Process fluid supply method

Abstract

The invention provides a substrate processing system and a processing fluid supply method. A processing fluid supply apparatus in a substrate processing system according to one embodiment of the present invention comprises: a circulation path; a gas supply passage; a cooling unit provided in the circulation passage and cooling the processing fluid in a gaseous state to generate a processing fluid in a liquid state; a pump provided on the downstream side of the cooling unit in the circulation passage; a branch passage that is connected to the downstream side of the pump in the circulation passage and that branches the processing fluid in the liquid state from the branch portion; a heating unit that is provided on the downstream side of the branch unit and heats the processing fluid in a liquid state to generate a processing fluid in a supercritical state; and a pressure regulating unit that is provided downstream of the heating unit in the circulation passage and upstream of the gas supply passage, and that depressurizes the processing fluid in the supercritical state to generate a processing fluid in a gaseous state. As a result, it is possible to reduce the effect of pulsation generated by the pump when the processing fluid in a liquid state is delivered by the pump.

Description

[0001] This application is a divisional application of a patent application with an application date of September 23, 2019, application number 201910899672.3, and invention name “Substrate processing system and processing fluid supply method”. Technical Field

[0002] Embodiments of the present invention relate to substrate processing systems and processing fluid supply methods. Background Art

[0003] For a long time, there has been known a substrate processing device that forms an anti-drying liquid film on the surface of a semiconductor wafer (hereinafter referred to as a wafer) serving as a substrate, and brings the wafer formed with the liquid film into contact with a processing fluid in a supercritical state to dry the wafer (for example, refer to patent document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-251547. Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] The present invention provides a technology capable of reducing the influence of pulsation generated by a pump when a treatment fluid in a liquid state is delivered by the pump.

[0009] Technical means for solving technical problems

[0010] A substrate processing system according to one embodiment of the present invention includes: a substrate processing device for processing a substrate using a processing fluid; and a processing fluid supply device for supplying the processing fluid to the substrate processing device. The processing fluid supply device includes a circulation passage, a gas supply passage, a cooling unit, a pump, a branch passage, a heating unit, and a pressure regulating unit. The circulation passage circulates the processing fluid. The gas supply passage supplies the processing fluid in a gaseous state to the circulation passage. The cooling unit is provided in the circulation passage, and cools the processing fluid in a gaseous state to generate the processing fluid in a liquid state. The pump is provided on the downstream side of the cooling unit in the circulation passage. The branch passage is connected to the downstream side of the pump in the circulation passage, and the processing fluid in a liquid state is branched from the branch part. The heating unit is provided on the downstream side of the branch part, and heats the processing fluid in a liquid state to generate the processing fluid in a supercritical state. The pressure regulating unit is provided on the downstream side of the heating unit in the circulation passage and on the upstream side of the gas supply passage, and decompresses the processing fluid in a supercritical state to generate the processing fluid in a gaseous state.

[0011] Effects of the Invention

[0012] According to the present invention, when a treatment fluid in a liquid state is delivered by a pump, the influence of pulsation generated by the pump can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing a configuration example of a substrate processing apparatus according to an embodiment.

[0014] Figure 2 It is a diagram showing a configuration example of a liquid processing unit according to an embodiment.

[0015] Figure 3 It is a schematic perspective view showing a structural example of a drying unit according to an embodiment.

[0016] Figure 4 It is a diagram showing an example of the overall system configuration of a substrate processing system according to an embodiment.

[0017] Figure 5 It is a diagram showing the transition of the circulation pressure of the circulation passage and the internal pressure of the drying unit according to the embodiment.

[0018] Figure 6 It is a diagram for explaining the standby process of the substrate processing system according to the embodiment.

[0019] Figure 7 It is a diagram for explaining a pressure increasing process and a pressure maintaining process of the substrate processing system according to the embodiment.

[0020] Figure 8 It is a diagram for explaining the flow processing of the substrate processing system according to the embodiment.

[0021] Fig. 9 It is a diagram for explaining the decompression process of the substrate processing system according to the embodiment.

[0022] Fig.10 It is a diagram for explaining a pressure increasing process and a pressure maintaining process of a substrate processing system according to a modified example of the embodiment.

[0023] Fig.11 It is a diagram for explaining the flow processing of the substrate processing system according to the modified example of the embodiment.

[0024] Fig.12 Detailed Description of the Invention It is a flowchart showing the processing procedure of the processing fluid supply process according to the embodiment.

[0025] Description of Reference Numerals

[0026] W chip

[0027] 1. Substrate processing device

[0028] 18 Drying unit (an example of a substrate processing unit)

[0029] 44 heater (an example of another heating unit)

[0030] 60 Treatment fluid supply device

[0031] 61 Gas supply passage

[0032] 62 Circulation Pathway

[0033] 63 branch pathways

[0034] 67 filters

[0035] 68 compressor (an example of cooling unit)

[0036] 70 pumps

[0037] 72 Branch

[0038] 74 spiral heater (an example of a heating unit)

[0039] 75 Back pressure valve (an example of a pressure regulating unit)

[0040] 100 substrate handling system. DETAILED DESCRIPTION

[0041] Hereinafter, with reference to the attached drawings, the embodiments of the substrate processing system and the processing fluid supply method disclosed in the present application are described in detail. In addition, the embodiments shown below do not limit the present invention. In addition, it should be noted that the drawings are only schematic, and there are situations where the relationship between the sizes of the elements, the proportions of the elements, etc. are different from the actual situation. There are also parts in which the relationship or proportion of the sizes of the drawings are different from each other.

[0042] For a long time, there has been known a substrate processing device that forms an anti-drying liquid film on the surface of a semiconductor wafer (hereinafter referred to as a wafer) serving as a substrate, and brings the wafer formed with the above-mentioned liquid film into contact with a processing fluid in a supercritical state to dry the wafer.

[0043] In the processing fluid supply device that supplies the processing fluid to the above-mentioned substrate processing device, the piping from the processing fluid supply source to the substrate processing device is formed in series. Therefore, even if foreign matter in the processing fluid is filtered out by the filter, the number of times it can be filtered is limited.

[0044] Therefore, a circulation passage for the treatment fluid is formed in the treatment fluid supply device, and a filter is provided in the circulation passage, so that the number of filtrations can be increased to improve the performance of removing foreign matter.

[0045] However, when the incompressible liquid treatment fluid is pumped out and circulated in the circulation path, there is a problem that the pulsation generated by the pump is greatly affected. For example, due to the pulsation, there is a possibility that the pump or piping is damaged, or a load is applied to the welding part or the screw part, thereby shortening the life of the pump or piping.

