Substrate processing apparatus, fluid supply system, and substrate processing method

Abstract

To provide a substrate processing apparatus or the like enhancing the responsibility of flow amount control of a supercritical fluid.SOLUTION: A substrate processing apparatus comprises: a processing container; and a processing fluid supply part 80 that supplies a processing fluid in a supercritical state to the processing container. The processing fluid supply part includes: a heat part that generates the processing fluid in the supercritical state by heating fluid supply lines 71 and 72A, a pump 67, and the processing fluid; a first flow amount adjustment part 250 that adjusts a supply flow amount of the processing fluid; a pressure sensor 243 that measures a pressure of the processing fluid; a pressure sensor 142A that measures the pressure of the processing fluid; a branching point 62A that is provided between the pump and the first flow amount adjustment part; a connection point 61 that is provided upstream from the pump; a branching line 73A that connects the branching point with the connection point; a back pressure valve 131A that adjusts the supply flow amount of the processing fluid; and a control part that controls the back pressure valve 131A on the basis of a first pressure of the processing fluid in a liquid state to be measured by the pressure sensor 243 and a second pressure of the processing fluid in the liquid state to be measured by the pressure sensor 142A.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus, a fluid supply system, and a substrate processing method.

Background Art

[0002] There is known a substrate processing apparatus including a processing container that houses a substrate whose surface is wetted with a liquid, and a processing fluid supply unit that supplies a processing fluid in a supercritical state toward the liquid (see, for example, Patent Document 1). In the substrate processing apparatus, the processing fluid supply unit is controlled based on the output from a pressure sensor provided downstream of the processing container.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of enhancing the responsiveness of flow rate control of a supercritical fluid.

Means for Solving the Problems

[0005] A substrate processing apparatus according to an aspect of the present disclosure includes a processing container having a processing space capable of accommodating a substrate whose surface is wetted with a liquid, and a processing fluid supply unit that supplies a processing fluid in a supercritical state to the processing container. The processing fluid supply unit includes a fluid supply line having one end connected to a fluid supply source and the other end connected to the processing container, a pump provided in the fluid supply line, a heating unit provided in the fluid supply line downstream of the pump for heating the processing fluid to generate the processing fluid in a supercritical state, a first flow rate adjustment unit provided in the fluid supply line between the pump and the heating unit for adjusting the supply flow rate of the processing fluid supplied to the processing container, a first pressure measurement unit provided in the fluid supply line between the first flow rate adjustment unit and the heating unit for measuring the pressure of the processing fluid, a second pressure measurement unit provided in the fluid supply line between the pump and the first flow rate adjustment unit for measuring the pressure of the processing fluid, a branch point provided between the pump and the first flow rate adjustment unit in the fluid supply line, a connection point provided upstream of the pump in the fluid supply line, a branch line connecting the branch point and the connection point, a second flow rate adjustment unit provided in the branch line for adjusting the supply flow rate of the processing fluid supplied to the processing container, and a control unit for controlling the second flow rate adjustment unit based on a first pressure of the processing fluid in a liquid state measured by the first pressure measurement unit and a second pressure of the processing fluid in a liquid state measured by the second pressure measurement unit.

Advantages of the Invention

[0006] According to the present disclosure, the responsiveness of the flow rate control of the supercritical fluid can be enhanced.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding members or components are denoted by the same or corresponding reference numerals, and duplicate descriptions are omitted.

[0009] [Configuration of Substrate Processing Apparatus] With reference to FIG. 1, the configuration of a substrate processing apparatus 1 according to an embodiment will be described. FIG. 1 is a diagram showing a configuration example of the substrate processing apparatus 1 according to an embodiment. Hereinafter, in order to clarify the positional relationship, an X-axis, a Y-axis, and a Z-axis orthogonal to each other are defined, and the positive direction of the Z-axis is the vertically upward direction.

[0010] As shown in FIG. 1, the substrate processing apparatus 1 includes a loading / unloading station 2, a processing station 3, and a control device 6. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other.

[0011] The loading / unloading station 2 includes a carrier placement unit 11 and a transfer unit 12. A carrier C is placed on the carrier placement unit 11. The carrier C houses a plurality of substrates in a horizontal state. The substrate is, for example, a semiconductor wafer (hereinafter referred to as "wafer W").

[0012] The transfer unit 12 is provided adjacent to the carrier placement unit 11. Inside the transfer unit 12, a transfer device 13 and a delivery unit 14 are arranged.

[0013] The transfer device 13 includes a wafer holding mechanism for holding the wafer W. The transfer device 13 can move in the horizontal direction, move in the vertical direction, and turn around the vertical axis. The transfer device 13 transfers the wafer W between the carrier C and the delivery unit 14 using the wafer holding mechanism.

[0014] The processing station 3 is provided adjacent to the transfer unit 12. The processing station 3 includes a transfer block 4, a plurality of processing blocks 5, and a plurality of supply units 19.

[0015] The transfer block 4 includes a transfer area 15 and a transfer device 16. The transfer area 15 is, for example, a rectangular parallelepiped region extending along the arrangement direction (X-axis direction) of the loading / unloading station 2 and the processing station 3. The transfer device 16 is arranged in the transfer area 15.

[0016] The transfer device 16 includes a wafer holding mechanism for holding the wafer W. The transfer device 16 can move in the horizontal direction, move in the vertical direction, and turn around the vertical axis. The transfer device 16 transfers the wafer W between the delivery unit 14 and the plurality of processing blocks 5 using the wafer holding mechanism.

[0017] The plurality of processing blocks 5 are arranged adjacent to the conveyance area 15 on both sides of the conveyance area 15. Specifically, the plurality of processing blocks 5 are arranged on one side (the positive Y-axis direction side) and the other side (the negative Y-axis direction side) of the conveyance area 15 in a direction (Y-axis direction) orthogonal to the arrangement direction (X-axis direction) of the loading / unloading station 2 and the processing station 3.

[0018] Although not shown in the figure, the plurality of processing blocks 5 are arranged in multiple stages (for example, three stages) along the vertical direction. The conveyance of the wafer W between the processing blocks 5 arranged in each stage and the delivery unit 14 is performed by one conveyance device 16 arranged in the conveyance block 4. The number of stages of the plurality of processing blocks 5 is not limited to three stages.

[0019] Each processing block 5 includes a liquid processing unit 17 and a drying unit 18.

[0020] The liquid processing unit 17 performs a cleaning process for cleaning the upper surface, which is the pattern formation surface of the wafer W. The liquid processing unit 17 performs a liquid film formation process for forming a liquid film on the upper surface of the wafer W after the cleaning process. The configuration of the liquid processing unit 17 will be described later.

[0021] The drying unit 18 performs a supercritical drying process on the wafer W after the liquid film formation process. Specifically, the drying unit 18 dries the wafer W by bringing the wafer W after the liquid film formation process into contact with a processing fluid in a supercritical state (hereinafter also referred to as "supercritical fluid"). The configuration of the drying unit 18 will be described later.

[0022] The liquid processing unit 17 and the drying unit 18 are arranged along the conveyance area 15 (along the X-axis direction). The liquid processing unit 17 is arranged closer to the loading / unloading station 2 than the drying unit 18.

[0023] Each processing block 5 includes one liquid processing unit 17 and one drying unit 18 respectively. The substrate processing apparatus 1 is provided with the same number of liquid processing units 17 and drying units 18.

[0024] The drying unit 18 includes a processing area 181 and a delivery area 182. In the processing area 181, supercritical drying treatment is performed. In the delivery area 182, the wafer W is delivered between the transfer block 4 and the processing area 181. The processing area 181 and the delivery area 182 are arranged along the transfer area 15.

