Substrate processing device

Abstract

To suggest the preferred arrangement of a filter in a flow channel of a process fluid in the technique of processing a substrate with a supercritical processing fluid.SOLUTION: A substrate processing device includes a processing chamber including an internal space that can accommodate a substrate, a supply part that can supply a process fluid as liquid, a heating part that heats the liquid process fluid supplied from the supply part at or above a supercritical temperature of the process fluid and makes the process fluid transit to a supercritical state, a flow channel formation part that forms a flow channel of the process fluid from the fluid supply part to the processing chamber through the heating part, a first filter part that is inserted in a flow channel between the supply part and the heating part and filters the liquid process fluid, and a second filter part that is inserted in a flow channel between the heating part and the processing chamber and filters the liquid process fluid in the supercritical state.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a technique for placing a substrate in a processing chamber and processing it with a processing fluid in a supercritical state. [Background technology]

[0002] Processing processes for various substrates, such as semiconductor substrates and glass substrates for display devices, include treating the surface of the substrate with various processing fluids. Wet processing using liquids such as chemicals and rinses as processing fluids has been widely used. In recent years, processing using processing fluids in a supercritical state has also been put to practical use to dry substrates after such wet processing. This is particularly useful in drying substrates having a patterned surface on which a fine pattern is formed. This is because processing fluids in a supercritical state have a lower surface tension than liquids and have the property of penetrating deep into the gaps in the pattern. Using such processing fluids enables efficient drying processing. It is also possible to reduce the risk of pattern collapse due to surface tension during drying.

[0003] For example, in a substrate processing apparatus described in Patent Document 1, a substrate is placed on a flat support member and accommodated in a processing chamber. In the processing chamber, processing fluid is introduced into a space above the substrate and a space below the support member, and a laminar flow of the processing fluid is formed in these spaces to process the substrate. Filters are inserted in both the pipes that supply the processing fluid above the substrate and the pipes that supply the processing fluid below the substrate to filter the processing fluid and remove any contaminants that may be contained therein. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-036123 Summary of the Invention [Problem to be solved by the invention]

[0005] In substrate processing techniques that use supercritical processing fluids to process substrates, the processing fluid typically undergoes phase transitions between several states, such as gas, liquid, and supercritical states, during the processing process. Such phase transitions can occur within the piping through which the processing fluid flows. Meanwhile, the desired specifications for filters installed in piping systems vary depending on whether the fluid to be processed is gas or liquid. In other words, if the filter specifications do not match the type of fluid flowing through the filter or the purpose of its placement, problems may arise, such as failure to achieve the desired filtering performance or excessive strain on the filter or piping, which may adversely affect them.

[0006] Therefore, the position of the filter in the piping system and the type of filter to be disposed are important in order to obtain good filtering results, but the above-mentioned prior art does not mention this point in detail. As such, in an apparatus for performing processing using a supercritical processing fluid, careful consideration is required regarding the placement of filters in the piping system, but it cannot be said that sufficient knowledge has been accumulated from this perspective, and it is therefore desirable to establish a technology for optimizing the placement of filters.

[0007] The present invention has been made in view of the above-mentioned problems, and has as its object to propose a preferable arrangement of a filter in a flow path of a processing fluid in a technology for processing a substrate with a supercritical processing fluid. [Means for solving the problem]

[0008] One aspect of the present invention is a substrate processing apparatus for processing a substrate with a processing fluid in a supercritical state, comprising: a processing chamber having an internal space capable of accommodating the substrate; a fluid supply unit capable of supplying the processing fluid as a liquid; a heating unit that heats the liquid processing fluid supplied from the fluid supply unit to a temperature above the critical temperature of the processing fluid to transition it to a supercritical state; a flow path forming unit that forms a flow path for the processing fluid from the fluid supply unit through the heating unit to the processing chamber; a first filter unit interposed in the flow path between the fluid supply unit and the heating unit and filtering the liquid processing fluid; and a second filter unit interposed in the flow path between the heating unit and the processing chamber and filtering the processing fluid in a supercritical state.

[0009] In the invention configured as described above, in order to supply a processing fluid in a supercritical state to the processing chamber, the processing fluid supplied as a liquid from the fluid supply unit is heated by the heating unit to become supercritical and introduced into the processing chamber. A first filter unit is provided in the liquid flow path from the fluid supply unit to the heating unit, and a second filter unit is provided in the flow path of the processing fluid in a supercritical state (hereinafter sometimes simply referred to as "supercritical fluid") from the heating unit to the processing chamber.

[0010] In this way, the flow path of the processing fluid can be clearly zoned, with the upstream side of the heating unit being the area where liquid flows and the downstream side being the area where supercritical fluid flows. By placing filters in each zone, it becomes possible to apply filters specialized for the fluid to be processed. In other words, a filter suitable for processing liquids can be used as the first filter unit, and a filter suitable for processing supercritical fluids can be used as the second filter unit. [Effects of the Invention]

[0011] As described above, according to the present invention, the flow path for conveying the processing fluid to the processing chamber is clearly zoned into an area for handling liquid and an area for handling supercritical fluid, and a filter is disposed in each area. Therefore, by selecting a filter according to the fluid to be processed, the filter's performance can be fully utilized, and substrates can be processed using clean processing fluid from which contaminants have been removed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing a schematic configuration of a substrate processing system equipped with an embodiment of a substrate processing apparatus according to the present invention; [Figure 2] 1 is a side view showing the overall configuration of a wet treatment apparatus. [Figure 3] 4A and 4B are diagrams for explaining the operation of the wet treatment apparatus. [Figure 4] FIG. 1 is a side view showing the configuration of a supercritical processing apparatus. [Figure 5] FIG. 2 is a diagram showing details of supply and discharge paths of processing fluids. [Figure 6] 1 is a flowchart showing a process executed by a supercritical processing apparatus. [Figure 7] 1A and 1B are diagrams showing pressure changes in a processing chamber and a storage tank. [Figure 8] FIG. 10 is a view showing a second embodiment of the substrate processing apparatus. [Figure 9] FIG. 10 is a view showing a third embodiment of the substrate processing apparatus. [Figure 10] FIG. 10 is a view showing a fourth embodiment of the substrate processing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0013] First Embodiment 1 is a diagram showing the schematic configuration of a substrate processing system equipped with a first embodiment of a substrate processing apparatus according to the present invention. This substrate processing system 1 is a processing system for wet-processing various substrates, such as semiconductor wafers, by supplying a processing liquid to the upper surface of the substrate and then drying the substrate, and has a system configuration suitable for carrying out a substrate processing method according to the present invention. Substrate processing system 1 primarily comprises a wet-processing apparatus 2, a substrate transfer apparatus 3, a supercritical processing apparatus 4, and a control apparatus 9.

