0003] In Patent Documents 1 and 2, a circulation return pipe is also provided. The upstream end of the circulation return pipe is connected to the liquid supply pipe between the heater and the on-off valve, and the downstream end of the circulation return pipe is connected to the tank. Thus, a portion of the processing liquid supplied from the tank to the liquid supply pipe returns to the tank via the circulation return pipe. The processing liquid is heated by the heater while circulating through the liquid supply pipe and the circulation return pipe, thereby controlling the temperature of the processing liquid in the tank and the pipe within a specified range.

[0004] Patent Document 2 discloses a technique for replacing old processing liquid in a tank and in piping with new processing liquid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-192863 [Patent Document 2] Japanese Patent Publication No. 2021-174973 Summary of the Invention [Problem to be solved by the invention]

[0006] When replacing the processing liquid, it is required to replace the old processing liquid in the tank and the piping with a new processing liquid while suppressing the intrusion of impurities into the piping.

[0007] Therefore, an object of the present disclosure is to provide a technique that can replace the processing liquid in the tank and the piping while suppressing the intrusion of impurities into the piping. [Means for solving the problem]

[0008] A first aspect is a substrate processing apparatus including: a first tank for storing a processing liquid; a tank drainage unit including a first tank drainage pipe for discharging the processing liquid from the first tank and a first tank drainage valve inserted in the first tank drainage pipe; a tank supply unit including a first tank supply pipe for supplying a processing liquid to the first tank as a replacement liquid and a first tank supply valve inserted in the first tank supply pipe; and an upstream end of the tank connected to the first tank. and a downstream end connected to the first tank. a first filter inserted in the connecting pipe; a first valve inserted in the connecting pipe downstream of the first filter; a first filter return pipe having an upstream end connected to a drain port of the first filter or a portion of the connecting pipe between the first filter and the first valve, and a downstream end connected to the first tank; a first filter circulation valve inserted in the first filter return pipe; a first filter drain pipe having an upstream end connected to the drain port of the first filter, the portion of the connecting pipe, or a portion of the first filter return pipe between the connecting pipe and the first filter circulation valve; and a first filter drain valve inserted in the first filter drain pipe. a first heater provided in the connecting pipe upstream of the first filter and configured to heat the treatment liquid flowing through the connecting pipe; an inner return pipe having an upstream end connected to a portion of the connecting pipe between the first heater and the first filter and a downstream end connected to the first tank; and an inner circulation valve interposed in the inner return pipe. Equipped with.

[0010] No. 2 The embodiment of a tank drainage section including a first tank for storing a processing liquid, a first tank drainage pipe for discharging the processing liquid in the first tank and a first tank drainage valve inserted in the first tank drainage pipe; a first tank supply pipe for supplying the processing liquid to the first tank as a replacement liquid and a tank supply section including a first tank supply valve inserted in the first tank supply pipe; a connecting pipe having an upstream end connected to the first tank; a first filter inserted in the connecting pipe; a first valve inserted in the connecting pipe downstream of the first filter; a first filter return pipe having an upstream end connected to the drain port of the first filter or a portion of the connecting pipe between the first filter and the first valve, and a downstream end connected to the first tank; a first filter circulation valve interposed in the first filter return pipe; a first filter drain pipe having an upstream end connected to the drain port of the first filter, the portion of the connecting pipe, or a portion of the first filter return pipe between the connecting pipe and the first filter circulation valve; and a first filter drain valve interposed in the first filter drain pipe.A method for replacing a processing liquid in a substrate processing apparatus, comprising: a first tank drainage process, in which the first tank drainage valve is opened to drain the processing liquid from the first tank through the first tank drainage pipe while maintaining a filled state in which the inside of the connecting pipe is filled with the processing liquid downstream of the first valve; a first tank supply process, after the first tank drainage process, in which the first tank supply valve is opened to supply the replacement liquid to the first tank through the first tank supply pipe while maintaining the filled state; a first filter processing liquid replacement process, in which the first filter drainage valve is opened to flow the replacement liquid from the first tank into the upstream end of the connecting pipe while maintaining the filled state, and the processing liquid in the first filter is pushed out into the first filter drainage pipe by the replacement liquid; and a connecting pipe processing liquid replacement process, after the first filter processing liquid replacement process, in which the first valve is opened to push out and discharge the processing liquid in the connecting pipe by the replacement liquid.

[0011] No. 3 The embodiment is 2 In this embodiment, in the first tank drainage process, the first tank supply process, and the first filter treatment liquid replacement process, both the first valve and a second valve inserted in the connecting pipe downstream of the first valve are closed.

[0012] No. 4 The embodiment is 2 or 3 In the method for replacing a processing liquid according to the aspect of the present invention, in the connecting pipe processing liquid replacing step, the processing liquid inside the connecting pipe is pushed out by the replacement liquid heated by a first heater.

[0013] No. 5 The embodiment is 2 From 4 The treatment liquid replacement method according to any one of the above aspects further comprises a circulation step that is carried out between the first filter treatment liquid replacement step and the connecting pipe treatment liquid replacement step, and that opens the first filter circulation valve while maintaining the filling state, and circulates the replacement liquid.

[0014] No. 6 The embodiment is 4 A processing liquid replacement method according to the above aspect, further comprising a heating circulation process that is carried out between the first filter processing liquid replacement process and the connecting pipe processing liquid replacement process, in which the first heater provided in the connecting pipe upstream of the first filter performs a heating operation while maintaining the filling state, and the first filter circulation valve or the inner circulation valve is opened to circulate the replacement liquid, and the inner circulation valve is inserted in the inner return pipe that branches off from the connecting pipe between the first filter and the first heater and returns to the first tank.

[0015] No. 7 The embodiment is 2 From 6 A method for replacing a processing liquid according to any one of the above aspects, wherein in the first tank drainage step, the first tank drainage valve is closed before the liquid level of the processing liquid reaches a first liquid delivery section provided in the connecting pipe.

[0016] No. 8 The embodiment is 2 From 7 A method for replacing a treatment liquid according to any one of the above aspects, wherein in the first filter treatment liquid replacement process, the treatment liquid inside the first filter is pushed out by the replacement liquid into the first filter drain pipe connected to the drain port of the first filter, and the flow rate of the treatment liquid in the first filter treatment liquid replacement process is set to be smaller than the flow rate of the treatment liquid in the first tank drainage process.

[0017] No. 9 The embodiment is 2 From 8A method for replacing a processing liquid according to any one of the above aspects, comprising: a second tank draining process, which is performed before the first tank draining process, and which opens a second tank draining valve to discharge the processing liquid in a second tank connected to the first tank via the first tank supply pipe, through the second tank draining pipe connected to the second tank and having the second tank draining valve inserted therein; and a second tank supplying process, which is performed after the second tank draining process and in parallel with the first tank draining process, and which opens a second tank supplying valve to supply the replacement liquid to the second tank through the second tank supplying pipe connected to the second tank and having the second tank supplying valve inserted therein.

[0018] No. 10 The embodiment is 9 The processing liquid replacement method according to the embodiment further comprises a second filter processing liquid replacement process, which is carried out between the second tank supply process and the first tank supply process, and which opens a second filter drain valve inserted in a second filter drain pipe having an upstream end connected to the drain port of a second filter inserted in the first tank supply pipe or a portion of the first tank supply pipe downstream of the second filter, to allow the replacement liquid in the second tank to flow into the upstream end of the first tank supply pipe, and to push the processing liquid inside the second filter into the second filter drain pipe with the replacement liquid.

[0019] No. 11 The embodiment is 9 or 10 In the method for replacing a processing liquid according to the aspect, in the first tank liquid supply step, a second heater provided in the first tank liquid supply pipe performs a heating operation.

[0020] No. 12 The embodiment is 9 From 11 In the method for replacing a treatment liquid according to any one of the above aspects, a downstream end of the connecting pipe is connected to the second tank. [Effects of the Invention]

[0021] According to the first aspect, by opening the first tank drain valve, old processing liquid in the first tank can be drained through the first tank drain pipe. Next, by opening the first tank supply valve, new processing liquid can be supplied to the first tank as replacement liquid through the first tank supply pipe. Next, by opening the first filter drain valve, replacement liquid in the first tank can be drained through the first filter and the first filter drain pipe. Therefore, the old processing liquid in the first filter can be pushed out and drained by the replacement liquid, and the first filter can be filled with replacement liquid.

[0022] Next, by opening the first valve, the replacement liquid in the first tank can be used to push out and discharge the old processing liquid in the connecting pipe. When the replacement liquid is used to push out the old processing liquid in the connecting pipe, the old processing liquid has already been discharged from the first filter, so the cleaner replacement liquid can be used to push out and discharge the old processing liquid in the connecting pipe. This reduces the possibility of impurities getting into the connecting pipe.

[0023] As described above, the processing liquid in the tank and the connecting pipe can be replaced while preventing impurities from entering the connecting pipe.

[0024] Moreover, The replacement liquid can be circulated through the inner return pipe without passing through the flow path downstream of the first valve in the connecting pipe. The first heater can heat the circulating treatment liquid, raising its temperature. When the temperature of the treatment liquid becomes high enough, opening the first valve allows the high-temperature replacement liquid to push out the old treatment liquid in the connecting pipe. This prevents impurities from precipitating in the old treatment liquid due to low temperatures.

[0025] No. 2 According to this aspect, the processing liquid in the tank and the connecting pipe can be replaced while preventing impurities from entering the connecting pipe.

[0026] No. 3 According to this aspect, the filled state can be maintained more reliably.

[0027] No. 4 According to this aspect, it is possible to suppress the precipitation of impurities in the old processing liquid due to low temperatures.

[0028] No. 5 According to this aspect, the impurity concentration of the replacement liquid can be reduced in the circulation step, and therefore, in the connecting pipe treatment liquid replacement step after the circulation step, the old treatment liquid in the connecting pipe can be pushed out with the cleaner replacement liquid.

[0029] No. 6 According to this aspect, the temperature of the replacement liquid can be increased in the heating and circulation process. Therefore, in the connecting pipe treatment liquid replacement process after the heating and circulation process, the old treatment liquid in the connecting pipe can be pushed out by the higher temperature replacement liquid. Therefore, it is possible to suppress the precipitation of impurities in the old treatment liquid due to low temperature.

[0030] No. 7 According to this aspect, it is possible to avoid the first liquid delivery section from operating in a state where there is no liquid.

[0031] No. 8 According to this aspect, although the area of ​​the drain port of the first filter is small, the flow rate in the first filter treated liquid replacement process is small, so pressure rise can be suppressed. Therefore, malfunctions in the first filter and piping can be suppressed. On the other hand, the flow rate of the treated liquid in the first tank draining process is high, so old treated liquid can be quickly discharged from the first tank. Therefore, throughput can be improved.

[0032] No. 9 According to this aspect, the discharge of the old processing liquid from the first tank and the supply of the replacement liquid to the second tank are carried out in parallel, thereby improving throughput.

[0033] No. 10 According to this aspect, in the second filter treatment liquid replacement step, the old treatment liquid inside the second filter can be replaced with replacement liquid, and therefore, in the subsequent first tank liquid supply step, cleaner replacement liquid can be supplied from the second tank to the first tank.

[0034] No. 11 According to this aspect, in the first tank liquid supply step, high-temperature replacement liquid can be supplied to the first tank. Therefore, in the subsequent first filter treatment liquid replacement step, the high-temperature replacement liquid can push the old treatment liquid in the first filter into the first filter drain pipe. Therefore, it is possible to suppress the precipitation of impurities in the old treatment liquid due to low temperatures.

[0035] No. 12 According to this aspect, the first tank, the second tank, the first tank supply pipe, and the connecting pipe can form a circulation path for the processing liquid. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus. [Figure 2] FIG. 1 is a diagram schematically illustrating an example of a configuration of a substrate processing apparatus. [Figure 3] FIG. 1 is a diagram schematically illustrating an example of the configuration of a substrate processing apparatus corresponding to one processing unit. [Figure 4] FIG. 2 is a functional block diagram illustrating an example of an internal configuration of a control unit. [Figure 5] 5 is a flowchart showing an example of a treatment liquid replacement process according to the first embodiment. [Figure 6] 4 is a timing chart showing an example of a processing liquid replacement process according to the first embodiment. [Figure 7] FIG. 10 is a diagram for explaining a first tank drainage step. [Figure 8] FIG. 10 is a diagram for explaining a first tank liquid supply process. [Figure 9] FIG. 10 is a diagram illustrating a first filter treatment liquid changing step. [Figure 10] FIG. 10 is a diagram illustrating a heating circulation process. [Figure 11] FIG. 10 is a diagram illustrating a circulating treatment liquid exchange process. [Figure 12]FIG. 10 is a diagram for explaining a heating, circulating, and liquid supplying process. [Figure 13] FIG. 2 is a diagram schematically illustrating an example of a piping system including a first filter drain pipe. [Figure 14] FIG. 10 is a diagram schematically illustrating an example of the configuration of a substrate processing apparatus according to a second embodiment. [Figure 15] 10 is a flowchart showing an example of a treatment liquid replacement process according to a second embodiment. [Figure 16] 10 is a timing chart showing an example of a processing liquid replacement process according to the second embodiment. [Figure 17] FIG. 10 is a diagram for explaining a second tank drainage step. [Figure 18] 10A and 10B are diagrams for explaining a first tank drainage process and a second tank supply process. [Figure 19] FIG. 10 is a diagram illustrating a second filter treatment liquid changing step. [Figure 20] FIG. 10 is a diagram for explaining a first tank liquid supply process. [Figure 21] FIG. 10 is a diagram illustrating a first filter treatment liquid changing step. [Figure 22] FIG. 10 is a diagram illustrating a circulating treatment liquid exchange process. [Figure 23] FIG. 10 is a diagram for explaining a heating, circulating, and liquid supplying process. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, embodiments will be described with reference to the accompanying drawings. Note that the drawings are schematic, and for the sake of convenience, components may be omitted or simplified as appropriate. Furthermore, the relative sizes and positions of components shown in the drawings are not necessarily accurately depicted and may be changed as appropriate.

