Substrate processing apparatus and substrate processing method

Abstract

To reduce the particle level of a substrate after supercritical drying.SOLUTION: A substrate processing device according to the present disclosure carries out a supercritical drying process on a substrate having a liquid stuck to the surface, using a process liquid in a supercritical state. The substrate processing device comprises: a processing container having an internal space in which supercritical drying is performed on the substrate; a housing in which a processing region where the processing container is disposed and a carry-out / in region for carrying the substrates in and out are installed, respectively; a delivery part which is provided in the carry-out / in region, and which receives / delivers the substrate having entered from the outside of the housing into the carry-out / in region from / to a substrate conveyance arm; a substrate transfer mechanism that transfers the substrate between the delivery part and the processing container; and a gas supply part which is provided in the carry-out / in region so as to be able to supply a dry gas.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] In the manufacture of semiconductor devices in which a laminated structure of integrated circuits is formed on the surface of a substrate such as a semiconductor wafer, liquid processing such as chemical cleaning or wet etching is performed. In order to more reliably prevent collapse of patterns that have become increasingly fine in recent years, a drying method using a processing fluid in a supercritical state has recently been used in the drying step, which is the final step of liquid processing (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-091772 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides techniques that can reduce particle levels on substrates after supercritical drying. [Means for solving the problem]

[0005] According to one embodiment of the present disclosure, there is provided a substrate processing apparatus that performs supercritical drying processing on a substrate having a liquid adhering to its surface using a processing fluid in a supercritical state, the substrate processing apparatus comprising: a processing vessel having an internal space in which the supercritical drying processing is performed on the substrate; a housing having a processing area in which the processing vessel is disposed and a loading / unloading area for loading and unloading a substrate therein; a transfer unit provided in the loading / unloading area for transferring the substrate to and from a substrate transport arm that has entered the loading / unloading area from outside the housing; a substrate transfer mechanism that transfers the substrate between the transfer unit and the processing vessel; and a gas supply unit provided to supply a dry gas to the loading / unloading area. [Effects of the Invention]

[0006] According to the above-described embodiments of the present disclosure, particle levels on substrates after supercritical drying can be reduced. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic cross-sectional view of a substrate processing system according to an embodiment of the substrate processing apparatus. [Figure 2] 2 is a vertical cross-sectional view showing the configuration of a supercritical drying unit included in the substrate processing system of FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view of a processing vessel included in the supercritical drying unit of FIG. 2. [Figure 4] 3 is a schematic diagram showing an entrance and a door provided in the housing of the supercritical drying unit of FIG. 2. FIG. [Figure 5] FIG. 3 is a diagram showing the configuration of a piping system for supplying and discharging a processing fluid to and from the supercritical drying unit of FIG. 2. [Figure 6A] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6B] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6C] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6D] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6E] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6F] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6G] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6H] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6I] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. [Figure 6J] FIG. 4 is an operational diagram illustrating the operation of the supercritical drying unit. DETAILED DESCRIPTION OF THE INVENTION

[0008] A configuration of a substrate processing system 1 according to an embodiment of the substrate processing apparatus will be briefly described below with reference to Fig. 1. For simplicity of description, an XYZ Cartesian coordinate system (see the lower left of Fig. 1) is set and will be referred to as appropriate.

[0009] As shown in FIG. 1, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3.

[0010] The carry-in / out station 2 includes a load port 11 and a transfer block 12. A plurality of carriers C are placed on the load port 11. Each carrier C accommodates a plurality of substrates W (e.g., semiconductor wafers) in a horizontal position, spaced apart in the vertical direction.

[0011] A transport device 13 and a delivery unit 14 are provided within the transport block 12. The delivery unit 14 has an unprocessed substrate placement section on which one or more unprocessed substrates W (substrates W before being processed in the processing station 3) are temporarily placed, and a processed substrate placement section on which one or more processed substrates W (substrates W that have been processed in the processing station 3) are temporarily placed. The transport device 13 can transport substrates W between any carrier C placed on the load port 11 and the delivery unit 14.

[0012] The processing station 3 includes a transport block 4 and a pair of processing blocks 5 provided on both sides of the transport block 4 in the Y direction. Each processing block 5 includes a liquid processing unit 17, a supercritical drying unit 18, and a processing fluid supply cabinet 19. In this embodiment, the liquid processing unit 17 and the supercritical drying unit 18 are single-wafer processing units.

[0013] Liquid processing unit 17 is a rotary liquid processing unit well known in the technical field of semiconductor device manufacturing, and includes a spin chuck and multiple nozzles (neither of which are shown). The spin chuck holds substrate W in a horizontal position and rotates it about a vertical axis. The nozzles supply various processing fluids required for liquid processing of substrate W to substrate W held and rotating on the spin chuck. Supercritical drying unit 18 will be described later. Processing fluids required for processing are supplied to liquid processing unit 17 and supercritical drying unit 18 from a processing fluid supply cabinet 19.

[0014] The transport block 4 includes a transport area 15 and a transport device 16 disposed in the transport area 15. The transport device 16 can transport the substrate W between the delivery unit 14, any liquid processing unit 17, and any supercritical drying unit 18.

[0015] Each processing block 5 may have a multi-layer (e.g., three-layer) structure. In this case, each layer is provided with one liquid processing unit 17, one supercritical drying unit 18, and one processing fluid supply cabinet 19. In this case, one transport device 16 may be able to access the liquid processing units 17 and the supercritical drying units 18 in all layers.

[0016] The substrate processing system 1 includes a control device 6. The control device 6 is, for example, a computer, and includes an arithmetic processing unit 61 and a memory unit 62. The arithmetic processing unit 61 includes a microcomputer having a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), input / output ports, and various circuits. The CPU of the microcomputer reads and executes a program stored in the ROM to control the transfer devices 13 and 16, the liquid processing unit 17, the supercritical drying unit 18, and the processing fluid supply cabinet 19. The program may be recorded on a computer-readable recording medium and installed from the recording medium into the memory unit 62 of the control device 6. Examples of computer-readable recording media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card. The memory unit 62 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk.

[0017] Next, a transfer flow of the substrate W in the above-described substrate processing system 1 will be briefly described.