[0014] The wet processing device 2 receives a substrate to be processed and performs a predetermined wet processing. The type of processing is not particularly limited. Wet processing includes development processing, cleaning processing, etc., and after the development processing, etc., a puddle of an organic solvent such as IPA liquid is created on the pattern-forming surface of the substrate. The substrate transport device 3 transports the substrate from the wet processing device 2 while maintaining the puddle state, and transports it into the supercritical processing device 4. The supercritical processing device 4 corresponds to the substrate processing device according to the present invention, and performs a drying process (supercritical drying process) on the transported substrate using a processing fluid in a supercritical state. These are installed in a clean room. Therefore, the substrate transport device 3 transports the substrate in the air atmosphere and at atmospheric pressure.

[0015] The control device 9 controls the operation of each of these devices to achieve predetermined processing. For this purpose, the control device 9 is equipped with a CPU 91, a memory 92, a storage 93, an interface 94, and the like. The CPU 91 executes various control programs. The memory 92 temporarily stores processing data. The storage 93 stores the control programs executed by the CPU 91. The interface 94 exchanges information with users and external devices. The operations of the devices described below are achieved by the CPU 91 executing control programs written in advance in the storage 93 and causing each part of the device to perform a predetermined operation.

[0016] When the CPU 91 executes a predetermined control program, functional blocks such as a wet processing control unit 95 that controls the operation of the wet processing apparatus 2, a transport control unit 96 that controls the operation of the substrate transport apparatus 3, and a supercritical processing control unit 97 that controls the operation of the supercritical processing apparatus 4 are realized in software in the control device 9. Note that at least a part of each of these functional blocks may be configured by dedicated hardware.

[0017] The "substrate" in this embodiment can be any of a variety of substrates, including semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks. The following description will be given with reference to the drawings, taking as an example a substrate processing apparatus used primarily for processing disc-shaped semiconductor wafers. However, the present invention can be similarly applied to processing the various substrates exemplified above. Various substrate shapes can also be used.

[0018] In the following description, a substrate having a pattern formed on only one main surface will be used as an example. Here, the main surface on which a pattern or the like is formed will be referred to as the "front surface," and the opposite main surface on which no pattern is formed will be referred to as the "rear surface." Furthermore, the main surface of the substrate facing downward will be referred to as the "bottom surface," and the main surface of the substrate facing upward will be referred to as the "top surface." In the following description, the top surface will be referred to as the front surface.

[0019] 2 and 3 are diagrams showing an example of the configuration of a wet-processing apparatus. More specifically, FIG. 2 is a side view showing the overall configuration of the wet-processing apparatus, and FIG. 3 is a diagram for explaining the operation of the wet-processing apparatus. This wet-processing apparatus 2 is an apparatus that processes a substrate S by supplying a processing liquid to the upper surface of the substrate. The operation of the wet-processing apparatus 2 is controlled by a wet-processing control unit 95 of the control device 9.

[0020] The wet processing apparatus 2 supplies a processing liquid to the surface (pattern formation surface) Sa of the substrate S to perform wet processing such as surface processing and cleaning of the substrate S. For this purpose, the wet processing apparatus 2 includes a substrate holding unit 21, a splash guard 22, and processing liquid supply units 23 and 24 inside a processing chamber 200. The operations of these units are controlled by a wet processing control unit 95 provided in the control device 9. The substrate holding unit 21 has a disk-shaped spin chuck 211 having approximately the same diameter as the substrate S, and a plurality of chuck pins 212 are provided on the periphery of the spin chuck 211. The chuck pins 212 abut against the periphery of the substrate S to support the substrate S, allowing the spin chuck 211 to hold the substrate S in a horizontal position while spaced apart from its upper surface.

[0021] The spin chuck 211 is supported by a rotation support shaft 213 extending downward from the center of its lower surface so that its upper surface is horizontal. The rotation support shaft 213 is rotatably supported by a rotation mechanism 214 attached to the bottom of the processing chamber 200. The rotation mechanism 214 has a built-in rotation motor (not shown), and when the rotation motor rotates in response to a control command from the control device 9, the spin chuck 211 directly connected to the rotation support shaft 213 rotates around the rotation axis AX indicated by the dashed dotted line. In FIG. 2, the up-down direction is the vertical direction. As a result, the substrate S is rotated around the rotation axis AX while remaining in a horizontal position.

[0022] A splash guard 22 is provided to surround the substrate holding part 21 from the side. The splash guard 22 has a generally cylindrical cup 221 provided to cover the peripheral part of the spin chuck 211, and a liquid receiving part 222 provided below the outer periphery of the cup 221. The cup 221 moves up and down in response to a control command from the control device 9. The cup 221 moves up and down between a lower position where the upper end of the cup 221 is lowered below the peripheral part of the substrate S held by the spin chuck 211 as shown in FIG. 2, and an upper position where the upper end of the cup 221 is located above the peripheral part of the substrate S as shown in FIG. 3.

[0023] 2, when the cup 221 is in the lower position, the substrate S held by the spin chuck 211 is exposed to the outside of the cup 221. This prevents the cup 221 from becoming an obstacle when, for example, the substrate S is loaded onto or unloaded from the spin chuck 211.

[0024] 3, when the cup 221 is in the upper position, it surrounds the peripheral edge of the substrate S held by the spin chuck 211. This prevents the processing liquid shaken off from the peripheral edge of the substrate S during liquid supply, which will be described later, from scattering inside the chamber 200, making it possible to reliably collect the processing liquid. That is, droplets of the processing liquid shaken off from the peripheral edge of the substrate S as the substrate S rotates adhere to the inner wall of the cup 221 and flow downward, and are collected by the liquid receiving portion 222 arranged below the cup 221. In order to collect multiple processing liquids individually, multiple stages of cups may be provided concentrically.

[0025] The processing liquid supply unit 23 has a structure in which a nozzle 234 is attached to the tip of an arm 233 that extends horizontally from a pivotal support shaft 232 that is rotatably provided on a base 231 fixed to the processing chamber 200. The pivotal support shaft 232 rotates in response to a control command from the control device 9, causing the arm 233 to swing, and the nozzle 234 at the tip of the arm 233 moves between a retracted position retracted laterally from above the substrate S as shown in FIG. 2 and a processing position above the substrate S as shown in FIG.

[0026] The nozzle 234 is connected to a processing liquid supply source 238, and when an appropriate processing liquid is delivered from the processing liquid supply source 238, the processing liquid is ejected from the nozzle 234 toward the substrate S. As shown in FIG. 2B , the spin chuck 211 rotates at a relatively slow speed to rotate the substrate S, and a processing liquid L1 is supplied from the nozzle 234 positioned above the center of rotation of the substrate S, thereby processing the surface Sa of the substrate S with the processing liquid L1. The processing liquid L1 can be a liquid having various functions, such as a developer, an etching liquid, a cleaning liquid, or a rinse liquid, and the composition thereof is optional. Furthermore, processing may be performed using a combination of multiple types of processing liquids.