[0038] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0039] Furthermore, in the following description, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the ordering that may result from these ordinal numbers.

[0040] When expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless otherwise specified, the expressions not only strictly represent the positional relationship but also represent a state in which there is a relative displacement in terms of angle or distance within a range in which tolerance or equivalent functionality is obtained. When expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) are used, the expressions not only represent a state in which there is strict quantitative equality but also represent a state in which there is a difference in which tolerance or equivalent functionality is obtained, unless otherwise specified. When expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, the expressions not only represent a geometrically strict shape but also represent a shape with, for example, irregularities or chamfers within a range in which equivalent effects are obtained, unless otherwise specified. When the expressions "comprise," "include," "have," "includes," "includes," or "have" are used to describe one component, the expressions are not exclusive expressions that exclude the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0041] First Embodiment <General configuration of substrate processing apparatus> FIG. 1 is a plan view schematically illustrating an example of the configuration of a substrate processing apparatus 100. As shown in FIG. 1, the substrate processing apparatus 100 is a single-wafer processing apparatus that can be used, for example, for processing to remove organic contaminants adhering to the surface of a semiconductor substrate (wafer) W, which is an example of a substrate. Examples of organic residues include unnecessary resist remaining on the surface of the substrate W after an ion implantation process or the like that implants impurities into the surface of the substrate W, and organic contaminants derived from resist adhering near the outer periphery of the surface of the substrate W. The substrate processing apparatus 100 can also be used for removing inorganic residues and etching the substrate W.

[0042] The substrate processing apparatus 100 includes a load port LP as a container holding mechanism that holds a plurality of carriers C as containers, and a plurality of (12 in this embodiment) processing units 10 that process substrates W. Specifically, for example, three sets of processing units 10, each consisting of four processing units 10 arranged in a plane, are arranged stacked in the vertical direction.

[0043] The substrate processing apparatus 100 further includes, for example, an indexer robot IR, a center robot CR, and a control unit 90. The indexer robot IR can transport substrates W, for example, between the load port LP and the center robot CR. The center robot CR can transport substrates W, for example, between the indexer robot IR and each processing unit 10. The control unit 90 can control, for example, the operation of each component provided in the substrate processing apparatus 100 and the opening and closing of valves.

[0044] 1, the load port LP and each processing unit 10 are arranged at intervals in the horizontal direction. In the load port LP, a plurality of carriers C, each accommodating a plurality of substrates W, are arranged along a horizontal arrangement direction D in a plan view. The load port LP functions as a loading section that loads the substrates W. Here, the indexer robot IR can, for example, transport a plurality of substrates W one by one from the carrier C to the substrate mounting section 110, and can also transport a plurality of substrates W one by one from the substrate mounting section 110 to the carrier C. The substrate mounting section 110 includes a mounting table on which the substrate W is placed.

[0045] The center robot CR can, for example, transport multiple substrates W one by one from the substrate platform 110 to each processing unit 10, and can also transport multiple substrates W one by one from each processing unit 10 to the substrate platform 110. Furthermore, for example, the center robot CR can transport substrates W between multiple processing units 10 as needed. The indexer robot IR, the substrate platform 110, and the center robot CR function as a substrate transfer section that receives substrates W from the loading section (load port LP) and transfers them to the processing units 10.

[0046] In the example of FIG. 1, the indexer robot IR has a hand H that is U-shaped in a plan view. Here, the indexer robot IR has two hands H. The two hands H are arranged at different heights. Each hand H can support a substrate W in a horizontal position. The indexer robot IR can move the hand H in the horizontal and vertical directions. Furthermore, the indexer robot IR can change the orientation of the hand H by rotating (spinning) around an axis along the vertical direction. The indexer robot IR moves along the arrangement direction D on a path that passes through the transfer position (the position where the indexer robot IR is depicted in FIG. 1). The transfer position is a position where the indexer robot IR and the substrate platform 110 face each other in a direction perpendicular to the arrangement direction D in a plan view. The indexer robot IR can have its hand H face any carrier C and any substrate platform 110. Here, for example, by moving the hand H, the indexer robot IR can perform a load-in operation to load the substrate W into the carrier C and an unload-out operation to unload the substrate W from the carrier C. Also, for example, by moving the hand H at the transfer position, the indexer robot IR can perform a load-in operation to load the substrate W into the substrate mounting part 110 and an unload-out operation to unload the substrate W from the substrate mounting part 110.

[0047] In the example of FIG. 1, the center robot CR has a hand H that is U-shaped in a plan view, similar to the indexer robot IR. Here, the center robot CR has two hands H. The two hands H are arranged at different heights. Each hand H can support a substrate W in a horizontal position. The center robot CR can move each hand H in the horizontal and vertical directions. Furthermore, the center robot CR can change the orientation of the hand H by rotating (spinning) around an axis along the vertical direction. The center robot CR is surrounded by multiple processing units 10 in a plan view. The center robot CR can have its hand H face any of the processing units 10 and the substrate platform 110. Here, for example, by moving its hand H, the center robot CR can perform a load operation to load a substrate W into each processing unit 10 and an unload operation to unload the substrate W from each processing unit 10. Furthermore, for example, the center robot CR can move the hand H to perform a carry-in operation of carrying the substrate W into the substrate platform 110 and an unloading operation of carrying the substrate W out of the substrate platform 110.

[0048] An unprocessed substrate W is taken out of the carrier C by the indexer robot IR and handed over to the center robot CR via the substrate mounting part 110. The center robot CR loads this unprocessed substrate W into the processing unit 10. The processing unit 10 processes the substrate W. The processed substrate W is taken out of the processing unit 10 by the center robot CR, and after passing through other processing units 10 as necessary, is handed over to the indexer robot IR via the substrate mounting part 110. The indexer robot IR loads the processed substrate W into the carrier C. In this manner, the substrate W is processed.

[0049] In the example of FIG. 1, a user interface 94 is provided. The user interface 94 has, for example, a display and an input device, neither of which are shown. The display is, for example, a liquid crystal display or the like. The display is controlled by the control unit 90 to display various information. The input device is, for example, a keyboard and a mouse or the like. The input device outputs information input by a user to the control unit 90. For example, the user can use the input device to instruct the substrate processing apparatus 100 to start operating.

[0050] <Processing unit> Fig. 2 is a diagram schematically illustrating an example of the configuration of the substrate processing apparatus 100, and Fig. 3 is a diagram schematically illustrating an example of the configuration of the substrate processing apparatus 100 corresponding to one processing unit 10. In the example of Fig. 2, two towers TW are shown. In the example of Fig. 2, each tower TW is composed of four processing units 10. That is, in each tower TW, the four processing units 10 are arranged side by side in the vertical direction. Note that the number of processing units 10 constituting the tower TW is not limited to four and can be changed as appropriate.

[0051] 2 and 3, each processing unit 10 includes a processing chamber 11, a substrate holder 12, a nozzle 13, and a guard 14. The processing chamber 11 forms a processing chamber and houses the substrate holder 12, the nozzle 13, and the guard 14.

[0052] The substrate holding unit 12 holds the substrate W in a horizontal position. Here, the horizontal position means a position in which the thickness direction of the substrate W is aligned with the vertical direction. The substrate holding unit 12 also rotates the substrate W around a rotation axis that passes through the center of the substrate W and extends in the vertical direction. The substrate holding unit 12 is also called a spin chuck. The substrate holding unit 12 may hold the edge of the substrate W with multiple chuck pins, or may hold the back surface of the substrate W by vacuum suction.

[0053] The nozzle 13 ejects the processing liquid toward the main surface of the substrate W held by the substrate holder 12. When the processing liquid lands on the main surface of the rotating substrate W, the processing liquid is subjected to centrifugal force and flows outward on the main surface of the substrate W, and is splashed outward from the periphery of the substrate W. The processing liquid acts on the main surface of the substrate W, thereby processing the substrate W.

[0054] The guard 14 has a cylindrical shape that surrounds the substrate holder 12 and receives the processing liquid that has splashed from the periphery of the substrate W.

[0055] <Supply unit> 2 and 3, the substrate processing apparatus 100 includes a supply unit (processing liquid supply apparatus) 20 that supplies a processing liquid to the processing unit 10. The supply unit 20 is appropriately provided across the fluid box 120 and the processing liquid cabinet 130 (see FIG. 1).

[0056] The supply unit 20 includes a first tank 21a. The first tank 21a stores the processing liquid, and the processing liquid is supplied to the processing unit 10 via a unit liquid supply pipe 30.

[0057] The processing liquid includes, for example, at least one of a chemical liquid such as an etching liquid, a rinse liquid for rinsing away the chemical liquid, and a static elimination liquid for neutralizing the substrate W. More specifically, the processing liquid includes at least one of a hydrofluoric acid-hydrogen peroxide solution (FPM) obtained by mixing hydrofluoric acid, hydrogen peroxide, and water, hydrofluoric acid (HF), tetramethylammonium hydroxide (TMAH), a mixture of sulfuric acid and hydrogen peroxide (SPM), ammonia water, and a mixture of ammonia, hydrogen peroxide, and water (SC-1). The processing liquid may be a single liquid rather than a mixture. For example, a single liquid such as hydrofluoric acid, hydrogen peroxide, or sulfuric acid can be used as the processing liquid.

[0058] 2 and 3, the first tank 21a is connected to various piping systems. Specific examples of each piping system will be described below.

[0059] <Unit supply pipe> In the example of FIG. 2, the processing liquid in the first tank 21a is supplied to a plurality of processing units 10, but for simplicity, the following description will focus on the piping system corresponding to one processing unit 10.

[0060] In the example of Fig. 3, the first tank 21a is connected to the nozzle 13 of the processing unit 10 via a unit liquid supply pipe 30. That is, the upstream end 30a of the unit liquid supply pipe 30 is connected to the first tank 21a, and the downstream end 30b of the unit liquid supply pipe 30 is connected to the nozzle 13. In the example of Fig. 3, the upstream end 30a of the unit liquid supply pipe 30 is connected to the bottom of the first tank 21a. That is, the upstream end 30a of the unit liquid supply pipe 30 opens at the bottom surface of the first tank 21a.

[0061] In the example of FIG. 3, the unit liquid supply pipe 30 is provided with a first liquid delivery section 31, a first heater 32, a first filter 33, a first valve 404, a flow rate sensor 36, a flow rate adjustment section 35, and a unit liquid supply valve 34.

[0062] The first liquid delivery unit 31 is a drive mechanism that causes the processing liquid to flow from the first tank 21a toward the nozzle 13, and is, for example, a pump.

[0063] The first heater 32 has a heat source such as a thermocouple and heats the processing liquid flowing inside the unit liquid supply pipe 30 to a temperature suitable for processing. In the example of Fig. 3, two first heaters 32 are provided in the unit liquid supply pipe 30, but one first heater 32 or three or more first heaters 32 may be provided. In the example of Fig. 3, the first heater 32 is provided between the first filter 33 and the first liquid delivery section 31.

[0064] The first filter 33 captures impurities contained in the processing liquid, thereby reducing the impurity concentration in the processing liquid downstream of the first filter 33. In the example of FIG. 3, the first filter 33 is provided between the first valve 404 and the first heater 32.

[0065] The first valve 404 switches between open and closed states of the unit liquid supply pipe 30. The first valve 404 also switches between open and closed states of the outer main circulation pipe 40, as will be described later.

[0066] The flow rate adjuster 35 and the flow rate sensor 36 are inserted into the unit liquid supply pipe 30 downstream of the first valve 404. The flow rate adjuster 35 adjusts the flow rate of the processing liquid supplied to the processing unit 10. The flow rate adjuster 35 is, for example, a mass flow controller. The flow rate sensor 36 measures the flow rate of the processing liquid supplied to the processing unit 10 and outputs a signal indicating the measured value to the control unit 90. The control unit 90 controls the flow rate adjuster 35 based on the measured value of the flow rate sensor 36, thereby enabling high-precision control of the flow rate of the processing liquid.

[0067] The unit liquid supply valve 34 is inserted into the unit liquid supply pipe 30 at a portion close to the nozzle 13. In the example of Fig. 3, the unit liquid supply valve 34 is provided between the flow rate adjuster 35 and the nozzle 13. The unit liquid supply valve 34 switches the unit liquid supply pipe 30 between open and closed states, thereby switching between discharging and stopping the discharge of the processing liquid from the nozzle 13.

[0068] When the first liquid delivery unit 31 is operated with the unit liquid supply valve 34 and the first valve 404 open, the processing liquid in the first tank 21a flows through the unit liquid supply pipe 30 toward the processing unit 10. The processing liquid is discharged toward the substrate W from the discharge port of the nozzle 13 in the processing unit 10.

[0069] <Circulation piping system> In the example of Fig. 3, a plurality of circulation piping systems are provided to return the treatment liquid from the first tank 21a to the first tank 21a. In the example of Fig. 3, an outer main circulation piping 40 (corresponding to an example of a connecting piping), an outer secondary circulation piping 41 (corresponding to an example of a connecting piping), a first filter circulation piping 42, and a first inner circulation piping 43 are provided.

[0070] <Outside main circulation piping> In the example of FIG. 3, a portion of the outer main circulation pipe 40 doubles as a portion of the unit liquid supply pipe 30, as will be described later. The outer main circulation pipe 40 includes a supply pipe 401, a connecting pipe 402, and a return pipe 403. In the example of FIG. 3, portions of the supply pipe 401 and the connecting pipe 402 double as upstream portions of the unit liquid supply pipe 30, and the upstream end of the supply pipe 401 (i.e., the upstream end 30a) is connected to, for example, the bottom of the first tank 21a. The downstream end of the supply pipe 401 is connected to the upstream end of the connecting pipe 402, the downstream end of the connecting pipe 402 is connected to the upstream end of the return pipe 403, and the downstream end of the return pipe 403 is connected to, for example, the ceiling of the first tank 21a. In other words, the downstream end of the return pipe 403 opens inside the first tank 21a. The supply pipe 401, the connecting pipe 402, and the return pipe 403 may be formed by a single pipe.