[0025] The delivery area 182 is arranged closer to the liquid processing unit 17 than the processing area 181. In each processing block 5, the liquid processing unit 17, the delivery area 182, and the processing area 181 are arranged in this order along the transfer area 15.

[0026] One supply unit 19 is arranged for three processing blocks 5. For example, one supply unit 19 is arranged for three processing blocks 5 stacked in the vertical direction.

[0027] The supply unit 19 supplies a processing fluid to the drying unit 18. Specifically, the supply unit 19 includes a group of supply devices including a flow meter, a flow regulator, a back pressure valve, a heater, etc., and a housing that houses the group of supply devices. In the present embodiment, the supply unit 19 supplies carbon dioxide (CO 2 ) to the drying unit 18 as the processing fluid. The configuration of the supply unit 19 will be described later. It is possible to supply the processing fluid from one supply unit 19 to three processing blocks 5.

[0028] The control device 6 is, for example, a computer, and includes a control unit 7 and a storage unit 8. The control unit 7 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), input / output ports, etc., and various circuits. The CPU of the microcomputer reads and executes the program stored in the ROM to realize the control of the transfer devices 13, 16, the liquid processing unit 17, the drying unit 18, the supply unit 19, etc.

[0029] The program was stored in a computer-readable storage medium and may have been installed from the storage medium into the storage unit 8 of the control device 6. Examples of computer-readable storage media include hard disks (HD), flexible disks (FD), compact disks (CD), magneto-optical disks (MO), memory cards, and the like.

[0030] The storage unit 8 is realized by, for example, semiconductor memory elements such as RAM and flash memory, or storage devices such as hard disks and optical disks.

[0031] In the substrate processing apparatus 1 configured as described above, first, the transfer device 13 of the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement unit 11 and places the taken-out wafer W on the delivery unit 14. The wafer W placed on the delivery unit 14 is taken out from the delivery unit 14 by the transfer device 16 of the processing station 3 and carried into the liquid processing unit 17.

[0032] The wafer W carried into the liquid processing unit 17 is subjected to a cleaning process and a liquid film forming process by the liquid processing unit 17, and then is carried out of the liquid processing unit 17 by the transfer device 16. The wafer W carried out of the liquid processing unit 17 is carried into the drying unit 18 by the transfer device 16 and is subjected to a drying process by the drying unit 18.

[0033] The wafer W dried by the drying unit 18 is carried out of the drying unit 18 by the transfer device 16 and placed on the delivery unit 14. The processed wafer W placed on the delivery unit 14 is returned to the carrier C on the carrier placement unit 11 by the transfer device 13.

[0034] 〔Configuration of Liquid Processing Unit〕 Referring to FIG. 2, the configuration of the liquid processing unit 17 will be described. FIG. 2 is a diagram showing a configuration example of the liquid processing unit 17. The liquid processing unit 17 is configured as a single-wafer cleaning apparatus that cleans the wafers W one by one, for example, by spin cleaning.

[0035] As shown in FIG. 2, the liquid processing unit 17 holds the wafer W substantially horizontally by a wafer holding mechanism 25 disposed in an outer chamber 23 that forms a processing space, and rotates the wafer W by rotating the wafer holding mechanism 25 around a vertical axis.

[0036] The liquid processing unit 17 causes the nozzle arm 26 to enter above the rotating wafer W, and supplies a chemical solution and a rinse solution from a chemical solution nozzle 26a provided at the tip of the nozzle arm 26 in a predetermined order, thereby performing a cleaning process on the upper surface of the wafer W.

[0037] A chemical solution supply path 25a is also formed inside the wafer holding mechanism 25 in the liquid processing unit 17. The lower surface of the wafer W is also cleaned by the chemical solution and the rinse solution supplied from the chemical solution supply path 25a.

[0038] For the cleaning process, for example, first, particles and organic contaminants are removed by an SC1 solution (a mixed solution of ammonia and hydrogen peroxide water), which is an alkaline chemical solution. Next, a rinse cleaning is performed with deionized water (hereinafter referred to as "DIW"), which is a rinse solution.

[0039] Next, the natural oxide film is removed by a diluted hydrofluoric acid aqueous solution (hereinafter referred to as "DHF"), which is an acidic chemical solution, and then a rinse cleaning is performed with DIW.

[0040] Each of the above-mentioned various chemical solutions is received in the outer chamber 23 and the inner cup 24 disposed in the outer chamber 23, and is discharged from the drain port 23a provided at the bottom of the outer chamber 23 and the drain port 24a provided at the bottom of the inner cup 24. The atmosphere in the outer chamber 23 is exhausted from the exhaust port 23b provided at the bottom of the outer chamber 23.

[0041] The liquid film forming process is performed after the rinsing process in the cleaning process. Specifically, the liquid processing unit 17 supplies liquid-state IPA (Isopropyl Alcohol) (hereinafter also referred to as "IPA liquid") to the upper and lower surfaces of the wafer W while rotating the wafer holding mechanism 25. Thereby, the DIW remaining on both surfaces of the wafer W is replaced with IPA. Thereafter, the liquid processing unit 17 gently stops the rotation of the wafer holding mechanism 25.

[0042] The wafer W that has completed the liquid film forming process is transferred to the transfer device 16 by a transfer mechanism (not shown) provided in the wafer holding mechanism 25 in a state where a liquid film of IPA liquid is formed on its upper surface (the surface is wetted by the IPA liquid), and is carried out from the liquid processing unit 17.

[0043] The liquid film formed on the wafer W prevents pattern collapse from occurring due to the evaporation (vaporization) of the liquid on the upper surface of the wafer W during the transfer of the wafer W from the liquid processing unit 17 to the drying unit 18 or during the loading operation into the drying unit 18.

[0044] 〔Configuration of Drying Unit〕 Referring to FIGS. 3 and 4, the configuration of the drying unit 18 will be described. FIG. 3 is a schematic perspective view showing a configuration example of the drying unit 18. FIG. 4 is a diagram showing a configuration example of the drying unit 18.

[0045] As shown in FIG. 3, the drying unit 18 includes a main body 31, a holding plate 32, and a lid member 33. An opening 34 for loading and unloading the wafer W is formed in the housing-shaped main body 31. The holding plate 32 holds the wafer W to be processed in the horizontal direction. The lid member 33 supports the holding plate 32. The lid member 33 seals the opening 34 when the wafer W is loaded into the main body 31. The main body 31 is an example of a processing container.

[0046] The main body 31 is a container having a processing space formed therein that can accommodate a wafer W with a diameter of, for example, 300 mm. Supply ports 35 and 36 and a discharge port 37 are provided in the wall of the main body 31. The supply ports 35 and 36 and the discharge port 37 are connected to a supply flow path and a discharge flow path for flowing a supercritical fluid through the drying unit 18, respectively.

[0047] The supply port 35 is connected to a side surface of the housing-shaped main body 31 opposite to the opening 34. The supply port 36 is connected to the bottom surface of the main body 31. The discharge port 37 is connected to the lower side of the opening 34. Although two supply ports 35 and 36 and one discharge port 37 are shown in FIG. 3, the numbers of the supply ports 35 and 36 and the discharge port 37 are not particularly limited.

[0048] A fluid supply header 38 and 39 and a fluid discharge header 40 are provided inside the main body 31. A plurality of supply ports are formed side by side in the longitudinal direction of the fluid supply headers 38 and 39. A plurality of discharge ports are formed side by side in the longitudinal direction of the fluid discharge header 40.

