Liquid handling device and liquid handling method

Abstract

A liquid processing apparatus according to an embodiment includes a storage tank, a first circulation line, and a second circulation line. The storage tank stores a processing liquid. The first circulation line is configured to return the processing liquid sent from the storage tank to the storage tank through a first filter. The second circulation line is connected to the first circulation line. The second circulation line is configured to return the processing liquid to the storage tank through a second filter. A length of a flow path of the second circulation line is shorter than a length of a flow path of the first circulation line. A flow rate of the processing liquid flowing into the second circulation line is lower than a flow rate of the processing liquid flowing into a position of the first circulation line that is located downstream of a connection point of the first circulation line and the second circulation line. A filtration amount per unit time in the second filter is lower than a filtration amount per unit time in the first filter.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a liquid processing apparatus and a liquid processing method. BACKGROUND

[0002] A liquid processing apparatus capable of supplying a processing liquid to a processing unit via a circulation line is disclosed in Patent Literature 1. In the liquid processing apparatus, the processing liquid that is not supplied to the processing unit is returned to a storage apparatus through the circulation line.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2011-35135 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present disclosure provides a technique for improving the cleanliness of a processing liquid.

[0008] SOLUTION TO PROBLEM

[0009] A liquid processing apparatus according to one embodiment of the present disclosure includes a storage tank, a first circulation line, and a second circulation line. The storage tank stores a processing liquid. The first circulation line is used to return the processing liquid sent out from the storage tank to the storage tank through a first filter. The second circulation line is connected to the first circulation line and is used to return the processing liquid to the storage tank through a second filter. The length of a flow path of the second circulation line is shorter than the length of a flow path of the first circulation line. The flow rate of the processing liquid flowing into the second circulation line is less than the flow rate of the processing liquid flowing into a position of the first circulation line that is located on a downstream side from a connection position of the first circulation line and the second circulation line. The filtration amount per unit time in the second filter is less than the filtration amount per unit time in the first filter.

[0010] EFFECT OF THE INVENTION

[0011] According to the present disclosure, it is possible to improve the cleanliness of a processing liquid. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a diagram showing an outline structure of a substrate processing system according to an embodiment.

[0013] Figure 2 is a schematic view showing a structure of a processing unit according to an embodiment.

[0014] Figure 3 is a diagram showing an outline structure of a processing liquid supply source according to an embodiment.

[0015] Figure 4is a flowchart illustrating a flow of a flow control process in a second circulation line involved in the embodiment.

[0016] Figure 5 is a flowchart illustrating an abnormality detection control involved in the embodiment.

[0017] Figure 6 is a diagram showing a schematic structure of a processing liquid supply source of a substrate processing system involved in a modification example of the embodiment.

[0018] Figure 7 is a diagram showing a schematic structure of a processing liquid supply source of a substrate processing system involved in a modification example of the embodiment.

[0019] Figure 8 is a diagram showing a schematic structure of a part of a substrate processing system involved in a modification example of the embodiment. DETAILED DESCRIPTION

[0020] Hereinafter, the embodiments of the liquid processing apparatus and the liquid processing method disclosed in the present application will be described in detail with reference to the drawings. Furthermore, the disclosed liquid processing apparatus and liquid processing method are not limited by the embodiments shown below.

[0021] <Outline of Substrate Processing System>

[0022] Referring to Figure 1 , the schematic structure of a substrate processing system 1 (an example of a liquid processing apparatus) involved in the embodiment will be described. Figure 1 is a diagram showing the schematic structure of the substrate processing system 1 involved in the embodiment. Hereinafter, in order to make the positional relationship clear, X-axis, Y-axis, and Z-axis orthogonal to each other are defined, and the vertical upward direction is set as the positive direction of the Z-axis.

[0023] As shown in Figure 1 , the substrate processing system 1 is provided with a load / unload station 2 and a processing station 3. The load / unload station 2 is provided adjacent to the processing station 3.

[0024] The load / unload station 2 is provided with a carrier placement portion 11 and a conveyance portion 12. A plurality of carriers C that accommodate a plurality of substrates, in the embodiment, semiconductor wafers W (hereinafter, referred to as wafers W), in a horizontal state are placed in the carrier placement portion 11.

[0025] The conveyance portion 12 is provided adjacent to the carrier placement portion 11, and is provided with a substrate conveyance device 13 and a handover portion 14 inside the conveyance portion 12. The substrate conveyance device 13 is provided with a wafer holding mechanism for holding a wafer W. In addition, the substrate conveyance device 13 is movable in the horizontal direction and the vertical direction and is rotatable around the vertical axis, and performs conveyance of the wafer W between the carrier C and the handover portion 14 using the wafer holding mechanism.

[0026] The processing station 3 is provided adjacent to the conveyance section 12. The processing station 3 is provided with a conveyance section 15 and a plurality of processing units 16. The plurality of processing units 16 are arranged on both sides of the conveyance section 15.