[0046] Therefore, it is desired to reduce the influence of pulsation generated by the pump when the liquid treatment fluid is delivered by the pump.

[0047] <Structure of substrate processing apparatus>

[0048] First, refer to Figure 1 , the structure of the substrate processing apparatus 1 according to the embodiment will be described. Figure 1 1 is a diagram showing a configuration example of a substrate processing apparatus 1 according to an embodiment. In the following, in order to clarify the positional relationship, mutually orthogonal X-axis, Y-axis, and Z-axis are defined, and the positive direction of the Z-axis is defined as the upward direction in the vertical direction.

[0049] like Figure 1 As shown, the substrate processing device 1 includes a feeding station 2 and a processing station 3. The feeding station 2 and the processing station 3 are arranged adjacent to each other.

[0050] The loading and unloading station 2 includes a carrier placement unit 11 and a conveying unit 12. A plurality of carriers C storing a plurality of semiconductor wafers W (hereinafter referred to as "wafers W") in a horizontal state are placed on the carrier placement unit 11.

[0051] The conveying section 12 is provided adjacent to the carrier placing section 11. Inside the conveying section 12, a conveying device 13 and an interface 14 are arranged.

[0052] The conveying device 13 has a wafer holding mechanism for holding the wafer W. The conveying device 13 can move in the horizontal direction and the vertical direction and rotate around the vertical axis, and conveys the wafer W between the carrier C and the delivery unit 14 using the wafer holding mechanism.

[0053] The processing station 3 is disposed adjacent to the conveying portion 12. The processing station 3 includes a conveying block 4 and a plurality of processing blocks 5.

[0054] The transport block 4 includes a transport area 15 and a transport device 16. The transport area 15 is, for example, a rectangular parallelepiped area extending in the arrangement direction (X-axis direction) of the transport station 2 and the processing station 3. The transport device 16 is disposed in the transport area 15.

[0055] The conveying device 16 has a wafer holding mechanism for holding the wafer W. The conveying device 16 can move in the horizontal direction and the vertical direction and rotate around the vertical axis, and conveys the wafer W between the interface 14 and the plurality of processing blocks 5 using the wafer holding mechanism.

[0056] The plurality of processing blocks 5 are arranged adjacent to the conveying area 15 on both sides of the conveying area 15. Specifically, the plurality of processing blocks 5 are arranged on one side (positive Y-axis side) and the other side (negative Y-axis side) of the conveying area 15 in a direction (Y-axis direction) orthogonal to the arrangement direction (X-axis direction) of the in-and-out station 2 and the processing station 3.

[0057] Although not shown in the figure, the plurality of processing blocks 5 are arranged in multiple layers (for example, three layers) in the vertical direction. Furthermore, the wafer W is transported between the processing blocks 5 arranged in each layer and the interface 14 by a transport device 16 arranged in the transport block 4. In addition, the number of layers of the plurality of processing blocks 5 is not limited to three layers.

[0058] Each processing block 5 includes a liquid processing unit 17, a drying unit 18, and a supply unit 19. The drying unit 18 is an example of a substrate processing unit.

[0059] The liquid processing unit 17 performs a cleaning process for cleaning the pattern forming surface, ie, the upper surface of the wafer W. In addition, the liquid processing unit 17 performs a liquid film forming process for forming a liquid film on the upper surface of the wafer W after the cleaning process. The structure of the liquid processing unit 17 will be described later.

[0060] The drying unit 18 performs supercritical drying on the wafer W after the liquid film forming process. Specifically, the drying unit 18 dries the wafer W by bringing the wafer W after the liquid film forming process into contact with a processing fluid in a supercritical state (hereinafter also referred to as a "supercritical fluid"). The structure of the drying unit 18 will be described later.

[0061] The supply unit 19 supplies the treatment fluid to the drying unit 18. Specifically, the supply unit 19 includes: a supply device group including a flow meter, a flow regulator, a back pressure valve, a heater, etc.; and a housing for storing the supply device group. In this embodiment, the supply unit 19 supplies CO2 as the treatment fluid to the drying unit 18. The structure of the supply unit 19 will be described later.

[0062] In addition, the supply unit 19 and the treatment fluid supply device 60 (see Figure 4 ) is connected. In the embodiment, the treatment fluid supply device 60 supplies CO2 as the treatment fluid to the supply unit 19. The details of the treatment fluid supply device 60 will be described later.

[0063] The liquid processing unit 17, the drying unit 18, and the supply unit 19 are arranged along the conveying area 15 (i.e., along the X-axis direction). Among the liquid processing unit 17, the drying unit 18, and the supply unit 19, the liquid processing unit 17 is arranged at a position closest to the feeding and unfeeding station 2, and the supply unit 19 is arranged at a position farthest from the feeding and unfeeding station 2.

[0064] Thus, each processing block 5 has one liquid processing unit 17, one drying unit 18, and one supply unit 19. That is, in the substrate processing apparatus 1, the same number of liquid processing units 17, conveying devices 16, and supply units 19 are provided.

[0065] The drying unit 18 includes a processing area 181 for performing supercritical drying and a delivery area 182 for delivering wafers W between the transport block 4 and the processing area 181. The processing area 181 and the delivery area 182 are arranged along the transport area 15.

[0066] Specifically, of the processing area 181 and the interface area 182, the interface area 182 is arranged closer to the liquid processing unit 17 than the processing area 181. That is, in each processing block 5, the liquid processing unit 17, the interface area 182, the processing area 181 and the supply unit 19 are arranged along the conveying area 15 in this order.

[0067] like Figure 1 As shown, the substrate processing apparatus 1 includes a control device 6. The control device 6 is, for example, a computer, and has a control unit 7 and a storage unit 8.

[0068] The control unit 7 includes a microcomputer and various circuits having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, etc. The CPU of the microcomputer reads and executes the program stored in the ROM to control the conveying devices 13 and 16, the liquid processing unit 17, the drying unit 18, the supply unit 19, etc.

[0069] In addition, the above-mentioned program is stored in a computer-readable storage medium, and can also be installed from other storage media to the storage unit 8 of the control device 6. Examples of computer-readable storage media include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

[0070] The storage unit 8 can be realized by, for example, a semiconductor storage element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk.