[0027] The other processing liquid supply unit 24 also has a configuration corresponding to that of the above-described first processing liquid supply unit 23. That is, the second processing liquid supply unit 24 has a base 241, a pivot shaft 242, an arm 243, a nozzle 244, etc., and these configurations are equivalent to those corresponding to those in the first processing liquid supply unit 23. The pivot shaft 242 rotates in response to a control command from the control device 9, causing the arm 243 to swing. The nozzle 244 at the tip of the arm 243 supplies the processing liquid to the surface Sa of the substrate S.

[0028] In this embodiment, the second processing liquid supply unit 24 is used for the purpose of forming a liquid film for preventing drying on the substrate S after wet processing. That is, the substrate S after wet processing is transported to the supercritical processing device 4 and subjected to supercritical drying processing, but in order to prevent the surface of the substrate S from being exposed and oxidized during transportation or the fine pattern formed on the surface from collapsing, the substrate S is transported with its surface covered with a puddle-shaped liquid film.

[0029] The liquid that constitutes the liquid film is a substance with a surface tension lower than that of water, which is the main component of the processing liquid used in the cleaning process, such as an organic solvent such as isopropyl alcohol (IPA) or acetone, which is supplied from an organic solvent supply source 248.

[0030] Here, two sets of processing liquid supply units are provided in the wet processing apparatus 2, but the number of processing liquid supply units provided, their structures, and functions are not limited to this. For example, only one set of processing liquid supply units may be provided, or three or more sets may be provided. Furthermore, one processing liquid supply unit may be provided with multiple nozzles. For example, multiple nozzles may be provided at the tip of one arm. Furthermore, in addition to the above-mentioned mode in which the processing liquid is discharged while the nozzle is positioned at a predetermined position, for example, a mode in which the nozzle discharges the processing liquid while scanning and moving along the surface Sa of the substrate S may also be included.

[0031] Returning to FIG. 1, the explanation will be continued. The substrate transfer device 3 is provided with a transfer robot 30 having a hand 31 attached to the tip of an extendable and rotatable arm. The hand 31 can support the substrate by partially abutting against the underside of the substrate, and as shown by the dotted line in FIG. 1, is movable toward and away from both the wet treatment device 2 and the supercritical treatment device 4. This allows substrates to be loaded into and unloaded from both the wet treatment device 2 and the supercritical treatment device 4. The operation of the transfer robot 30 is controlled by a transfer control unit 96 of the control device 9. There are many well-known technologies for this type of transfer robot, and any of these can be appropriately selected and used in this embodiment, so a detailed description will be omitted.

[0032] 4 is a side view showing the configuration of a supercritical processing apparatus. The supercritical processing apparatus 4 corresponds to a first embodiment of the substrate processing apparatus according to the present invention, and is an apparatus that performs a drying process using a processing fluid in a supercritical state on a substrate S after wet processing. More specifically, the supercritical processing apparatus 4 is an apparatus that receives the substrate S after wet processing, replaces the liquid remaining on the substrate S with the processing fluid in a supercritical state, and then discharges the processing fluid, thereby finally bringing the substrate S to a dry state.

[0033] The supercritical processing apparatus 4 includes a processing unit 41, a transfer unit 43, and a supply unit 45. The processing unit 41 is the main unit that performs the supercritical drying process. The transfer unit 43 receives the substrate S after wet processing that is transported by the substrate transport device 3 and transports it into the processing unit 41, and also transfers the processed substrate S from the processing unit 41 to an external transport device. The supply unit 45 supplies chemical substances, power, energy, etc. required for processing to the processing unit 41 and the transfer unit 43. These operations are controlled by the control device 9, particularly the supercritical processing control unit 97.

[0034] The processing unit 41 has a structure in which a processing chamber 412 is mounted on a base 411. The processing chamber 412 is constructed by combining several metal blocks, and its interior is hollow, constituting a processing space SP. The substrate S to be processed is loaded into the processing space SP and undergoes processing. A slit-shaped opening 421 that is elongated in the X direction is formed on the (-Y) side surface of the processing chamber 412. The processing space SP communicates with the outside space via the opening 421. The cross-sectional shape of the processing space SP is approximately the same as the opening shape of the opening 421. In other words, the processing space SP has a cross-sectional shape that is long in the X direction and short in the Z direction, and is a cavity that extends in the Y direction.

[0035] A lid member 413 is provided on the (-Y) side surface of the processing chamber 412 so as to close the opening 421. By closing the opening 421 of the processing chamber 412 with the lid member 413, an airtight processing container is formed. This makes it possible to process the substrate S under high pressure in the internal processing space SP. A flat support tray 415 is attached in a horizontal position to the (+Y) side surface of the lid member 413. The upper surface of the support tray 415 forms a support surface on which the substrate S can be placed. The lid member 413 is supported by a support mechanism (not shown) so as to be freely movable horizontally in the Y direction.

[0036] The lid member 413 can be moved toward and away from the processing chamber 412 by an advancing / retracting mechanism 453 provided in the supply unit 45. Specifically, the advancing / retracting mechanism 453 has a linear motion mechanism such as a linear motor, a linear motion guide, a ball screw mechanism, a solenoid, or an air cylinder. Such a linear motion mechanism moves the lid member 413 in the Y direction. The advancing / retracting mechanism 453 operates in response to a control command from the control device 9.

[0037] When the cover member 413 moves in the (-Y) direction to move away from the processing chamber 412 and the support tray 415 is pulled out from the processing space SP through the opening 421 as shown by the dotted line, access to the support tray 415 becomes possible. That is, it becomes possible to place the substrate S on the support tray 415 and to remove the substrate S placed on the support tray 415. On the other hand, when the cover member 413 moves in the (+Y) direction, the support tray 415 is accommodated in the processing space SP. When a substrate S is placed on the support tray 415, the substrate S is carried into the processing space SP together with the support tray 415.

[0038] The lid member 413 moves in the (+Y) direction to close the opening 421, thereby sealing the processing space SP. A seal member 422 is provided between the (+Y) side surface of the lid member 413 and the (-Y) side surface of the processing chamber 412, thereby maintaining the processing space SP in an airtight state. The seal member 422 is made of, for example, rubber. In addition, the lid member 413 is fixed to the processing chamber 412 by a locking mechanism (not shown). As described above, in this embodiment, the lid member 413 can be switched between a closed state (solid line) in which the lid member 413 closes the opening 421 to seal the processing space SP, and a separated state (dotted line) in which the lid member 413 is separated significantly from the opening 421 to allow the substrate S to be inserted or removed.