[0018] An external transfer robot (not shown) places a carrier C containing unprocessed substrates W on the load port 11. The transfer device 13 takes one substrate W from the carrier C and carries it into the delivery unit 14. The transfer device 16 takes the substrate W from the delivery unit 14 and carries it into the liquid processing unit 17.

[0019] In the liquid processing unit 17, a liquid processing consisting of multiple steps is performed. In a non-limiting embodiment, the liquid processing includes at least one chemical liquid processing step, at least one rinsing step, and an IPA substitution step. In the chemical liquid processing step, a cleaning chemical liquid or a wet etching chemical liquid is supplied from a nozzle to the substrate W being rotated by the spin chuck. In the rinsing step, a rinse liquid (e.g., DIW (pure water)) is supplied from a nozzle to the substrate W being rotated by the spin chuck to wash away the chemical liquid and reaction products remaining on the surface of the substrate W. In the IPA substitution step, IPA (isopropyl alcohol) is supplied from a nozzle to the substrate W being rotated by the spin chuck to replace the rinse liquid on the surface of the substrate W (including the surface of the recesses of the pattern) with IPA. Thereafter, the rotation speed of the substrate is reduced to an extremely low speed while IPA is still being supplied from the nozzle to adjust the IPA film thickness, and then the supply of IPA is stopped and the rotation of the substrate W is stopped. This results in a state in which an IPA liquid film (IPA puddle) having a desired thickness is covered on the surface of the substrate W. The contents of the processing steps before this are arbitrary, as long as the surface of the substrate W (including the surface of the recesses of the pattern) is ultimately covered with an IPA liquid film having a desired thickness.

[0020] Next, the substrate W with the IPA puddle formed on its surface is removed from the liquid processing unit 17 by the transfer device 16 and loaded into the supercritical drying unit 18. In the supercritical drying unit 18, the substrate W is dried using supercritical drying technology according to the procedure described below. The supercritical drying technology is advantageously used to dry substrates on which fine patterns with high aspect ratios are formed, because surface tension that can cause pattern collapse does not act on the pattern. Thereafter, the transfer device 16 removes the dried substrate W from the supercritical drying unit 18 and loads it into the delivery unit 14. The transfer device 13 removes the substrate W from the delivery unit 14 and stores it in the original carrier C placed on the load port 11. This completes the series of processes for one substrate.

[0021] Next, the configuration and operation of the supercritical drying unit 18 will be described in detail.

[0022] As shown in Fig. 2, the supercritical drying unit 18 has a housing (enclosure) 100. Inside the housing 100, there are defined a processing region 101 (the region on the right side in Fig. 2) in which a processing vessel 111 formed as a supercritical processing chamber is disposed, and a loading / unloading region 102 (the region on the left side in Fig. 2) which serves as a working area for loading and unloading the substrate W. The housing 100 is a roughly rectangular box-shaped structure that substantially completely encloses the processing region 101 and the loading / unloading region 102. See also Fig. 1 for details of the housing 100.

[0023] The supercritical drying unit 18 further includes a substrate holding tray 112 (hereinafter simply referred to as "tray 112") that holds the substrate W within the processing vessel 111. The tray 112 includes a lid 113 that covers an opening 111C provided in the sidewall of the processing vessel 111, and a horizontally extending substrate holding portion 114 that is integrally connected to the lid (lid body) 113. The substrate holding portion 114 includes a plate 115 and a plurality of support pins 116 provided on the upper surface of the plate 115. The substrate W is placed horizontally on the support pins 116 with its front surface (the surface on which a device or pattern is formed) facing upward. When the substrate W is placed on the support pins 116, a gap is formed between the upper surface of the plate 115 and the lower surface (back surface) of the substrate W.

[0024] 3, the plate 115 has a generally rectangular shape as a whole in a plan view. The area of ​​the plate 115 is larger than that of the substrate W, and when the substrate W is placed at a predetermined position on the substrate holder 114, the substrate W is completely covered by the plate 115 when viewed from directly below.

[0025] 2, the plate 115 is formed with a plurality of (for example, three) through holes 118 that vertically penetrate the plate 115. The plurality of through holes 118 serve to allow a processing fluid supplied to a space below the plate 115 to flow into a space above the plate 115. The through holes 118 also serve to allow lift pins 171, which will be described later, to pass through when the substrate W is transferred between the substrate holder 114 and the arm of the transfer device 16 (see FIG. 1).

[0026] The tray 112 can be moved horizontally (in the X direction) between a closed position (the position on the right side in FIG. 2) and an open position (the position on the left side in FIG. 2) by a tray moving mechanism 112M, which is schematically shown by a hollow square box in FIG. 2. Although not shown in detail, the tray moving mechanism 112M can be composed of, for example, a guide rail that extends in the X direction on the floor plate 100F of the housing 100, and a moving body that is coupled to the lid portion 113 and runs along the guide rail.

[0027] When the tray 112 is in the closed position, the substrate holding part 114 is located in the processing region 101, more specifically, in the internal space (processing space) of the processing vessel 111, and the lid part 113 closes the opening 111C in the sidewall of the processing vessel 111. When the tray 112 is in the open position, the substrate holding part 114 is located in the loading / unloading region 102 outside the processing vessel 111, and the substrate W can be transferred between the substrate holding part 114 and the transfer arm of the transfer device 16 via lift pins 171, which will be described later. Furthermore, when the tray 112 is in the open position, the lid part 113 opens the opening 111C in the sidewall of the processing vessel 111. Therefore, the tray moving mechanism 112M can also be said to be a lid opening / closing mechanism.

[0028] 2, a substrate lifter 170 is provided in the loading / unloading area 102. The substrate lifter 170 has a plurality of lift pins 171 (for example, three), a base 172 to the upper surface of which the lift pins 171 are fixed, and an elevating mechanism (not shown) that raises and lowers the base 172. The lift pins 171 are provided at positions such that when the lift pins 171 are raised to the raised position (shown by solid lines in FIG. 2), they pass through the through holes 118 of the tray 112 that is in the open position.