[0071] 3, unit liquid supply pipe 30 is composed of supply pipe 401, connecting pipe 402, and branch liquid supply pipe 302 branching from connecting pipe 402. The upstream end of branch liquid supply pipe 302 is connected to the middle of connecting pipe 402, and the downstream end of branch liquid supply pipe 302 is connected to nozzle 13. In this piping system, upstream end 30a of unit liquid supply pipe 30 corresponds to the upstream end of supply pipe 401, and downstream end 30b of unit liquid supply pipe 30 corresponds to the downstream end of branch liquid supply pipe 302. A unit liquid supply valve 34, a flow rate adjuster 35, and a flow rate sensor 36 are inserted in branch liquid supply pipe 302.

[0072] 2, the outer main circulation piping 40 is arranged vertically near a plurality of processing units 10 arranged vertically. Such an outer main circulation piping 40 may also be called tower piping.

[0073] 3, the first liquid delivery section 31, the first heater 32, the first filter 33, and the first valve 404 are provided in the supply pipe 401. Also in the example of Fig. 3, a second valve 405 is inserted in the return pipe 403 of the outer main circulation pipe 40. The second valve 405 switches the return pipe 403 between open and closed states.

[0074] With the first valve 404 and the second valve 405 open, the first liquid delivery unit 31 operates, causing the processing liquid in the first tank 21a to return to the first tank 21a through the outer main circulation pipe 40. Since the first heater 32 is provided in the feed pipe 401, the high-temperature processing liquid heated by the first heater 32 flows inside the outer main circulation pipe 40. This makes it possible to maintain the temperature of the processing liquid in the first tank 21a and the outer main circulation pipe 40 within a specified temperature range suitable for processing the substrate W. Furthermore, since the first filter 33 is inserted in the feed pipe 401, the impurity concentration of the processing liquid in the first tank 21a and the outer main circulation pipe 40 can also be reduced.

[0075] <Outside secondary circulation piping> The outer secondary circulation piping 41 includes a secondary return pipe 411. The secondary return pipe 411 is a pipe for returning the processing liquid flowing through the branch liquid supply pipe 302 branching from the outer main circulation piping 40 toward each processing unit 10 to the first tank 21a. In the example of FIG. 3, the upstream end of the secondary return pipe 411 is connected to the branch liquid supply pipe 302 between the unit liquid supply valve 34 and the flow rate adjuster 35. In the example of FIG. 3, the downstream end of the secondary return pipe 411 is connected to the middle of the return pipe 403, specifically, to a portion upstream of the second valve 405. The outer secondary circulation piping 41 is composed of the supply pipe 401, a portion of the crossover pipe 402, a portion of the branch liquid supply pipe 302, the secondary return pipe 411, and a portion of the return pipe 403. Hereinafter, the portion of the branch liquid supply pipe 302 from the upstream end to the upstream end of the secondary return pipe 411 and the piping consisting of the secondary return pipe 411 will also be referred to as the branch circulation piping 413.

[0076] A secondary circulation valve 412 is inserted in the secondary return pipe 411. The secondary circulation valve 412 switches the secondary return pipe 411 between open and closed states.

[0077] When the first valve 404, the second valve 405 and the secondary circulation valve 412 are open, the first liquid delivery section 31 operates, and the treatment liquid in the first tank 21a returns to the first tank 21a through the outer main circulation pipe 40 and the branch circulation pipe 413.

[0078] <First filter circulation piping> The first filter circulation pipe 42 includes a first filter return pipe 421. The first filter return pipe 421 is a pipe for returning the treated liquid flowing into the first filter 33 to the first tank 21a. In the example of FIG. 3, the first filter 33 has a drain port 33c, and the upstream end of the first filter return pipe 421 is connected to the drain port 33c of the first filter 33. The drain port 33c is an opening for discharging the treated liquid from inside the housing of the first filter 33. The internal space of the housing of the first filter 33 is divided into an outlet space and an inlet space by the filter body, and the drain port 33c may open to either the outlet space or the inlet space. Here, it is assumed that the drain port 33c opens to the outlet space. The downstream end of the first filter return pipe 421 is connected to, for example, the ceiling of the first tank 21a. In other words, the downstream end of the first filter return pipe 421 opens inside the first tank 21a. The first filter circulation pipe 42 is composed of a part of the supply pipe 401 , the first filter 33 and the first filter return pipe 421 .

[0079] A first filter circulation valve 422 is inserted in the first filter return pipe 421. The first filter circulation valve 422 switches the first filter return pipe 421 between open and closed states.

[0080] With the first filter circulation valve 422 open, the first liquid delivery unit 31 operates, and the treatment liquid in the first tank 21a returns to the first tank 21a through the first filter circulation pipe .

[0081] <1st inner circulation piping> The first inner circulation pipe 43 includes a first inner return pipe 431. The first inner return pipe 431 is a pipe for returning the treatment liquid that has passed through the first heater 32 to the first tank 21a before passing through the first filter 33, and is a pipe that branches off from the supply pipe 401 between the first heater 32 and the first filter 33 and returns to the first tank 21a. In other words, the upstream end of the first inner return pipe 431 is connected to a portion of the supply pipe 401 between the first heater 32 and the first filter 33, and the downstream end of the first inner return pipe 431 is connected to, for example, the ceiling of the first tank 21a. The downstream end of the first inner return pipe 431 opens inside the first tank 21a. The first inner circulation pipe 43 is composed of a portion of the supply pipe 401 and the first inner return pipe 431.

[0082] A first inner circulation valve 432 is inserted in the first inner return pipe 431. The first inner circulation valve 432 switches the first inner return pipe 431 between open and closed states.

[0083] When the first inner circulation valve 432 is open, the first liquid delivery unit 31 operates, and the treatment liquid in the first tank 21a returns to the first tank 21a through the first inner circulation pipe 43.

[0084] <Recovery tube> 3, a recovery pipe 22 is also provided for returning the processing liquid discharged from the nozzle 13 of the processing unit 10 to the first tank 21a. In the example of FIG. 3, the upstream end of the recovery pipe 22 is connected to the processing unit 10, and the downstream end of the recovery pipe 22 is connected to the middle of the secondary return pipe 411. Specifically, the downstream end of the recovery pipe 22 is connected to the secondary return pipe 411 downstream of the secondary circulation valve 412. A recovery valve 23 is inserted in the recovery pipe 22. The recovery valve 23 switches the recovery pipe 22 between open and closed states.

[0085] The processing liquid discharged from the nozzle 13 flows over the main surface of the substrate W, splashes outward from the periphery of the substrate W, is received by the inner peripheral surface of the guard 14, and is guided to the upstream end of the recovery pipe 22. When the recovery valve 23 is open, the processing liquid flows inside the recovery pipe 22 and is supplied into the first tank 21a. This allows the processing liquid to be reused. Note that the processing liquid recovered from the recovery pipe 22 may contain more impurities due to the processing of the substrate W, or the concentrations of components necessary for processing the substrate W may be reduced. In other words, the recovered processing liquid is degraded.

[0086] <Tank liquid supply section> As shown in FIG. 3, the supply unit 20 also includes a tank liquid supply unit 60. The tank liquid supply unit 60 supplies the processing liquid to the first tank 21a. The processing liquid supplied by the tank liquid supply unit 60 is new and has hardly deteriorated. The temperature of the processing liquid supplied by the tank liquid supply unit 60 is room temperature, for example, about 25°C.

[0087] The tank liquid supply unit 60 includes a tank liquid supply pipe 61 and a tank liquid supply valve 62. The upstream end of the tank liquid supply pipe 61 is connected to a processing liquid supply source 63, and the downstream end of the tank liquid supply pipe 61 is connected to, for example, the ceiling of the first tank 21a. The tank liquid supply valve 62 is inserted into the tank liquid supply pipe 61. The tank liquid supply valve 62 switches the tank liquid supply pipe 61 between open and closed states. When the tank liquid supply valve 62 is opened, new processing liquid is supplied from the processing liquid supply source 63 to the first tank 21a through the tank liquid supply pipe 61. The tank liquid supply pipe 61 and the tank liquid supply valve 62 in the first embodiment correspond to the first tank liquid supply pipe and the first tank liquid supply valve 62 in the third to ninth aspects in the section of Means for Solving the Problems, respectively.

[0088] <Drainage system> <First tank drain pipe> As shown in FIG. 3, a tank drainage unit including a first tank drainage pipe 80 and a first tank drainage valve 802 is provided. The first tank drainage pipe 80 is a pipe for discharging the processing liquid in the first tank 21a. In the example of FIG. 3, a portion of the first tank drainage pipe 80 also serves as a portion of the outer main circulation pipe 40. Specifically, the first tank drainage pipe 80 is composed of a portion of the supply pipe 401 and a branch drainage pipe 801 branching from the supply pipe 401. The upstream end of the branch drainage pipe 801 is connected to the middle of the supply pipe 401, in the example of FIG. 3, a portion between the first heater 32 and the first filter 33. The downstream end of the branch drainage pipe 801 is connected to a drain tank 83. The processing liquid stored in the drain tank 83 is discharged to the outside. 3, the upstream end of the first tank drainage pipe 80 corresponds to the upstream end of the supply piping 401 (i.e., upstream end 30a), and is connected to the first tank 21a. The downstream end of the first tank drainage pipe 80 corresponds to the downstream end of a branch drainage pipe 801. A first tank drainage valve 802 is inserted in the branch drainage pipe 801. The first tank drainage valve 802 switches the branch drainage pipe 801 between open and closed states.

[0089] When the first tank drain valve 802 is open, the first liquid delivery unit 31 operates, causing the treatment liquid in the first tank 21a to flow into the drain tank 83 through the first tank drain pipe 80. This causes the treatment liquid in the first tank 21a to be discharged.

[0090] <Circulation drainage tube> In the example of Fig. 3, a circulation drain pipe 81 is provided for discharging the treatment liquid in the outer main circulation pipe 40 and the outer secondary circulation pipe 41. The upstream end of the circulation drain pipe 81 is connected to the return pipe 403 downstream of the downstream end of the secondary return pipe 411. In the example of Fig. 3, the upstream end of the circulation drain pipe 81 is connected to the return pipe 403 upstream of the second valve 405. The downstream end of the circulation drain pipe 81 is connected to a drain tank 83. A circulation drain valve 812 is inserted in the circulation drain pipe 81. The circulation drain valve 812 switches the circulation drain pipe 81 between open and closed.

[0091] When the first valve 404, the secondary circulation valve 412, and the circulation drain valve 812 are open, the first liquid delivery section 31 operates, causing the treatment liquid in the first tank 21a to flow into the drain tank 83 through the outer main circulation piping 40, the branch circulation piping 413, and the circulation drain pipe 81.

[0092] <First filter drainage tube> In the example of FIG. 3, a first filter drain pipe 82 is provided for discharging the treated liquid from the first filter 33. In the example of FIG. 3, a portion of the first filter drain pipe 82 also serves as a portion of the first filter return pipe 421. In the example of FIG. 3, the first filter drain pipe 82 is composed of a portion of the first filter return pipe 421 and a branch drain pipe 821 branching from the first filter return pipe 421. The branch drain pipe 821 is connected to the middle of the first filter return pipe 421, in the example of FIG. 3, between the drain port 33c of the first filter 33 and the first filter circulation valve 422. The downstream end of the branch drain pipe 821 is connected to the drain tank 83. The upstream end of the first filter drain pipe 82 corresponds to the upstream end of the first filter return pipe 421 and is connected to the drain port 33c of the first filter 33. The downstream end of the first filter drain pipe 82 corresponds to the downstream end of the branch drain pipe 821. A first filter drain valve 822 is inserted into the branch drain pipe 821. The first filter drain valve 822 switches the branch drain pipe 821 between open and closed states.

[0093] When the first filter drain valve 822 is open and the first liquid delivery unit 31 is operated, the treatment liquid in the first tank 21a flows into the drain tank 83 through the forward piping 401, the first filter 33, and the first filter drain pipe 82.

[0094] <Sensor> In the example of Fig. 3, a sensor 50 is provided in the first tank 21a. The sensor 50 is a sensor for detecting the amount of processing liquid stored in the first tank 21a. As a specific example, the sensor 50 includes a liquid level sensor. The liquid level sensor is also called a level sensor. The liquid level sensor may be, for example, a float-type level sensor or a capacitance-type level sensor.

[0095] 3, the sensor 50 includes a first liquid level sensor 51, a second liquid level sensor 52, and a third liquid level sensor 53. The first liquid level sensor 51, the second liquid level sensor 52, and the third liquid level sensor 53 are provided at different height positions within the first tank 21a. In the example of FIG. 3, the first liquid level sensor 51 is provided at the lowest position, the third liquid level sensor 53 is provided at the highest position, and the second liquid level sensor 52 is provided at a height position between the first liquid level sensor 51 and the third liquid level sensor 53.

[0096] The sensor 50 outputs a signal indicating the detection result to the control unit 90. Specifically, the first liquid level sensor 51, the second liquid level sensor 52, and the third liquid level sensor 53 each output a signal indicating the detection result to the control unit 90.

[0097] <Control unit> The control unit 90 can comprehensively control the substrate processing apparatus 100. For example, the control unit 90 can control the transfer of the indexer robot IR, the transfer of the center robot CR, the rotation of the substrate holder 12 of each processing unit 10, the opening and closing of each valve of the supply unit 20, the drive control of the first liquid delivery unit 31, and the heating control of the first heater 32. The control unit 90 can also receive signals from the sensor 50 and the flow rate sensor 36.