[0039] The processing space SP is kept airtight while the substrate S is processed within the processing space SP. In this embodiment, the fluid supply unit 457 in the supply unit 45 delivers a processing fluid, such as carbon dioxide, that is a substance suitable for supercritical processing. The processing fluid is then pressurized within the processing chamber 412 to bring it to a supercritical state. The processing fluid is supplied to the processing unit 41 in a gaseous or liquid state. Carbon dioxide is a chemical suitable for supercritical drying because it reaches a supercritical state at relatively low temperatures and pressures and has the property of dissolving organic solvents commonly used in substrate processing. The critical point at which carbon dioxide reaches a supercritical state is an atmospheric pressure (critical pressure) of 7.38 MPa and a temperature (critical temperature) of 31.1°C.

[0040] When the processing space SP is filled with the processing fluid and the processing space SP reaches an appropriate temperature and pressure, the processing space SP is filled with the processing fluid in a supercritical state. In this manner, the substrate S is processed by the processing fluid in the processing chamber 412. The supply unit 45 is provided with a fluid recovery part 455, and the processed fluid is recovered by the fluid recovery part 455. The fluid supply part 457 and the fluid recovery part 455 are controlled by the supercritical processing control part 97.

[0041] The processing space SP has a shape and volume that can accommodate the support tray 415 and the substrate S supported thereon. That is, the processing space SP has a roughly rectangular cross-sectional shape that is wider than the width of the support tray 415 in the horizontal direction and greater than the combined height of the support tray 415 and the substrate S in the vertical direction, and a depth that can accommodate the support tray 415. In this way, the processing space SP has a shape and volume that can accommodate the support tray 415 and the substrate S. However, there is only a small gap between the support tray 415 and the substrate S and the inner wall surface of the processing space SP. Therefore, a relatively small amount of processing fluid is required to fill the processing space SP.

[0042] The fluid supply unit 457 supplies the processing fluid to the processing space SP further to the (+Y) side than the (+Y) side end of the substrate S. Meanwhile, the fluid recovery unit 55 discharges the processing fluid that flows through the space above the substrate S and the space below the support tray 415 in the processing space SP further to the (-Y) side than the (-Y) side end of the substrate S. As a result, laminar flows of the processing fluid from the (+Y) side to the (-Y) side are formed above the substrate S and below the support tray 415 in the processing space SP.

[0043] The supercritical processing control unit 97 of the control device 9 determines the pressure and temperature in the processing space SP based on the detection results from a detection unit (not shown), and controls the fluid supply unit 457 and the fluid recovery unit 455 based on the results. This appropriately manages the supply of the processing fluid to the processing space SP and the discharge of the processing fluid from the processing space SP, and adjusts the pressure and temperature in the processing space SP in accordance with a predetermined processing recipe.

[0044] The transfer unit 43 is responsible for transferring the substrate S between the substrate transport device 3 and the support tray 415. For this purpose, the transfer unit 43 includes a main body 431, a lifting member 433, a base member 435, and multiple lift pins 437. The lifting member 433 is a columnar member extending in the Z direction and is supported by a support mechanism (not shown) so as to be movable in the Z direction relative to the main body 431. A base member 435 having a substantially horizontal upper surface is attached to the top of the lifting member 433. Multiple lift pins 437 are erected upward from the upper surface of the base member 435. Each of the lift pins 437 supports the substrate S in a horizontal position from below by abutting its upper end with the lower surface of the substrate S. In order to stably support the substrate S in a horizontal position, it is desirable to provide three or more lift pins 437 whose upper ends have the same height.

[0045] The lifting member 433 can be moved up and down by a lifting mechanism 451 provided in the supply unit 45. Specifically, the lifting mechanism 451 has a linear motion mechanism such as a linear motor, a linear motion guide, a ball screw mechanism, a solenoid, or an air cylinder, and this linear motion mechanism moves the lifting member 433 in the Z direction. The lifting mechanism 451 operates in response to a control command from the control device 9.

[0046] The base member 435 moves up and down as the lifting member 433 moves up and down, and the plurality of lift pins 437 move up and down integrally therewith. This allows the transfer of the substrate S between the transfer unit 43 and the support tray 415. More specifically, as shown by the dotted line in FIG. 4 , the substrate S is transferred with the support tray 415 pulled out to the outside of the chamber. For this purpose, the support tray 415 is provided with through holes 419 for inserting the lift pins 437. When the base member 435 moves up, the upper ends of the lift pins 437 pass through the through holes 419 and reach a position higher than the upper surface of the support tray 415. In this state, the substrate S transferred by the transfer robot 30 is transferred from the hand 31 of the transfer robot 30 to the lift pins 437. When the lift pins 437 move down, the substrate S is transferred from the lift pins 437 to the support tray 415. The substrate S can be removed by reversing the above procedure.

[0047] Next, a more detailed description will be given of the supply path of the processing fluid to the processing chamber 412 and the discharge path of the processing fluid from the processing chamber 412. In the above, it has been simply explained that the processing fluid is supplied from the fluid supply unit 457 to the processing chamber 412 and recovered from the processing chamber 412 to the fluid recovery unit 455. In an actual device, the fluid supply unit 457 and the fluid recovery unit 455 have the following configurations.

[0048] FIG. 5 is a diagram showing the details of the supply and discharge paths of the processing fluid. Note that in FIG. 5, for convenience of illustration, the orientation of the processing chamber 412 is opposite to that in FIG. 4. That is, in FIG. 4, the processing fluid is introduced into the processing chamber 412 from the right side of the page and discharged to the left side of the page. On the other hand, in FIG. 5, the processing fluid is introduced into the processing chamber 412 from the left side of the page and discharged to the right side of the page, which is the opposite of the above. That is, the processing chamber 412 in FIG. 5 shows the side opposite to that of the processing chamber 412 in FIG. 4.

[0049] First, we will explain the detailed structure of fluid supply unit 457. Fluid supply unit 457 mainly comprises a fluid supply source 700, a refinement unit 710, a supply unit 720, and piping groups 730 and 740 that connect these. These operate in response to control commands from supercritical process control unit 97.

[0050] The fluid supply source 700 outputs a substance (carbon dioxide in this embodiment) that acts as a processing fluid in supercritical processing as needed. The fluid supply source 700 may be provided as a part of the substrate processing system 1 and may be configured as a container, such as a cylinder, that stores the substance. Alternatively, the fluid supply source 700 may be an external supply source provided separately from the substrate processing system 1.