[0029] A loading / unloading entrance 180 for loading / unloading the substrate W into / from the housing 100 is provided in the wall of the housing 100 facing the transfer area 15. The loading / unloading entrance 180 is indicated by a dashed line in FIG. 2 and is formed in the wall of the housing 100 on the front side in FIG. 2. The loading / unloading entrance 180 can be opened and closed by a door 182 (shown only in FIG. 4). The door 182 may be in the form of a cantilevered flap as shown in FIG. 4, or may be in the form of a sliding door that can move up and down or horizontally (in the X direction).

[0030] As will be described later, when the purge gas (dry gas) used is nitrogen gas, a high nitrogen gas concentration may adversely affect an operator in the vicinity of the substrate processing system 1. Furthermore, if the atmosphere of the transfer area 15 flows into the loading / unloading area 102, the purging effect will be reduced. For this reason, it is preferable that the door 182 closes the loading / unloading opening 180 so that there is no or almost no flow of atmosphere between the loading / unloading area 102 and the transfer area 15 (see FIG. 1) through the loading / unloading opening 180.

[0031] When the lift pins 171 of the substrate lifter 170 are in the raised position, the substrate transport arm (not shown in FIG. 2) of the transport device 16 (see FIG. 1) that has entered the loading / unloading area 102 through the loading / unloading entrance 180 can place the substrate W on the lift pins 171 and can also remove the substrate W that is on the lift pins 171. In other words, the lift pins 171 are a transfer unit that transfers the substrate to and from the substrate transport arm. The tray 112 and tray moving mechanism 112M described above can also be said to be a substrate transfer mechanism that transfers the substrate W between the transfer unit (lift pins 171) and the processing vessel 111. When the lift pins 171 are in the lowered position (shown by the dashed line in FIG. 2), the lift pins 171 do not hinder the horizontal movement of the tray 112.

[0032] Now, let us return to the description of the processing vessel 111 and the tray 112. When the tray 112 is in the closed position (the position on the right side in FIG. 2), the plate 115 divides the internal space of the processing vessel 111 into an upper space 111A above the plate 115 in which the substrate W is present during processing, and a lower space 111B below the plate 115. However, the upper space 111A and the lower space 111B are not completely separated, and the upper space 111A and the lower space 111B communicate with each other via through holes 118 and elongated holes 119 formed in the plate 115, and a gap between the peripheral edge of the plate 115 and the inner wall surface of the processing vessel 111.

[0033] The processing vessel 111 is provided with a first discharge part 121 and a second discharge part 122. The first discharge part 121 and the second discharge part 122 discharge a processing fluid (carbon dioxide (hereinafter, for convenience, also referred to as "CO2") in this example) supplied from a supply source 130 of a supercritical fluid (processing fluid in a supercritical state) into the internal space of the processing vessel 111.

[0034] The first discharge unit 121 is provided below the plate 115 of the tray 112 when it is in the closed position. The first discharge unit 121 discharges CO2 (processing fluid) into the lower space 111B toward the lower surface of the plate 115 (upward). The first discharge unit 121 may be configured as a through-hole formed in the bottom wall of the processing vessel 111. The first discharge unit 121 may also be a nozzle body attached to the bottom wall of the processing vessel 111.

[0035] The second discharge unit 122 is provided to be located in front of (a position advanced in the positive X direction) the substrate W placed on the substrate holder 114 of the tray 112 when the tray 112 is in the closed position. The second discharge unit 122 supplies CO2 into the upper space 111A in a generally horizontal direction or slightly obliquely downward. In the illustrated embodiment, the second discharge unit 122 is provided on the side wall of the processing vessel 111 opposite to the lid unit 113.

[0036] 3, the second discharge unit 122 is configured with a rod-shaped nozzle body. In detail, the second discharge unit 122 is formed by drilling a plurality of discharge ports 122b in a pipe 122a extending in the width direction (Y direction) of the substrate W. The plurality of discharge ports 122b are aligned, for example, at equal intervals in the Y direction. Each discharge port 122b supplies CO2 into the upper space 112A toward the opening 111C (generally in the negative X direction).

[0037] The processing vessel 111 is further provided with a fluid discharge unit 124 that discharges the processing fluid from the internal space of the processing vessel 111. The fluid discharge unit 124 is configured as a header having substantially the same configuration as the second discharge unit 122. In detail, the fluid discharge unit 124 is formed by drilling a plurality of discharge ports 124b in a pipe 124a extending in the horizontal direction. The plurality of discharge ports 124b are aligned at equal intervals in the Y direction, for example. Each discharge port 124b faces upward and toward the elongated hole 119 in the plate 115.

[0038] In the illustrated embodiment, the fluid discharge part 124 is provided in a recess formed in the bottom wall of the processing vessel 111 near the opening 111C. As shown by the arrows in FIG. 6H, CO2 flows through the region above the substrate W in the upper space 111A, then flows into the lower space 111B through the elongated holes 119 formed in the plate 115 (or through communication paths provided on the periphery of the plate 115), and is then discharged from the fluid discharge part 124.

[0039] The processing vessel 111 is provided with a locking mechanism for fixing the tray 112 in a closed position. The locking mechanism has a bar-shaped locking member 125 that moves up and down by a lifting mechanism (e.g., an air cylinder or a ball screw) (not shown) along a guide hole or a guide groove formed in the processing vessel 111. In Fig. 2, the locking member 125 in the raised position (locked position) is shown by a solid line, and the locking member 125 in the lowered position (unlocked position) is shown by a dashed line.

[0040] As shown schematically by arrow V in FIG. 2, the processing vessel 111 is provided with a suction line for vacuum-adsorbing the lid 113 of the tray 112 in the closed position to the opposing surface of the processing vessel 111. The suction line is connected to a suction device such as a vacuum pump. After the tray 112 is moved to the closed position, the lid 113 is sucked, thereby crushing the seal member 200 (schematically shown only in FIG. 2) provided between the lid 113 and the processing vessel 111 and bringing the lid 113 into tight contact with the opposing surface of the processing vessel 111. This allows the locking member 125 to smoothly move to the raised position (locked position) shown in FIG. 2. By positioning the locking member 125 in the raised position, the tray 112 does not move in the opening direction (negative X direction) even if the internal pressure of the processing vessel 111 increases.