[0098] FIG. 4 is a functional block diagram illustrating an example of the internal configuration of the control unit 90. The control unit 90 is an electronic circuit and includes, for example, a data processing unit 91 and a storage unit 92. In the specific example of FIG. 3, the data processing unit 91 and the storage unit 92 are connected to each other via a bus 93. The data processing unit 91 may be, for example, an arithmetic processing device such as a CPU (Central Processor Unit). The storage unit 92 may include a non-transitory storage unit (e.g., a ROM (Read Only Memory) or a hard disk) 921 and a temporary storage unit (e.g., a RAM (Random Access Memory)) 922. The non-transitory storage unit 921 may store, for example, a program that defines the processing to be performed by the control unit 90. The data processing unit 91 executes this program, allowing the control unit 90 to perform the processing defined in the program. Of course, some or all of the processing performed by the control unit 90 may be performed by hardware such as a dedicated logic circuit.

[0099] Note that a storage unit other than the storage unit 92 may be connected to the control unit 90. The various information stored in the storage unit 92 may be stored in the other storage unit.

[0100] <Normal operation> Next, an example of normal operation of the substrate processing apparatus 100 will be outlined. The normal operation here refers to the operation of the substrate processing apparatus 100 processing a substrate W. Here, it is assumed that, during normal operation, the first valve 404, the second valve 405, the secondary circulation valve 412, and the first filter circulation valve 422 are always open, and the first liquid delivery unit 31 and the first heater 32 are always operating. As a result, the processing liquid in the first tank 21a circulates through the outer main circulation piping 40, the outer secondary circulation piping 41, and the first filter circulation piping 42, and the temperatures of the processing liquid in the first tank 21a, the outer main circulation piping 40, the outer secondary circulation piping 41, and the first filter circulation piping 42 are maintained within a specified temperature range. Furthermore, since the circulating processing liquid passes through the first filter 33, the impurity concentration of the processing liquid can also be reduced.

[0101] When a substrate W is carried into the processing unit 10 from the center robot CR, the substrate holder 12 holds the substrate W in a horizontal position. The substrate holder 12 rotates the substrate W, and the unit liquid supply valve 34 opens, causing the nozzle 13 to eject the processing liquid toward the main surface of the rotating substrate W. The processing liquid that has landed on the main surface of the substrate W flows outward over the main surface of the substrate W due to centrifugal force and is scattered from the periphery of the substrate W. The processing liquid acts on the main surface of the substrate W, thereby processing the substrate W.

[0102] The processing liquid splashed from the periphery of the substrate W is received by the guard 14 and guided to the upstream end of the recovery pipe 22. Here, the recovery valve 23 is open, and the processing liquid flows into the first tank 21a through the recovery pipe 22. As a result, a portion of the processing liquid supplied to the processing unit 10 is recovered into the first tank 21a through the recovery pipe 22.

[0103] When the processing of the substrate W is completed, the control unit 90 closes the unit liquid supply valve 34. This stops the discharge of the processing liquid from the nozzle 13 onto the substrate W. Thereafter, the processing unit 10 supplies other processing liquids to the substrate W as needed, and performs various processes on the substrate W. Thereafter, the processing unit 10 performs a drying process on the substrate W. For example, the substrate holder 12 increases the rotation speed to perform a spin drying process on the substrate W. This completes the processing of the substrate W. Then, the center robot CR unloads the processed substrate W from the processing unit 10, and the next substrate W is loaded into the processing unit 10. Thereafter, the same operations are repeated.

[0104] In the above example, a portion of the processing liquid supplied to the processing unit 10 is recovered into the first tank 21a through the recovery pipe 22. The processing liquid recovered from the processing unit 10 may contain impurities due to the processing of the substrate W, or the concentrations of components necessary for the processing may be reduced. In other words, the recovered processing liquid is deteriorated compared to the processing liquid before recovery. Then, as the processing liquid is repeatedly supplied to the processing unit 10, the degree of deterioration of the processing liquid in the first tank 21a increases.

[0105] <Replacing the processing solution> Therefore, in the substrate processing apparatus 100, an exchange process is performed to exchange the old processing liquid in the first tank 21a with a new processing liquid (corresponding to a replacement liquid). Here, as will be described in detail later, not only the old processing liquid in the first tank 21a but also the old processing liquid in the outer main circulation pipe 40 and the branch circulation pipe 413 is exchanged with the new processing liquid. The new processing liquid here is, for example, a processing liquid that has not yet been used to process a substrate W.

[0106] The replacement process is performed, for example, when the number of processed substrates W since the previous replacement process reaches or exceeds a predetermined number. Alternatively, the replacement process may be performed when a predetermined period of time has elapsed since the previous replacement process. The conditions for performing the replacement process may be changed as appropriate.

[0107] 5 is a flowchart showing an example of a processing liquid replacement process according to the first embodiment, and FIG. 6 is a timing chart showing an example of a processing liquid replacement process according to the first embodiment. Here, as an example, during the replacement process, the unit liquid supply valve 34 is always closed, and the supply unit 20 does not supply processing liquid to the processing unit 10. Also, initially, the first liquid delivery unit 31 and the first heater 32 are not operating, the tank liquid supply valve 62 is closed, and the first valve 404 and the second valve 405 are open. For simplicity of explanation, the following description will focus on the configuration corresponding to one processing unit 10.

[0108] First, the supply unit 20 drains the processing liquid from the first tank 21a (step S1: first tank draining step). FIG. 7 is a diagram for explaining the first tank draining step. The supply unit 20 drains the old processing liquid from the first tank 21a through the first tank draining pipe 80 while maintaining a filled state in which at least a portion of the inside of the outer main circulation pipe 40 and the branch circulation pipe 413 is filled with the old processing liquid. As a more specific example, after closing the first valve 404 and the second valve 405, the control unit 90 opens the first tank draining valve 802 and activates the first liquid delivery unit 31.

[0109] By closing the first valve 404 and the second valve 405, the old processing liquid in the outer main circulation pipe 40 and the branch circulation pipe 413 between the first valve 404 and the second valve 405 comes to a standstill. Therefore, the old processing liquid fills the outer main circulation pipe 40 and the branch circulation pipe 413 between the first valve 404 and the second valve 405. In FIG. 7, this state is schematically shown by a thick line. This also applies to the other drawings referred to below.

[0110] Meanwhile, when the first tank drain valve 802 opens and the first liquid supply unit 31 operates, the old processing liquid in the first tank 21a flows into the drain tank 83 through the first tank drain pipe 80. In FIG. 7, the flow of the processing liquid is schematically indicated by dashed block arrows. This also applies to the other drawings referenced below. As the processing liquid in the first tank 21a flows into the first tank drain pipe 80, the amount of processing liquid stored in the first tank 21a decreases over time.

[0111] As an example, the supply unit 20 terminates the tank draining process when the amount of old processing liquid stored in the first tank 21a becomes smaller than the first specified amount. For example, the supply unit 20 performs the tank draining process until the stored amount becomes almost zero. This allows almost all of the old processing liquid in the first tank 21a to be drained. As a specific example, the control unit 90 closes the first tank draining valve 802 and stops the operation of the first liquid delivery unit 31 when a predetermined first tank draining time has elapsed since the first liquid level sensor 51 detected the liquid level of the processing liquid. The first tank draining time is a time sufficient for the amount of processing liquid stored in the first tank 21a to become almost zero, and is set in advance, for example. The control unit 90 may close the first tank draining valve 802 so that the liquid level of the processing liquid does not reach the first liquid delivery unit 31. In other words, the first tank draining time is set in advance so that the liquid level of the processing liquid does not reach the first liquid delivery unit 31. This makes it possible to avoid the first liquid delivery section 31 from operating in the absence of liquid, and to avoid malfunction of the first liquid delivery section 31.

[0112] The first tank drainage time may be input by the user to the user interface 94. The user interface 94 outputs information about the input first tank drainage time to the control unit 90. The control unit 90 stores the information about the first tank drainage time in, for example, the memory unit 92. This also applies to other set times described later.

[0113] The above-described first tank draining process allows almost all of the old processing liquid to be discharged from the first tank 21a. Meanwhile, since the first valve 404 and the second valve 405 are closed during the first tank draining process, the old processing liquid fills the outer main circulation pipe 40 and the branch circulation pipe 413 at least between the first valve 404 and the second valve 405. In reality, the entire outer main circulation pipe 40 and the branch circulation pipe 413 may be filled with the old processing liquid.

[0114] Next, the supply unit 20 supplies new processing liquid (corresponding to replacement liquid) to the first tank 21a while maintaining the filled state (step S2: first tank liquid supply step). FIG. 8 is a diagram for explaining the first tank liquid supply step. The control unit 90 opens the tank liquid supply valve 62. As a result, new processing liquid from the processing liquid supply source 63 is supplied to the first tank 21a through the tank liquid supply pipe 61. Therefore, the amount of processing liquid stored in the first tank 21a increases over time.

[0115] Here, the supply unit 20 performs the first tank liquid supply step until the amount of processing liquid stored in the first tank 21a becomes equal to or greater than the first required amount necessary for the first filter processing liquid replacement step (step S3) described below. The first required amount will be described in detail later, but here it is assumed to be greater than the amount stored when the first liquid level sensor 51 detects the liquid level. For example, the control unit 90 temporarily terminates the first tank liquid supply step when a predetermined liquid supply setting time has elapsed since the first liquid level sensor 51 detected the liquid level. In other words, the control unit 90 temporarily closes the tank liquid supply valve 62. The liquid supply setting time is preset to a time sufficient to store equal to or greater than the first required amount of processing liquid in the first tank 21a.

[0116] If the first valve 404 and the second valve 405 are closed during this first tank liquid supply step, the old processing liquid is more reliably filled inside the outer main circulation pipe 40 and the branch circulation pipe 413 at least between the first valve 404 and the second valve 405. In other words, the filled state is more reliably maintained.

[0117] Next, while maintaining the filled state, the supply unit 20 replaces the old processing liquid in the first filter 33 with a new processing liquid (step S3: first filter processing liquid replacement step). FIG. 9 is a diagram for explaining the first filter processing liquid replacement step. While keeping the first valve 404 and the second valve 405 closed, the control unit 90 opens the first filter drain valve 822, closes the first filter circulation valve 422, and activates the first liquid delivery unit 31. As a result, the new processing liquid in the first tank 21a flows into the upstream end (i.e., upstream end 30a) of the outgoing pipe 401, pushing the old processing liquid in the flow path from the upstream end 30a to the first filter 33 into the first filter drain pipe 82, and the old processing liquid is discharged from the first filter drain pipe 82 to the drain tank 83.

[0118] As a result, the old treatment liquid in the flow path from the upstream end 30a to the first filter 33 is replaced with the new treatment liquid, successively from the upstream side. When almost all of the old treatment liquid has been discharged from the first filter 33, the new treatment liquid then flows from the first filter 33 into the first filter drain pipe 82. As a result, the old treatment liquid in the flow path from the upstream end 30a to the first filter 33 can be replaced with the new treatment liquid. In other words, the flow path from the upstream end 30a to the first filter 33 is filled with the new treatment liquid.

[0119] The control unit 90 closes the first filter drain valve 822 to terminate the first filter treatment liquid replacement process when a predetermined filter setting time has elapsed since the start of the first filter treatment liquid replacement process. This filter setting time is set in advance to a time sufficient for new treatment liquid to pass through the first filter 33 and flow into the first filter drain pipe 82. As a specific example, the filter setting time may be set so that the product of the flow rate of the treatment liquid by the first liquid delivery unit 31 and the filter setting time is equal to or greater than the capacity of the flow path from the upstream end 30a to the first filter 33.

[0120] As described above, in the first filter treatment liquid replacement process, new treatment liquid in the first tank 21a flows into the upstream end 30a and pushes out the old treatment liquid in the flow path from the upstream end 30a to the first filter 33 into the first filter drain pipe 82. Therefore, the immediately preceding first tank liquid supply process is preferably performed so that a first required amount of treatment liquid capable of pushing out the old treatment liquid is stored in the first tank 21a. The first required amount is, for example, an amount such that the liquid level of the new treatment liquid does not reach the first liquid delivery section 31, more preferably an amount such that the liquid level is located within the first tank 21a, throughout the entire period of the first filter treatment liquid replacement process. As a specific example, the first required amount is equal to or greater than the sum of the volume of the internal flow path of the feed pipe 401 from the upstream end 30a to the inlet of the first filter 33 and the volume of the internal space of the first filter 33.

[0121] If the first valve 404 and the second valve 405 are closed even during this first filter treatment liquid replacement process, the old treatment liquid is more reliably filled inside the outer main circulation pipe 40 and the branch circulation pipe 413 at least between the first valve 404 and the second valve 405. In other words, the filled state is more reliably maintained.

[0122] Next, the supply unit 20 heats the new processing liquid while maintaining the filled state (step S4: heating circulation process). FIG. 10 is a diagram for explaining the heating circulation process. The control unit 90 opens the first inner circulation valve 432 while keeping the first valve 404 and the second valve 405 closed, operates the first liquid delivery unit 31, and causes the first heater 32 to perform a heating operation. The control unit 90 may also open the first filter circulation valve 422. As a result, the processing liquid in the first tank 21a flows through the first filter circulation pipe 42 and the first inner circulation pipe 43 and returns to the first tank 21a. In other words, the new processing liquid circulates through the first filter circulation pipe 42 and the first inner circulation pipe 43 without passing through the flow path downstream of the first valve 404. The first heater 32 heats the processing liquid during circulation, so the temperatures of the processing liquid in the first tank 21a, the first filter circulation pipe 42, and the first inner circulation pipe 43 rise. The first heater 32 raises the temperature of the processing liquid to, for example, about 40 to 50 degrees Celsius.