[0027] The conveyance section 15 is provided with a substrate conveyance device 17 inside. The substrate conveyance device 17 is provided with a wafer holding mechanism for holding the wafer W. In addition, the substrate conveyance device 17 is movable in the horizontal direction and the vertical direction and is rotatable about a vertical axis, and performs conveyance of the wafer W between the handover section 14 and the processing units 16 using the wafer holding mechanism.

[0028] The processing units 16 perform substrate processing on the wafer W conveyed by the substrate conveyance device 17. The processing units 16 hold the conveyed wafer and perform substrate processing on the held wafer. The processing units 16 perform substrate processing by supplying a processing liquid to the held wafer. The processing liquid is a CF-based cleaning liquid such as HFC (HydroFluoroCarbon) for processing the wafer W, a cleaning liquid such as DHF (Diluted HydroFluoric acid) for cleaning the residue of the wafer W. In addition, the processing liquid is a rinse liquid such as DIW (DeIonized Water), a displacement liquid such as IPA (IsoPropyl Alcohol).

[0029] In addition, the substrate processing system 1 is provided with a control device 4. The control device 4 is, for example, a computer, and is provided with a control section 18 and a storage section 19. A program for controlling various processes performed in the substrate processing system 1 is stored in the storage section 19. The control section 18 controls the operation of the substrate processing system 1 by reading out and executing the program stored in the storage section 19.

[0030] In addition, the program can be recorded in a storage medium readable by a computer, and installed in the storage section 19 of the control device 4 from the storage medium. As the storage medium readable by a computer, for example, there are a hard disk (HD), a floppy disk (FD), a compact disc (CD), a magneto-optical disk (MO), a memory card, and the like.

[0031] In the substrate processing system 1 configured as described above, first, the substrate conveyance device 13 of the in-out station 2 takes out the wafer W from the carrier C placed on the carrier placement section 11, and places the taken-out wafer W on the handover section 14. The wafer W placed on the handover section 14 is taken out from the handover section 14 by the substrate conveyance device 17 of the processing station 3 and conveyed to the processing units 16.

[0032] After the substrate processing of the wafer W taken into the processing unit 16 by the processing unit 16, the wafer W is carried out from the processing unit 16 by the substrate carrying device 17 and placed on the handover section 14. Then, the processed wafer W placed on the handover section 14 is returned to the carrier C of the carrier placement section 11 by the substrate carrying device 13.

[0033] <Outline of Processing Unit>

[0034] Next, an outline of the processing unit 16 will be described with reference to Figure 2 Figure 2 is a schematic view showing the structure of the processing unit 16 according to the embodiment. The processing unit 16 is provided with a chamber 20, a substrate holding mechanism 30, a processing liquid supply section 40, and a recovery cup 50.

[0035] The chamber 20 houses the substrate holding mechanism 30, the processing liquid supply section 40, and the recovery cup 50. A FFU (Fan Filter Unit) 21 is provided at the top of the chamber 20. The FFU 21 is used to form a downflow in the chamber 20.

[0036] The substrate holding mechanism 30 is provided with a holding section 31, a support section 32, and a drive section 33. The holding section 31 is used to horizontally hold the wafer W. The support section 32 is a member extending in the vertical direction, and the base end portion of the support section 32 is rotatably supported by the drive section 33, and the front end portion of the support section 32 horizontally supports the holding section 31. The drive section 33 is used to rotate the support section 32 about the vertical axis.

[0037] The substrate holding mechanism 30 rotates the holding section 31 supported by the support section 32 by rotating the support section 32 using the drive section 33. Thus, the wafer W held by the holding section 31 is rotated.

[0038] The processing liquid supply section 40 is used to supply the wafer W with a processing liquid. The processing liquid supply section 40 is connected to a processing liquid supply source 70. The processing liquid supply section 40 is provided with a plurality of nozzles. For example, a plurality of nozzles are provided corresponding to each processing liquid. Each nozzle is used to spray the wafer W with the processing liquid supplied from each processing liquid supply source 70.

[0039] The recovery cup 50 is configured to surround the holding section 31 and is used to capture the processing liquid scattered from the wafer W due to the rotation of the holding section 31. A drain 51 is formed at the bottom of the recovery cup 50, and the processing liquid captured by the recovery cup 50 is drained to the outside of the processing unit 16 from the drain 51. In addition, an exhaust port 52 for draining the gas supplied from the FFU 21 to the outside of the processing unit 16 is formed at the bottom of the recovery cup 50.