[0071] In the substrate processing apparatus 1 constructed as described above, first, the transport device 13 of the transport station 2 takes out the wafer W from the carrier C placed on the carrier placement portion 11, and places the taken-out wafer W on the delivery portion 14. The wafer W placed on the delivery portion 14 is taken out from the delivery portion 14 by the transport device 16 of the processing station 3, and then is transported to the liquid processing unit 17.

[0072] The wafer W sent to the liquid processing unit 17 is subjected to cleaning and liquid film forming processes by the liquid processing unit 17 and then sent out from the liquid processing unit 17 by the transport device 16. The wafer W sent out from the liquid processing unit 17 is sent to the drying unit 18 by the transport device 16 and subjected to drying processes by the drying unit 18.

[0073] The wafer W dried by the drying unit 18 is delivered from the drying unit 18 by the conveyor 16 and placed on the interface 14. Then, the processed wafer W placed on the interface 14 is returned to the carrier C of the carrier placement unit 11 by the conveyor 13.

[0074] <Structure of liquid processing unit>

[0075] Next, refer to Figure 2 , the structure of the liquid processing unit 17 is described. Figure 2 1 is a diagram showing a configuration example of the liquid processing unit 17. The liquid processing unit 17 is configured as, for example, a single-wafer cleaning device that cleans wafers W one by one by spin cleaning.

[0076] like Figure 2 As shown, in liquid processing unit 17, wafer W is held substantially horizontally by wafer holding mechanism 25 disposed in outer chamber 23 forming a processing space, and wafer W is rotated by rotating wafer holding mechanism 25 about a vertical axis.

[0077] Then, the liquid processing unit 17 moves the nozzle arm 26 to the top of the rotating wafer W, and supplies chemical liquid and rinse liquid in a predetermined order from the chemical liquid nozzle 26a provided at the front end of the nozzle arm 26 to clean the upper surface of the wafer W.

[0078] In the liquid processing unit 17, a chemical liquid supply path 25a is also formed inside the wafer holding mechanism 25. The lower surface of the wafer W is also cleaned by the chemical liquid and the rinse liquid supplied from the chemical liquid supply path 25a.

[0079] In the cleaning process, for example, first, alkaline chemical solution, SC1 solution (a mixture of ammonia gas and hydrogen peroxide solution) is used to remove particles and organic contaminants, and then deionized water (hereinafter referred to as "DIW") is used as a rinse solution to perform rinsing.

[0080] Next, the natural acidification film was removed using a dilute hydrofluoric acid aqueous solution (Diluted Hydro Fluoric Acid: hereinafter referred to as "DHF") as an acidic chemical solution, and then rinsed with DIW.

[0081] The various liquid medicines are received in the outer chamber 23 or the inner cup 24 disposed in the outer chamber 23, and are discharged from the drain port 23a provided at the bottom of the outer chamber 23 or the drain port 24a provided at the bottom of the inner cup 24. In addition, the atmosphere in the outer chamber 23 is discharged from the exhaust port 23b provided at the bottom of the outer chamber 23.

[0082] The liquid film forming process is performed after the rinsing process in the cleaning process. Specifically, the liquid processing unit 17 rotates the wafer holding mechanism 25 while supplying liquid IPA (Isopropyl Alcohol) (hereinafter referred to as "IPA liquid") to the upper and lower surfaces of the wafer W. Thus, the DIW remaining on both sides of the wafer W is replaced with IPA. Then, the liquid processing unit 17 slowly stops the rotation of the wafer holding mechanism 25.

[0083] The wafer W that has completed the liquid film forming process, while maintaining the liquid film of the IPA liquid formed on its upper surface, is delivered to the transport device 16 by a delivery mechanism (not shown) provided in the wafer holding mechanism 25 and is sent out from the liquid processing unit 17 .

[0084] The liquid film formed on the wafer W evaporates (gasifies) during the period when the wafer W is transported from the liquid processing unit 17 to the drying unit 18 and during the action of transporting the wafer W to the drying unit 18, thereby preventing the pattern from being destroyed.

[0085] <Structure of drying unit>

[0086] Next, refer to Figure 3 , the structure of the drying unit 18 is described. Figure 3 It is a schematic perspective view showing a structural example of the drying unit 18 .

[0087] The drying unit 18 includes a main body 31, a holding plate 32, and a cover member 33. The main body 31, which is in the form of a shell, is provided with an opening 34 for carrying in and out the wafer W. The holding plate 32 holds the wafer W to be processed in a horizontal direction. The cover member 33 supports the holding plate 32 and seals the opening 34 when the wafer W is carried into the main body 31.

[0088] The main body 31 is a container having a processing space formed therein that can accommodate a wafer W having a diameter of, for example, 300 mm, and a supply port 35, 36 and a discharge port 37 are provided on its wall. The supply ports 35, 36 and the discharge port 37 are respectively connected to a supply flow path and a discharge flow path for circulating a supercritical fluid in the drying unit 18.

[0089] The supply port 35 is connected to the side surface opposite to the opening 34 in the shell-shaped main body 31. In addition, the supply port 36 is connected to the bottom surface of the main body 31. Moreover, the discharge port 37 is connected to the lower side of the opening 34. In addition, Figure 3 In the figure, two supply ports 35, 36 and one discharge port 37 are shown, but the number of the supply ports 35, 36 and the discharge port 37 is not particularly limited.

[0090] In addition, fluid supply heads 38 and 39 and a fluid discharge head 40 are provided inside the main body 31. In addition, the fluid supply heads 38 and 39 are formed with a plurality of supply ports arranged in the longitudinal direction of the fluid supply heads 38 and 39, and in the fluid discharge head 40, a plurality of discharge ports are formed with a plurality of discharge ports arranged in the longitudinal direction of the fluid discharge head 40.

[0091] The fluid supply head 38 is connected to the supply port 35 and is provided inside the housing-shaped main body 31 adjacent to the side surface opposite to the opening 34. The plurality of supply ports formed in the fluid supply head 38 are arranged to face the opening 34 side.

[0092] The fluid supply head 39 is connected to the supply port 36 and is provided at the center of the bottom surface of the housing-shaped main body 31. The plurality of supply ports formed in a row in the fluid supply head 39 face upward.

[0093] The fluid discharge head 40 is connected to the discharge port 37 and is provided adjacent to the side surface of the opening 34 in the shell-shaped main body 31 and below the opening 34. The plurality of discharge ports formed in a row in the fluid discharge head 40 face upward.