[0051] A pipe 731, which is part of a pipe group 730, is connected to the fluid supply source 700. The processing fluid delivered from the fluid supply source 700 passes through the pipe 731 in a rightward direction in FIG. 1. Valves V70, V71, a purifier 711, a filter 712, a condenser 713, and a valve V72 are inserted in this order in the processing fluid flow direction of the pipe 731. The valve V70 is, for example, a pressure regulating valve that has the function of adjusting the pressure of the processing fluid passed through the pipe 731. The other valves V71, V72 are on-off valves that switch the flow of the fluid on and off.

[0052] Valve V70 circulates the processing fluid at a pressure specified by a control command from the supercritical processing control unit 97 through pipe 731. Purifier 711 and filter 712 remove impurities from the processing fluid to improve its purity. Condenser 713 condenses the processing fluid sent out as a gas from fluid supply source 700. When valves V71 and V72 are opened, the processing fluid is output from pipe 731.

[0053] Pipe 731 merges with pipe 735, which is connected to a storage tank 717 (described later), on the output side of valve V72. Pipe 732 after the merger is equipped with a condenser 714, a pressure pump 715, and a filter 716. Condenser 714 is provided to more reliably maintain the processing fluid in a liquid state. Pressure pump 715 pressurizes the liquid processing fluid and sends it out. Filter 716 removes impurities from the processing fluid.

[0054] Pipe 732 branches into two pipes 733 and 734 on the output side of filter 716. Pipe 733 is connected to the top of storage tank 717, and has valve V74, which is an on-off valve, inserted midway through. Also, pipe 734 has valve V75, which is an on-off valve, inserted therein.

[0055] The storage tank 717 is a high-pressure vessel capable of storing pressurized liquid processing fluid. A level sensor 718 is provided in the storage tank 717 to control the liquid level. Therefore, the internal space of the storage tank 717 is not liquid-tight, and the vaporized processing fluid is stored in the space above the liquid level under pressure similar to that of the liquid. The storage tank 717 is also equipped with a heater 719, which can heat the processing fluid in the tank in response to a control command from the supercritical processing control unit 97.

[0056] A pipe 735 is connected to the bottom of the storage tank 717, and the pipe 735 merges with the pipe 731 and is connected to the pipe 732. When a valve V73, which is an on-off valve inserted in the pipe 735, is opened, the liquid processing fluid in the storage tank 717 flows into the pipe 732 via the pipe 735. If a valve V74 on the pipe 733 is also opened, a reflux path is formed that refluxes the processing fluid from the storage tank 717 via the pipes 735, 732, and 733 back to the storage tank 717. If the pressure pump 715 pressurizes the processing fluid while circulating it through this reflux path, the pressure of the processing fluid can be increased in stages. Finally, the processing fluid is stored in the storage tank 717 at a pressure increased to a pressure designated by a control command from the supercritical processing control unit 97.

[0057] An output pipe 736 is connected to the top of the storage tank 717, and the pipe 736 merges with the pipe 734 via the valve V76, which is an on-off valve. The gaseous treatment fluid that fills the upper part of the internal space of the storage tank 717 is output from the pipe 736. The gaseous treatment fluid flows into the pipe 741 after the pipes 734 and 736 are merged, and when the valve V76 is opened, the gaseous treatment fluid flows into the pipe 741, and when the valve V75 is opened, the liquid treatment fluid flows into the pipe 741.

[0058] In this way, the purification unit 710 of the fluid supply section 457 has the function of removing impurities from the processing fluid supplied from the fluid supply source 700 and selectively outputting the processing fluid in the phase required for subsequent processing, specifically the gas phase and liquid phase.

[0059] Pipe 741 is part of a group of pipes 740 that constitutes an introduction flow path for introducing a processing fluid from purification unit 710 to processing chamber 412. Pipe 741 branches into two pipes 743 and 744, each of which is provided with filters 721 and 722. These pipes 743 and 744 merge to form pipe 745, which further branches into two pipes 747 and 748.

[0060] A flow meter 723, a heater 725, and an on-off valve V78 are inserted in this order into the pipe 742 along the flow direction of the processing fluid (toward the right in the figure), and the pipe 742 is ultimately connected to the processing chamber 412. More specifically, the pipe 742 communicates with the internal space SP above the support tray 415 (FIG. 4) that supports the substrate S. Meanwhile, a flow meter 724, a heater 726, and an on-off valve V79 are inserted in this order into the pipe 743 along the flow direction of the processing fluid. The pipe 742 communicates with the internal space SP of the processing chamber 412 below the support tray 415 (FIG. 4) that supports the substrate S. As a result, in the internal space SP, the processing fluid is supplied to the spaces above and below the substrate S placed on the support tray 415.

[0061] Flow meters 723 and 724 measure the flow rates of the processing fluid at their respective positions and transmit the results to the supercritical processing control unit 97. Heaters 725 and 726 heat the processing fluid to a predetermined temperature in response to control commands from the supercritical processing control unit 97. Filters 727 and 728 finally remove impurities from the processing fluid introduced into the processing chamber 412.

[0062] In this manner, the fluid supply unit 457 can supply a processing fluid that has been purified and whose temperature and pressure have been adjusted to predetermined target values ​​to the processing chamber 412. The supply sequence of the processing fluid from the fluid supply unit 457 to the processing chamber 412 will be described in detail later.

[0063] The processing fluid supplied to processing chamber 412 is delivered from storage tank 717, which stores processing fluid pressurized by pressure pump 715. Therefore, the pressure of the processing fluid delivered from fluid supply source 700 may be lower than the pressure required for processing. If fluid supply source 700 can stably deliver processing fluid at a pressure appropriate for processing, the gas-phase processing fluid may be supplied directly from fluid supply source 700 via piping 737, as shown by the dotted line in Figure 5, rather than being taken from storage tank 717. Alternatively, pressure-regulated processing fluid may be supplied from the output side of valve V70.

[0064] As described above, in the fluid supply section 457 of this embodiment, the purification unit 710 has the function of purifying and liquefying the processing fluid output as a gas from the fluid supply source 700 and then storing the liquefied processing fluid. The processing fluid output as a liquid from the purification unit 710 is heated in the supply unit 720 to become a supercritical state and is introduced into the processing chamber 412.

[0065] Several filters are arranged along the flow path of such a processing fluid. Specifically, filter 711 is inserted in pipe 731 through which the processing fluid flows as a gas. Since the processing fluid is always in a gaseous state at this time and its pressure is regulated by valve V70, which is a pressure regulating valve, a filter unit suitable for handling gas of that pressure can be applied to filter 711. For example, a filter unit having a structure in which a filter element is housed in a resin housing can be used.

[0066] Meanwhile, the upstream filters provided in the supply unit 720, i.e., filters 721 and 722, are inserted into a pipe 741 through which the processing fluid flows as a high-pressure liquid. The processing fluid flowing through the pipe 741 is always liquid, and its pressure is stable. Therefore, a filter unit suitable for processing such a liquid, such as a filter unit with a structure in which a filter element is housed in a metal housing, can be used. Here, the filter units used for the two filters 721 and 722 are assumed to have the same structure.