[0049] The fluid supply header 38 is connected to the supply port 35. The fluid supply header 38 is provided adjacent to a side surface of the housing-shaped main body 31 opposite to the opening 34 inside the main body 31. The plurality of supply ports formed side by side in the fluid supply header 38 face the opening 34 side.

[0050] The fluid supply header 39 is connected to the supply port 36. The fluid supply header 39 is provided at the center of the bottom surface inside the housing-shaped main body 31. A plurality of supply ports formed side by side in the fluid supply header 39 face upward.

[0051] The fluid discharge header 40 is connected to the discharge port 37. The fluid discharge header 40 is provided inside the housing-shaped main body 31 adjacent to the side surface on the opening 34 side and below the opening 34. A plurality of discharge ports formed side by side in the fluid discharge header 40 face upward.

[0052] The fluid supply headers 38 and 39 supply supercritical fluid into the main body 31. The fluid discharge header 40 guides and discharges the supercritical fluid in the main body 31 to the outside of the main body 31. The supercritical fluid discharged to the outside of the main body 31 through the fluid discharge header 40 contains IPA liquid dissolved in the supercritical fluid in a supercritical state from the surface of the wafer W.

[0053] As shown in FIG. 4, the second supply line 72 of the supply unit 19 is connected to the drying unit 18. The second supply line 72 branches into two supply lines inside the drying unit 18 (omitted in FIG. 4), one is connected to the supply port 35, and the other is connected to the supply port 36 (omitted in FIG. 4). In the second supply line 72, a first flow rate adjustment unit 250, a pressure sensor 243, and a heater 68 are provided in order from the upstream side (supply unit 19 side).

[0054] The first flow rate adjustment unit 250 adjusts the supply flow rate of the processing fluid supplied to the main body 31. The first flow rate adjustment unit 250 has valves 211 to 213 and orifices 221 to 223.

[0055] Valves 211, 212, and 213 are connected in parallel with each other. Valves 211, 212, and 213 are valves that adjust the on and off of the flow of the processing fluid. Valves 211, 212, and 213 each allow the processing fluid to flow through orifices 221, 222, and 223 in the open state and prevent the processing fluid from flowing through orifices 221, 222, and 223 in the closed state. Valves 211, 212, and 213 are an example of a first on-off valve.

[0056] Orifices 221, 222, and 223 are connected in series with valves 211, 212, and 213 respectively. Orifices 221, 222, and 223 each reduce the flow rate of the gaseous or liquid processing fluid supplied from the supply unit 19 through valves 211, 212, and 213 and play a role in adjusting the pressure. Orifices 221, 222, and 223 can allow the processing fluid with adjusted pressure to flow through the downstream second supply line 72. Orifices 221, 222, and 223 are an example of a first throttle.

[0057] The pressure sensor 243 measures the pressure of the processing fluid flowing through the second supply line 72 between the first flow rate adjustment unit 250 and the heater 68. That is, the pressure sensor 243 can measure the pressure on the secondary side of orifices 221, 222, and 223. The output of the pressure sensor 243 is transmitted to the control unit 7. The pressure sensor 243 is an example of a first pressure measurement unit.

[0058] The heater 68 is, for example, a spiral heater. The heater 68 is wound around the second supply line 72 and heats the gaseous or liquid processing fluid flowing through the second supply line 72 to generate a supercritical state processing fluid. The heater 68 is an example of a heating unit.

[0059] A discharge line 76 is connected to the discharge port 37. The discharge line 76 is provided with a pressure sensor 242, a valve 214, a flow meter 251, and a back pressure valve 231 in order from the upstream side, that is, the main body 31 side. The discharge line 76, the pressure sensor 242, the valve 214, the flow meter 251, and the back pressure valve 231 constitute a part of the discharge unit.

[0060] The pressure sensor 242 measures the pressure of the process fluid flowing through the discharge line 76 immediately after the main body 31. That is, the pressure sensor 242 can measure the pressure of the process fluid inside the main body 31. The output of the pressure sensor 242 is transmitted to the control unit 7. The pressure sensor 242 is an example of a third pressure measurement unit.

[0061] The valve 214 is a valve that adjusts the on and off of the flow of the process fluid. In the open state, the process fluid flows to the downstream discharge line 76, and in the closed state, the process fluid does not flow to the downstream discharge line 76.

[0062] The flow meter 251 measures the discharge flow rate of the process fluid flowing through the discharge line 76. The output of the flow meter 251 is transmitted to the control unit 7.

[0063] When the pressure on the primary side of the discharge line 76 exceeds the set pressure, the back pressure valve 231 adjusts the valve opening degree to allow the fluid to flow to the secondary side, thereby maintaining the pressure on the primary side at the set pressure. For example, the set pressure of the back pressure valve 231 is adjusted by the control unit 7 based on the output of the pressure sensor 242. The back pressure valve 231 is an example of a pressure adjustment unit.

[0064] A temperature sensor 241 for detecting the temperature of the process fluid inside the main body 31 is provided. The output of the temperature sensor 241 is transmitted to the control unit 7.

[0065] In the drying unit 18, the IPA liquid between the patterns formed on the wafer W comes into contact with a supercritical fluid in a high-pressure state (for example, 16 MPa), gradually dissolves in the supercritical fluid, and the space between the patterns is gradually replaced by the supercritical fluid. Finally, the space between the patterns is filled only with the supercritical fluid.

[0066] After the IPA liquid is removed from between the patterns, by reducing the pressure inside the main body 31 from a high pressure state to atmospheric pressure, CO 2It changes from the supercritical state to the gaseous state, and only the gas occupies the space between the patterns. In this way, the IPA liquid between the patterns is removed, and the drying process of the wafer W is completed.

[0067] Supercritical fluids have a lower viscosity compared to liquids (e.g., IPA liquid), a higher ability to dissolve liquids, and no interface exists between the supercritical fluid and the liquid or gas in an equilibrium state. Thus, in the drying process using supercritical fluids, the liquid can be dried without being affected by surface tension. Therefore, according to the embodiment, it is possible to suppress the patterns from collapsing during the drying process.

[0068] In the embodiment, IPA liquid is used as the liquid for preventing drying, and supercritical CO 2 is used as the processing fluid. Although an example using is shown, other liquids than IPA may be used as the liquid for preventing drying, and other fluids than supercritical CO 2 may be used as the processing fluid.

[0069] 〔Configuration of the supply unit〕 Referring to FIG. 5, the configuration of the supply unit 19 will be described. FIG. 5 is a diagram showing a configuration example of the supply unit 19. The supply unit 19 shown in FIG. 5 supplies the processing fluid to three drying units 18A, 18B, and 18C. The drying units 18A to 18C correspond to the drying unit 18 in FIG. 4.

[0070] The supply unit 19 has a first supply line 71 connected to a processing fluid supply source 90, and a plurality of second supply lines 72A, 72B, and 72C connected to the first supply line 71. The second supply lines 72A, 72B, and 72C are connected to the first supply line 71 at a plurality of branch points 77A, 77B provided in the first supply line 71. Specifically, the second supply line 72A is connected to the first supply line 71 at the branch point 77A, and the second supply lines 72B and 72C are connected to the first supply line 71 at the branch point 77B. The second supply lines 72A to 72C correspond to the second supply line 72 in FIG. 4. The second supply line 72A is connected to the drying unit 18A, the second supply line 72B is connected to the drying unit 18B, and the second supply line 72C is connected to the drying unit 18C. The processing fluid supply source 90 is an example of a fluid supply source, and the first supply line 71 and the second supply lines 72A to 72C constitute a part of the fluid supply line.

[0071] A connection point 61 is provided on the first supply line 71. On the first supply line 71, a filter 64, a capacitor 65, a tank 66, and a pump 67 are provided in order from the upstream side (the processing fluid supply source 90 side). The connection point 61 is provided on the upstream side of the filter 64.