[0094] The fluid supply heads 38 and 39 supply the supercritical fluid into the main body 31. In addition, the fluid discharge head 40 guides the supercritical fluid in the main body 31 to the outside of the main body 31 and discharges it. In addition, the supercritical fluid discharged to the outside of the main body 31 through the fluid discharge head 40 contains IPA liquid dissolved in the supercritical fluid in a supercritical state from the surface of the wafer W.

[0095] In the drying unit 18, the IPA liquid between the patterns formed on the wafer W gradually dissolves in the supercritical fluid by contacting the supercritical fluid in a high pressure state (e.g., 16 MPa), and gradually replaces the supercritical fluid between the patterns. Thus, the patterns are finally filled only with the supercritical fluid.

[0096] Then, after the IPA liquid is removed from the pattern space, the pressure inside the main body 31 is reduced from the high pressure state to the atmospheric pressure, and CO2 changes from the supercritical state to the gas state, and the pattern space is occupied only by the gas. In this way, the IPA liquid between the patterns is removed, and the drying process of the wafer W is completed.

[0097] Here, the supercritical fluid has a lower viscosity than a liquid (e.g., IPA liquid), has a higher ability to dissolve liquids, and does not have an interface between the supercritical fluid and a liquid or gas in equilibrium. Thus, in a drying process using a supercritical fluid, the liquid can be dried without being affected by surface tension. Therefore, according to an embodiment, it is possible to suppress the destruction of a pattern during the drying process.

[0098] In addition, in the embodiment, an example of using IPA liquid as the anti-drying liquid and using supercritical CO2 as the processing fluid is shown, but liquids other than IPA can also be used as the anti-drying liquid, and fluids other than supercritical CO2 can also be used as the processing fluid.

[0099] <Structure of substrate processing system>

[0100] Next, refer to Figure 4 , the structure of the substrate processing system 100 of the embodiment is described. Figure 4 1 is a diagram showing an example of the overall system configuration of the substrate processing system 100 according to the embodiment. In addition, each unit of the substrate processing system 100 described below can be controlled by the control unit 7.

[0101] The substrate processing system 100 includes a processing fluid supply source 90, a processing fluid supply device 60, and a substrate processing device 1. The processing fluid supply device 60 supplies the processing fluid supplied from the processing fluid supply source 90 to the substrate processing device 1. As described above, the substrate processing device 1 has a drying unit 18 and a supply unit 19, and processes the wafer W in the drying unit 18 using the processing fluid supplied through the supply unit 19.

[0102] The processing fluid supply device 60 has a gas supply passage 61, a circulation passage 62, and a branch passage 63. The gas supply passage 61 is connected to a processing fluid supply source 90, and a processing fluid in a gas state is supplied from the processing fluid supply source 90 to the circulation passage 62. In addition, the processing fluid supply source 90 is connected to a connection portion 66 via a valve 64 and a flow regulator 65.

[0103] The circulation passage 62 is a circulation passage that starts circulation from the connection portion 66, which is a portion connected to the gas supply passage 61, and then returns to the connection portion 66. In the circulation passage 62, a filter 67, a compressor 68, a tank 69, a pump 70, a pressure sensor 71, a branch portion 72, a spiral heater 74, a back pressure valve 75, and a valve 76 are provided in order from the upstream side with reference to the connection portion 66.

[0104] The filter 67 filters the gaseous processing fluid flowing in the circulation passage 62 to remove foreign matter contained in the processing fluid. By removing foreign matter in the processing fluid through the filter 67, it is possible to suppress the generation of particles on the surface of the wafer W during the drying process of the wafer W using the supercritical fluid.

[0105] The compressor 68 is an example of a cooling unit. The compressor 68 is connected to a cooling water supply unit (not shown), for example, so that the cooling water and the gaseous treatment fluid can perform heat exchange. Thus, the compressor 68 cools the gaseous treatment fluid flowing in the circulation passage 62 to generate a liquid treatment fluid.

[0106] The tank 69 stores the liquid treatment fluid generated by the compressor 68. The pump 70 delivers the liquid treatment fluid stored in the tank 69 to the downstream side of the circulation passage 62. That is, the pump 70 forms a circulation flow of the treatment fluid that starts from the tank 69, passes through the circulation passage 62, and returns to the tank 69. The pressure sensor 71 measures the circulation pressure of the treatment fluid flowing in the circulation passage 62.

[0107] One or more branch passages 63 branch from the branch portion 72 of the circulation passage 62. In other words, one or more branch passages 63 are connected to the branch portion 72. The branch passages 63 are connected to the corresponding substrate processing devices 1, and the processing fluid in the liquid state flowing in the circulation passage 62 is supplied to the corresponding substrate processing devices 1.

[0108] In addition, a valve 73 is provided in the branch passage 63 in the treatment fluid supply device 60. The valve 73 is a valve for regulating the opening and closing of the flow of the treatment fluid. In the open state, the treatment fluid flows to the branch passage 63 on the downstream side, and in the closed state, the treatment fluid does not flow to the branch passage 63 on the downstream side.

[0109] The spiral heater 74 is an example of a heating unit and is wound around the circulation passage 62 to heat the treatment fluid in a liquid state flowing through the circulation passage 62 to generate the treatment fluid in a supercritical state.

[0110] The back pressure valve 75 is an example of a pressure regulating unit and is configured to maintain the primary pressure at the set pressure by adjusting the valve opening to allow the fluid to flow to the secondary side when the primary pressure of the circulation passage 62 exceeds the set pressure.

[0111] The back pressure valve 75 reduces the pressure of the supercritical treatment fluid flowing in the circulation passage 62 to generate a gaseous treatment fluid. The valve opening and set pressure of the back pressure valve 75 can be changed at any time by the control unit 7 .

[0112] The valve 76 is a valve that regulates the opening and closing of the flow of the treatment fluid. In the open state, the treatment fluid flows to the circulation passage 62 on the downstream side, and in the closed state, the treatment fluid does not flow to the circulation passage 62 on the downstream side.

[0113] Then, the gaseous process fluid generated by the back pressure valve 75 returns to the connection portion 66 of the circulation passage 62 via the valve 76 .

[0114] Next, the system configuration in the substrate processing apparatus 1 is described. The processing fluid flowing in the branch passage 63 is supplied to the drying unit 18 via the supply passage 41 of the supply unit 19, and is discharged from the drying unit 18 to the outside via the discharge passage 42. In addition, the branch passage 63 of the processing fluid supply device 60 and the supply passage 41 of the substrate processing apparatus 1 are connected by a connection passage 80 arranged in a factory or the like.