[0041] The housing 100 is provided with an exhaust port 184 for discharging the atmosphere in the loading / unloading area 102. The exhaust port 184 is connected via an exhaust path (exhaust pipe) 185 to an exhaust duct (which is suction-decompressed) of a semiconductor device manufacturing factory in which the substrate processing system 1 is installed. A valve 186, such as a butterfly valve, is provided in the exhaust port 184 or the exhaust path 185. The flow rate of gas discharged from the exhaust port 184 can be adjusted by adjusting the opening of the valve 186.

[0042] Next, the supply / discharge system for supplying and discharging the processing fluid (CO2) to and from the processing vessel 111 in the supercritical drying unit 18 will be described with reference to FIG. 5. In the piping diagram shown in FIG. 5, the circled T indicates a temperature sensor, and the circled P indicates a pressure sensor. The OLF indicates an orifice (fixed throttle) that reduces the pressure of the CO2 flowing in the downstream piping to a desired value. The SV indicates a safety valve (relief valve) that prevents damage to the piping, sensors, and other components of the supercritical drying device due to unexpected excessive pressure. The F indicates a filter that removes contaminants such as particles contained in the CO2. The CV indicates a check valve. The FV indicates a flow meter. The H indicates a heater for regulating the temperature of the CO2. The V indicates an on-off valve. When it is necessary to distinguish one of the above various components from another, a number will be added to the end of the alphabet (for example, "on-off valve V2"). Ten on-off valves V are depicted in Figure 5, and reference symbols V1 to V10 are assigned to them to distinguish them from one another.

[0043] The supercritical drying apparatus has a supercritical fluid supply device 130 as a supply source of supercritical fluid (supercritical CO2). The supercritical fluid supply device 130 has a well-known configuration including, for example, a carbon dioxide gas cylinder, a pressure pump, a heater, etc. The supercritical fluid supply device 130 has the ability to deliver supercritical CO2 at a pressure exceeding the supercritical state guarantee pressure (specifically, approximately 16 MPa) described below.

[0044] A main supply line 132 is connected to the supercritical fluid supply device 130. In this specification, a member called a "line" can be configured by a pipe (a piping member).

[0045] The main supply line 132 branches into a first supply line 134 and a second supply line 136 at a branch point 133. The first supply line 134 is connected to a first discharge part 121 of the processing vessel 111. The second supply line 136 is connected to a second discharge part 122 of the processing vessel 111. In the piping diagram of FIG. 5, the first supply line 134 extends between the branch point 133 and the second discharge part 122 in a generally U-shape as a whole.

[0046] An exhaust line 138 is connected to the fluid exhaust unit 124 of the processing vessel 111. A pressure regulating valve 140 is provided in the exhaust line 138. By adjusting the aperture of the pressure regulating valve 140, the primary pressure of the pressure regulating valve 140 can be adjusted, and therefore the pressure inside the processing vessel 111 can be adjusted. In addition, by adjusting the aperture of the pressure regulating valve 140, the exhaust rate of the processing fluid from the processing vessel 111 can also be adjusted.

[0047] 1 or its subordinate controller performs feedback control of the opening degree (specifically, the position of the valve element) of the pressure regulating valve 140 based on the deviation between the measured value (PV) of the pressure in the processing vessel 111 and the set value (SV) so that the pressure in the processing vessel 111 is maintained at the set value. As the measured value of the pressure in the processing vessel 111, for example, the detection value of a pressure sensor designated by reference symbol PS, which is provided between the on-off valve V3 of the exhaust line 138 and the processing vessel 111, as shown in FIG. 5, can be used. The pressure regulating valve 140 can be set to a fixed opening degree based on a command value from the control device 6 (rather than being feedback controlled).

[0048] A bypass line 144 branches off from the first supply line 134 at a branch point 142 provided on the first supply line 134. The bypass line 144 is connected to the discharge line 138 at a junction point 146 provided on the discharge line 138. The junction point 146 is located upstream of the pressure regulating valve 140.

[0049] A branch discharge line 150 branches off from the discharge line 138 at a branch point 148 set in the discharge line 138 upstream of the pressure regulating valve 140. The downstream end of the branch discharge line 150 is, for example, open to the atmospheric space outside the supercritical drying apparatus or connected to a factory exhaust duct. The downstream end of the discharge line 138 is connected to the factory exhaust duct directly or via a recovery device (not shown) that recovers useful components (e.g., IPA) contained in CO2.

[0050] A purge gas supply line 161 is connected to a junction 160 located immediately upstream of the filter F of the first supply line 134. The upstream end of the purge gas supply line 161 is connected to a purge gas supply source 162. In the purge gas supply line 161, an on-off valve V9, a heater H for heating the purge gas, a check valve CV, and an on-off valve V10 are installed in this order from the upstream side. In this embodiment, the purge gas is a gas having a lower water content (humidity) than the air in the clean room, i.e., a dry gas, and more specifically, nitrogen gas (N2 gas). The purge gas can be one provided as factory utility gas.

[0051] It is preferable to provide a heat insulating material or a pipe heater in the portion of the purge gas supply line 161 downstream of the heater H and in the portion from the junction 160 of the first supply line 134 to the first discharge portion 121 to keep the line (piping) warm. Examples of pipe heaters include a tape heater (ribbon heater), a jacket heater, and a mantle heater. The piping may have a double pipe structure, with the purge gas flowing in the inner pipe and the heated fluid flowing in the outer pipe.

[0052] In an exemplary embodiment, insulation is provided in the region of the purge gas supply line 161 from the heater H to the on-off valve V10, and piping heaters are provided in the purge gas supply line 161 between the on-off valve V10 and the junction 160 and in the first supply line 134 between the junction 160 and the connection point to the processing vessel 111.

[0053] Next, a description will be given of the processing of one substrate W and one associated cycle of operation of the supercritical drying unit 18. The operation described below is performed automatically under the control of the control device 6 shown in FIG. 1 or its subordinate controller.

[0054] Prior to the loading of the substrate W, the locking member 125 is lowered to the lowered position, and the tray 112 is placed in a standby state for opening (Step 1). At this time, purge gas (hot N2 gas (heated nitrogen gas) is used here) is already being discharged into the processing vessel 111 from the first discharge unit 121. This state is shown in FIG. 6A. The purge gas is discharged by closing the on-off valves V2, V4, V5, and V6 and opening the on-off valves V9 and V10. The other on-off valves may be in any state. At this time, the on-off valves V6 and V7 may be opened and the pressure adjustment valve 140 may be set to an appropriate small opening to supply purge gas into the processing vessel 111 while evacuating air from the processing vessel 111 via the fluid discharge unit 124.