[0123] 6, in this heating circulation step (step S4), the control unit 90 opens the tank liquid supply valve 62. This causes the tank liquid supply unit 60 to supply new processing liquid to the first tank 21a. In other words, the first tank liquid supply step is performed in parallel with the heating circulation step. As new processing liquid is supplied to the first tank 21a, the amount of processing liquid stored in the first tank 21a increases over time.

[0124] The tank liquid supply unit 60 may store in the first tank 21a a second required amount or more of new processing liquid required for the next circulating processing liquid replacement step (step S5). The second required amount will be described in detail later. For example, the control unit 90 closes the tank liquid supply valve 62 when a predetermined liquid supply setting time has elapsed since the tank liquid supply valve 62 opened. The liquid supply setting time is preset to a time period that allows the first tank 21a to store at least the second required amount of processing liquid.

[0125] Furthermore, when the temperature of the processing liquid falls within a specified temperature range, the control unit 90 closes the first inner circulation valve 432. The temperature of the processing liquid is measured, for example, by a temperature sensor (not shown), and a signal indicating the measurement result is output to the control unit 90. The control unit 90 controls the first heater 32 based on the measurement value of the temperature sensor, and closes the first inner circulation valve 432 when the measurement value becomes equal to or higher than the specified temperature.

[0126] Next, the supply unit 20 replaces the old processing liquid in the outer main circulation pipe 40 and the branch circulation pipe 413 with a new processing liquid (step S5: circulating processing liquid replacing step: connecting pipe processing liquid replacing step). FIG. 11 is a diagram for explaining the circulating processing liquid replacing step. The control unit 90 opens the first valve 404 and the circulating drain valve 812 and activates the first liquid delivery unit 31. As a result, the heated new processing liquid pushes the old processing liquid in the outer main circulation pipe 40 and the branch circulation pipe 413 into the circulating drain pipe 81. The old processing liquid flows into the drain tank 83 through the circulating drain pipe 81. As a result, the old processing liquid in the outer main circulation pipe 40 and the branch circulation pipe 413 is replaced with the new processing liquid sequentially from the upstream side. When the old processing liquid is discharged from the outer main circulation pipe 40 and the branch circulation pipe 413 into the circulating drain pipe 81, the new processing liquid is also discharged into the circulating drain pipe 81. This allows the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 to be replaced with a new processing liquid.

[0127] The control unit 90 closes the circulating drain valve 812 when a predetermined circulation set time has elapsed since the start of the circulating treatment liquid replacement process. The circulation set time is set in advance to a time sufficient for new treatment liquid to pass through the outer main circulation piping 40 and the branch circulation piping 413 and flow into the circulating drain pipe 81. As a specific example, the circulation set time may be set so that the product of the flow rate of the treatment liquid by the first liquid supply unit 31 and the circulation set time is equal to or greater than the sum of the capacity of the outer main circulation piping 40 between the first filter 33 and the second valve 405 and the capacity of the branch circulation piping 413.

[0128] Next, the supply unit 20 supplies the processing liquid to the first tank 21a while circulating the processing liquid (step S6: heating, circulation, and liquid supply process). FIG. 12 is a diagram for explaining the heating, circulation, and liquid supply process. The control unit 90 opens the second valve 405 and the tank liquid supply valve 62. By opening the tank liquid supply valve 62, new processing liquid is supplied to the first tank 21a from the processing liquid supply source 63. As a result, the amount of processing liquid stored in the first tank 21a increases over time. Furthermore, by opening the first valve 404 and the second valve 405 and operating the first liquid delivery unit 31, the processing liquid in the first tank 21a returns to the first tank 21a through the outer main circulation pipe 40 and the branch circulation pipe 413. The first heater 32 heats the processing liquid during circulation, so that the temperature of the processing liquid in the first tank 21a can be kept within a specified temperature range.

[0129] When the processing liquid in the first tank 21a reaches a specified amount, the control unit 90 closes the tank liquid supply valve 62. For example, when the third liquid level sensor 53 detects the liquid level of the processing liquid, the control unit 90 closes the tank liquid supply valve 62.

[0130] <Advantages of the First Embodiment> As described above, according to this processing liquid replacement process, the old processing liquid in the first tank 21a can be discharged and new processing liquid can be stored in the first tank 21a.

[0131] Moreover, the supply unit 20 is provided with the first tank 21a, the tank supply pipe 61, the tank supply valve 62, the first tank drain pipe 80, the first tank drain valve 802, the outer main circulation pipe 40 and the outer secondary circulation pipe 41 which are examples of connecting pipes, the first valve 404, the first filter 33, the first filter drain pipe 82, the first filter drain valve 822, the first filter return pipe 421, and the first filter circulation valve 422. Therefore, the first tank drain step (step S1), the first tank supply step (step S2), the first filter treatment liquid replacement step (step S3), and the circulating treatment liquid replacement step (step S5) can be performed in this order.

[0132] That is, in the first tank drainage step (step S1), the first tank drainage valve 802 opens, allowing most of the old processing liquid in the first tank 21a to be discharged. The first tank drainage step ends when the liquid level of the old processing liquid does not reach the first liquid delivery unit 31. Preferably, the first tank drainage step ends so that the level of the old processing liquid reaches the same level as the upstream end 30a. As a result, in the next first tank liquid supply step (step S2), the new processing liquid is stored in the first tank 21a, continuous with the level of the old processing liquid. Therefore, gas is less likely to be mixed at the boundary between the old and new processing liquids. Furthermore, malfunctions of the first liquid delivery unit 31 can also be suppressed.

[0133] Then, in the next first filter treatment liquid replacement step (step S3), the first filter drain valve 822 opens, and new treatment liquid pushes the old treatment liquid from the upstream end 30a of the supply pipe 401 to the first filter 33 into the first filter drain pipe 82. This makes it possible to discharge the old treatment liquid and fill the interior with new treatment liquid while suppressing the intrusion of gas into the supply pipe 401 and the first filter 33. Ideally, no gas is mixed into the interior. Furthermore, because new treatment liquid passes through the first filter 33, impurities in the first filter 33 can also be discharged into the first filter drain pipe 82.

[0134] In the above example, in the next heating circulation step (step S4), the first filter circulation valve 422 opens, causing the processing liquid to circulate through the first tank 21a and the first filter circulation pipe 42. This circulation causes the processing liquid to pass through the first filter 33, thereby reducing the impurity concentration of the processing liquid in the first tank 21a.

[0135] In the next circulating processing liquid replacement step (step S5), the first valve 404 and the circulating drain valve 812 are opened, allowing new processing liquid with a low impurity concentration to pass through the cleaner first filter 33 and push the old processing liquid inside the outer main circulation piping 40 and the branch circulation piping 413 into the circulating drain pipe 81. This makes it possible to discharge the old processing liquid and fill the inside of the outer main circulation piping 40 and the branch circulation piping 413 with new processing liquid while suppressing the intrusion of gas and impurities into the inside of the outer main circulation piping 40 and the branch circulation piping 413. Ideally, no gas gets mixed into the inside of the outer main circulation piping 40 and the branch circulation piping 413.

[0136] Therefore, even when the supply unit 20 initially supplies the processing liquid to the processing unit 10 after the processing liquid replacement process, it is possible to supply a cleaner processing liquid to the processing unit 10 while suppressing fluctuations in the flow rate of the processing liquid caused by gas in the piping.

[0137] Moreover, in the above example, the new processing liquid heated by the first heater 32 is used in the circulating processing liquid replacement step (step S5). That is, the processing liquid at a temperature higher than room temperature pushes out the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413. For comparison, consider the case where the new processing liquid at room temperature pushes out the old processing liquid. In this case, the temperature of the old processing liquid drops, and impurities contained in the processing liquid may precipitate due to the temperature drop. If the impurities precipitate, they may remain on the inner walls of the outer main circulation pipe 40 and the branch circulation pipe 413. In contrast, as described above, when the new processing liquid at a high temperature pushes out the old processing liquid, the temperature drop of the old processing liquid can be suppressed, and the precipitation of impurities can be suppressed. Therefore, it is possible to suppress impurities from remaining inside the outer main circulation pipe 40 and the branch circulation pipe 413.

[0138] In the above example, in the circulating heating step (step S4), the circulating processing liquid is heated by the first heater 32. This makes it possible to more reliably keep the temperature of the processing liquid in the first tank 21a within the specified temperature range. This allows new processing liquid at a more appropriate temperature to be used in the circulating processing liquid replacement step.

[0139] In the above example, both the first valve 404 and the second valve 405 are closed during the first tank draining step (step S1), the first tank supplying step (step S2), the first filter-treated liquid replacing step (step S3), and the heating circulation step (step S4) (see FIG. 6). This allows the old treatment liquid to be more reliably stationary inside the outer main circulation pipe 40 and the branch circulation pipe 413 between the first valve 404 and the second valve 405. Therefore, even at the start of the circulating treatment liquid replacing step (step S5), the filled state can be more reliably maintained, and the intrusion of gas during the circulating treatment liquid replacing step can be more reliably suppressed.

[0140] <Flow rate setting> Next, we will explain the flow rate of the treatment liquid delivered by the first liquid delivery unit 31. Hereinafter, the flow rates of the treatment liquid in the first tank discharge step (step S1), first filter treatment liquid replacement step (step S3), heating circulation step (step S4), circulating treatment liquid replacement step (step S5), and heating circulation liquid supply step (step S6) will be referred to as flow rate F1 to flow rate F5, respectively.

[0141] 6, in the first filter treatment liquid replacement step (step S3), the first liquid delivery unit 31 delivers the treatment liquid at a flow rate F2 that is smaller than the flow rate F1 in the first tank drainage step (step S1). The flow rate F1 is set to, for example, about 20 L (liters) / min, and the flow rate F2 is set to, for example, about 10 L / min.

[0142] 3, the upstream end of the first filter drain pipe 82 is connected to the drain port 33c of the first filter 33. The drain port 33c of the first filter 33 may be smaller than the inlet and outlet of the first filter 33. In this case, the diameter of the first filter drain pipe 82 is smaller than the diameter of the forward piping 401. As shown in FIG. 9, in the first filter-treated liquid replacement process, the treatment liquid delivered by the first liquid delivery unit 31 flows through a path that passes through the first filter drain pipe 82, which has a small flow path area, and therefore the pressure of the treatment liquid is likely to increase.

[0143] Therefore, by setting the flow rate F2 smaller than the flow rate F1, it is possible to mitigate the pressure rise during the filtering liquid replacement process, thereby suppressing malfunctions of the first filter 33 or the piping system caused by the pressure rise.

[0144] On the other hand, in the first tank draining step, as shown in Fig. 7, the treatment liquid flows through the first tank draining pipe 80. The flow path area of ​​the first tank draining pipe 80 can be designed to be larger than the area of ​​the drain port 33c, so that an increase in the flow rate of the treatment liquid is unlikely to result in an increase in the pressure of the treatment liquid. Furthermore, by setting the flow rate F1 in the first tank draining step to be larger than the flow rate F2, the old treatment liquid in the first tank 21a can be more quickly discharged through the first tank draining pipe 80.

[0145] 6, the flow rate F3 in the heating circulation step (step S4) is set to be larger than the flow rate F2. The flow rate F3 is set to, for example, about 20 L / min. This allows the temperature in the first tank 21a to be raised to the specified temperature range more quickly during the heating circulation step, while also allowing the impurity concentration of the treatment liquid in the first tank 21a to be reduced more quickly. The flow path areas of the first filter circulation pipe 42 and the first inner circulation pipe 43 can be designed to be larger than the area of ​​the drain port 33c, thereby mitigating pressure increases.

[0146] 6, the flow rate F4 in the circulating treatment liquid replacement step (step S6) is also set to be larger than the flow rate F2. The flow rate F4 is set to, for example, about 20 L / min. This allows the old treatment liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 to be replaced with new treatment liquid more quickly in the circulating treatment liquid replacement step. The flow path areas of the outer main circulation pipe 40 and the branch circulation pipe 413 can be designed to be larger than the area of ​​the drain port 33c, which also reduces pressure increases.

[0147] 6, the flow rate F5 in the heating, circulating, and supplying process (step S5) is set to be greater than all of the flow rates F1 to F4. The flow rate F5 is set to, for example, about 40 L / min. This allows the temperature in the first tank 21a to be raised to a specified temperature range more quickly during the heating, circulating, and supplying process, while also allowing the impurity concentration of the processing liquid in the first tank 21a to be reduced more quickly. Furthermore, because the flow path areas of the outer main circulation pipe 40 and the branch circulation pipe 413 are designed to be large, even if the flow rate F5 is set to be large, an increase in the pressure of the processing liquid is also suppressed.

[0148] <Modification of the method for replacing the processing liquid> The above-described method for replacing the processing liquid is one example, and various modifications are possible as follows.

[0149] 6, the tank liquid supply valve 62 is open in the first tank liquid supply step (step S1), the heating circulation step (step S4), and the heating circulation liquid supply step (step S6), and is closed in the first filter treatment liquid replacement step (step S3) and the circulating treatment liquid replacement step (step S5). However, this is not necessarily limited to this, and the timing of supplying new treatment liquid can be changed as appropriate.

[0150] For example, the tank liquid supply valve 62 may be opened during at least one of the first filtering treatment liquid replacement step (step S3) and the circulating treatment liquid replacement step (step S5). In other words, the first tank liquid supply step may be performed in parallel with these steps.

[0151] When the tank liquid supply valve 62 opens in the first filter treatment liquid replacement step, the new treatment liquid in the first tank 21a is used to push out and discharge the old treatment liquid in the flow path from the upstream end 30a to the first filter 33, while the new treatment liquid is supplied to the first tank 21a. In other words, while the new treatment liquid is discharged from the first tank 21a, the new treatment liquid is replenished from the tank liquid supply unit 60 to the first tank 21a. For this reason, the amount of storage in the first tank 21a at the end of the immediately preceding first tank liquid supply step (step S2) may be smaller than the first required amount.