[0072] The filter 64 filters the gaseous processing fluid flowing in the first supply line 71 and removes foreign substances contained in the processing fluid. By removing foreign substances in the processing fluid with the filter 64, 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 a supercritical fluid.

[0073] The capacitor 65 is connected to a cooling water supply unit (not shown), for example, and can exchange heat between the cooling water and the gaseous processing fluid. Thereby, the capacitor 65 cools the gaseous processing fluid flowing in the first supply line 71 to generate a liquid-state processing fluid. The capacitor 65 is an example of a cooling unit.

[0074] The tank 66 stores the process fluid in a liquid state generated by the capacitor 65. The pump 67 sends out the process fluid in a liquid state stored in the tank 66 to the downstream side of the first supply line 71.

[0075] A branch point 62A is provided on the second supply line 72A, a branch point 62B is provided on the second supply line 72B, and a branch point 62C is provided on the second supply line 72C. The branch point 62A is provided between the valve 115A and the drying unit 18A, the branch point 62B is provided between the valve 115B and the drying unit 18B, and the branch point 62C is provided between the valve 115C and the drying unit 18C. The supply unit 19 has a first branch line 73A connected to the branch point 62A, a first branch line 73B connected to the branch point 62B, and a first branch line 73C connected to the branch point 62C.

[0076] In the first branch line 73A, a valve 116A, a back pressure valve 131A, and a valve 114A are provided in order from the upstream side (branch point 62A side). In the first branch line 73B, a valve 116B, a back pressure valve 131B, and a valve 114B are provided in order from the upstream side (branch point 62B side). In the first branch line 73C, a valve 116C, a back pressure valve 131C, and a valve 114C are provided in order from the upstream side (branch point 62C side).

[0077] The valve 116A is a valve that adjusts the on and off of the flow of the process fluid. In the open state, the process fluid flows into the downstream first branch line 73A, and in the closed state, the process fluid does not flow into the downstream first branch line 73A. The valves 116B and 116C have the same configuration as the valve 116A.

[0078] When the pressure on the primary side of the back pressure valve 131A exceeds the set pressure, the back pressure valve 131A adjusts the valve opening degree and allows fluid to flow to the secondary side, thereby maintaining the pressure on the primary side at the set pressure. For example, the set pressure of the back pressure valve 131A is adjusted by the control unit 7 based on the outputs of the pressure sensor 142A and the pressure sensor 243. The back pressure valves 131B and 131C have the same configuration as the back pressure valve 131A. The back pressure valves 131A to 131C are an example of the second flow rate adjustment unit.

[0079] The valve 114A is a valve that adjusts the on and off of the flow of the processing fluid. In the open state, the processing fluid flows to the downstream first branch line 73A, and in the closed state, the processing fluid does not flow to the downstream first branch line 73A. The valves 114B and 114C have the same configuration as the valve 114A.

[0080] The supply unit 19 has a second branch line 74 connected to the first branch lines 73A to 73C. The first branch lines 73A to 73C are connected to the second branch line 74 at a plurality of connection points 75A and 75B provided on the second branch line 74. Specifically, the first branch line 73A is connected to the second branch line 74 at the connection point 75A, and the first branch lines 73B and 73C are connected to the second branch line 74 at the connection point 75B. The second branch line 74 is connected to the connection point 61. That is, the second branch line 74 connects the first branch lines 73A to 73C and the connection point 61. Note that the second branch line 74 may not be provided, and the first branch lines 73A to 73C may be directly connected to the first supply line 71 upstream of the filter 64 at independent connection points.

[0081] In the second supply line 72A, between the branch point 77A and the branch point 62A, in order from the upstream side (the branch point 77A side), a pressure sensor 141A, a third flow rate adjustment unit 150A, a pressure sensor 142A, and a valve 115A are provided. In the second supply line 72B, between the branch point 77B and the branch point 62B, in order from the upstream side (the branch point 77B side), a pressure sensor 141B, a third flow rate adjustment unit 150B, a pressure sensor 142B, and a valve 115B are provided. In the second supply line 72C, between the branch point 77B and the branch point 62C, in order from the upstream side (the branch point 77B side), a pressure sensor 141C, a third flow rate adjustment unit 150C, a pressure sensor 142C, and a valve 115C are provided.

[0082] The pressure sensor 141A measures the pressure of the process fluid flowing through the second supply line 72A upstream of the third flow rate adjustment unit 150A. The output of the pressure sensor 141A is transmitted to the control unit 7. The pressure sensors 141B and 141C have the same configuration as the pressure sensor 141A.

[0083] The third flow rate adjustment unit 150A adjusts the flow rate of the process fluid flowing through the first branch line 73A. The third flow rate adjustment units 150B and 150C have the same configuration as the third flow rate adjustment unit 150A.

[0084] The pressure sensor 142A measures the pressure of the process fluid flowing through the second supply line 72A between the third flow rate adjustment unit 150A and the valve 115A. That is, the pressure sensor 142A can measure the pressure on the primary side of the orifices 221, 222, and 223. The pressure sensors 142B and 142C have the same configuration as the pressure sensor 142A. The pressure sensors 142A to 142C are an example of the second pressure measurement unit.

[0085] The valve 115A is a valve that adjusts the on and off of the flow of the process fluid. In the open state, the process fluid flows into the downstream second supply line 72A, and in the closed state, the process fluid does not flow into the downstream second supply line 72A. The valves 115B and 115C have the same configuration as the valve 115A.

[0086] Referring to FIG. 6, the configuration of the third flow rate adjustment unit 150A will be described. FIG. 6 is a diagram showing a configuration example of the third flow rate adjustment unit 150A and its surroundings. The third flow rate adjustment units 150B and 150C have the same configuration as the third flow rate adjustment unit 150A.

[0087] As shown in FIG. 6, the third flow rate adjustment unit 150A has orifices 120 to 123 and valves 111 to 113. Orifices 121, 122, and 123 are connected in parallel to orifice 120. Valve 111 is connected in series to orifice 121. Valve 112 is connected in series to orifice 122. Valve 113 is connected in series to orifice 123.

[0088] Orifices 120 to 123 serve to reduce the flow velocity of the processing fluid flowing through the second supply line 72A and adjust the pressure. Orifices 120 to 123 can allow the processing fluid with adjusted pressure to flow through the downstream second supply line 72A.

[0089] Valves 111 to 113 are valves that adjust the on and off of the flow of the processing fluid. In the open state, the processing fluid flows through the downstream second supply line 72A, and in the closed state, the processing fluid does not flow through the downstream second supply line 72A.

[0090] The basic operation of the supply unit 19 will be described. The gaseous processing fluid supplied from the processing fluid supply source 90 to the first supply line 71 is supplied to the condenser 65 through the filter 64, cooled by the condenser 65, and liquefied. The liquefied processing fluid is stored in the tank 66. The liquid processing fluid stored in the tank 66 is made into a high-pressure fluid by the pump 67, and a part of it is supplied to the drying units 18A to 18C. The high-pressure fluid supplied to the drying units 18A to 18C is brought into a supercritical state by the heater 68 and used for drying. Another part of the high-pressure fluid flows into the first branch lines 73A to 73C and returns from the connection point 61 to the first supply line 71. In this way, the processing fluid circulates within the supply unit 19.