[0055] Next, as shown in FIG. 6B , the tray 112 is moved to the open position (step 2). This allows the purge gas supplied into the processing vessel 111 to flow into the loading / unloading area 102 through the opening 111C. The concentration of the purge gas in the loading / unloading area 102 increases over time, which reduces the humidity (water content in the atmosphere) in the loading / unloading area 102. At this time, the atmosphere in the processing vessel 111 is also purged with the purge gas. At this time, it is preferable to open the valve 186 and exhaust the atmosphere in the loading / unloading area 102 through the exhaust path 185. This can promote replacement of the atmosphere in the loading / unloading area 102 with nitrogen gas and reliably prevent the nitrogen gas from leaking into the transfer area 15.

[0056] 6C, the lift pins 171 are raised to the raised position and inserted into the through holes 118 of the plate 115, and the plate 115 is placed in a waiting state for transfer (Step 3). At this time, the purge gas being supplied into the processing vessel 111 continues to flow into the loading / unloading area 102 through the opening 111C.

[0057] Once the atmosphere inside the processing vessel 111 and the loading / unloading area 102 has been sufficiently replaced with the purge gas, the door 182 of the loading / unloading port 180 is opened, and the arm of the transfer device 16 (see FIG. 1) holding the substrate W having the IPA puddle formed on its surface enters the loading / unloading area 102 through the loading / unloading port 180 and places the substrate W on the lift pins 171 (step 4). This state is shown in FIG. 6D.

[0058] "The atmosphere in the loading / unloading area 102 has been sufficiently replaced with the purge gas" means, for example, that the humidity in the loading / unloading area 102 has fallen below a predetermined value (e.g., 25% humidity) or that the purge gas (nitrogen gas) concentration has risen to a predetermined value (e.g., 85% nitrogen concentration). To detect this, a sensor for detecting the humidity or nitrogen concentration of the atmosphere in the loading / unloading area 102 may be provided. Alternatively, the humidity or nitrogen concentration of the atmosphere in the loading / unloading area 102 may be considered to have reached the desired value when a predetermined time has elapsed since the start of step 2.

[0059] In order to shorten the time for one cycle, it is preferable to quickly replace the atmosphere in the loading / unloading area 102 with purge gas. For this purpose, in step 1, the opening 111C of the processing vessel 111 may not be sealed by the lid 113, and the purge gas may be leaked from the processing vessel 111 into the loading / unloading area 102 through the gap between the processing vessel 111 and the lid 113. Alternatively, when the tray 112 starts to move to the open position and the lid 113 starts to open the opening in step 2, the discharge flow rate of the purge gas from the first discharge part 121 may be increased.

[0060] In step 1, when the purge gas is leaked from the processing vessel 111 into the loading / unloading area 102 as described above, it is not necessary to exhaust the processing vessel 111 through the exhaust line 138. This allows the purge gas to be effectively used for adjusting the atmosphere in the loading / unloading area 102 without being discarded. However, the purge gas may be exhausted from the processing vessel 111 through the exhaust line 138 by sealing the space between the processing vessel 111 and the lid 113.

[0061] Once the substrate W is placed on the lift pins 171, the lift pins 171 are lowered to their lowered positions. During the lowering process, the substrate W is transferred from the lift pins 171 to the tray 112 (more specifically, the support pins 116 of the substrate holder 114) (step 5). This state is shown in FIG. 6E.

[0062] Next, the tray 112 moves to the closed position, whereby the substrate holder 114 holding the substrate W is accommodated in the internal space of the processing vessel 111, and the opening 111C of the processing vessel 111 is closed by the lid 113 (Step 6). This state is shown in FIG. 6F. Once the opening 111C is closed by the lid 113, the discharge of the purge gas from the first discharge part 121 is stopped.

[0063] When the substrate W is placed on the tray 112 in step 5, the substrate W is positioned in the main flow of purge gas flowing from the opening 111C to the loading / unloading area 102. The flow of purge gas must not adversely affect the IPA puddles on the surface of the substrate W (e.g., IPA evaporation, fluctuation, or falling off the substrate to a significant degree). To prevent such adverse effects, the discharge flow rate of the purge gas from the first discharge unit 121 may be reduced once the substrate W is placed on the tray 112. Alternatively, after the tray 112 carrying the substrate W starts moving toward the processing vessel 111 in step 6, the discharge flow rate of the purge gas from the first discharge unit 121 may be reduced once the distance between the substrate W and the opening 111C becomes equal to or less than a predetermined distance. Furthermore, if the humidity in the loading / unloading area 102 is sufficiently low, the discharge of the purge gas from the first discharge unit 121 may be stopped once the substrate W is placed on the tray 112.

[0064] Purge gas can also be discharged into the processing vessel 111 from the second discharge unit 122. In this case, the line shown by the dashed dotted line in FIG. 5 is used. However, when purge gas is discharged from the second discharge unit 122, the purge gas is more likely to directly collide with the IPA paddles on the substrate W, particularly as the tray 112 holding the substrate W approaches the closed position, increasing the risk of the adverse effects described above. To avoid this adverse effect, for example, precise control of the discharge flow rate of the purge gas is required. For this reason, it is preferable to discharge the purge gas from the first discharge unit 121. If the purge gas is discharged from the first discharge unit 121, there is almost no risk of the purge gas directly colliding with the IPA paddles on the substrate W at a high flow rate, regardless of the position of the tray 112 holding the substrate.

[0065] After the substrate W is accommodated in the processing vessel 111, the lid 113 is sucked through a suction line provided in the wall of the processing vessel 111 (see arrow V in FIG. 6G), and the lid 113 is adsorbed to the processing vessel 111 (step 7). As a result, the seal member 200 (schematically shown only in FIG. 2 by a black circle) that seals between the opposing surfaces of the lid 113 and the processing vessel 111 is significantly crushed.