[0040] <Outline of Processing Liquid Supply Source> ​

[0041] Next, a processing liquid supply source 70 will be described with reference to Figure 3 Figure 3 Fig. 1 is a diagram showing an outline structure of the processing liquid supply source 70 according to the embodiment. Here, the processing liquid supply source 70 that supplies IPA will be described as an example. Figure 3 The structure of the processing liquid supply source 70 shown in Fig. 1 is not limited to the structure of the processing liquid supply source that supplies IPA, and can be applied to the structure of the processing liquid supply source that supplies other processing liquid. In addition, in the embodiment, the processing liquid supply source 70 that supplies IPA to two processing liquid supply portions 40 will be described as an example, but is not limited thereto. The processing liquid supply source 70 can supply IPA to a plurality of processing liquid supply portions 40. In addition, the processing liquid supply source 70 can supply IPA to one processing liquid supply portion 40. Figure 3

[0042] The processing liquid supply source 70 includes a tank 71, a processing liquid replenishment portion 72, a discharge line 73, a first circulation line 74, a second circulation line 75, a supply line 76, and a return line 77.

[0043] The tank 71 (an example of a storage tank) stores IPA (an example of a processing liquid). The processing liquid replenishment portion 72 supplies new IPA to the tank 71. For example, in a case where the IPA of the tank 71 is replaced, or in a case where the IPA of the tank 71 is less than a given amount, the processing liquid replenishment portion 72 supplies new IPA to the tank 71.

[0044] In a case where the IPA of the tank 71 is replaced, the discharge line 73 discharges the IPA from the tank 71 to the outside, and the IPA is discarded. In a case where the IPA of the tank 71 is replaced, the IPA can be circulated while new IPA is supplied, and the IPA remaining in the first circulation line 74, the second circulation line 75, the supply line 76, and the return line 77 can be discarded. That is, the IPA including the IPA remaining in the first circulation line 74 and the like can be replaced.

[0045] The first circulation line 74 is configured to return the IPA sent from the tank 71 to the tank 71. The first circulation line 74 is configured to flow the IPA outside the tank 71 and return to the tank 71 again. The first circulation line 74 is configured to be able to supply the IPA to a plurality of processing units 16.

[0046] ​​A pump 80, a heater 81, a first pressure sensor 82, a filter 83, a second pressure sensor 84, a flow meter 85, a temperature sensor 86, and a back pressure valve 87 are provided in the first circulation line 74. Specifically, in the first circulation line 74, the pump 80, the heater 81, the first pressure sensor 82, the filter 83, the second pressure sensor 84, the flow meter 85, the temperature sensor 86, and the back pressure valve 87 are provided in this order from the upstream side in the flow direction of the IPA with reference to the tank 71.

[0047] The pump 80 is used to pressurize and deliver the IPA in the first circulation line 74. The pressurized and delivered IPA circulates in the first circulation line 74 and is returned to the tank 71.

[0048] The heater 81 is provided in the first circulation line 74 and is used to adjust the temperature of the IPA. Specifically, the heater 81 is used to heat the IPA. The heater 81 controls the amount of heating of the IPA based on a signal from the control device 4 (refer to Figure 1 ) to adjust the temperature of the IPA. For example, the amount of heating of the IPA by the heater 81 is adjusted based on the temperature of the IPA detected by the temperature sensor 86.

[0049] For example, the control device 4 controls the heater 81 to adjust the temperature of the IPA to a given temperature. The given temperature is a temperature that makes the temperature of the IPA sprayed from the nozzle of the processing liquid supply section 40 toward the wafer W at the time of supply a predetermined processing temperature. The given temperature is a temperature set based on the heat capacity of the filter 102 provided in the supply line 76 or the like.

[0050] The first pressure sensor 82 detects the pressure of the primary side of the filter 83. That is, the first pressure sensor 82 detects the pressure of the IPA flowing into the filter 83.

[0051] The filter 83 is used to remove contaminant substances, i.e., foreign matter, such as particles, included in the IPA flowing in the first circulation line 74.

[0052] The second pressure sensor 84 detects the pressure of the secondary side of the filter 83. That is, the second pressure sensor 84 detects the pressure of the IPA flowing out of the filter 83.

[0053] The flow meter 85 measures the flow rate of the IPA flowing in the first circulation line 74. The temperature sensor 86 detects the temperature of the IPA flowing in the first circulation line 74. The temperature sensor 86 is provided at a position of the first circulation line 74 that is upstream of the portion at which the supply line 76 is connected.

[0054] The back pressure valve 87 increases the valve opening degree when the pressure of the IPA on the upstream side of the back pressure valve 87 is greater than a given pressure. The back pressure valve 87 decreases the valve opening degree when the pressure of the IPA on the upstream side of the back pressure valve 87 is less than the given pressure. The back pressure valve 87 has a function of maintaining the pressure of the processing liquid on the upstream side at the given pressure. The given pressure is a pressure set in advance. The valve opening degree of the back pressure valve 87 is controlled by the control device 4.

[0055] The back pressure valve 87 is able to adjust the flow rate of the IPA in the first circulation line 74 by the controlled valve opening degree. That is, the back pressure valve 87 is provided in the first circulation line 74 for adjusting the flow rate of the IPA returning to the tank 71 through the first circulation line 74. Further, the flow rate of the IPA in the first circulation line 74 can also be adjusted by controlling the discharge pressure of the pump 80. The flow rate of the IPA in the first circulation line 74 is controlled based on the flow rate of the IPA detected by the flow meter 85.