[0091] 〔Substrate Processing Method〕 Referring to FIGS. 7 to 14, a substrate processing method according to an embodiment will be described. Hereinafter, a drying method (substrate processing method) executed using the drying unit 18A will be described. FIGS. 7 to 14 are diagrams showing the substrate processing method according to the embodiment. FIGS. 7 to 14 show, as an example, the specific operations of the supply unit 19 when a processing fluid is supplied to the drying unit 18A. During the operations shown in FIGS. 7 to 14, the pump 67 continues to operate. As shown in FIGS. 7 to 14, the processing fluid supply unit 80 includes the supply unit 19, the first flow rate adjustment unit 250, the pressure sensor 243, and the heater 68 in the drying unit 18A. The processing fluid supply unit 80 may include the control device 6. The processing fluid supply unit 80 is an example of a fluid supply system.

[0092] <Standby process> The standby process is a process of waiting for the supply of the processing fluid after the wafer W is transferred to the drying unit 18A. In the standby process, as shown in FIG. 7, the valves 111 to 113 are opened. Also, the valves 114A, 115A, and 116A are opened, and the valves 211 to 214 are closed. The processing fluid guided to the second supply line 72A passes through the orifice 120 and reaches the branch point 62A via the orifices 121 to 123, and flows into the first branch line 73A. The processing fluid guided to the first branch line 73A reaches the connection point 61 via the valve 116A, the back pressure valve 131A, the valve 114A, and the second branch line 74, and further returns to the tank 66 via the filter 64 and the capacitor 65.

[0093] During this series of operations, the control unit 7 receives the output from the pressure sensor 142A and adjusts the set pressure of the back pressure valve 131A so that the pressure of the processing fluid flowing downstream of the orifice 120 in the second supply line 72A becomes a preset pressure (for example, 19.0 MPa). That is, the control unit 7 controls the pressure of the processing fluid at the branch point 62A by changing the amount of the processing fluid flowing through the first branch line 73A.

[0094] In the standby process, the processing fluid is not supplied from the processing fluid supply source 90, and the processing fluid circulates in the supply unit 19. At this time, since the valves 111 to 113 are in the open state, it is difficult for the processing fluid to stay in the third flow rate adjustment unit 150A. Therefore, the generation of particles due to the stay can be suppressed.

[0095] <Pressure boosting process> After the standby process, a pressure boosting process is performed. The pressure boosting process is a process of raising the pressure in the main body 31 to the processing pressure. In the pressure boosting process, first, the pressure is raised by supplying the supercritical state processing fluid at the first flow rate into the main body 31. Thereafter, the pressure is further raised by supplying the supercritical state processing fluid at the second flow rate higher than the first flow rate into the main body 31. Thereafter, the pressure is further raised by supplying the supercritical state processing fluid at the third flow rate higher than the second flow rate into the main body 31. That is, the pressure is raised in three stages.

[0096] In the pressure boosting at the first flow rate, as shown in FIG. 8, the valves 111 to 113 are in the closed state, and the valves 114A, 115A, and 116A are in the open state. The processing fluid guided to the second supply line 72A reaches the branch point 62A via one orifice 120 without passing through the three orifices 121 to 123.

[0097] A part of the processing fluid that reaches the branch point 62A is supplied to the drying unit 18A, and the other part flows from the branch point 62A to the first branch line 73A. The processing fluid guided to the first branch line 73A reaches the connection point 61 via the valve 116A, the back pressure valve 131A, the valve 114A, and the second branch line 74, and further returns to the tank 66 via the filter 64 and the capacitor 65.

[0098] During this series of operations, the control unit 7 receives the output from the pressure sensor 142A and adjusts the set pressure of the back pressure valve 131A so that the pressure of the process fluid flowing downstream of the orifice 120 in the second supply line 72A becomes a preset pressure (for example, 7.0 MPa). That is, the control unit 7 controls the pressure of the process fluid at the branch point 62A by changing the amount of the process fluid flowing into the first branch line 73A.

[0099] In the drying unit 18A, the valve 211 is opened and the valves 212, 213, and 214 are closed. Therefore, the process fluid supplied to the drying unit 18 reaches the heater 68 via the orifice 221 without passing through the orifices 222 and 223, and is heated by the heater 68 to be in a supercritical state. Then, the process fluid in the supercritical state is supplied to the main body 31 at the first flow rate. The pressure inside the main body 31 to which the process fluid in the supercritical state is supplied gradually increases from 0 MPa. In the pressure increase at the first flow rate, since the pressure of the process fluid at the branch point 62A is maintained at the preset pressure, the supply pressure of the process fluid in the supercritical state to the main body 31 is constant.

[0100] During the pressure increase at the first flow rate, the control unit 7 receives the output from the pressure sensor 242, and when the pressure inside the main body 31 reaches the preset pressure, it shifts to the pressure increase at the second flow rate. The preset pressure may be 3.0 MPa or less, for example, 1.0 MPa. Without using the pressure value as a reference, when a preset time has elapsed since the start of the pressure increase at the first flow rate, it may shift to the pressure increase at the second flow rate.

[0101] In the pressure increase at the second flow rate, first, as shown in FIG. 9, the valve 212 is opened. The states of the other valves are the same as those shown in FIG. 8. As a result, the process fluid supplied to the drying unit 18A reaches the heater 68 via not only the orifice 221 but also the orifice 222, and is heated by the heater 68 to be in a supercritical state. Therefore, the flow rate of the process fluid in the supercritical state supplied to the main body 31 increases to the second flow rate.

[0102] During this series of operations, the control unit 7 receives the output from the pressure sensor 242 and adjusts the set pressure of the back pressure valve 131A so that the pressure inside the main body 31 gradually increases with a predetermined change. That is, the control unit 7 changes the amount of the process fluid flowing through the first branch line 73A to control the pressure of the process fluid at the branch point 62A. Since the pressure of the process fluid at the branch point 62A gradually increases, the supply pressure of the supercritical state process fluid to the main body 31 also gradually increases. When the pressure inside the main body 31 reaches a preset pressure, the control unit 7 shifts to the pressure increase at the third flow rate. The preset pressure may be 7.0 MPa or less, for example, 7.0 MPa. Even if the pressure value is not used as a reference, when a preset time has elapsed since the start of the pressure increase at the second flow rate, the control unit 7 may shift to the pressure increase at the third flow rate.

[0103] In the pressure increase at the third flow rate, first, as shown in FIG. 10, the valve 213 is opened. The states of the other valves are the same as those shown in FIG. 9. As a result, the process fluid supplied to the drying unit 18A reaches the heater 68 via the orifices 221, 222, and 223 and is heated by the heater 68 to be in a supercritical state. Therefore, the flow rate of the supercritical state process fluid supplied to the main body 31 increases to the third flow rate.

[0104] During this series of operations, the control unit 7 receives the output from the pressure sensor 242 and adjusts the set pressure of the back pressure valve 131A so that the pressure inside the main body 31 gradually increases with a predetermined change. That is, the control unit 7 changes the amount of the process fluid flowing through the first branch line 73A to control the pressure of the process fluid at the branch point 62A. Since the pressure of the process fluid at the branch point 62A gradually increases, the supply pressure of the supercritical state process fluid to the main body 31 also gradually increases.

[0105] In the pressure increase at the third flow rate, as the pressure of the process fluid at the branch point 62A increases, the differential pressure between the upstream side and the downstream side of the orifice 120 decreases. Therefore, when the pressure of the process fluid at the branch point 62A reaches a preset pressure (for example, 11.0 MPa), the control unit 7 opens the valve 111 as shown in FIG. 11. The states of the other valves are the same as those shown in FIG. 10. As a result, even if the differential pressure between the upstream side and the downstream side of the orifice 120 decreases, the process fluid can continue to flow through the first branch line 73A and the second branch line 74. During this period, the pressure in the main body 31 rises from, for example, 7.0 MPa to 13.0 MPa.