[0152] In short, the flow rate of the treatment liquid from the tank liquid supply unit 60 and the flow rate F2 of the treatment liquid from the first liquid supply unit 31 should be set so that the liquid level of the new treatment liquid is located upstream of the first liquid supply unit 31, preferably within the first tank 21a, throughout the entire period of the first filter treatment liquid replacement process. In this case, the amount of storage in the first tank 21a at the end of the first tank liquid supply process may be smaller than the first required amount, so that the time required for the first tank liquid supply process can be shortened and the throughput of the replacement process can be improved.

[0153] Similarly, when the tank liquid supply valve 62 opens in the circulating processing liquid replacement step, the new processing liquid is supplied to the first tank 21a while the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 is pushed out and discharged by the new processing liquid. That is, while the new processing liquid is discharged from the first tank 21a, the new processing liquid is replenished to the first tank 21a from the tank liquid supply unit 60. For this reason, the amount of storage in the first tank 21a at the end of the immediately preceding heating circulation step (step S4) may be smaller than the second required amount.

[0154] In short, the flow rate of the processing liquid from the tank liquid supply unit 60 and the flow rate F4 of the processing liquid from the first liquid supply unit 31 should be set so that the liquid level of the new processing liquid is located upstream of the first liquid supply unit 31, preferably within the first tank 21a, throughout the entire period of the circulating processing liquid replacement process. In this case, the amount of storage in the first tank 21a at the end of the heating circulation process may be smaller than the second required amount, which can shorten the time required for the heating circulation process. In other words, the throughput of the replacement process can be improved.

[0155] Alternatively, in the first tank liquid supply step (step S2), the tank liquid supply unit 60 may supply the first tank 21a with a processing liquid amount equal to or greater than the sum of the first required amount and the second required amount. In this case, the control unit 90 may close the tank liquid supply valve 62 in the heating circulation step (step S4).

[0156] 6, the first filter circulation valve 422 and the first filter drainage valve 822 open and close in a complementary manner. However, this is not necessarily limited to this. The first filter circulation valve 422 and the first filter drainage valve 822 may open and close independently of each other. In this case, the first filter circulation valve 422 may be closed during at least one of the first tank drainage step (step S1), the first tank liquid supply step (step S2), the circulating treatment liquid replacement step (step S5), and the heating, circulating, and liquid supply step (step S6).

[0157] Furthermore, in the heating circulation step (step S4), at least one of the first filter circulation valve 422 and the first inner circulation valve 432 may be opened. In the heating circulation step, when the processing liquid flows through at least one of the first filter circulation pipe 42 and the first inner circulation pipe 43, the processing liquid passes through the first heater 32. This makes it possible to keep the processing liquid within a specified temperature range. Of course, when the first filter circulation valve 422 is open, the processing liquid passes through the first filter 33, and therefore the impurity concentration of the processing liquid can also be reduced.

[0158] Incidentally, at the start of the process of replacing the processing liquid, old processing liquid may remain inside the branch liquid supply pipe 302 of the unit liquid supply pipe 30. It is desirable to replace such old processing liquid with new processing liquid.

[0159] Therefore, in the circulating processing liquid replacement step (step S5), supply unit 20 may replace the old processing liquid inside branch liquid supply pipe 302 of unit liquid supply pipe 30 (which corresponds to an example of a connecting pipe) with a new processing liquid. Specifically, control unit 90 may open unit liquid supply valve 34 and recovery valve 23. This allows the new processing liquid to push the old processing liquid inside branch liquid supply pipe 302 into nozzle 13 and be discharged from nozzle 13. The old processing liquid discharged from nozzle 13 is discharged through recovery pipe 22 and circulating liquid drain pipe 81. This allows the old processing liquid inside unit liquid supply pipe 30 and recovery pipe 22 to be replaced with a new processing liquid while suppressing the inflow of gas and impurities into the inside of these pipes.

[0160] <Modification of device configuration> In the example described above, the first filter drain pipe 82 is connected to the drain port 33c of the first filter 33, but this is not necessarily limited to this. Fig. 13 is a diagram schematically showing an example of a piping system including the first filter drain pipe 82. In the example of Fig. 13, the upstream end of the first filter return pipe 421 is connected to the outer main circulation piping 40 (specifically, the forward piping 401) between the outlet of the first filter 33 and the first valve 404. In addition, the upstream end 82a of the first filter drain pipe 82 is connected to the forward piping 401 between the outlet of the first filter 33 and the first valve 404.

[0161] Even with this structure, when the first filter drain valve 822 is opened in the first filter treatment liquid replacement step, the old treatment liquid in the flow path from the upstream end 30a to the first filter 33 is pushed into the first filter drain pipe 82 by the new treatment liquid in the first tank 21a. This allows the old treatment liquid in the flow path to be replaced with the new treatment liquid. Therefore, in the subsequent circulating treatment liquid replacement step, the new treatment liquid passes through the cleaner first filter 33 and pushes out the old treatment liquid from inside the outer main circulation pipe 40 and the branch circulation pipe 413. This reduces the possibility of impurities remaining inside the outer main circulation pipe 40 and the branch circulation pipe 413.

[0162] Furthermore, even with this structure, when the first filter circulation valve 422 is opened during the heating circulation step, the processing liquid in the first tank 21a returns to the first tank 21a through the first filter circulation piping 42. Because the processing liquid passes through the first filter 33 during circulation, the concentration of impurities contained in the processing liquid can be reduced. Therefore, during the next circulating processing liquid supply step, the cleaner processing liquid pushes out the old processing liquid inside the outer main circulation piping 40 and the branch circulation piping 413. This makes it possible to further reduce impurities remaining inside the outer main circulation piping 40 and the branch circulation piping 413.

[0163] The upstream end 82a of the first filter drain pipe 82 may be connected to a portion of the supply pipe 401 between the outlet of the first filter 33 and the first valve 404, or to a portion of the first filter return pipe 421 between the supply pipe 401 and the first filter circulation valve 422. In the example of Fig. 13, the connectable destinations of the upstream end 82a of the first filter drain pipe 82 are schematically shown by thick lines.

[0164] <Second embodiment> FIG. 14 is a diagram schematically illustrating an example of the configuration of a substrate processing apparatus 100 according to a second embodiment. FIG. 14 illustrates a configuration corresponding to one processing unit 10. In the second embodiment, a supply unit 20 includes a first tank 21a and a second tank 21b. The second tank 21b stores a processing liquid and supplies the processing liquid to the first tank 21a through a tank supply pipe 44. An upstream end 44a of the tank supply pipe 44 is connected to, for example, the bottom of the second tank 21b, and a downstream end 44b of the tank supply pipe 44 is connected to, for example, the ceiling of the first tank 21a. That is, the upstream end 44a of the tank supply pipe 44 opens into the second tank 21b, and the downstream end 44b of the tank supply pipe 44 opens into the first tank 21a.

[0165] A second liquid supply unit 37 and a tank liquid supply valve 442 are inserted in the tank liquid supply pipe 44. The second liquid supply unit 37 is a drive mechanism, such as a pump, that causes the processing liquid to flow from the second tank 21b toward the first tank 21a. The tank liquid supply valve 442 is provided downstream of the second liquid supply unit 37. The tank liquid supply valve 442 switches the tank liquid supply pipe 44 between open and closed states. The tank liquid supply pipe 44 and the tank liquid supply valve 442 in the second embodiment correspond to the first tank liquid supply pipe and the first tank liquid supply valve 62 in the tenth to twelfth aspects in the section on Means for Solving the Problems, respectively.

[0166] In the example of FIG. 14 , a second heater 38 and a second filter 39 are also provided in the tank liquid supply pipe 44. The second heater 38 has a heat source such as a thermocouple and heats the treatment liquid flowing inside the tank liquid supply pipe 44. In the example of FIG. 14 , two second heaters 38 are provided in the tank liquid supply pipe 44, but one second heater 38 or three or more second heaters 38 may be provided. In the example of FIG. 14 , the second heater 38 is provided between the second filter 39 and the second liquid delivery unit 37. The second filter 39 captures impurities contained in the treatment liquid. This reduces the impurity concentration in the treatment liquid downstream of the second filter 39.

[0167] 14, the downstream end of the outer main circulation pipe 40 is connected to the second tank 21b. That is, the downstream end of the outer main circulation pipe 40 opens into the second tank 21b. The first tank 21a, the outer main circulation pipe 40, the second tank 21b, and the tank liquid supply pipe 44 form a circulation path through which the treatment liquid circulates.

[0168] Tank liquid supply unit 60 supplies new processing liquid to second tank 21b. In the example of Fig. 14, the downstream end of tank liquid supply pipe 61 is connected to, for example, the ceiling of second tank 21b. In other words, the downstream end of tank liquid supply pipe 61 opens inside second tank 21b. Note that tank liquid supply pipe 61 and tank liquid supply valve 62 in the second embodiment correspond to second tank liquid supply pipe and second tank liquid supply valve 62 in the tenth to twelfth aspects in the section of Means for Solving the Problems, respectively.

[0169] In the example of FIG. 14, a circulation pipe 45, a second filter circulation pipe 46, and a second inner circulation pipe 47 are also provided.

[0170] The circulation pipe 45 includes a return pipe 451. The return pipe 451 is a pipe for returning the processing liquid that has passed through the second filter 39 to the second tank 21b. In the example of FIG. 14, the upstream end of the return pipe 451 is connected to the tank supply pipe 44 between the second filter 39 and the tank supply valve 442. The downstream end of the return pipe 451 is connected to, for example, the ceiling part of the second tank 21b. In other words, the downstream end of the return pipe 451 opens inside the second tank 21b. The circulation pipe 45 is made up of a part of the tank supply pipe 44 and the return pipe 451. A circulation valve 452 is inserted in the return pipe 451. The circulation valve 452 switches the return pipe 451 between opening and closing.

[0171] The second filter circulation pipe 46 includes a second filter return pipe 461. The second filter return pipe 461 is a pipe for returning the treated liquid that passes through the second filter 39 to the second tank 21b. In the example of FIG. 14, the second filter 39 has a drain port 39c, and the upstream end of the second filter return pipe 461 is connected to the drain port 39c of the second filter 39. The drain port 39c is an opening for discharging the treated liquid from inside the housing of the second filter 39. The internal space of the housing of the second filter 39 is partitioned by the filter body into an outlet space and an inlet space, and the drain port 39c may open to either the outlet space or the inlet space. In this example, the drain port 39c is assumed to open to the outlet space.

[0172] The downstream end of the second filter return pipe 461 is connected to, for example, the ceiling of the second tank 21b and opens into the second tank 21b. The second filter circulation pipe 46 is made up of a part of the tank liquid supply pipe 44, the second filter 39, and the second filter return pipe 461. A second filter circulation valve 462 is inserted in the second filter return pipe 461. The second filter circulation valve 462 switches the second filter return pipe 461 between open and closed states.

[0173] The second inner circulation pipe 47 includes a second inner return pipe 471. The second inner return pipe 471 is a pipe for returning the processing liquid that has passed through the second heater 38 to the second tank 21b before passing through the second filter 39. The second inner return pipe 471 branches off from the tank supply pipe 44 between the second heater 38 and the second filter 39 and returns to the second tank 21b. That is, the upstream end of the second inner return pipe 471 is connected to a portion of the tank supply pipe 44 between the second heater 38 and the second filter 39, and the downstream end of the second inner return pipe 471 is connected to, for example, the ceiling of the second tank 21b. The downstream end of the second inner return pipe 471 opens inside the second tank 21b. The second inner circulation pipe 47 is composed of a portion of the tank supply pipe 44 and the second inner return pipe 471. A second inner circulation valve 472 is inserted in the second inner return pipe 471. The second inner circulation valve 472 switches the second inner return pipe 471 between open and closed states.

[0174] In the example of FIG. 14, a second tank drain pipe 84 and a second filter drain pipe 85 are provided. The second tank drain pipe 84 is a pipe for discharging the processing liquid in the second tank 21b. In the example of FIG. 14, a portion of the second tank drain pipe 84 also serves as a portion of the tank supply pipe 44. Specifically, the second tank drain pipe 84 is composed of a portion of the tank supply pipe 44 and a branch drain pipe 841 branching from the tank supply pipe 44. The upstream end of the branch drain pipe 841 is connected to the middle of the tank supply pipe 44, in the example of FIG. 14, to a portion between the second heater 38 and the inlet of the second filter 39. The downstream end of the branch drain pipe 841 is connected to the drain tank 83. A second tank drain valve 842 is inserted in the branch drain pipe 841. The second tank drain valve 842 switches the branch drain pipe 841 between open and closed states.

[0175] The second filter drain pipe 85 is a pipe for discharging the treated liquid from the second filter 39. In the example of FIG. 14, a portion of the second filter drain pipe 85 also serves as a portion of the second filter return pipe 461. That is, the second filter drain pipe 85 is composed of a portion of the second filter return pipe 461 and a branch drain pipe 851 branching from the second filter return pipe 461. The branch drain pipe 851 is connected midway through the second filter return pipe 461, in the example of FIG. 14, to a portion between the drain port 39c of the second filter 39 and the second filter circulation valve 462. The downstream end of the branch drain pipe 851 is connected to the drain tank 83. A second filter drain valve 852 is inserted into the branch drain pipe 851. The second filter drain valve 852 switches the branch drain pipe 851 between open and closed states.

[0176] In the example of FIG. 14, a sensor 55 is provided in the second tank 21b. The sensor 55 is a sensor for detecting the amount of processing liquid stored in the second tank 21b. As a specific example, the sensor 55 includes a liquid level sensor. The liquid level sensor is also called a level sensor. The liquid level sensor may be, for example, a float-type level sensor or a capacitance-type level sensor. In the example of FIG. 14, the sensor 55 includes a first liquid level sensor 56, a second liquid level sensor 57, and a third liquid level sensor 58. The first liquid level sensor 56, the second liquid level sensor 57, and the third liquid level sensor 58 are similar to the first liquid level sensor 51, the second liquid level sensor 52, and the third liquid level sensor 53, respectively.