[0115] The supply passage 41 is provided with a valve 43 , a heater 44 , a temperature sensor 45 , an orifice 46 , a filter 47 , and a valve 48 in this order from the upstream side.

[0116] The valve 43 is a valve that regulates the opening and closing of the flow of the treatment fluid. In the open state, the treatment fluid flows to the supply passage 41 on the downstream side, and in the closed state, the treatment fluid does not flow to the supply passage 41 on the downstream side.

[0117] The heater 44 is another example of a heating unit. The heater 44 heats the liquid treatment fluid in the supply passage 41 to generate a supercritical treatment fluid. The temperature sensor 45 detects the temperature of the supercritical treatment fluid generated by the heater 44.

[0118] The orifice 46 reduces the flow rate of the supercritical processing fluid generated by the heater 44 to adjust the pressure. The orifice 46 allows the supercritical processing fluid whose pressure is adjusted to, for example, about 16 MPa to flow through the supply passage 41 on the downstream side.

[0119] The filter 47 filters the supercritical processing fluid flowing in the supply passage 41 to remove foreign matter contained in the processing fluid. By removing foreign matter in the processing fluid through the filter 47, it is possible to suppress the generation of particles on the surface of the wafer W during the drying process of the wafer W using the supercritical fluid.

[0120] The valve 48 is a valve that regulates the opening and closing of the flow of the process fluid. In the open state, the process fluid flows toward the drying unit 18 on the downstream side, and in the closed state, the process fluid does not flow toward the drying unit 18 on the downstream side.

[0121] The drying unit 18 is provided with a temperature sensor 49 . The temperature sensor 49 detects the temperature of the treatment fluid filled in the drying unit 18 .

[0122] In the discharge passage 42, a pressure sensor 50, a valve 51, a flow meter 52, and a back pressure valve 53 are provided in order from the upstream side. The pressure sensor 50 measures the pressure of the treatment fluid flowing in the discharge passage 42. In addition, the pressure sensor 50 is directly connected to the drying unit 18 via the discharge passage 42, so the pressure of the treatment fluid measured by the pressure sensor 50 is a value substantially equal to the internal pressure of the treatment fluid in the drying unit 18.

[0123] The valve 51 is a valve for regulating the opening and closing of the flow of the treatment fluid. In the open state, the treatment fluid flows to the discharge passage 42 on the downstream side, and in the closed state, the treatment fluid does not flow to the discharge passage 42 on the downstream side. The flow meter 52 measures the flow rate of the treatment fluid flowing in the discharge passage 42.

[0124] The back pressure valve 53 is configured to adjust the valve opening to allow the fluid to flow to the secondary side when the primary side pressure of the discharge passage 42 exceeds the set pressure, thereby maintaining the primary side pressure at the set pressure. In addition, the valve opening and the set pressure of the back pressure valve 53 can be changed by the control unit 7 at any time.

[0125] <Substrate Processing of Embodiment>

[0126] Next, refer to Figures 5 to 9 , details of substrate processing in the substrate processing system 100 of the embodiment. Figure 5 1 is a diagram showing changes in the circulation pressure of the circulation passage 62 and the internal pressure of the drying unit 18 according to the embodiment.

[0127] like Figure 5As shown, the substrate processing system 100 performs a standby process until time T1. During the standby process, the internal pressure of the drying unit 18 is a predetermined pressure P0 (eg, atmospheric pressure), and the circulation pressure of the circulation path 62 is a predetermined pressure P4 (eg, 19 MPa).

[0128] Figure 6 1 is a diagram for explaining the standby process of the substrate processing system 100 according to the embodiment. Figure 6 As shown, during the standby process, the valve 64 is in an open state, so the process fluid in a gaseous state is supplied from the process fluid supply source 90 to the circulation passage 62 via the valve 64 , the flow regulator 65 and the connection portion 66 .

[0129] Furthermore, the treatment fluid circulating in the circulation passage 62 is also in a gaseous state downstream of the back pressure valve 75 , so the gaseous treatment fluid flowing in the gas supply passage 61 and the circulation passage 62 merge at the connection portion 66 .

[0130] Then, the gaseous treatment fluid after the confluence is filtered by the filter 67 on the downstream side of the connection portion 66. Here, compared with filtering the treatment fluid in a liquid state or a supercritical state, the filter 67 filters the treatment fluid in a gaseous state, which can improve the performance of removing foreign matter contained in the treatment fluid.

[0131] That is, in the embodiment, the filter 67 is provided at the flow portion of the gaseous processing fluid in the circulation passage 62, thereby effectively removing foreign matter contained in the processing fluid. Therefore, according to the embodiment, when the wafer W is dried using the supercritical fluid, the generation of particles on the surface of the wafer W can be effectively suppressed.

[0132] The gaseous treatment fluid filtered by the filter 67 is cooled by the compressor 68 to become a liquid treatment fluid, which is stored in the tank 69. Then, the treatment fluid stored in the tank 69 is sent to the downstream side of the circulation passage 62 by the pump 70.

[0133] Then, the liquid treatment fluid that has passed through the branching portion 72 is heated by the spiral heater 74 to become a supercritical treatment fluid. Thereafter, the supercritical treatment fluid is decompressed by the back pressure valve 75 to become a gaseous treatment fluid.

[0134] Furthermore, the valve opening of the back pressure valve 75 is controlled by, for example, PID (Proportional-Integral-Differential) control based on the pressure measured by the pressure sensor 71 so that the circulation pressure of the circulation passage 62 is maintained at a predetermined pressure P4.

[0135] Then, the processing fluid in the gas state at the back pressure valve 75 flows to the connection portion 66 via the opened valve 76. When the substrate processing system 100 performs standby processing, the processing fluid is not supplied to the substrate processing apparatus 1, and therefore the valve 73 of the branch path 63 is closed.

[0136] Here, in the embodiment, the spiral heater 74 is used to change the phase of the treatment fluid from the liquid state to the supercritical state between the pump 70 and the back pressure valve 75. That is, the treatment fluid between the pump 70 and the valve 73 or the back pressure valve 75 that can be closed is not filled with the incompressible liquid state treatment fluid, but a part of it becomes the compressible supercritical state treatment fluid.

[0137] Thus, even when the incompressible liquid state treatment fluid is sent out by the pump 70 and circulated in the circulation passage 62, the pulsation generated by the pump 70 can be absorbed at the supercritical state portion. Therefore, according to the embodiment, when the liquid state treatment fluid is sent out by the pump 70, the influence of the pulsation generated by the pump 70 can be reduced.