[0106] When the pressure of the process fluid at the branch point 62A reaches a higher preset pressure (for example, 14.5 MPa), the control unit 7 also opens the valve 112 as shown in FIG. 12. The states of the other valves are the same as those shown in FIG. 11. As a result, even if the differential pressure between the upstream side and the downstream side of the orifice 120 further decreases, the process fluid can continue to flow through the first branch line 73A and the second branch line 74. During this period, the pressure in the main body 31 rises from, for example, 13.0 MPa to 15.0 MPa.

[0107] When the pressure of the process fluid at the branch point 62A reaches an even higher preset pressure (for example, 17.0 MPa), the control unit 7 also opens the valve 113 as shown in FIG. 13. The states of the other valves are the same as those shown in FIG. 12. As a result, even if the differential pressure between the upstream side and the downstream side of the orifice 120 further decreases, the process fluid can continue to flow through the first branch line 73A and the second branch line 74. During this period, the pressure in the main body 31 rises from, for example, 15.0 MPa to 16.0 MPa.

[0108] In this way, the pressure increase process is performed.

[0109] <Flow process> After the boosting process, a circulation process is performed. The circulation process is a process of drying the liquid film of the IPA liquid on the wafer W conveyed into the main body 31 using a processing fluid in a supercritical state. In the circulation process, as shown in FIG. 14, valves 111 to 113 are opened. Also, valves 114A, 115A, and 116A are opened. The processing fluid guided to the second supply line 72A reaches the branch point 62A via four orifices 120 to 123.

[0110] A part of the processing fluid that has reached the branch point 62A is supplied to the drying unit 18A, and the other part flows from the branch point 62A to the first branch line 73A. The processing fluid guided to the first branch line 73A reaches the connection point 61 via the valve 116A, the back pressure valve 131A, the valve 114A, and the second branch line 74, and then returns to the tank 66 via the filter 64 and the capacitor 65.

[0111] Also, in the drying unit 18A, valves 211 to 214 are opened. Therefore, the processing fluid flows into the second supply line 72A and is supplied into the main body 31 from the supply port 35. Also, the processing fluid flows from the discharge port 37 of the main body 31 through the discharge line 76 and is discharged to the outside through the valve 214, the flow meter 251, and the back pressure valve 231.

[0112] During this series of operations, first, the control unit 7 receives the first pressure P1 of the processing fluid in the liquid state measured by the pressure sensor 243 and the second pressure P2 of the processing fluid in the liquid state measured by the pressure sensor 142A. Next, the control unit 7 calculates the supply flow rate of the processing fluid flowing through the second supply line 72A based on the first pressure P1 and the second pressure P2. Next, the control unit 7 adjusts the set pressure of the back pressure valve 131A so that the calculated supply flow rate of the processing fluid becomes the set flow rate during the circulation process.

[0113] The control unit 7 calculates the supply flow rate Q of the processing fluid flowing through the second supply line 72, for example, by the calculation formula of Equation (1).

[0114] Q = Cd·(ΔP) 1 / 2 ···(1) In formula (1), ΔP is the value obtained by subtracting the first pressure P1 from the second pressure P2 (ΔP = P2 - P1), and Cd is the flow coefficient.

[0115] The flow coefficient Cd can be calculated by the calculation formula of formula (2) when the process fluid is circulated through the main body 31 under predetermined conditions and the first pressure P1, the second pressure P2, and the discharge flow rate of the process fluid measured by the flow meter 251 are stable.

[0116] Qs = Cd·(ΔPs) 1 / 2 ···(2) In formula (2), Qs is the discharge flow rate of the process fluid measured by the flow meter 251 at the time when the first pressure P1, the second pressure P2, and the discharge flow rate of the process fluid measured by the flow meter 251 are stable. In formula (2), ΔPs is the differential pressure between the second pressure P2 and the first pressure P1 (ΔPs = P2 - P1) at the time when the first pressure P1, the second pressure P2, and the discharge flow rate of the process fluid measured by the flow meter 251 are stable.

[0117] The flow coefficient Cd may be calculated for each of the drying units 18A to 18C. In this case, excellent uniformity of the supply flow rate can be obtained among the plurality of drying units 18A to 18C. The flow coefficient Cd may be calculated for each state of the valves 211 to 213. The flow coefficient Cd may include the flow coefficient when one of the three valves 211 to 213 is in the open state, the flow coefficient when two of the three valves 211 to 213 are in the open state, and the flow coefficient when all of the three valves 211 to 213 are in the open state.

[0118] The flow coefficient Cd when the valve 211 is in the open state A is calculated by the calculation formula of formula (2) in a state where the valve 211 is in the open state, the valves 212 and 213 are in the closed state, and the process fluid is circulated through the main body 31 under predetermined conditions. The flow coefficient Cd when the valve 212 is in the open state B , and the flow coefficient Cd when the valve 213 is in the open state C is the flow coefficient Cd A and is calculated in the same manner.

[0119] Flow coefficient Cd when valves 211 and 212 are in the open state AB is calculated by the calculation formula of Equation (2) in a state where valves 211 and 212 are in the open state, valve 213 is in the closed state, and a processing fluid is circulated through the main body 31 under predetermined conditions. Flow coefficient Cd when valves 212 and 213 are in the open state BC , and flow coefficient Cd when valves 211 and 213 are in the open state AC is calculated in the same manner as the flow coefficient Cd AB .

[0120] Flow coefficient Cd when all of valves 211 to 213 are in the open state ABC is calculated by the calculation formula of Equation (2) in a state where valves 211, 212, and 213 are in the open state and a processing fluid is circulated through the main body 31 under predetermined conditions. Flow coefficient Cd when all of valves 211 to 213 are in the open state ABC is the flow coefficient Cd A and the flow coefficient Cd B and the flow coefficient Cd C sum (Cd A +Cd B +Cd C ).

[0121] In the circulation process, the control unit 7 also receives the output from the pressure sensor 242 and adjusts the set pressure of the back pressure valve 231 so that the pressure in the main body 31 is maintained at the set pressure during the circulation process.

[0122] <Discharge process> The discharge process is performed after the circulation process. The discharge process is a process of discharging the processing fluid from the main body 31. In the discharge process, valves 211, 212, and 213 are in the closed state. The states of other valves are the same as those shown in FIG. 14. When the pressure in the main body 31 becomes lower than the critical pressure of the processing fluid due to the discharge process, the supercritical state processing fluid vaporizes and detaches from the concave portion of the pattern. Thereby, the drying process for one wafer W is completed.

[0123] When the processing fluid is supplied to the drying units 18B and 18C, the valves 111 to 113, 211 to 213, etc. are controlled in the same manner as when the processing fluid is supplied to the drying unit 18A.

[0124] As described above, in the substrate processing apparatus 1, during the flow-through process, first, the control unit 7 calculates the supply flow rate of the processing fluid flowing through the second supply line 72A based on the first pressure P1 measured by the pressure sensor 243 and the second pressure P2 measured by the pressure sensor 142A. Next, the control unit 7 adjusts the set pressure of the back pressure valve 231 so that the calculated supply flow rate of the processing fluid becomes the set flow rate during the flow-through process. In this case, since the back pressure valve 231 can be controlled based on the supply flow rate of the liquid-state processing fluid flowing upstream of the main body 31, the responsiveness of the flow rate control of the supercritical fluid can be enhanced. As a result, excellent uniformity of the supply flow rate can be obtained among the plurality of drying units 18A to 18C. Also, excellent uniformity of the supply flow rate can be obtained among the plurality of processes performed in a specific drying unit 18A to 18C. Further, it is not necessary to provide a flow meter for controlling the back pressure valve 231 upstream of the main body 31.