[0067] The filters 721 and 722 are connected in parallel on the flow path. In other words, filter units of the same structure are arranged in parallel on the liquid flow path. The main reasons for this arrangement are as follows: The first reason is to ensure a sufficiently large flow rate of the processing fluid in this section; and the second reason is to suppress a drop in the temperature of the filter units.

[0068] The first reason will be explained in more detail. The flow path of the processing fluid branches into two paths downstream of the filters 721 and 722, and each path delivers the processing fluid to one of the spaces above the substrate S and below the support tray 415 within the processing space SP. Because the processing fluid to be supplied to both of these spaces flows through the pipe 741, the filter that receives this fluid needs to have a large capacity.

[0069] In this sense, it would be sufficient to use a single filter unit with a larger capacity. However, many filter units with excellent particle removal performance are small, and simply using a large-capacity filter unit would not provide the necessary filtering performance. Therefore, by connecting small, high-performance filter units in parallel, it is possible to achieve both high filtering performance and large capacity.

[0070] Three or more filter units may be connected in parallel, however, increasing the number of connecting parts such as pipes and joints may increase the sources of contamination, so it is preferable to determine the number of filter units to be installed taking into consideration the balance between performance and capacity.

[0071] Next, the second reason will be explained in more detail. The filter at this position handles liquids, and because liquid-phase fluids have higher viscosity than other states, the pressure loss in the filter is also relatively large. As a result, the temperature of the processing fluid passing through the filter drops due to a sudden drop in pressure, which cools the filter unit. Experiments conducted by the inventors of this application have confirmed the phenomenon of condensation actually occurring on the housing. In particular, in filter units with metal housings, condensation can cause corrosion and rust.

[0072] A more serious problem is that the processing fluid itself cools and partially solidifies in the filter unit, causing clogging of the filter. This reduces the flow rate of the processing fluid and further increases the pressure loss, making clogging difficult to resolve. Furthermore, fluctuations in the flow rate of the processing fluid have a significant impact on the processing in the processing chamber 412.

[0073] By connecting filter units in parallel and distributing the flow of the processing fluid, pressure loss in each filter unit is reduced and temperature drops are also gradual, significantly reducing the risk of clogging due to condensation on the housing or solidification of the processing fluid inside the filter unit.

[0074] The filters 727 and 728, located immediately before the processing chamber 412 in the flow path, ultimately determine the cleanliness of the processing fluid introduced into the processing space SP, and therefore require high particle removal performance. Therefore, a filter unit with a metal housing, which is less likely to become a new source of contamination, is suitable. Although temperature drop may occur in this case, unlike the filters 721 and 722, it is not a major problem. This is because the fluid being handled is a supercritical fluid with low viscosity, resulting in low pressure loss. Furthermore, because the processing fluid is heated by the heaters 725 and 726, there is little risk of the temperature dropping to a level low enough to cause condensation or solidification of the processing fluid.

[0075] In addition, since the processing fluid is distributed to the two flow paths in advance, it is not necessarily necessary to connect filter units in parallel in each flow path. Furthermore, for the filters 727 and 728, high-performance small filter units may be connected in parallel, with a higher priority on performance.

[0076] Although filter units designed for processing supercritical fluids are generally not readily available, it is possible to treat supercritical fluids as liquids with extremely low viscosity and use filters designed for such liquids. For example, filters 727 and 728 can be constructed using filter units with the same structure as filters 721 and 722. This provides cost benefits by allowing the filter body and replacement parts to be standardized.

[0077] The processing fluid flows as a liquid through filter 716, which is provided downstream of pressure pump 715. Because this processing fluid has a relatively large volume and undergoes large pressure changes, it is desirable to use a filter unit suitable for such applications. For example, a filter unit with a structure in which a filter element is housed in a metal housing can be used. Note that, although multiple filter units may be connected in parallel here as well, because the filter at this position does not necessarily require high particle removal performance, it is also possible to use a single filter unit with a large capacity but somewhat inferior performance.

[0078] In this way, several filters are arranged in the flow path of the processing fluid, and each of them is selected appropriately depending on the state of the fluid to be handled and the performance required.

[0079] Next, we will explain the detailed structure of the fluid recovery unit 455. The fluid supply unit 455 mainly comprises a high-pressure exhaust tank 505, a low-pressure exhaust tank 508, and a group of pipes 530 connecting these. These operate in response to control commands from the supercritical process control unit 97.

[0080] A pipe 531, which is part of a pipe group 530, is connected to the upper part of the processing chamber 412. Meanwhile, a pipe 532 is connected to the lower part of the processing chamber 412. These pipes 531, 532 respectively discharge the processing fluid that has flowed above and below the support tray 415 in the internal space SP from the processing chamber 412 to the outside. A pressure gauge 503 is provided on the pipe 531.

[0081] A flow meter 501 and a valve V51, which is an on-off valve, are inserted in this order into pipe 531 along the flow direction of the processing fluid. On the other hand, a flow meter 502 and a valve V52, which is an on-off valve, are inserted in this order into pipe 532 along the flow direction of the processing fluid. Pipes 531 and 532 join at the output sides of valves V51 and V52. After joining, pipe 533 has valve V53, which is a pressure adjustment valve, and valve V54, which is an on-off valve, inserted therein.

[0082] The pipe 533 is connected to a high-pressure exhaust tank 505, and the processing fluid discharged from the processing chamber 412 is stored in the high-pressure exhaust tank 505 via the pipe 533. The high-pressure exhaust tank 505 is provided with a heater 506, which maintains the temperature of the processing fluid stored therein at an appropriate level.

[0083] A pipe 544 is connected to the top of the high-pressure exhaust tank 505, and a valve V55 which is an on-off valve, a valve V56 which is a pressure adjusting valve, and a heater 507 are inserted in the pipe 544, and the pipe 544 is finally connected to a low-pressure exhaust tank 508. Therefore, a processing fluid as a gas whose pressure and temperature have been appropriately adjusted flows into the low-pressure exhaust tank 508. The processing fluid in the low-pressure exhaust tank 508 is finally recovered by an external recovery device (not shown) via the pipe 545. A pressure sensor 510 is provided in the pipe 545 to detect the pressure of the gas discharged to the outside.

[0084] Furthermore, a pipe 546 is connected to the bottom of the high-pressure exhaust tank 505, while a pipe 547 is connected to the bottom of the low-pressure exhaust tank 508. These pipes join to form pipe 548, to which a valve V57, which is an on-off valve, is connected. When valve V57 is opened, the liquid treatment fluid stored in the high-pressure exhaust tank 505 and the low-pressure exhaust tank 508 is discharged to an external recovery device.