[0138] Back to Figure 5 In the substrate processing system 100, a pressure-raising process is performed from time T1 to time T4 to raise the internal pressure of the drying unit 18 to a predetermined pressure P1 (e.g., 16 MPa). Then, a pressure-maintaining process is performed from time T4 to time T5 to maintain the pressure in the drying unit 18 at P1.

[0139] Figure 7 It is a figure for demonstrating the pressure-increasing process and the holding process of the substrate processing system 100 of this embodiment. In addition, in the following description, description of the same part as the process state which has already been demonstrated may be abbreviate|omitted.

[0140] like Figure 7 As shown, since the drying unit 18 is filled with the process fluid, at time T1 when the pressure increasing process is started, the valves 73 , 43 , and 48 are opened and the valve 51 is closed.

[0141] Thus, the treatment fluid circulating in the circulation path 62 reaches the heater 44 in a liquid state, and changes into a supercritical state in the heater 44. Then, the treatment fluid in a supercritical state is filled into the drying unit 18.

[0142] Thus, in the embodiment, the processing fluid is supplied from the processing fluid supply device 60 to the substrate processing device 1 in a liquid state instead of a gas state or a supercritical state. Thus, even if there is a deviation in the distance between the processing fluid supply device 60 and the substrate processing device 1, that is, the length of the connecting passage 80, the adverse conditions caused by the deviation in the length can be reduced.

[0143] When valves 73, 43, and 48 are opened, the valve opening of back pressure valve 75 is fully closed and valve 76 is closed to temporarily stop the circulation of the processing fluid in circulation path 62. Thus, the processing fluid can be quickly supplied to substrate processing apparatus 1.

[0144] Then, if Figure 5 As shown, immediately after the pressure increase process is started, the circulation pressure of the circulation passage 62 is temporarily reduced from the pressure P4, and as the drying unit 18 is filled with the process fluid, the circulation pressure rises.

[0145] Then, at time T2 after a predetermined time (e.g., 3 seconds) has passed from time T1, Figure 7 As shown, the valve opening of the back pressure valve 75 is changed from the fully closed state to a predetermined fixed opening, and the valve 76 is opened to restart the circulation of the treatment fluid in the circulation passage 62 .

[0146] Then, if Figure 5 As shown in FIG. 1 , the circulation pressure of the circulation passage 62 further rises, and at time T3 when it reaches a predetermined pressure P3 (for example, 18 MPa), as shown in FIG. Figure 7 As shown in FIG. 1 , the valve opening of the back pressure valve 75 is switched to PID control. Figure 5 As shown, after the circulation pressure of the circulation passage 62 reaches the pressure P4, the circulation pressure can be maintained at the pressure P4.

[0147] In this way, the valve opening of the back pressure valve 75 is not rapidly switched from the fully closed state to the PID control, but is limited to a predetermined fixed opening for a certain period of time, thereby suppressing the circulation pressure of the circulation passage 62 from overshooting from the pressure P4 during the PID control.

[0148] Then, at time T4 after a while when the internal pressure of the drying unit 18 reaches the predetermined pressure P1, Figure 7 As shown in FIG. 1 , the valve 48 located on the upstream side of the drying unit 18 is closed, and the pressure in the drying unit 18 is maintained at the pressure P1.

[0149] The holding process is performed until the IPA concentration and CO2 concentration of the mixed fluid of the processing fluid and the IPA liquid mixed between the patterns formed on the chip W reach the specified concentrations (for example, the IPA concentration is less than 30% and the CO2 concentration is more than 70%).

[0150] Following the holding process, in the substrate processing system 100, the flow process is performed from time T5 to time T6. Figure 8 It is a diagram for explaining the flow processing of the substrate processing system 100 according to the embodiment.

[0151] like Figure 8 As shown, the processing fluid is circulated in the drying unit 18, so at the time T5 when the circulation process starts, the valve 51 is opened and the valve opening of the back pressure valve 53 is PID controlled. Figure 5 As shown, the internal pressure of the drying unit 18 is continuously maintained at a predetermined pressure P1.

[0152] In addition, during the circulation process, the processing fluid is continuously supplied to the substrate processing device 1, so the circulation pressure of the circulation path 62 is reduced from the pressure P4 to the pressure P2 (for example, 17 MPa). In addition, in the embodiment, the discharge capacity of the pump 70 is substantially equal to the consumption of the processing fluid in the circulation process, so Figure 8 As shown, the valve opening of the back pressure valve 75 is brought into a fully closed state and the valve 76 is brought into a closed state, so that the circulation of the treatment fluid in the circulation passage 62 is stopped.

[0153] Here, in the flow treatment of the embodiment, the temperature of the treatment fluid in the drying unit 18 may be above 90° C. If the temperature of the treatment fluid in the drying unit 18 is lower than a predetermined temperature (e.g., 83° C.), the treatment fluid will not become a 100% supercritical state, and thus foreign matter dissolved in the treatment fluid may precipitate in the drying unit 18.

[0154] Then, due to the precipitated foreign matter, there is a possibility that a large number of particles will be generated on the surface of the wafer W when the wafer W is dried using the supercritical fluid.

[0155] However, in the embodiment, the temperature of the processing fluid in the drying unit 18 is set to 90° C. or higher, so that when the wafer W is dried using a supercritical fluid, it is possible to suppress the generation of particles on the surface of the wafer W. In addition, the temperature of the processing fluid in the drying unit 18 is preferably set to 95° C. or higher.

[0156] In addition, in the embodiment, in order to maintain the processing fluid in the drying unit 18 at a relatively high temperature, the temperature of the processing fluid in the supercritical state generated in the heater 44 may be higher than the temperature of the processing fluid in the drying unit 18. For example, the temperature of the processing fluid in the supercritical state generated in the heater 44 may be in the range of 110°C to 120°C.

[0157] Thus, even if the temperature of the process fluid decreases due to adiabatic expansion when passing through the orifice 46 , the temperature of the process fluid in the drying unit 18 can be maintained at 90° C. or higher.

[0158] Furthermore, in an embodiment, when the temperature of the processing fluid in the drying unit 18 is too high (for example, when the temperature of the processing fluid is higher than 100° C.), the liquid film of the IPA liquid formed on the wafer W is dried due to the high temperature of the processing fluid.

[0159] This may cause problems such as damage to the pattern formed on the wafer W, so it is preferable that the temperature of the processing fluid in the drying unit 18 is not too high.