[0056] The first circulation line 74 is for making the IPA (an example of a processing liquid) sent out from the tank 71 (an example of a storage tank) pass through the filter 83 (an example of a first filter) and then return to the tank 71.

[0057] The second circulation line 75 is connected to the first circulation line 74. The second circulation line 75 is connected to the first circulation line 74 at a connection point 74a provided between the second pressure sensor 84 and the flow meter 85. The second circulation line 75 is provided so that the IPA flows outside the tank 71 and then returns to the tank 71. The second circulation line 75 branches from the first circulation line 74 and is provided so that the IPA returns to the tank 71. The length of the flow path of the second circulation line 75 is shorter than the length of the flow path of the first circulation line 74. The flow rate of the IPA (an example of a processing liquid) flowing into the second circulation line 75 is less than the flow rate of the IPA flowing into a position on the first circulation line 74 that is downstream of the connection point 74a of the first circulation line 74 and the second circulation line 75.

[0058] The flow meter 90, the constant pressure valve 91, the first pressure sensor 92, the filter 93, and the second pressure sensor 94 are provided in the second circulation line 75. Specifically, in the second circulation line 75, the flow meter 90, the constant pressure valve 91, the first pressure sensor 92, the filter 93, and the second pressure sensor 94 are provided in this order from the side of the first circulation line 74. That is, in the second circulation line 75, the flow meter 90, the constant pressure valve 91, the first pressure sensor 92, the filter 93, and the second pressure sensor 94 are provided in this order from the upstream side in the flow direction of the IPA.

[0059] Flow meter 90 measures the flow rate of IPA flowing in the second circulation line 75. Pressure regulating valve 91 adjusts the pressure of IPA downstream of the pressure regulating valve 91. Pressure regulating valve 91 (adjustment unit) is provided in the second circulation line 75 to adjust the flow rate of IPA flowing into filter 93 (an example of a second filter). For example, pressure regulating valve 91 adjusts the pressure of IPA by setting the flow rate of IPA flowing into filter 93 to a given flow rate. Pressure regulating valve 91 adjusts the pressure of IPA based on a signal from control device 4. That is, pressure regulating valve 91 (an example of an adjustment unit) is controlled by control device 4.

[0060] The first pressure sensor 92 detects the pressure on the primary side of the filter 93. That is, the first pressure sensor 92 detects the pressure of the IPA flowing into the filter 93.

[0061] Filter 93 is used to remove foreign matter from the IPA flowing in the second circulation line 75. Filter 93 is a smaller filter than filter 83 provided in the first circulation line 74. The filtration volume per unit time in filter 93 (an example of the second filter) is less than the filtration volume per unit time in filter 83 (an example of the first filter). Filter 93 is, for example, a POU (Point of Use) filter. By using a smaller filter such as a POU filter, the enlargement of the second circulation line 75, i.e., the enlargement of the substrate processing system 1, is suppressed.

[0062] The second pressure sensor 94 detects the pressure on the secondary side of the filter 93. That is, the second pressure sensor 94 detects the pressure of the IPA flowing out of the filter 93.

[0063] The second circulation line 75 is connected to the first circulation line 74 and is used to return the IPA (an example of the treatment liquid) to the tank 71 (an example of the storage tank) after passing through the filter 93 (an example of the second filter).

[0064] Supply line 76 is connected to first circulation line 74. Supply line 76 is connected to the first circulation line 74 downstream of the specific temperature sensor 86 and upstream of the back pressure valve 87. Multiple supply lines 76 are provided corresponding to multiple processing liquid supply units 40. Supply line 76 branches from the first circulation line 74 and is configured to supply IPA to the processing liquid supply units 40. Supply line 76 connects the first circulation line 74 to the processing liquid supply units 40 for supplying IPA to wafer W.

[0065] A flow meter 100, a constant pressure valve 101, a filter 102, and an on-off valve 103 are provided in the supply line 76. Specifically, in the supply line 76, the flow meter 100, the constant pressure valve 101, the filter 102, and the on-off valve 103 are provided in this order from the first circulation line 74 side. That is, in the supply line 76, the flow meter 100, the constant pressure valve 101, the filter 102, and the on-off valve 103 are provided in this order from the upstream side in the flow direction of the IPA flowing from the first circulation line 74 to the processing liquid supply part 40.

[0066] The flow meter 100 measures the flow rate of the IPA flowing in the supply line 76. The constant pressure valve 101 adjusts the pressure of the IPA on the downstream side of the constant pressure valve 101. For example, the constant pressure valve 101 adjusts the pressure of the IPA so that the ejection amount of the IPA ejected from the nozzle of the processing liquid supply part 40 becomes a given ejection amount. That is, the constant pressure valve 101 adjusts the flow rate of the IPA ejected from the nozzle of the processing liquid supply part 40. The given ejection amount is an amount set in advance, and is set in accordance with the processing conditions of the wafer W. The constant pressure valve 101 adjusts the pressure of the IPA based on a signal from the control device 4.