[0066] In this state, locking member 125 is raised to the raised position (locked position) shown in FIG. 2 (step 8). At this time, lid 113 is in close contact with processing vessel 111, so locking member 125 can be raised smoothly. This state is shown in FIG. 6G. Next, the suction of lid 113 is released (step 9). Even after the suction of lid 113 is released, lid 113 remains pressed against processing vessel 111 by locking member 125, and the opposing surfaces of lid 113 and processing vessel 111 are sufficiently sealed by sealing member 200 shown in FIG. 2. In other words, a sealed processing space is formed inside processing vessel 111.

[0067] Next, in the processing vessel 111, the substrate W is subjected to supercritical drying processing according to a known procedure (step 10). An example of each step of the supercritical drying processing (pressurization step, circulation step, and exhaust step) will be briefly described below. Note that the on-off valves V9 and V10 of the purge gas supply line 161 are closed before the start of the supercritical drying processing and remain closed until the supercritical drying processing is completed. Note that the supercritical drying processing may be performed as long as it includes the pressurization step, circulation step, and exhaust step, and the detailed procedure of each step is not limited to that described below.

[0068] In the pressure increase process, the on-off valves V1, V2, V5, and V7 are opened, and the on-off valves V3, V4, V6, and V8 are closed. The opening of the control valve 140 is fixed to an appropriate fixed opening. CO2 in a supercritical state is sent from the supercritical fluid supply device 130 to the main supply line 132 and flows into the processing vessel 111 via the first supply line 134 and the first outlet 121. As CO2 is filled into the processing vessel 111, the pressure inside the processing vessel 111 increases.

[0069] By opening the on-off valve V5 immediately after the start of the pressurization process, a portion of the CO2 that has flowed into the first supply line 134 is released to the bypass line 144, thereby preventing gaseous CO2 from flowing at an excessively large flow rate and velocity into the atmospheric-pressure processing vessel 111. While the on-off valve V5 is open, the on-off valves V7 and V8 may be closed to allow CO2 to remain in the lines downstream of the processing vessel 111. When the internal pressure of the processing vessel 111 has increased to a certain level, the on-off valve V5 is closed, and the pressurization process is continued.

[0070] By causing CO2 to flow into the processing vessel 111 from the first discharge part 121 during the pressure increase stage, it is possible to prevent CO2 in a gaseous state from colliding with the IPA puddle on the surface of the substrate W at a high flow rate and adversely affecting the IPA.

[0071] When the pressure inside the processing vessel 11 exceeds the critical pressure of CO2 (approximately 8 MPa), the CO2 in a critical state dissolves in the IPA on the substrate W. The pressure increase stage continues until the pressure inside the processing vessel 111 reaches a pressure (supercritical state guarantee pressure) that ensures that the mixed fluid (CO2 + IPA) is maintained in a supercritical state, regardless of the IPA concentration in the mixed fluid on the substrate W or the temperature of the mixed fluid. The supercritical state guarantee pressure is approximately 16 MPa.

[0072] When it is detected that the pressure inside the processing vessel 111 has reached the supercritical state assurance pressure, the on-off valves V1, V2, V5, and V8 are closed, the on-off valves V3, V4, V6, and V7 are opened, the operation mode of the regulator valve 140 is switched to a feedback control mode, and the flow process is started. At this time, the control device 6 (or its subordinate controller) executes feedback control to adjust the aperture (operated variable MV) of the regulator valve 140 so that the pressure inside the processing vessel 111 is maintained at a set value (set value SV = 16 MPa). Specifically, the aperture (operated variable MV) of the regulator valve 140 is feedback-controlled so that the pressure inside the processing vessel 111 detected by the pressure sensor P installed in the discharge line 138 immediately downstream of the processing vessel 111 (measured value PV) matches the set value SV.

[0073] In the circulating step, supercritical CO2 supplied from the second discharge unit 122 into the processing vessel 111 flows in the region above the substrate and is then discharged from the fluid discharge unit 124. At this time, a laminar flow of supercritical CO2 flowing approximately parallel to the surface of the substrate W is formed in the processing vessel 111. The IPA in the mixed fluid (IPA+CO2) on the surface of the substrate W exposed to the laminar flow of supercritical CO2 is gradually replaced with supercritical CO2. Eventually, almost all of the IPA on the surface of the substrate W is replaced with supercritical CO2. The state during the circulating step is shown in FIG. 6H.

[0074] The mixed fluid consisting of IPA and supercritical CO2 discharged from the fluid discharge portion 124 is collected after flowing through the discharge line 138. The IPA contained in the mixed fluid can be separated and reused.

[0075] Once the replacement of the IPA on the substrate W with supercritical CO2 is complete, the on-off valves V1, V2, V3, V4, and V5 are closed, the on-off valves V6, V7, and V8 are opened, the adjustment valve 140 is fixed at a wide opening, and the process moves to the exhaust step, where the set pressure of the processing vessel 111 is lowered to atmospheric pressure. As the pressure in the processing vessel 111 decreases, the supercritical CO2 that was in the pattern on the substrate W becomes gaseous and escapes from the pattern, and the gaseous CO2 is exhausted from the processing vessel 111. Finally, the on-off valve V5 is opened, and the CO2 remaining between the on-off valves V1 and V5 is removed. This completes the supercritical drying process for one substrate W.

[0076] After the supercritical drying process of the substrate W is completed, the lid 113 is sucked through a suction line provided in the wall of the processing vessel 111, and the lid 113 is vacuum-adsorbed to the processing vessel 111 (step 11). In this state, the locking member 125 is lowered to the lowered position (unlocked position) (step 12). This state is shown in FIG. 6I. When the locking member 125 moves to the lowered position, the suction of the lid 113 is released (step 13).

[0077] When the suction of the cover 113 is released in step 13, the purge gas is again discharged from the first discharge unit 121 (see FIG. 6J). The purge gas does not significantly affect the state of the processed (dried) substrate W. However, continuing to supply the purge gas is beneficial for continuously maintaining a low-humidity atmosphere in the processing vessel 111 and the loading / unloading area 102, and can also shorten the time required for one cycle for the next substrate W, for example. Therefore, once the discharge of the purge gas is resumed in step 13, it is preferable to continue discharging the purge gas from the first discharge unit 121 until the final step of this cycle.