[0125] On the other hand, consider the case where the set pressure of the back pressure valve 131A is adjusted so that the pressure measured by the pressure sensor 242 provided in the discharge line 76 is maintained at the set pressure during the flow-through process. The pressure sensor 242 measures the pressure of the processing fluid downstream of the main body 31. The processing fluid downstream of the main body 31 is in a supercritical state or a gaseous state and is compressible. Also, the pressure sensor 242 is provided at a position farther from the back pressure valve 231 than the pressure sensors 243 and 142A. For this reason, when controlling the back pressure valve 231 based on the pressure measured by the pressure sensor 242, it is difficult to enhance the responsiveness of the flow rate control of the supercritical fluid.

[0126] Also, in the substrate processing apparatus 1, the pressure sensors 243 and 142A are provided upstream of the heater 68. For this reason, the supply flow rate of the liquid-state processing fluid can be reliably measured. As a result, the supply flow rate of the processing fluid to the main body 31 can be adjusted with high accuracy.

[0127] In the substrate processing apparatus 1, orifices 221 to 223 are provided at positions where the processing fluid in a liquid state flows. Since the density and viscosity of the processing fluid in a liquid state hardly change due to temperature changes and pressure changes, it is easy to calculate the flow coefficient Cd. On the other hand, for the processing fluid in a supercritical state, since the density and viscosity change due to temperature changes and pressure changes, it is difficult to calculate the flow coefficient Cd.

[0128] In the substrate processing apparatus 1, during standby processing, pressure increasing processing, circulation processing, and discharge processing, the processing fluid can always be circulated through the flow paths passing through the first supply line 71, the second supply lines 72A to 72C, the first branch lines 73A to 73C, and the second branch line 74. Therefore, the difference in temperature of the processing fluid supplied to the main body 31 during pressure increasing processing, circulation processing, and discharge processing can be reduced.

[0129] In the substrate processing apparatus 1, the flow rate of the processing fluid in a supercritical state supplied into the main body 31 during pressure increasing processing can be adjusted. For example, the processing fluid can be supplied at a small first flow rate, then at a large second flow rate, and then at an even larger third flow rate. There may be a fine pattern formed on the surface of the wafer W carried into the main body 31. In that case, if the processing fluid is supplied at a large flow rate, there is a risk of pattern collapse. On the other hand, by supplying the processing fluid at the first flow rate before supplying it at the second flow rate, while suppressing pattern collapse, the processing fluid in a supercritical state can be spread between the patterns, and pattern collapse can also be suppressed when supplying at the second and third flow rates. Furthermore, since the processing fluid can be supplied at the second and third flow rates that are larger than the first flow rate, after the processing fluid in a supercritical state has spread between the patterns, the time required for pressure increase can be shortened by supplying the processing fluid at the second and third flow rates.

[0130] In the substrate processing apparatus 1, the heater 68 is provided on the downstream side (main body 31 side) of the first flow rate adjustment unit 250. Therefore, it is easy to stabilize the temperature of the supercritical processing fluid when it is supplied into the main body 31. In particular, excellent temperature uniformity can be obtained among the plurality of drying units 18A to 18C.

[0131] Also, since the third flow rate adjustment units 150A to 150C are provided in the supply unit 19, the flow rate (circulation flow rate) of the processing fluid circulating through the first branch lines 73A to 73C can be stabilized. For example, during pressure increase at the first flow rate, the pressure inside the main body 31 is low, and the pressure of the processing fluid at the branch point 62A is also low, so the differential pressure between the upstream side and the downstream side of the orifice 120 becomes large. Even in this case, in the present embodiment, by closing the valves 111 to 113, the circulation flow rate can be reduced and the load on the pump 67 can be suppressed. Also, during pressure increase at the second flow rate, by appropriately opening the valves 111 to 113 according to the differential pressure between the upstream side and the downstream side of the orifice 120, the processing fluid can continue to flow through the first branch line 73A and the second branch line 74.

[0132] It should be considered that all aspects of the embodiments disclosed this time are illustrative and not restrictive. The above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and spirit of the appended claims.

[0133] For example, in the pressure increase process, when the first pressure P1 and the second pressure P2 are equal to or higher than a predetermined pressure, the control unit 7 may adjust the back pressure valve 231 based on the first pressure P1 and the second pressure P2 in the same manner as in the flow-through process. For example, when the processing fluid is CO 2 , the predetermined pressure may be 6.0 MPa. In this case, since the processing fluid in the second supply line 72A upstream of the heater 68 is in a liquid state, it is easy to calculate the flow coefficient Cd. The predetermined pressure may be the critical pressure of the processing fluid.

[0134] For example, the processing fluid used in the drying process is CO 2It may also be a fluid other than IPA (for example, a fluorine-based fluid), and any fluid capable of removing the liquid for preventing drying, which is filled on the wafer W, in a supercritical state can be used as the processing fluid. Also, the liquid for preventing drying is not limited to IPA, and any liquid that can be used as the liquid for preventing drying can be used. The substrate to be processed is not limited to the wafer W described above, and may be other substrates such as a glass substrate for LCD or a ceramic substrate.

Explanation of Signs

[0135] 1 Substrate processing apparatus 7 Control unit 31 Main body 61 Connection point 62A Branch point 67 Pump 68 Heater 71 First supply line 72, 72A, 72B, 72C Second supply line 73A, 73B, 73C First branch line 74 Second branch line 80 Processing fluid supply unit 131A Back pressure valve 142A, 243 Pressure sensor 250 First flow rate adjustment unit W Wafer

Claims

1. A processing container having a processing space capable of accommodating a substrate with its surface wetted by a liquid, A processing fluid supply unit for supplying a supercritical processing fluid to the processing container, Comprising, The processing fluid supply unit, A fluid supply line having one end connected to a fluid supply source and the other end connected to the processing container, A pump provided in the fluid supply line, A heating unit provided in the fluid supply line, downstream of the pump, for heating the processing fluid to generate the supercritical processing fluid, A first flow rate adjustment unit provided in the fluid supply line, between the pump and the heating unit, for adjusting the supply flow rate of the processing fluid supplied to the processing container, A first pressure measurement unit provided in the fluid supply line, between the first flow rate adjustment unit and the heating unit, for measuring the pressure of the processing fluid, A second pressure measurement unit provided in the fluid supply line, between the pump and the first flow rate adjustment unit, for measuring the pressure of the processing fluid, A branch point provided between the pump and the first flow rate adjustment unit in the fluid supply line, A connection point provided upstream of the pump in the fluid supply line, A branch line connecting the branch point and the connection point, A second flow rate adjustment unit provided in the branch line for adjusting the supply flow rate of the processing fluid supplied to the processing container, A control unit for controlling the second flow rate adjustment unit based on a first pressure of the processing fluid in a liquid state measured by the first pressure measurement unit and a second pressure of the processing fluid in a liquid state measured by the second pressure measurement unit, Having, A substrate processing apparatus.

2. The processing fluid is carbon dioxide, The control unit controls the second flow rate adjustment unit based on the first pressure and the second pressure when the first pressure and the second pressure are 6.0 MPa or more, The substrate processing apparatus according to Claim 1.

3. The first flow rate adjustment unit, A first on-off valve provided in the fluid supply line, A first throttle connected in series to the first on-off valve, Having, The substrate processing apparatus according to Claim 1.

4. Comprising a discharge unit for discharging the processing fluid from the processing container, The discharge unit, A discharge line connected to the processing container, A flow meter provided in the discharge line for measuring the discharge flow rate of the processing fluid discharged from the processing container, Having, The control unit calculates a coefficient of a calculation formula representing the relationship between the supply flow rate and the differential pressure based on the differential pressure between the second pressure and the first pressure and the discharge flow rate. The substrate processing apparatus according to claim 1.