[0085] The operation of the supercritical processing apparatus 4 configured as described above will be described with reference to Figures 6 and 7. The supercritical processing apparatus 4 performs a process of drying the substrate S after wet processing using a processing fluid in a supercritical state, i.e., a supercritical drying process. This process is realized by the CPU 91 of the control unit 9 executing a prepared control program and controlling each part of the apparatus.

[0086] Fig. 6 is a flowchart showing the process performed by the supercritical processing apparatus. Fig. 7 is a diagram showing the pressure changes in the processing chamber and storage tank during this process. The fluid supply unit 457 supplies gaseous and liquid processing fluids to the processing chamber 412 from a storage tank 717 that stores the processing fluids. Therefore, the pressure in the processing space SP of the processing chamber 412 (hereinafter referred to as "chamber internal pressure") and the pressure in the internal space of the storage tank 717 (hereinafter referred to as "tank internal pressure") change as the process progresses.

[0087] First, the substrate transfer device 3 and the supercritical processing device 4 work together to load the substrate S into the processing chamber 412 (step S101). Specifically, the transfer robot 30 of the substrate transfer device 3 holds the substrate S that has undergone the liquid film formation process in the wet processing device 2, and places the substrate S on the support tray 415 that has been pulled out of the processing chamber 412. More precisely, the substrate S is first transferred from the hand 31 of the transfer robot 30 to the lift pins 437 of the supercritical processing device 4, and then the substrate S is transferred from the lift pins 437 to the support tray 415.

[0088] The support tray 415 on which the substrate S is placed is housed in the processing chamber 412. The lid member 413 closes the opening 421 of the processing chamber 412, thereby sealing the processing space SP inside the processing chamber 412. In this way, the loading of the substrate S is completed. Since the processing chamber 412 is opened to the atmosphere in order to load the substrate S, the internal pressure of the processing chamber 412 is atmospheric pressure Pa in the initial state, as shown in the upper part of FIG.

[0089] While the substrate S is being transferred in this manner, a predetermined standby operation is performed in the fluid supply unit 457 (step S102). As will be described in detail later, the standby operation is an operation for preparing a required amount of processing fluid at a temperature and pressure suitable for use in subsequent processing in the fluid supply unit 457. As will be described later, in this embodiment, gaseous carbon dioxide at a temperature of 20°C and a pressure of 6 MPa and carbon dioxide heated to a temperature of 20°C and a pressure of 11 MPa to become supercritical are used for processing.

[0090] After the substrate S is loaded, the fluid supply unit 457 starts to introduce a gaseous processing fluid (step S103; time T1), which gradually increases the pressure inside the chamber. When the pressure inside the chamber increases to a predetermined first pressure P1 (step S104; time T2), the fluid supply unit 457 supplies a supercritical processing fluid, instead of the gas, into the processing chamber 412 (step S105; time T3).

[0091] As a result, the processing space SP of the processing chamber 412 is filled with the processing fluid in a supercritical state, and the chamber internal pressure is maintained at a constant second pressure P2 that is greater than the first pressure P1 and the critical pressure of the processing fluid (times T4 to T5). During this time, the liquid remaining on the substrate S is replaced by the supercritical processing fluid, dissolved in the processing fluid, and removed from the surface of the substrate S.

[0092] After a predetermined time has elapsed while the chamber internal pressure is maintained at approximately pressure P2 (step S106), discharge of the processing fluid from the processing chamber 412 begins (step S107; time T5), thereby depressurizing the processing space SP. After time T7, when the chamber internal pressure has decreased to near atmospheric pressure Pa, the transfer robot 30 unloads the substrate S (step S108), completing the processing of one substrate S. If there is another substrate to be processed, the process returns to step S101 (step S109), and the above processing is repeated.

[0093] 7, as the processing fluid stored in the storage tank 717 is consumed, the pressure inside the tank gradually decreases. To restore this pressure, a standby operation is performed to replenish the storage tank 717 with pressurized processing fluid (step S111). The standby operation can be performed after time T6, when the supply of processing fluid from the storage tank 717 to the processing chamber 412 is stopped. Therefore, as shown in FIG. 7, the standby operation can be started while the processing chamber 412 is being depressurized.

[0094] When performing supercritical drying processing on a substrate S, it is desirable to increase the tank internal pressure to a pressure that is approximately the same as or slightly higher than the first pressure P1 during the standby operation so that the chamber internal pressure can be increased to the first pressure P1 in step S103 of the processing.

[0095] Specifically, the processing fluid output from the fluid supply source 700 is pressurized by the pressure pump 715 and flows into the storage tank 717, thereby increasing the pressure inside the tank to a target value. For this purpose, the valves V71, V72, and V74 are opened, while the valves V73, V75, and V76 are closed.

[0096] Therefore, the processing fluid output from the fluid supply source 700 and having its pressure adjusted by the valve V70 is pressurized to a predetermined pressure by the pressure pump 715 and stored in the storage tank 717. The amount of liquid in the tank is monitored by the level sensor 718, and the supply of the processing fluid continues until a predetermined amount of liquid at a predetermined pressure has accumulated. In addition, the temperature of the processing fluid in the tank is adjusted by the heater 719.

[0097] Thus, during the standby period when no processing fluid is supplied from the storage tank 717 to the processing chamber 412 (before time T1 and after time T6 in FIG. 7), a process for maintaining the liquid volume, pressure, and temperature in the tank at predetermined values ​​is performed as a standby operation. The target pressure value is the first pressure P1 or a pressure slightly higher than this, which is 6 MPa in this embodiment. The target temperature is 20°C in this embodiment. The target liquid volume value is set to an amount that is sufficient to supply the processing fluid to the processing chamber 412 in the supercritical drying process described above.

[0098] As described above, in the first embodiment of the substrate processing apparatus according to the present invention, filters optimized according to the state of the processing fluid at each position are arranged at multiple positions on the flow path of the processing fluid, which is output as a gas, liquefied, and finally heated to a supercritical state and introduced into the processing chamber, to purify the processing fluid. In other words, each filter is arranged at a position in the processing fluid flow path where the processing fluid is in a gaseous state, a liquid state, or a supercritical state.

[0099] This allows for the placement of a filter optimized for the state and purpose of the processing fluid. As a result, substrates can be processed satisfactorily using an effectively purified processing fluid. Furthermore, substances contained in the processing fluid that may become a source of substrate contamination may be a mixture of substances that are easily removed when the processing fluid is in a gaseous state, liquid state, or supercritical state. By placing a filter in each flow path of the processing fluid of each phase, these contaminants can be effectively removed.

[0100] As described above, in the above embodiment, the supercritical processing apparatus 4 corresponds to the "substrate processing apparatus" of the present invention, and the processing chamber 412 having the processing space SP as the "internal space" functions as the "processing chamber" of the present invention. Also, the fluid supply unit 457 functions as the "supply unit" of the present invention.