[0177] 14, one first heater 32 is provided. In this case, the amount of heat per unit time that one first heater 32 imparts to the processing liquid in the supply pipe 401 is smaller than the amount of heat per unit time that two second heaters 38 impart to the processing liquid in the tank liquid supply pipe 44.

[0178] <Replacing the processing solution> 15 is a flowchart showing an example of a processing liquid replacement process according to the second embodiment, and FIG. 16 is a timing chart showing an example of a processing liquid replacement process according to the second embodiment. Here, as an example, during the replacement process, the unit liquid supply valve 34 is always closed, and the supply unit 20 does not supply the processing liquid to the processing unit 10. Also, initially, the first liquid supply unit 31, the second liquid supply unit 37, the first heater 32, and the second heater 38 are not operating, the tank liquid supply valve 62 is closed, and the first valve 404 and the second valve 405 are open. For simplicity of explanation, the following description will focus on the configuration corresponding to one processing unit 10.

[0179] First, the supply unit 20 drains the processing liquid from the second tank 21b (step S10: second tank draining step). FIG. 17 is a diagram for explaining the second tank draining step. The supply unit 20 drains the old processing liquid from the second tank 21b through the second tank draining pipe 84 while maintaining a filled state in which at least a portion of the inside of the outer main circulation pipe 40 and the branch circulation pipe 413 is filled with the old processing liquid. As a more specific example, after closing the first valve 404 and the second valve 405, the control unit 90 opens the second tank draining valve 842 and activates the second liquid delivery unit 37.

[0180] Closing the first valve 404 and the second valve 405 stops the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 between the first valve 404 and the second valve 405. Therefore, the old processing liquid fills the inside of the outer main circulation pipe 40 and the branch circulation pipe 413 between the first valve 404 and the second valve 405. Here, the first valve 404 is closed until the start of a circulating processing liquid replacement step (corresponding to step S15: connecting pipe processing liquid replacement step) described below, and the second valve 405 is closed until the start of a heating, circulating, and liquid supply step (step S16) described below.

[0181] On the other hand, when the second tank drain valve 842 opens and the second liquid delivery unit 37 operates, the old processing liquid in the second tank 21b flows into the drain tank 83 through the second tank drain pipe 84. As a result, the amount of processing liquid stored in the second tank 21b decreases over time.

[0182] As an example, the supply unit 20 terminates the second tank draining process when the amount of old processing liquid stored in the second tank 21b becomes smaller than the first specified amount. For example, the supply unit 20 performs the second tank draining process until the stored amount becomes almost zero. This allows almost all of the old processing liquid in the second tank 21b to be drained. As a specific example, the control unit 90 closes the second tank draining valve 842 and stops the operation of the second liquid delivery unit 37 when a predetermined second tank draining time has elapsed since the first liquid level sensor 56 detected the liquid level of the processing liquid. The second tank draining time is a time sufficient for the amount of processing liquid stored in the second tank 21b to become almost zero, and is set in advance, for example. The control unit 90 may close the second tank draining valve 842 so that the liquid level of the processing liquid does not reach the second liquid delivery unit 37. In other words, the second tank draining time is set in advance so that the liquid level of the processing liquid does not reach the second liquid delivery unit 37.

[0183] Next, the supply unit 20 discharges the old processing liquid from the first tank 21a, while the tank supply unit 60 supplies new processing liquid (corresponding to the replacement liquid) to the second tank 21b (step S11: first tank drainage and second tank supply process). FIG. 18 is a diagram for explaining the first tank drainage and second tank supply process. The control unit 90 opens the first tank drainage valve 802 and the tank supply valve 62 and activates the first liquid delivery unit 31. As a result, the old processing liquid in the first tank 21a flows into the drain tank 83 through the first tank drainage pipe 80, as in the first embodiment. Here, as in the first embodiment, the supply unit 20 performs the first tank drainage process until the storage volume becomes almost zero. As a result, almost all of the old processing liquid in the first tank 21a can be discharged.

[0184] Furthermore, when the tank supply valve 62 is opened, new processing liquid is supplied from the processing liquid supply source 63 to the second tank 21b through the tank supply pipe 61. As a result, the amount of processing liquid stored in the second tank 21b increases over time.

[0185] The supply unit 20 performs the second tank liquid supply step until the amount of processing liquid stored in the second tank 21b becomes equal to or greater than a third required amount necessary for the second filter processing liquid replacement step (step S12) described below. The third required amount will be described in detail later, but here it is assumed to be greater than the amount stored when the first liquid level sensor 56 detects the liquid level. For example, the control unit 90 executes the next second filter processing liquid replacement step (step S13) when a predetermined second liquid supply setting time has elapsed since the first liquid level sensor 56 detected the liquid level. The second liquid supply setting time is preset to a time sufficient to store equal to or greater than the third required amount of processing liquid in the second tank 21b.

[0186] 19 is a diagram illustrating the second filter treatment liquid replacement process. The control unit 90 opens the second filter drain valve 852 and activates the second liquid delivery unit 37. This causes new treatment liquid in the second tank 21b to flow into the upstream end 44a of the tank supply pipe 44, pushing out the old treatment liquid in the flow path from the upstream end 44a to the second filter 39 into the second filter drain pipe 85. This causes the old treatment liquid to flow into the drain tank 83 through the second filter drain pipe 85. After the old treatment liquid is discharged from the second filter 39, new treatment liquid then flows from the second filter 39 into the second filter drain pipe 85. This allows the old treatment liquid in the second filter 39 to be replaced with new treatment liquid.

[0187] The control unit 90 closes the second filter drain valve 852 to terminate the second filter treatment liquid replacement process when a specified second filter setting time has elapsed since the start of the second filter treatment liquid replacement process. This second filter setting time is preset to a time sufficient for new treatment liquid to pass through the second filter 39 and flow into the second filter drain pipe 85.

[0188] As described above, in the second filter treatment liquid replacement step, new treatment liquid in the second tank 21b flows into the upstream end 44a and pushes out the old treatment liquid in the flow path from the upstream end 44a to the second filter 39 into the second filter drain pipe 85. Therefore, the immediately preceding second tank liquid supply step (step S11) is preferably performed so that a third required amount of treatment liquid capable of pushing out the old treatment liquid is stored in the second tank 21b. The third required amount is an amount such that the liquid level of the new treatment liquid does not reach the second liquid delivery section 37, more preferably an amount such that the liquid level is located within the second tank 21b, throughout the entire period of the second filter treatment liquid replacement step.

[0189] 16, during the second filter treatment liquid replacement process, the tank supply valve 62 is open, and therefore the tank supply unit 60 continues to supply new treatment liquid to the second tank 21b. In this case, the flow rate of the treatment liquid by the second liquid delivery unit 37 is preferably set to a value such that the liquid level of the new treatment liquid does not reach the second liquid delivery unit 37, more preferably, is located within the second tank 21b, throughout the entire period of the second filter treatment liquid replacement process.

[0190] 16, the first tank drain valve 802 closes at the same time as the second filter drain valve 852 opens. That is, the draining of the processing liquid from the first tank 21a and the supplying of the processing liquid to the second tank 21b are completed at the same time. However, in reality, these may be delayed. If the draining of the processing liquid from the first tank 21a is not yet complete when the third required amount of processing liquid is stored in the second tank 21b, the supply unit 20 may perform the next second filter processing liquid replacement process without waiting for the completion of the draining of the processing liquid from the first tank 21a.

[0191] When the drainage from the first tank 21a (first tank drainage step) and the second filter treatment liquid replacement step are completed, the supply unit 20 supplies new treatment liquid from the second tank 21b to the first tank 21a (step S13: first tank liquid supply step). FIG. 20 is a diagram for explaining the first tank liquid supply step. The control unit 90 opens the tank liquid supply valve 442 and activates the second liquid delivery unit 37. As a result, the new treatment liquid in the second tank 21b is supplied to the first tank 21a through the tank liquid supply pipe 44.

[0192] The previous second filter treatment liquid replacement process has already discharged the old treatment liquid in the flow path from the upstream end 44a to the second filter 39, so it is possible to prevent this old treatment liquid from being supplied to the first tank 21a. Furthermore, the new treatment liquid from the second tank 21b passes through the cleaner second filter 39, so that new treatment liquid with fewer impurities can be supplied to the first tank 21a.

[0193] 16, in the first tank liquid supply step, the tank liquid supply valve 62 is open, and therefore the tank liquid supply unit 60 continues to supply new processing liquid to the second tank 21b. In this case, the flow rate of the processing liquid to the second tank 21b and the flow rate of the processing liquid by the second liquid delivery unit 37 are preferably set to values ​​such that the liquid level of the new processing liquid does not reach the second liquid delivery unit 37, more preferably, is located within the second tank 21b, throughout the entire period of the first tank liquid supply step.

[0194] 16, the control unit 90 controls the second heater 38 to perform a heating operation in the first tank liquid supply step. As a result, the processing liquid heated by the second heater 38 and having a temperature higher than room temperature is supplied to the first tank 21a.

[0195] The supply unit 20 performs the first tank liquid supply step until the amount of processing liquid stored in the first tank 21a becomes equal to or greater than a fourth required amount necessary for the first filter processing liquid replacement step (step S14) described below. The fourth required amount will be described in detail later, but here it is assumed to be greater than the amount stored when the first liquid level sensor 51 detects the liquid level. For example, the control unit 90 executes the next first filter processing liquid replacement step (step S14) when a predetermined first liquid supply setting time has elapsed since the first liquid level sensor 51 detected the liquid level. The first liquid supply setting time is preset to a time sufficient to store equal to or greater than the fourth required amount of processing liquid in the first tank 21a.

[0196] 21 is a diagram illustrating the first filter treatment liquid replacement process. The control unit 90 opens the first filter drain valve 822 and activates the first liquid delivery unit 31. This causes new treatment liquid in the first tank 21a to flow into the upstream end 30a of the unit liquid supply pipe 30, pushing the old treatment liquid in the flow path from the upstream end 30a to the first filter 33 into the first filter drain pipe 82 and discharging it through the first filter drain pipe 82 into the drain tank 83. After the old treatment liquid is discharged from the first filter 33, new treatment liquid then flows from the first filter 33 into the first filter drain pipe 82. This allows the old treatment liquid in the first filter 33 to be replaced with new treatment liquid.

[0197] Moreover, in the above example, the second heater 38 heats the treatment liquid in the immediately preceding first tank liquid supply step. As a result, in the first filter treatment liquid replacement step, the heated high-temperature treatment liquid pushes out the old treatment liquid in the flow path from the upstream end 30a to the first filter 33. Therefore, it is possible to suppress the precipitation of impurities in the old treatment liquid due to low temperatures.

[0198] The control unit 90 closes the first filter drain valve 822 to terminate the first filter treatment liquid replacement process when a specified first filter setting time has elapsed since the start of the first filter treatment liquid replacement process. This first filter setting time is set to a time sufficient for new treatment liquid to pass through the first filter 33 and flow into the first filter drain pipe 82.

[0199] As described above, in the first filter treatment liquid replacement process, new treatment liquid in the first tank 21a flows into the upstream end 30a and pushes out the old treatment liquid in the flow path from the upstream end 30a to the first filter 33 into the first filter drain pipe 82. Therefore, the immediately preceding first tank liquid supply process is preferably carried out so that a fourth required amount of treatment liquid capable of pushing out the old treatment liquid is stored in the first tank 21a. The fourth required amount is an amount such that the liquid level of the new treatment liquid does not reach the first liquid delivery section 31, more preferably an amount such that the liquid level is located within the first tank 21a, throughout the entire period of the first filter treatment liquid replacement process.

[0200] 16, during the first filter treatment liquid replacement process, the tank supply valve 62 and the tank supply valve 442 are open, so that the tank supply unit 60 continues to supply new treatment liquid to the second tank 21b and from the second tank 21b to the first tank 21a. In this case, the flow rate of the treatment liquid by the first liquid delivery unit 31 is preferably set to a value such that the liquid level of the new treatment liquid does not reach the first liquid delivery unit 31, more preferably such that the liquid level is located within the first tank 21a, throughout the entire period of the first filter treatment liquid replacement process. The same applies to the flow rate by the second liquid delivery unit 37.

[0201] Next, the supply unit 20 replaces the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 with a new processing liquid (step S15: circulating processing liquid replacing step). FIG. 22 is a diagram for explaining the circulating processing liquid replacing step. The control unit 90 opens the first valve 404 and the circulation drain valve 812 and activates the first liquid delivery unit 31. As a result, the new processing liquid that has passed through the cleaner first filter 33 pushes the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 into the circulation drain pipe 81 and is discharged through the circulation drain pipe 81 to the drain tank 83. Therefore, the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 can be replaced with a new processing liquid while suppressing the inflow of gas and impurities into the inside of the outer main circulation pipe 40 and the branch circulation pipe 413.

[0202] In the circulating processing liquid replacement step, the control unit 90 may also cause the first heater 32 to perform a heating operation. This allows the high-temperature new processing liquid heated by the first heater 32 and the second heater 38 to push out the old processing liquid inside the outer main circulation piping 40 and the branch circulation piping 413. This makes it difficult for impurities in the old processing liquid to precipitate due to low temperatures, thereby reducing the possibility of impurities remaining inside the outer main circulation piping 40 and the branch circulation piping 413.

[0203] 16, during the circulating processing liquid replacement process, the tank supply valve 62 and the tank supply valve 442 are open. Therefore, the supply of new processing liquid to the first tank 21a and the second tank 21b continues. In this case, the flow rate of the first liquid delivery unit 31 is set to a level that does not allow the liquid level of the processing liquid to reach the first liquid delivery unit 31, preferably to a level that allows the liquid level to be located within the first tank 21a. The same applies to the flow rate of the second liquid delivery unit 37.