5. The control unit (a) heating and waiting for the processing fluid before supplying the processing fluid into the processing vessel; (b) increasing the pressure in the processing vessel to a processing pressure by supplying the processing fluid into the processing vessel; (c) supplying the processing fluid into the processing vessel and discharging the processing fluid in the processing vessel from the discharge unit; (d) stopping the supply of the processing fluid into the processing vessel and discharging the processing fluid in the processing vessel from the discharge unit; and executes In (c), the control unit controls the second flow rate adjustment unit based on the first pressure and the second pressure. The substrate processing apparatus according to claim 4.

6. The discharge unit includes a third pressure measurement unit provided in the discharge line for measuring the pressure in the processing vessel, and a pressure adjustment unit provided in the discharge line for adjusting the pressure in the processing vessel. and has In (c), the control unit controls the pressure adjustment unit based on the pressure in the processing vessel measured by the third pressure measurement unit. The substrate processing apparatus according to claim 5.

7. (b) (b1) increasing the pressure in the processing vessel to the critical pressure of the processing fluid; (b2) increasing the pressure in the processing vessel from the critical pressure of the processing fluid to the processing pressure; and has In (b2), the control unit controls the second flow rate adjustment unit based on the first pressure and the second pressure. The substrate processing apparatus according to claim 6.

8. The processing fluid supply unit includes a cooling unit provided in the fluid supply line for cooling the gaseous processing fluid to generate the liquid-state processing fluid, and a pump provided in the fluid supply line and downstream of the cooling unit. and has The substrate processing apparatus according to any one of claims 1 to 7.

9. A fluid supply system for supplying a supercritical-state processing fluid to a processing vessel having a processing space capable of accommodating a substrate with its surface wetted by a liquid, a fluid supply line having one end connected to a fluid supply source and the other end connected to the processing vessel, a pump provided in the fluid supply line, A heating unit provided in the fluid supply line, provided downstream of the pump, for heating the processing fluid to generate the processing fluid in a supercritical state; A first flow rate adjustment unit provided in the fluid supply line, provided between the pump and the heating unit, for adjusting the supply flow rate of the processing fluid supplied to the processing vessel; A first pressure measurement unit provided in the fluid supply line, provided between the first flow rate adjustment unit and the heating unit, for measuring the pressure of the processing fluid; A second pressure measurement unit provided in the fluid supply line, provided between the pump and the first flow rate adjustment unit, for measuring the pressure of the processing fluid; A branch point provided between the pump and the first flow rate adjustment unit in the fluid supply line; A connection point provided upstream of the pump in the fluid supply line; A branch line connecting the branch point and the connection point; A second flow rate adjustment unit provided in the branch line, for adjusting the supply flow rate of the processing fluid supplied to the processing vessel; A control unit for controlling the second flow rate adjustment unit based on a first pressure of the processing fluid in a liquid state measured by the first pressure measurement unit and a second pressure of the processing fluid in a liquid state measured by the second pressure measurement unit; A fluid supply system having the above components.

10. The processing fluid is carbon dioxide, When the first pressure and the second pressure are 6.0 MPa or more, the control unit controls the second flow rate adjustment unit based on the first pressure and the second pressure. The fluid supply system according to claim 9.

11. The first flow rate adjustment unit includes A first on-off valve provided in the fluid supply line; A first throttle connected in series with the first on-off valve; having The fluid supply system according to claim 9.

12. A cooling unit provided in the fluid supply line, for cooling the processing fluid in a gaseous state to generate the processing fluid in a liquid state; A pump provided in the fluid supply line, provided downstream of the cooling unit; having The fluid supply system according to any one of claims 9 to 11.

13. A substrate processing method using a substrate processing apparatus, wherein The substrate processing apparatus includes A processing vessel having a processing space capable of accommodating a substrate with its surface wetted by a liquid; A processing fluid supply unit for supplying a processing fluid in a supercritical state to the processing vessel; comprising The processing fluid supply unit includes A fluid supply line, one end of which is connected to a fluid supply source and the other end of which is connected to the processing vessel; A pump provided in the fluid supply line, A heating unit provided in the fluid supply line, provided downstream of the pump, for heating the processing fluid to generate the processing fluid in a supercritical state; A first flow rate adjustment unit provided in the fluid supply line, provided between the pump and the heating unit, for adjusting the supply flow rate of the processing fluid supplied to the processing vessel; A first pressure measurement unit provided in the fluid supply line, provided between the first flow rate adjustment unit and the heating unit, for measuring the pressure of the processing fluid; A second pressure measurement unit provided in the fluid supply line, provided between the pump and the first flow rate adjustment unit, for measuring the pressure of the processing fluid; A branch point provided between the pump and the first flow rate adjustment unit in the fluid supply line; A connection point provided upstream of the pump in the fluid supply line; A branch line connecting the branch point and the connection point; A second flow rate adjustment unit provided in the branch line for adjusting the supply flow rate of the processing fluid supplied to the processing vessel; Comprising Controlling the second flow rate adjustment unit based on a first pressure of the processing fluid in a liquid state measured by the first pressure measurement unit and a second pressure of the processing fluid in a liquid state measured by the second pressure measurement unit; A substrate processing method.

14. The processing fluid is carbon dioxide, When the first pressure and the second pressure are 6.0 MPa or more, controlling the second flow rate adjustment unit based on the first pressure and the second pressure; The substrate processing method according to claim 13.

15. The first flow rate adjustment unit is A first on-off valve provided in the fluid supply line; A first throttle connected in series with the first on-off valve; Comprising The substrate processing method according to claim 13.

16. The substrate processing apparatus includes a discharge unit for discharging the processing fluid from the processing vessel, The discharge unit is A discharge line connected to the processing vessel; A flow meter provided in the discharge line for measuring the discharge flow rate of the processing fluid discharged from the processing vessel; Comprising Calculating a coefficient of a calculation formula representing the relationship between the supply flow rate and the differential pressure based on the differential pressure between the second pressure and the first pressure and the discharge flow rate; The substrate processing method according to claim 13.

17. (a) Heating and waiting for the processing fluid before supplying the processing fluid into the processing vessel; (b) raising the pressure in the processing container to a processing pressure by supplying the processing fluid into the processing container; (c) supplying the processing fluid into the processing container and discharging the processing fluid in the processing container from the discharging portion; (d) stopping the supply of the processing fluid into the processing container and discharging the processing fluid in the processing container from the discharging portion; comprising; in (c), controlling the second flow rate adjusting portion based on the first pressure and the second pressure; The substrate processing method according to claim 16.

18. The discharging portion comprises a third pressure measuring portion provided in the discharging line for measuring the pressure in the processing container; a pressure adjusting portion provided in the discharging line for adjusting the pressure in the processing container; comprising; in (c), controlling the pressure adjusting portion based on the pressure in the processing container measured by the third pressure measuring portion; The substrate processing method according to claim 17.

19. (b) (b1) raising the pressure in the processing container to the critical pressure of the processing fluid; (b2) raising the pressure in the processing container from the critical pressure of the processing fluid to the processing pressure; comprising; in (b2), controlling the second flow rate adjusting portion based on the first pressure and the second pressure; The substrate processing method according to claim 18.

20. The processing fluid supply portion comprises a cooling portion provided in the fluid supply line for cooling the processing fluid in a gaseous state to generate the processing fluid in a liquid state; a pump provided in the fluid supply line and downstream of the cooling portion; comprising; The substrate processing method according to any one of claims 13 to 19.

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