[0078] Next, the tray 112 moves to the open position (step 14). The state at this time is the same as that shown in FIG. 6E. The discharge of purge gas from the first discharge unit 121 may start when the tray 112 starts to move to the open position. Note that if the first discharge unit 121 discharges purge gas at a high flow rate when the tray 112 is close to the internal space of the processing vessel 111 (for example, when the tray 112 is partially inside the processing vessel 111), the substrate W on the tray 112 may be misaligned. For this reason, the first discharge unit 121 may discharge purge gas at a low flow rate until the tray 112 is a predetermined distance away from the internal space of the processing vessel 111, and then the discharge flow rate of the purge gas may be increased after the tray 112 has moved away by the predetermined distance.

[0079] Next, the lift pins 171 are raised to the raised position (step 15). As a result, the lift pins 171 pass through the through holes 118 of the plate 115 and rise to lift the substrate W above the plate 115, and the substrate W enters a waiting state for transfer. The state at this time is the same as that shown in FIG. 6D.

[0080] Next, the door 182 of the loading / unloading entrance 180 is opened, and the arm of the transfer device 16 (see FIG. 1) holding the substrate W passes through the loading / unloading entrance 180 into the loading / unloading area 102 and removes the substrate W from the lift pins 171 (step 16). The state at this point is the same as that shown in FIG. 6C. Thereafter, the arm of the transfer device 16 retreats from the loading / unloading area 102, and the door 182 is closed.

[0081] Next, lift pins 171 are lowered to the lowered position (step 17). The state at this time is the same as in FIG. 6B. Next, tray 112 is moved to the closed position, resulting in the same state as in step 1. The state at this time is the same as in FIG. 6A.

[0082] Next, the operation of the exhaust path 185 for exhausting the atmosphere in the loading / unloading area 102 of the housing 100 will be described. Because the processing vessel 111 is sealed from step 7 to step 13, no new purge gas is supplied into the loading / unloading area 102. Furthermore, because the processing vessel 111 is sealed and the door 182 is closed from step 7 to step 13, no contaminants enter the loading / unloading area 102. Therefore, there is no need to exhaust the loading / unloading area 102 via the exhaust path 185 from step 7 to step 13.

[0083] During steps 2 to 6 and steps 14 to 17, the purge gas supplied to the processing vessel 111 flows into the loading / unloading area 102. By exhausting the atmosphere in the loading / unloading area 102 through the exhaust path 185, replacement of the atmosphere in the loading / unloading area 102 with the purge gas can be facilitated. The loading / unloading area 102 is preferably exhausted through the exhaust path 185 at a flow rate substantially equal to the flow rate of the purge gas flowing into the loading / unloading area 102. The opening of a valve 186 provided on the exhaust path 185 is adjusted to adjust the exhaust flow rate from the exhaust port. By adjusting the exhaust flow rate through the exhaust path 185 (e.g., by feedback control) so that the pressure in the loading / unloading area 102 and the pressure in the transfer area 15 are substantially equal, the movement of atmosphere between the loading / unloading area 102 and the transfer area 15 can be minimized. Atmosphere transfer can occur when the door 182 is open, or when there is a gap between the edge of the loading / unloading entrance 180 and the door 182 even when the door 182 is closed. If a gas that is harmful to the human body when its concentration in the atmosphere becomes high, such as nitrogen gas, is used as the purge gas, a large amount of purge gas leaking from the loading / unloading area 102 into the transfer area 15 could jeopardize the safety of the equipment operator or worker. However, such a risk can be prevented by roughly equalizing the pressure in the loading / unloading area 102 and the pressure in the transfer area 15.

[0084] According to the above embodiment, before the substrate W having IPA puddles formed on its surface is loaded, purge gas is supplied to the loading / unloading area 102 to reduce the amount of water (humidity) in the atmosphere of the loading / unloading area 102. This reduces the amount of water dissolved in the IPA (due to moisture absorption by the IPA), thereby preventing particles from remaining on the surface of the substrate after drying.

[0085] Furthermore, according to the above embodiment, the purge gas is supplied to the loading / unloading area 102 via the first discharge unit 121 and the internal space of the processing vessel 111. This reduces not only the moisture content of the atmosphere in the loading / unloading area 102 but also the moisture content of the internal space of the processing vessel 111. This prevents moisture from dissolving in the IPA on the substrate W even after the substrate W is loaded into the internal space of the processing vessel 111. Furthermore, there is no need to provide a dedicated purge gas supply device for supplying the purge gas to the loading / unloading area 102.

[0086] In the above embodiment, the purge gas is supplied into the loading / unloading area 102 entirely via the first discharge unit 121 and the internal space of the processing vessel 111, but this is not limiting. A purge gas discharge device 190 (shown by a dashed line in FIG. 2 ) that discharges purge gas directly into the loading / unloading area 102 may be provided, for example, on a wall of the housing 100 facing the loading / unloading area 102. The purge gas discharge device 190 may be a fan filter unit. In this case, the purge gas discharge device 190 may have the function of taking in air from a clean room in which the substrate processing system 1 is installed, filtering the air with a filter (e.g., a ULPA filter), and discharging the air into the loading / unloading area 102, as well as the function of discharging purge gas.

[0087] The purge gas discharge device 190 is preferably provided at a position where it does not spray gas directly onto the surface (top surface) of the substrate W supported by the lift pins 171 in the raised position in the loading / unloading area 102. This reduces the risk that the IPA puddle covering the top surface of the substrate W before processing will be adversely affected by the purge gas. The purge gas discharge device 190 is also preferably provided so as to discharge the purge gas sideways (in the X direction) toward an area lower than the surface of the substrate W supported by the lift pins 171, as shown in FIG.

[0088] By providing the purge gas discharge device 190, purge gas can be supplied into the loading / unloading area 102 regardless of whether the processing vessel 111 is open or closed. For example, in step 1, if purge gas can be supplied into the loading / unloading area 102 when the processing vessel 111 is closed, the inside of the loading / unloading area 102 can be brought to a predetermined purge gas concentration (or a predetermined humidity) in a short time. Furthermore, when the processing vessel 111 is open, purge gas can be supplied into the loading / unloading area 102 from the purge gas supply device and simultaneously supplied into the loading / unloading area 102 from the first discharge part 121 via the processing vessel 111, thereby bringing the inside of the loading / unloading area 102 to a predetermined purge gas concentration (or a predetermined humidity) in a short time.