[0067] The filter 102 is provided at a position on the supply line 76 on the upstream side of the connection part of the return line 77 and the supply line 76. The filter 102 is provided at a position on the supply line 76 on the downstream side of the constant pressure valve 101. The filter 102 is used to remove foreign matter in the IPA flowing in the supply line 76.

[0068] The filter 102 is a smaller filter than the filter 83 provided in the first circulation line 74. The filter 102 is, for example, a POU filter. By using a small filter such as a POU filter, the size of the supply line 76, that is, the size of the substrate processing system 1 is suppressed from becoming large.

[0069] The on-off valve 103 is used to switch whether or not to supply the IPA to the processing liquid supply part 40. The IPA is supplied to the processing liquid supply part 40 by opening the on-off valve 103. That is, the IPA is ejected from the nozzle of the processing liquid supply part 40 by opening the on-off valve 103. The IPA is not supplied to the processing liquid supply part 40 by closing the on-off valve 103. That is, the IPA is not ejected from the nozzle of the processing liquid supply part 40 by closing the on-off valve 103. The on-off valve 103 is opened and closed based on a signal from the control device 4.

[0070] The return line 77 is connected to the supply line 76, and is used to return the IPA from the supply line 76 to the tank 71. The return line 77 is connected to the supply line 76 at a connection part provided between the filter 102 and the on-off valve 103. The return line 77 is provided with a plurality of return lines corresponding to the plurality of processing liquid supply parts 40. An on-off valve 110 is provided in the return line 77.

[0071] The on-off valve 110 switches whether or not the IPA flows in the return line 77. By opening the on-off valve 110, the IPA flows from the supply line 76 to the return line 77. The IPA flowing to the return line 77 returns to the tank 71. By closing the on-off valve 110, the IPA does not flow to the return line 77. The on-off valve 110 is opened and closed based on a signal from the control device 4.

[0072] Each of the on-off valves 103, 110 switches the flow of the IPA to a position of the return line 77 or the supply line 76 on the side of the processing liquid supply part 40 from the connection part of the return line 77. At the time of supply of the IPA from the processing liquid supply part 40 to the wafer W, the on-off valve 110 provided to the return line 77 is closed, and the on-off valve 103 provided to the supply line 76 is opened. In addition, at the time of standby in which the IPA is not supplied from the processing liquid supply part 40 to the wafer W, the on-off valve 110 is opened, and the on-off valve is closed.

[0073] The plurality of return lines 77 are merged at a position on the downstream side of the on-off valve 110 in the flow direction of the IPA flowing in the return line 77, and are connected to the tank 71. The temperature sensor 111 is provided at a position on the downstream side of the part at which the plurality of return lines 77 are merged in the return line 77. The temperature sensor 111 detects the temperature of the IPA returned from the return line 77 to the tank 71. Further, the return line 77 can be connected to a position on the downstream side of the back pressure valve 87 of the first circulation line 74.

[0074] <Flow Control>

[0075] Next, the flow control processing will be described with reference to Figure 4 Figure 4 is a flowchart illustrating the flow control processing in the second circulation line 75 according to the embodiment.

[0076] The control device 4 determines whether or not the current substrate processing system 1 is initial operation (S100). Specifically, the control device 4 determines whether or not the substrate processing system 1 is initial operation or normal operation. The initial operation includes a replacement operation of the IPA of the tank 71, a replenishment operation of the IPA to the tank 71, and a start-up operation of the substrate processing system 1. The normal operation includes operations other than the initial operation. Further, at the time of the initial operation, as in the standby, the state in which the on-off valve 110 is opened and the on-off valve 103 is closed is attained.

[0077] ​In a case where the substrate processing system 1 is in the normal operation (S100: "No"), the control device 4 detects the pressure on the primary side of the filter 83 provided to the first circulation line 74 by the first pressure sensor 82 (S101). The control device 4 detects the pressure on the primary side of the filter 93 provided to the second circulation line 75 by the first pressure sensor 92 (S102).

[0078] The control device 4 controls the pressure of the IPA acting on the filter 93 on the basis of the detected pressures (S103). Specifically, the control device 4 controls the constant pressure valve 91 (an example of an adjustment section) so that the pressure of the IPA (an example of a processing liquid) acting on the filter 93 (an example of a second filter) is lower than the pressure of the IPA (an example of a processing liquid) acting on the filter 83 (an example of a first filter).

[0079] The amount of filtration in the filter 93 is controlled by controlling the constant pressure valve 91. Specifically, the control device 4 controls the constant pressure valve 91 so that the amount of filtration per unit time becomes a given first amount of filtration. The given first amount of filtration is a filtration amount that is set in advance and is an amount that is less than the amount of filtration per unit time in the filter 83.