[0160] In addition, the temperature of the process fluid in the drying unit 18 can be monitored by the temperature sensor 49 , and the temperature of the process fluid in the supercritical state generated in the heater 44 can be monitored by the temperature sensor 45 .

[0161] Following the flow process, in the substrate processing system 100, a decompression process is performed from time T6 to time T7. Fig. 9 It is a diagram for explaining the decompression process of the substrate processing system 100 according to the embodiment.

[0162] like Fig. 9 As shown, in order to reduce the pressure in the drying unit 18, at the time T6 when the decompression process starts, the valve 43 and the valve 48 of the supply passage 41 are closed, and the valve opening of the back pressure valve 53 of the discharge passage 42 is changed to a predetermined fixed opening. Figure 5 As shown, the internal pressure of the drying unit 18 is reduced from the pressure P1 to the pressure P0 (atmospheric pressure).

[0163] In addition, at time T6, if Fig. 9 As shown, the valve opening of the back pressure valve 75 in the circulation passage 62 is changed from the fully closed state to a predetermined fixed opening, and the valve 76 is opened to restart the circulation of the treatment fluid in the circulation passage 62. Then, at time T7 after a predetermined time (e.g., 3 seconds) has passed since time T6, the valve opening of the back pressure valve 75 is switched to PID control.

[0164] Therefore, if Figure 5 As shown, after the circulation pressure of the circulation passage 62 reaches the pressure P4, the circulation pressure can be maintained at the pressure P4. Then, at time T8, when the decompression process is completed, the substrate processing system 100 returns to the above-mentioned standby process.

[0165] <Modification>

[0166] Next, refer to Fig.10 and Fig.11 , a modified example of the implementation method is described. Fig.10 It is a diagram for explaining the pressure increasing process and the pressure holding process of the substrate processing system 100 according to the modification of the embodiment.

[0167] In addition, in this modification, the discharge capacity of the pump 70 is improved compared with the embodiment, which is different from the embodiment. Therefore, unlike the embodiment, the circulation of the treatment fluid in the circulation passage 62 can be continuously maintained without closing the back pressure valve 75 and the valve 76 when the pressure increase process is started.

[0168] That is, Fig.10 As shown in FIG. 1 , when the pressure-increasing process is started, the valve 76 is continuously maintained in the open state. In addition, the valve opening of the back pressure valve 75 is set to the value T1 (refer to FIG. 1 ) at the time when the pressure-increasing process is started. Figure 5 ) is changed from PID control to a predetermined fixed opening of 1. Then, at time T2 (refer to Figure 5 ), the valve opening of the back pressure valve 75 is changed from a specified fixed opening 1 to a specified fixed opening 2.

[0169] Then, the circulation pressure of the circulation passage 62 further increases and reaches a predetermined pressure P3 (see Figure 5 ) (for example, 18MPa) at time T3 (refer to Figure 5 ), the valve opening of the back pressure valve 75 is switched to PID control. As a result, the circulation pressure of the circulation passage 62 reaches the pressure P4 (refer to Figure 5 ) after which the circulating pressure can be maintained at pressure P4.

[0170] Fig.11 1 is a diagram for explaining the flow processing of the substrate processing system 100 according to a modified example of the embodiment. As described above, the discharge capacity of the pump 70 is improved in the modified example, so as Fig.11 As shown, the circulation of the treatment fluid in the circulation passage 62 can be continuously maintained even during the flow treatment.

[0171] Here, when the flow rate of the processing fluid flowing in the substrate processing apparatus 1 is too high, a disadvantage may occur that the pattern on the wafer W is destroyed due to the rapid flow of the processing fluid. Therefore, in the modified example, the circulation amount of the processing fluid in the circulation path 62 is increased, thereby reducing the supply amount of the processing fluid supplied to the substrate processing apparatus 1, so that the flow rate of the processing fluid flowing in the substrate processing apparatus 1 can be suppressed.

[0172] Specifically, the flow rate of the processing fluid flowing in the discharge passage 42 is measured by the flow meter 52 provided in the discharge passage 42 of the substrate processing apparatus 1, and the valve opening of the back pressure valve 75 is appropriately adjusted based on the flow rate of the processing fluid flowing in the discharge passage 42. Thus, in the modified example, the supply amount of the processing fluid supplied to the substrate processing apparatus 1 can be adjusted within a good range.

[0173] In addition, regarding the adjustment of the valve opening of the back pressure valve 75, it is possible to first confirm that the treatment fluid flows at a desired flow rate by the flow meter 52, and then fix the valve opening of the back pressure valve 75 at the time when this is confirmed. In addition, regarding the adjustment of the valve opening of the back pressure valve 75, it is also possible to perform feedback control on the valve opening of the back pressure valve 75 based on the flow rate of the treatment fluid measured at any time by the flow meter 52.

[0174] The substrate processing system 100 of the embodiment includes: a substrate processing device 1 for processing a substrate (wafer W) using a processing fluid; and a processing fluid supply device 60 for supplying the processing fluid to the substrate processing device 1. The processing fluid supply device 60 includes a circulation passage 62, a gas supply passage 61, a cooling unit (compressor 68), a pump 70, a branch passage 63, a heating unit (spiral heater 74) and a pressure regulating unit (back pressure valve 75). The circulation passage 62 circulates the processing fluid. The gas supply passage 61 supplies the processing fluid in a gaseous state to the circulation passage 62. The cooling unit (compressor 68) is arranged in the circulation passage 62 to cool the processing fluid in a gaseous state to generate a processing fluid in a liquid state. The pump 70 is arranged on the downstream side of the cooling unit (compressor 68) in the circulation passage 62. The branch passage 63 is connected to the downstream side of the pump 70 in the circulation passage 62 so that the processing fluid in a liquid state branches from the branch unit 72. The heating part (spiral heater 74) is arranged on the downstream side of the branch part 72, and heats the treatment fluid in a liquid state to generate a treatment fluid in a supercritical state. The pressure regulating part (back pressure valve 75) is arranged on the downstream side of the heating part (spiral heater 74) in the circulation passage 62 and on the upstream side of the gas supply passage 61, and decompresses the treatment fluid in a supercritical state to generate a treatment fluid in a gaseous state. Thus, when the treatment fluid in a liquid state is delivered by the pump 70, the influence of the pulsation generated by the pump 70 can be reduced.