[0089] In the above embodiment, a dry gas with low humidity was used as the purge gas. Note that "dry gas" refers to a gas with a lower moisture content (humidity) than the atmosphere (air) in the clean room in which the substrate processing system 1 is installed. More specifically, although high-temperature nitrogen gas was used as the purge gas (dry gas) in the above embodiment, room-temperature nitrogen gas can also be used. However, from the viewpoint of reducing the moisture content dissolved in the IPA puddle, it is preferable to use high-temperature nitrogen gas. Furthermore, the purge gas (dry gas) is not limited to nitrogen gas, but may be another gas with a low moisture content, such as dry air. Note that dry air refers to air in a clean room or equivalent air from which moisture has been removed using a dehumidifier (which is well known in the technical field of semiconductor device manufacturing).

[0090] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0091] The substrate is not limited to a semiconductor wafer, but may be any other type of substrate used in the manufacture of semiconductor devices, such as a glass substrate or a ceramic substrate. [Explanation of symbols]

[0092] W substrate 111 Processing container 101 Processing Area 102 Loading / unloading area 171 Delivery section (lift pin) 112 Substrate transfer mechanism (tray) 121,190 Gas Supply Department

Claims

1. A substrate processing apparatus that performs supercritical drying processing on a substrate having a liquid attached to its surface by using a processing fluid in a supercritical state, a processing vessel having an internal space in which a supercritical drying process is performed on the substrate; a housing having a processing area in which the processing vessel is disposed and a loading / unloading area for loading / unloading a substrate; a transfer section provided in the loading / unloading area for transferring a substrate between the transfer section and a substrate transport arm that has entered the loading / unloading area from outside the housing; a substrate transfer mechanism that transfers a substrate between the transfer unit and the processing vessel; a gas supply unit configured to supply a dry gas to the loading / unloading area; Equipped with the gas supply unit includes a gas discharge unit that discharges a dry gas into the internal space of the processing vessel, and when the internal space is in communication with the loading / unloading area, the dry gas discharged from the gas discharge unit into the internal space flows out into the loading / unloading area while purging the internal space, thereby supplying the dry gas to the loading / unloading area.

2. The substrate processing apparatus according to claim 1 , further comprising a heater that heats the dry gas before the dry gas is discharged from the gas discharge part into the internal space of the processing vessel.

3. 3. The substrate processing apparatus according to claim 1, wherein the gas discharge unit is connected to a supply source of the dry gas and a supply source of the processing fluid, and further comprising a switching mechanism that selectively connects the gas discharge unit to the supply source of the dry gas or the supply source of the processing fluid.

4. The substrate processing apparatus according to claim 1 , wherein the gas supply unit includes a gas discharge device having an outlet opening in the transfer area.

5. 5. The substrate processing apparatus according to claim 1, wherein the transfer section includes a lift pin that can be raised and lowered and supports the substrate from below with its tip, and the substrate transfer mechanism includes a tray that supports the substrate in a horizontal position and is movable horizontally between the loading / unloading area and the internal space of the processing vessel.

6. a control unit for controlling an operation of the substrate processing apparatus; 6. The substrate processing apparatus according to claim 1, wherein the control unit stops the discharge of the dry gas from the gas discharge unit or reduces the discharge flow rate of the dry gas to a level lower than the discharge flow rate before the substrate was transferred to the transfer unit during at least a part of a period from when the substrate, before being subjected to supercritical drying processing in the internal space of the processing vessel, is transferred to the transfer unit until when the substrate is transferred to the internal space of the processing vessel by the substrate transfer mechanism.

7. a control unit for controlling an operation of the substrate processing apparatus; 6. The substrate processing apparatus of claim 1, wherein when the substrate that has been subjected to supercritical drying processing in the internal space of the processing vessel is transferred from the internal space to the transfer section by the substrate transfer mechanism, the control unit stops the discharge of the dry gas from the gas discharge unit until the substrate is separated by a predetermined distance from the internal space, or discharges the dry gas at a first discharge flow rate, and after the substrate is separated by the predetermined distance from the internal space, increases the discharge flow rate of the dry gas to a second discharge flow rate that is greater than the first discharge flow rate.

8. The substrate processing apparatus according to claim 1 , further comprising an exhaust unit that exhausts the loading / unloading area of ​​the housing.

9. a control unit for controlling an operation of the substrate processing apparatus; 9. The substrate processing apparatus according to claim 8, wherein the control unit controls the gas supply unit and the exhaust unit so that a supply flow rate of the dry gas to the loading / unloading area by the gas supply unit and an exhaust flow rate from the exhaust unit are approximately balanced.

10. The substrate processing apparatus according to claim 1 , wherein the dry gas is nitrogen gas.

11. a processing vessel having an internal space in which a supercritical drying process is performed on a substrate; a housing having a processing area in which the processing vessel is disposed and a loading / unloading area for loading / unloading a substrate; a transfer section provided in the loading / unloading area for transferring a substrate between the transfer section and a substrate transport arm that has entered the loading / unloading area from outside the housing; a substrate transfer mechanism that transfers a substrate between the transfer unit and the processing vessel; a gas supply unit configured to supply a dry gas to the loading / unloading area; A substrate processing apparatus for drying a substrate having a liquid attached to a surface thereof by a supercritical drying process, comprising: supplying the dry gas to the loading / unloading area by the gas supply unit; After the moisture content of the atmosphere in the loading / unloading area becomes smaller than a predetermined value, the substrate having the liquid adhering to its surface is carried into the loading / unloading area by the substrate transport arm and delivered to the transfer section; transferring the substrate from the transfer unit to the substrate transfer mechanism; placing the substrate held by the substrate transfer mechanism in the internal space of the processing vessel; performing a supercritical drying process in the internal space of the processing vessel; A substrate processing method comprising:

12. 12. The substrate processing method of claim 11, wherein the gas supply unit includes a gas discharge unit that discharges a dry gas into the internal space of the processing vessel, and when the internal space is in communication with the loading / unloading area, the dry gas discharged from the gas discharge unit into the internal space flows out into the loading / unloading area while purging the internal space, thereby supplying the dry gas to the loading / unloading area.

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