[0080] In a case where the substrate processing system 1 is in the initial operation (S100: "Yes"), the control device 4 increases the flow rate of the IPA flowing in the first circulation line 74 compared to the flow rate of the IPA flowing in the first circulation line 74 at the time of the normal operation (S104). Specifically, the control device 4 controls at least one of the back pressure valve 87 and the pump 80 to increase the flow rate of the circulating IPA compared to the flow rate of the circulating IPA at the time of the normal operation.

[0081] The control device 4 detects the pressure on the primary side of the filter 83 provided to the first circulation line 74 by the first pressure sensor 82 (S105) and detects the pressure on the primary side of the filter 93 provided to the second circulation line 75 by the first pressure sensor 92 (S106).

[0082] The control device 4 controls the pressure of the IPA acting on the filter 93 on the basis of the detected pressures (S107). Specifically, the control device 4 controls the constant pressure valve 91 (an example of an adjustment section) so that the pressure of the IPA (an example of a processing liquid) acting on the filter 93 (an example of a second filter) is lower than the pressure of the IPA (an example of a processing liquid) acting on the filter 83 (an example of a first filter). In addition, the control device 4 increases the flow rate of the IPA (an example of a processing liquid) flowing into the second circulation line 75 by the constant pressure valve 91 (an example of an adjustment section) compared to the flow rate of the IPA flowing into the second circulation line 75 at the time of the normal operation.

[0083] The amount of filtration in the filter 93 is controlled by controlling the constant pressure valve 91. Specifically, the control device 4 controls the constant pressure valve 91 so that the amount of filtration per unit time becomes a given second filtration amount. The given second filtration amount is a filtration amount that is set in advance, and is an amount that is more than the given first filtration amount and less than the amount of filtration per unit time in the filter 83.

[0084] <Abnormality detection control>

[0085] Next, the abnormality detection control will be described with reference to Figure 5 Figure 5 is a flowchart illustrating the abnormality detection control according to the embodiment.

[0086] The control device 4 detects the pressure on the primary side of the filter 93 provided to the second circulation line 75 by the first pressure sensor 92 (S200), and detects the pressure on the secondary side of the filter 93 provided to the second circulation line 75 by the second pressure sensor 94 (S201).

[0087] The control device 4 calculates the pressure difference between the primary side and the secondary side of the filter 93 on the basis of the detected pressures (S202), and determines whether the pressure difference is equal to or more than a given upper limit value (S203). The given upper limit value is a value that is set in advance, and is a value that can be determined to be an abnormality such as clogging in the filter 93.

[0088] In a case where the pressure difference is equal to or more than the given upper limit value (S203: YES), the control device 4 warns of the occurrence of an abnormality in the filter 93 (S204). The control device 4, for example, causes a warning lamp to light or causes a monitor to display the occurrence of an abnormality, to notify or warn an operator or the like of the occurrence of an abnormality.

[0089] In a case where the pressure difference is less than the given upper limit value (S203: NO), the control device 4 ends the present processing.

[0090] Further, the control device 4 can also detect an abnormality in the filter 83 provided to the first circulation line 74 by the same control, and warn of the occurrence of an abnormality in the filter 83. In addition, the substrate processing system 1 can provide pressure sensors on the primary side and the secondary side of the filter 102 provided to the supply line 76, and detect the occurrence of an abnormality in the filter 102 by the same control, and warn of the occurrence of an abnormality.

[0091] <Effects>

[0092] ​The substrate processing system 1 (liquid processing apparatus) includes a tank 71 (an example of a storage tank), a first circulation line 74, and a second circulation line 75. The tank 71 stores IPA (an example of a processing liquid). The first circulation line 74 is used to return IPA sent from the tank 71 to the tank 71 after passing through a filter 83 (an example of a first filter). The second circulation line 75 is connected to the first circulation line 74 and is used to return IPA to the tank 71 after passing through a filter 93 (an example of a second filter). The length of the flow path of the second circulation line 75 is shorter than the length of the flow path of the first circulation line 74. The flow rate of IPA flowing into the second circulation line 75 is less than the flow rate of IPA flowing into a position of the first circulation line 74 that is on a downstream side of a connection portion 74a of the first circulation line 74 and the second circulation line 75. The filtration amount per unit time in the filter 93 is less than the filtration amount per unit time in the filter 83.

[0093] Thus, the substrate processing system 1 reduces the flow rate of IPA flowing to the second circulation line 75, and thus can improve the trapping ability of foreign matter in the filter 93. Therefore, the substrate processing system 1 can improve the cleanliness of IPA. In addition, the substrate processing system 1 can use a small filter 93 to remove foreign matter in IPA, and thus can suppress the increase in size of the system. In addition, the substrate processing system 1 shortens the length of the flow path of the second circulation line 75, and thus can shorten the passing time of IPA in the second circulation line 75. Therefore, the substrate processing system 1 can remove foreign matter in IPA at an early stage.