[0175] In the substrate processing system 100 of the embodiment, the processing fluid supply device 60 is provided between the gas supply passage 61 and the cooling unit (compressor 68) in the circulation passage 62, and further includes a filter 67 for filtering the processing fluid in a gaseous state. Thus, foreign matter contained in the processing fluid can be effectively removed, so when the wafer W is dried using the supercritical fluid, the generation of particles on the surface of the wafer W can be effectively suppressed.

[0176] In the substrate processing system 100 of the embodiment, the processing fluid supply device 60 supplies the processing fluid in a liquid state to the substrate processing device 1 from the branch path 63. Therefore, even if there is a deviation in the distance between the processing fluid supply device 60 and the substrate processing device 1, that is, the length of the connecting path 80, it is possible to reduce the adverse conditions caused by the deviation in the length.

[0177] In the substrate processing system 100 of the embodiment, the substrate processing device 1 has another heating unit (heater 44) and a substrate processing unit (drying unit 18). The other heating unit (heater 44) heats the processing fluid in a liquid state to generate a processing fluid in a supercritical state. The substrate processing unit (drying unit 18) processes the substrate (wafer W) using the processing fluid in a supercritical state supplied from the other heating unit (heater 44). Thus, pattern destruction can be suppressed during the drying process.

[0178] In the substrate processing system 100 of the embodiment, the supercritical processing fluid in the substrate processing section (drying unit 18) is 90° C. or higher. Thus, when the wafer W is dried using the supercritical fluid, generation of particles on the surface of the wafer W can be suppressed.

[0179] In the substrate processing system 100 of the embodiment, the temperature of the processing fluid in the supercritical state generated by the other heating unit (heater 44) is higher than the temperature of the processing fluid in the substrate processing unit (drying unit 18). Therefore, even if the temperature of the processing fluid decreases due to adiabatic expansion when passing through the throttle hole 46, the temperature of the processing fluid in the drying unit 18 can be maintained at 90°C or more.

[0180] <Details of treatment fluid supply process>

[0181] Next, refer to Fig.12 , details of the processing fluid supply processing performed by the processing fluid supply device 60 of the embodiment are described. Fig.12 Detailed Description of the Invention It is a flowchart showing the processing procedure of the processing fluid supply process according to the embodiment.

[0182] First, the control unit 7 operates the valve 64 and the flow regulator 65 to supply the gaseous treatment fluid from the treatment fluid supply source 90 to the circulation passage 62 (step S101). Then, the control unit 7 uses the filter 67 to filter the gaseous treatment fluid flowing in the circulation passage 62 (step S102).

[0183] Next, the control unit 7 uses the compressor 68 to cool the gaseous treatment fluid filtered by the filter 67 to generate a liquid treatment fluid (step S103). Then, the control unit 7 stores the liquid treatment fluid generated by the compressor 68 in the tank 69 (step S104).

[0184] Next, the control unit 7 causes the treatment fluid in a liquid state stored in the tank 69 to be delivered to the downstream side of the circulation passage 62 by the pump 70 (step S105). Then, the control unit 7 causes the treatment fluid in a liquid state delivered by the pump 70 to branch from the circulation passage 62 to the branch passage 63 (step S106).

[0185] Next, the control unit 7 heats the liquid treatment fluid flowing in the circulation passage 62 using the spiral heater 74 to generate a supercritical treatment fluid (step S107). Then, the control unit 7 decompresses the supercritical treatment fluid generated by the spiral heater 74 using the back pressure valve 75 to generate a gaseous treatment fluid (step S108).

[0186] Finally, the control unit 7 causes the gaseous treatment fluid generated by the back pressure valve 75 to merge with the gaseous treatment fluid supplied from the treatment fluid supply source 90 (step S109 ), thereby completing the treatment.

[0187] The processing fluid supply method of the embodiment includes: a supplying step (step S101); a step of generating a processing fluid in a liquid state (step S103); a branching step (step S106); and a step of generating a processing fluid in a supercritical state (step S107). The supplying step (step S101) supplies a processing fluid in a gas state to the circulation passage 62. The step of generating a processing fluid in a liquid state (step S103) cools the processing fluid in a gas state in the circulation passage 62 to generate a processing fluid in a liquid state. The branching step (step S106) branches the processing fluid in a liquid state from the circulation passage 62 to the branch passage 63. The step of generating a processing fluid in a supercritical state (step S107) heats the processing fluid in a liquid state in the circulation passage 62 to generate a processing fluid in a supercritical state. As a result, when the processing fluid in a liquid state is delivered by the pump 70, the influence of the pulsation generated by the above-mentioned pump 70 can be reduced.

[0188] The above is a description of the embodiment of the present invention, but the present invention is not limited to the above embodiment, and various changes can be made within the scope of the main purpose. For example, in the above embodiment, the following example is used, that is, the back pressure valve 75 is used as a pressure regulating unit for reducing the pressure of the supercritical state processing fluid to generate the liquid state processing fluid. However, the pressure regulating unit is not limited to the back pressure valve, and can also be, for example, a throttle hole.

[0189] It should be understood that all aspects of the embodiments disclosed in the present invention are illustrative and non-restrictive. In fact, the above-mentioned embodiments can be implemented in various ways. In addition, the above-mentioned embodiments can be omitted, replaced, and changed in various ways without exceeding the scope and gist of the attached claims.

Claims

1. A method for supplying a treatment fluid, It is characterized in that include: The step of supplying a treatment fluid in a gaseous state to the circulation passage; The step of cooling the treatment fluid in a gaseous state in the circulation passage to generate the treatment fluid in a liquid state; a step of causing the treatment fluid in a liquid state to branch from the circulation passage to a branch passage; and The step of heating the treatment fluid in a liquid state in the circulation passage to generate the treatment fluid in a supercritical state, The step of branching the treatment fluid is performed by closing a valve, wherein the valve is disposed in the circulation passage at a downstream side of a branch portion of the branch passage, and switches the flow of the treatment fluid in the circulation passage on and off.

2. The process fluid supply method according to claim 1, Features: In the step of branching the process fluid, the valve opening of a back pressure valve provided between the branch portion and the valve in the branch passage is set to a fully closed state.

3. The process fluid supply method according to claim 2, Features: In the step of branching the processing fluid, after the valve is closed and the valve opening of the back pressure valve is set to a fully closed state, when a specified time has passed, the valve is opened and the valve opening of the back pressure valve is changed to a specified fixed opening.

4. The process fluid supply method according to any one of claims 1 to 3, It is characterized in that In the step of generating the treatment fluid in a supercritical state, the valve is continuously maintained in an open state.

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