[0204] The control unit 90 closes the circulation drain valve 812 when a predetermined circulation set time has elapsed since the start of the circulating treatment liquid replacement process. The circulation set time is preset to a time sufficient for new treatment liquid to pass through the outer main circulation piping 40 and the branch circulation piping 413 and flow into the circulation drain pipe 81.

[0205] Next, the supply unit 20 circulates the processing liquid and supplies it to the second tank 21b (step S16: heating, circulation, and supply step). FIG. 23 is a diagram illustrating the heating, circulation, and supply step. The control unit 90 opens the second valve 405. The first valve 404, the second valve 405, and the tank supply valve 442 are opened, and the first liquid supply unit 31 and the second liquid supply unit 37 are operated, so that the processing liquid in the first tank 21a returns to the first tank 21a via the outer main circulation pipe 40, the branch circulation pipe 413, the second tank 21b, and the tank supply pipe 44. The first heater 32 and the second heater 38 heat the processing liquid during circulation, so that the temperatures of the processing liquid in the first tank 21a and the second tank 21b can be kept within a specified temperature range.

[0206] Furthermore, by opening the tank liquid supply valve 62, new processing liquid is supplied to the second tank 21b from the processing liquid supply source 63. The first liquid supply unit 31 and the second liquid supply unit 37 send out the processing liquid at an appropriately set flow rate, thereby circulating the processing liquid so that the amount of processing liquid stored in the first tank 21a and the second tank 21b reaches a specified amount, respectively. When the amount of processing liquid stored in the first tank 21a and the second tank 21b reaches a specified amount, respectively, the control unit 90 closes the tank liquid supply valve 62.

[0207] <Advantages of the second embodiment> As described above, according to this processing liquid replacement process, the old processing liquid can be discharged from the first tank 21a and the second tank 21b, and new processing liquid can be stored in the first tank 21a and the second tank 21b.

[0208] In the above example, after new processing liquid is supplied to the second tank 21b in the second tank liquid supply step (step S11), in the second filter processing liquid replacement step (step S12), the new processing liquid in the second tank 21b pushes out the old processing liquid in the flow path from the upstream end 44a to the second filter 39 into the second filter drain pipe 85. Therefore, the old processing liquid in the flow path from the upstream end 44a to the second filter 39 can be replaced with the new processing liquid while suppressing the intrusion of gas.

[0209] Then, after the second filter treatment liquid replacement step, a first tank liquid supply step (step S13) is performed. This makes it possible to prevent old treatment liquid in the flow path from the upstream end 44a to the second filter 39 from being supplied to the first tank 21a. Furthermore, new treatment liquid passes through the cleaner second filter 39 and is supplied to the first tank 21a. Therefore, a cleaner treatment liquid can be supplied to the first tank 21a.

[0210] In the above example, new processing liquid heated by the second heater 38 is supplied to the first tank 21a in the first tank liquid supply step. As a result, in the next first filter processing liquid replacement step (step S14), the heated high-temperature processing liquid pushes out the old processing liquid in the flow path from the upstream end 30a to the first filter 33. Therefore, it is possible to suppress the intrusion of gas and also to suppress the precipitation of impurities in the old processing liquid due to low temperatures.

[0211] Then, in the circulating processing liquid replacement step (step S15), the high-temperature new processing liquid that has passed through the clean first filter 33 pushes the old processing liquid inside the outer main circulation piping 40 and the branch circulation piping 413 into the circulation drain pipe 81. This makes it possible to replace the old processing liquid inside the outer main circulation piping 40 and the branch circulation piping 413 with a new, cleaner processing liquid while suppressing the inclusion of gas and the remaining impurities.

[0212] In the above example, the supply of new processing liquid to the second tank 21b and the discharge of old processing liquid from the first tank 21a are carried out in parallel (step S11), thereby improving the throughput of the processing liquid replacement process.

[0213] In the above example, both the first valve 404 and the second valve 405 are closed during the second tank draining step (step S10), the first tank draining and second tank supplying step (step S11), the second filter-treated liquid replacing step (step S12), the first tank supplying step (step S13), and the first filter-treated liquid replacing step (step S14) (see FIG. 16). This makes it possible to more reliably fill the outer main circulation pipe 40 and the branch circulation pipe 413 with old processing liquid between the first valve 404 and the second valve 405. In other words, it is possible to more reliably prevent gas from entering the interior.

[0214] In the above example, the processing liquid is not circulated before the circulating processing liquid replacement step (step S15). In other words, the heating and circulation step (step S4) in the first embodiment is not performed. This reduces the time required for the replacement process and improves throughput.

[0215] In the above example, the second heater 38 between the first tank 21a and the second tank 21b and the first heater 32 downstream of the first tank 21a heat the treatment liquid. Therefore, the amount of heat imparted to the treatment liquid can be increased compared to the first embodiment in which the treatment liquid is heated only by the first heater 32. Therefore, even if the heating circulation step is omitted, a treatment liquid with a sufficiently high temperature can be circulated in the circulating treatment liquid replacement step.

[0216] The flow rate settings applicable to each step described in the first embodiment can also be applied to the second embodiment. In addition, the various modifications described in the first embodiment can also be applied to the second embodiment.

[0217] As described above, the substrate processing apparatus 100 and the method for changing a processing liquid have been described in detail. However, the above description is merely an example in all respects, and the substrate processing apparatus 100 is not limited thereto. It is understood that countless variations not illustrated can be envisioned without departing from the scope of this disclosure. The configurations described in the above embodiments and variations can be combined or omitted as appropriate, as long as they are not mutually inconsistent.

[0218] For example, in the first embodiment, the first heater 32 may perform a heating operation in the circulating processing liquid replacement step without performing the heating circulation step (step S4). Even in this case, the old processing liquid inside the outer main circulation pipe 40 and the branch circulation pipe 413 can be pushed out by the new processing liquid that is higher than room temperature.

[0219] In the second embodiment, the heating circulation step (step S4) in the first embodiment may be performed as necessary. For example, the heating circulation step may be performed between the second filter-treated liquid replacement step (step S12) and the first tank liquid supply step (step S13), and at least one of the circulation valve 452, the second filter circulation valve 462, and the second inner circulation valve 472 may be opened during the heating circulation step. The heating circulation step may also be performed between the first filter-treated liquid replacement step (step S14) and the circulating treatment liquid replacement step (step S15). [Explanation of symbols]

[0220] 100 Substrate processing apparatus 21a First Tank 21b Second Tank 30 Connecting pipe (unit supply pipe) 30a upstream end 31 First liquid delivery section 32 First heater 33 First filter 33c, 39c drain outlet 38 Second heater 39 Second Filter 40 Connecting pipe (outside main circulation piping) 404 First Valve 405 Second Valve 41 Connecting pipe (outer secondary circulation piping) 421 First filter return pipe 422 First filter circulation valve 431 Inner return pipe (first inner return pipe) 432 Inner circulation valve (first inner circulation valve) 44 First tank supply pipe (tank supply pipe) 442 First tank supply valve (tank supply valve) 61 First tank supply pipe, second tank supply pipe (tank supply pipe) 62 First tank liquid supply valve, second tank liquid supply valve (tank liquid supply valve) 80 First tank drain pipe 81 Circulation drainage pipe 812 Circulation drain valve 82 First filter drain pipe 822 First filter circulation valve 84 Second tank drain pipe 842 Second tank drain valve 85 Second filter drain pipe 852 Second filter drain valve

Claims

1. a first tank for storing the treatment liquid; a tank drainage section including a first tank drainage pipe for draining the treatment liquid from the first tank and a first tank drainage valve inserted in the first tank drainage pipe; a tank liquid supply unit including a first tank liquid supply pipe for supplying a treatment liquid as a replacement liquid to the first tank and a first tank liquid supply valve inserted in the first tank liquid supply pipe; a connecting pipe having an upstream end connected to the first tank and a downstream end connected to the first tank; a first filter inserted in the connecting pipe; a first valve inserted in the connecting pipe downstream of the first filter; a first filter return pipe having an upstream end connected to a drain port of the first filter or a portion of the connecting pipe between the first filter and the first valve, and a downstream end connected to the first tank; a first filter circulation valve inserted in the first filter return pipe; a first filter drain pipe having an upstream end connected to the drain port of the first filter, the portion of the connecting pipe, or a portion of the first filter return pipe between the connecting pipe and the first filter circulation valve; a first filter drain valve inserted in the first filter drain pipe; a first heater provided in the connecting pipe upstream of the first filter, the first heater heating the treatment liquid flowing through the connecting pipe; an inner return pipe having an upstream end connected to a portion of the connecting pipe between the first heater and the first filter and a downstream end connected to the first tank; an inner circulation valve inserted in the inner return pipe; A substrate processing apparatus comprising:

2. A first tank for storing a treatment liquid; a tank drainage section including a first tank drainage pipe for draining the treatment liquid from the first tank and a first tank drainage valve inserted in the first tank drainage pipe; a tank liquid supply unit including a first tank liquid supply pipe for supplying a treatment liquid as a replacement liquid to the first tank and a first tank liquid supply valve inserted in the first tank liquid supply pipe; a connecting pipe having an upstream end connected to the first tank; a first filter inserted in the connecting pipe; a first valve inserted in the connecting pipe downstream of the first filter; a first filter return pipe having an upstream end connected to a drain port of the first filter or a portion of the connecting pipe between the first filter and the first valve, and a downstream end connected to the first tank; a first filter circulation valve inserted in the first filter return pipe; a first filter drain pipe having an upstream end connected to the drain port of the first filter, the portion of the connecting pipe, or a portion of the first filter return pipe between the connecting pipe and the first filter circulation valve; a first filter drain valve inserted in the first filter drain pipe; A method for replacing a processing liquid in a substrate processing apparatus comprising: a first tank drainage step of opening the first tank drainage valve and draining the treatment liquid from the first tank through the first tank drainage pipe while maintaining a filled state in which the treatment liquid is filled inside the connecting pipe downstream of the first valve; a first tank supply step of opening the first tank supply valve and supplying the replacement liquid to the first tank through the first tank supply pipe while maintaining the filled state after the first tank drainage step; a first filter treated liquid replacement step of opening the first filter drain valve while maintaining the filled state, causing the replacement liquid in the first tank to flow into the upstream end of the connecting pipe, and pushing the treated liquid inside the first filter into the first filter drain pipe with the replacement liquid; a connecting pipe processing liquid replacement step of opening the first valve after the first filter processing liquid replacement step, and forcing the processing liquid inside the connecting pipe with the replacement liquid to be discharged; A method for replacing a processing liquid comprising:

3. 3. The method for replacing a processing liquid according to claim 2, A method for replacing a processing liquid, wherein during the first tank drainage process, the first tank supply process, and the first filter processing liquid replacement process, both the first valve and a second valve inserted in the connecting pipe downstream of the first valve are closed.

4. 4. The method for exchanging a processing liquid according to claim 2 or 3, In the connecting pipe processing liquid replacing step, the processing liquid inside the connecting pipe is pushed out by the replacement liquid heated by a first heater.

5. 5. The method for exchanging a processing liquid according to claim 2, further comprising: The treatment liquid replacement method further comprises a circulation step, which is carried out between the first filter treatment liquid replacement step and the connecting pipe treatment liquid replacement step, in which the replacement liquid is circulated by opening the first filter circulation valve while maintaining the filling state.

6. 5. The method for replacing a processing liquid according to claim 4, a heating and circulating step that is performed between the first filter treatment liquid replacing step and the connecting pipe treatment liquid replacing step, in which, while maintaining the filled state, the first heater provided in the connecting pipe upstream of the first filter performs a heating operation, and the first filter circulation valve or the inner circulation valve is opened to circulate the replacement liquid; The inner circulation valve is inserted in an inner return pipe that branches off from the connecting pipe between the first filter and the first heater and returns to the first tank.

7. 7. The method for exchanging a processing liquid according to claim 2, further comprising: A method for replacing a processing liquid, wherein in the first tank draining step, the first tank draining valve is closed before the liquid level of the processing liquid reaches a first liquid delivery section provided in the connecting pipe.

8. 8. The method for exchanging a processing liquid according to claim 2, further comprising: In the first filter treated liquid replacing step, the treated liquid inside the first filter is pushed out by the replacement liquid into the first filter drain pipe connected to a drain port of the first filter, A method for replacing a treatment liquid, wherein a flow rate of the treatment liquid in the first filter treatment liquid replacing step is set to be smaller than a flow rate of the treatment liquid in the first tank draining step.

9. 9. The method for exchanging a processing liquid according to claim 2, further comprising: a second tank draining step, which is performed before the first tank draining step, and which comprises opening a second tank draining valve to drain the processing liquid in a second tank connected to the first tank via the first tank supply pipe through a second tank draining pipe connected to the second tank and having the second tank draining valve inserted therein; a second tank supply step of opening a second tank supply valve and supplying the replacement liquid to the second tank through a second tank supply pipe connected to the second tank and having the second tank supply valve inserted therein, in parallel with the first tank drainage step after the second tank drainage step; A method for replacing a processing liquid comprising:

10. 10. The method for replacing a processing liquid according to claim 9, a second filter treatment liquid replacement process, which is carried out between the second tank supply process and the first tank supply process, and which includes opening a second filter drain valve inserted in a drain port of a second filter inserted in the first tank supply pipe or a second filter drain pipe having an upstream end connected to a portion of the first tank supply pipe downstream of the second filter, to allow the replacement liquid in the second tank to flow into the upstream end of the first tank supply pipe, and to push the treatment liquid inside the second filter into the second filter drain pipe with the replacement liquid.

11. 11. The method for exchanging a treatment liquid according to claim 9 or 10, In the first tank liquid supply step, a second heater provided in the first tank liquid supply pipe performs a heating operation.

12. 12. The method for exchanging a processing liquid according to claim 9, further comprising: The downstream end of the connecting pipe is connected to the second tank.

Images