[0094] The substrate processing system 1 includes a constant pressure valve 91 (an example of an adjustment portion) and a control device 4. The constant pressure valve 91 is provided in the second circulation line 75 and is used to adjust the flow rate of IPA (an example of a processing liquid) flowing into the filter 93 (an example of a second filter). The control device 4 controls the constant pressure valve 91. The control device 4 controls the constant pressure valve 91 so that the pressure of IPA acting on the filter 93 is less than the pressure of IPA acting on the filter 83 (an example of a first filter).

[0095] Thus, the substrate processing system 1 can adjust the pressure acting on the filter 93 to improve the trapping ability of foreign matter in IPA in the filter 93, and thus can improve the cleanliness of IPA.

[0096] The control device 4 increases the flow rate of IPA (an example of a processing liquid) flowing into the second circulation line 75 at the time of initial operation than the flow rate of IPA (an example of a processing liquid) flowing into the second circulation line 75 at the time of normal operation, by means of the constant pressure valve 91 (an example of an adjustment portion).

[0097] Thus, the substrate processing system 1 can remove foreign matter in IPA at an early stage at the time of initial operation. Therefore, the substrate processing system 1 can shorten the time of initial operation and start processing of the wafer W at an early stage.

[0098] The control device 4 issues a warning when the pressure difference between the IPA (processing liquid) on the upstream side of the filter 93 (an example of the second filter) and the IPA on the downstream side of the filter 93 exceeds a given upper limit value.

[0099] Therefore, the substrate processing system 1 can detect abnormalities such as clogging of the filter 93 and notify the operator. Thus, the substrate processing system 1 can prevent the continuation of abnormal conditions in the filter 93, for example, it can prevent substrate processing from being performed when the cleanliness of the IPA has decreased.

[0100] <Variation Example>

[0101] The control device 4 can also control the pressure regulating valve 91 based on the pressure difference between the primary and secondary sides of the IPA installed on the filter 83 in the first circulation line 74. For example, the control device 4 controls the pressure regulating valve 91 so that the greater the pressure difference, the greater the flow of IPA into the second circulation line 75.

[0102] Therefore, the substrate processing system 1 can adjust the flow rate of IPA flowing into the second circulation line 75 according to the condition of the IPA flowing in the first circulation line 74.

[0103] like Figure 6 As shown, the substrate processing system 1 may also be provided with multiple second circulation lines 75. Figure 6 This diagram illustrates a schematic structure of the processing liquid supply source 70 of the substrate processing system 1 according to a modified embodiment. Multiple second circulation lines 75 are arranged in parallel. The multiple second circulation lines 75 converge downstream of each second pressure sensor 94. Furthermore, the multiple second circulation lines 75 may also be individually connected to a tank 71. Figure 6 The diagram shows an example of a processing fluid supply source 70 having two second circulation lines 75, but it is not limited to this. The processing fluid supply source 70 may also have three or more second circulation lines 75.

[0104] Therefore, the substrate processing system 1 can remove foreign matter contained in the IPA by using filters 93 provided in the multiple second circulation lines 75, thereby improving the cleanliness of the IPA. In addition, the substrate processing system 1 can remove foreign matter in the IPA at an early stage during the initial operation, thereby starting the processing of the wafer W at an earlier stage.

[0105] Alternatively, the substrate processing system 1 can set different pressures for each filter 93 installed in the plurality of second circulation lines 75. The substrate processing system 1 controls the pressure acting on each filter 93 by controlling each pressure regulating valve 91 installed in the plurality of second circulation lines 75.

[0106] Thus, the substrate processing system 1 can adjust the capturing ability of foreign matter in the IPA and the flow rate of the IPA flowing into a position on the downstream side from the portion to which the second circulation line 75 is connected in the first circulation line 74. Therefore, the substrate processing system 1 can adjust the capturing ability of foreign matter in the IPA at the time of supply and stabilize the IPA supplied from the processing liquid supply part 40 to the wafer W.

[0107] In addition, as shown in FIG. 1, the second circulation line 75 can also be connected to a position on the downstream side from the back pressure valve 87 of the first circulation line 74. Figure 7 Figure 7 FIG. 1 is a diagram showing a schematic configuration of a processing liquid supply source 70 of a substrate processing system 1 according to the embodiment.

[0108] Thus, the substrate processing system 1 can suppress a change in the flow rate of the IPA flowing into the supply line 76 in a case where the constant pressure valve 91 provided in the second circulation line 75 is controlled. Therefore, the substrate processing system 1 can improve the cleanliness of the IPA and stabilize the IPA ejected from the processing liquid supply part 40 at the time of supply.

[0109] In addition, as shown in FIG. 1, the processing unit 16A of the substrate processing system 1 can also be provided with an inner tank 121 and an outer tank 122 as the processing tank 120 (an example of a storage tank). The substrate processing system 1 can also be a system in which a plurality of wafers W are immersed in a processing liquid in the inner tank 121 to perform substrate processing. Figure 8 Figure 8 FIG. 1 is a diagram showing a schematic configuration of a processing liquid supply source 70 of a substrate processing system 1 according to the embodiment.

[0110] The processing tank 120 is supplied with, for example, an aqueous phosphoric acid solution and DIW to generate a processing liquid of a given phosphoric acid concentration as an etching liquid. The generated processing liquid is circulated in the processing tank 120 via the first circulation line 130. A pump 80, a filter 83, and the like are provided in the first circulation line 130.

[0111] The outer tank 122 flows in the etching liquid overflowing from the inner tank 121. The outer tank 122 is connected to the inner tank 121 through the first circulation line 130. The etching liquid of the outer tank 122 is supplied to the inner tank 121 via the first circulation line 130. That is, the etching liquid is circulated in the outer tank 122 and the inner tank 121 via the first circulation line 130.

[0112] ​​The second circulation line 131 is connected to the first circulation line 130. For example, the second circulation line 131 is connected to the first circulation line 130 at a position on the upstream side of the pump 80 in the flow direction of the etching liquid in the first circulation line 130. In addition, the second circulation line 131 can also be connected to the first circulation line 130 at a position on the downstream side of the filter 83 in the flow direction of the etching liquid in the first circulation line 130. The length of the flow path of the second circulation line 131 is shorter than the length of the flow path of the first circulation line 130. The second circulation line 131 is provided with the flow meter 90, the filter 93, and the like.

[0113] Thus, the substrate processing system 1 can remove foreign matter in the etching liquid flowing through the first circulation line 130 by the filter 93 provided to the second circulation line 131. Therefore, the substrate processing system 1 can improve the cleanliness of the etching liquid.

[0114] In addition, it should be considered that all points of the embodiments disclosed herein are illustrative and not restrictive. The above-described embodiments can be actually embodied in various ways. In addition, the above-described embodiments can be omitted, replaced, and changed in various ways without departing from the appended claims and the spirit thereof.

[0115] Explanation of Reference Numerals

[0116] 1: substrate processing system (liquid processing apparatus); 4: control device; 16: processing unit; 16A: processing unit; 40: processing liquid supply part; 70: processing liquid supply source; 71: tank (storage tank); 74: first circulation line; 75: second circulation line; 80: pump; 82: first pressure sensor; 83: filter (first filter); 84: second pressure sensor; 91: constant pressure valve (adjusting part); 92: first pressure sensor; 93: filter (second filter); 94: second pressure sensor; 130: first circulation line; 131: second circulation line.

Claims

1. A liquid treatment device comprising: a storage tank that stores a treatment liquid; a first circulation line through which the treatment liquid sent out from the storage tank is returned to the storage tank after passing through a first filter; and a second circulation line that is connected to the first circulation line and through which the treatment liquid is returned to the storage tank after passing through a second filter, the length of a flow path of the second circulation line being shorter than the length of a flow path of the first circulation line, the flow rate of the treatment liquid flowing into the second circulation line being less than the flow rate of the treatment liquid flowing into the first circulation line at a position on the first circulation line that is on a downstream side of a connection site of the first circulation line and the second circulation line, the filtration amount per unit time in the second filter being less than the filtration amount per unit time in the first filter, wherein the liquid treatment device further comprises: an adjustment portion provided in the second circulation line and configured to adjust the flow rate of the treatment liquid flowing into the second filter; and a control device that controls the adjustment portion, wherein the control device controls the adjustment portion such that the pressure of the treatment liquid acting on the second filter is lower than the pressure of the treatment liquid acting on the first filter.

2. The liquid treatment device according to claim 1, wherein the control device increases the flow rate of the treatment liquid flowing into the second circulation line at the time of initial operation than the flow rate of the treatment liquid flowing into the second circulation line at the time of normal operation by means of the adjustment portion.

3. The liquid treatment device according to claim 2, wherein the control device performs warning in a case where the pressure difference between the pressure of the treatment liquid on the upstream side of the second filter and the pressure of the treatment liquid on the downstream side of the second filter is equal to or greater than a given upper limit value.

4. The liquid treatment device according to any one of claims 1 to 3, wherein a plurality of the second circulation lines are provided. wherein 5. A liquid treatment method comprising the following steps: a first circulation step of returning a treatment liquid sent out from a storage tank to the storage tank after passing through a first filter provided in a first circulation line; a second circulation step of returning the treatment liquid to the storage tank after passing through a second filter provided in a second circulation line that is connected to the first circulation line; and an adjustment step of adjusting the flow rate of the treatment liquid flowing into the second filter by means of an adjustment portion provided in the second circulation line, wherein the length of a flow path of the second circulation line is shorter than the length of a flow path of the first circulation line, the flow rate of the treatment liquid flowing into the second circulation line is less than the flow rate of the treatment liquid flowing into the first circulation line at a position on the first circulation line that is on a downstream side of a connection site of the first circulation line and the second circulation line, the filtration amount per unit time in the second filter is less than the filtration amount per unit time in the first filter, and the adjustment portion is controlled such that the pressure of the treatment liquid acting on the second filter is lower than the pressure of the treatment liquid acting on the first filter. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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