[0101] In the above embodiment, the piping groups 730, 740 and the valves arranged on the piping collectively function as the "flow path forming portion" of the present invention. The heaters 725, 726 function as the "heating portion" of the present invention. The filters 721, 722 each correspond to the "filter unit" of the present invention, and together they constitute the "first filter portion" of the present invention. On the other hand, the filters 727, 728 each individually correspond to the "second filter portion" of the present invention. The piping 747, 748 in which these are arranged each correspond to the "branch path" of the present invention.

[0102] In the above embodiment, the fluid supply source 700 functions as the "gas supply source" of the present invention, and the purification unit 710 functions as the "liquefaction mechanism" of the present invention. Furthermore, the filter 712 functions as the "third filter section" of the present invention.

[0103] Second Embodiment 8 is a diagram showing a second embodiment of the substrate processing apparatus. Note that the substrate processing apparatuses of the second embodiment and each embodiment described below are obtained by partially modifying the configuration of the supply unit 720 in the first embodiment, but are otherwise identical to those of the first embodiment. Therefore, in order to clearly indicate the changes from the supply unit 720, the description of components whose structure and function are the same as those of the first embodiment will be omitted or will be given the same reference numerals and detailed explanations will be omitted.

[0104] 8, in supply unit 720A of the second embodiment, liquid filters 721A and 722A are provided on pipes branching off from pipe 741. That is, pipes 743 and 744 provided in the first embodiment are removed, and two pipes 747A and 748A branch off directly from pipe 741. One of the pipes, 747A, is equipped with liquid filter 721A, flow meter 723, heater 725, valve V78, and supercritical fluid filter 727.

[0105] Of these, filter 721A may be provided upstream of flow meter 723 as shown by the solid line in the drawing, or may be provided downstream of flow meter 723 as shown by the dotted line. The drawing shows that filter 721A is provided at one of these positions, and does not represent that it is provided at both positions.

[0106] Similarly, the other pipe 748A is provided with a liquid filter 722A, a flow meter 724, a heater 726, a valve V79, and a supercritical fluid filter 728. Again, the filter 722A can be located either before or after the flow meter 723.

[0107] According to this configuration, it is possible to reduce structures that can be sources of contamination by eliminating the pipes 743 and 744. In this case, the flow rate of the processing fluid in each of the filters 721A and 722A is approximately the same as that of the filters 721 and 722 connected in parallel, so that it is possible to use filter units equivalent to these individually.

[0108] <Third embodiment> 9 is a diagram showing a third embodiment of the substrate processing apparatus. The difference between this embodiment 720B and the first embodiment is that filters for supercritical fluids are connected in series. That is, another filter 727B is arranged upstream or downstream of filter 727. Also, another filter 728B is arranged upstream or downstream of filter 728. The two series-connected filters 727 and 727B may have the same structure, or may have different structures so as to be used according to the purpose. The same applies to the other two filters 728 and 728B.

[0109] While such a series connection of filters can improve particle removal performance, it also increases pressure loss in the flow path, which may be acceptable for a flow path of a supercritical fluid with extremely low viscosity.

[0110] <Fourth embodiment> FIG. 10 illustrates a fourth embodiment of the substrate processing apparatus. The difference between the fourth embodiment and the first embodiment is that the supercritical fluid filters 720C are connected in parallel. That is, filters 727C and 728C are connected in parallel to filter 727 and 728, respectively, which are arranged in the supercritical fluid flow path. As mentioned in the first embodiment, this parallel connection allows for the use of high-performance filter units with small capacities. This further enhances the cleanliness of the processing fluid introduced into the processing chamber 412.

[0111] <Other variations> The present invention is not limited to the above-described embodiment, and various modifications other than those described above are possible without departing from the spirit of the present invention. For example, the fluid supply unit 457 in the above embodiment includes components such as a flow meter that are generally provided in a flow path of a processing fluid but are not directly related to the present invention. The present invention can be realized even if these components are omitted.

[0112] Also, for example, in the above embodiment, the processing fluid is introduced into and discharged from the processing chamber 412 separately from the upper and lower sides of the support tray 415. However, this is not an essential requirement.

[0113] In the above embodiment, since the fluid supply source 700 outputs the processing fluid as a gas, a gas filter 712 is inserted in the piping 731, which serves as a flow path for the gas. If the fluid supply source outputs the processing fluid as a liquid, this filter may be changed to one for a liquid or may be omitted.

[0114] Furthermore, as shown by the dotted line in FIG. 5, when a pipe 737 is provided that connects the fluid supply source 700 directly to the valve V76, it is desirable that a gas filter be inserted into this pipe 737.

[0115] Furthermore, the various chemical substances and numerical values ​​used in the processing of the above-described embodiments are only examples, and various other substances can be used instead as long as they are consistent with the technical concept of the present invention described above.

[0116] As described above with reference to specific embodiments, in the substrate processing apparatus according to the present invention, for example, the flow path may be branched into a plurality of branch paths, each of which may be connected to a processing chamber, and a heating unit and a second filter unit may be provided for each of the branch paths. With this configuration, processing fluids can be supplied to the processing chamber from a plurality of locations, and by providing a heating unit and a second filter unit for each of the flow paths, the temperature and cleanliness of the supplied processing fluids can be maintained at an appropriate level.

[0117] In this case, the flow path may be configured to branch at the output side of the first filter unit, or a first filter unit may be provided for each branch path. In either configuration, the processing fluid that has passed through the first filter unit as a liquid can be supplied to the processing chamber as a supercritical fluid.

[0118] For example, the first filter section may have a configuration including multiple filter units with the same structure connected in parallel. There is a trade-off between filter performance and pressure loss, and pressure loss tends to be particularly large in the first filter section, which handles liquids. It is also difficult to prepare high-performance, large-capacity filters. Therefore, by connecting multiple filters with the required performance in parallel, capacity can be increased without sacrificing performance.

[0119] Furthermore, if the pressure loss is large, the pressure of the processing fluid will decrease, which can cause a problem of a drop in the temperature of the processing fluid. In particular, if the filter unit has a structure in which the filter element is housed in a metal housing, condensation caused by a drop in the temperature of the processing fluid can cause rust and corrosion of the housing. By connecting filters in parallel and distributing the processing fluid, it is possible to reduce this temperature drop.

[0120] For example, the second filter section may have a filter unit with the same structure as the filter unit. The processing fluid handled by the second filter section is in a supercritical state, but it cannot be said that filter units optimized for this are sufficiently available on the market. If a supercritical fluid is considered to be a liquid with extremely low viscosity, a filter unit for such a liquid can be applied. This makes it possible to use a filter unit with the same structure as the filter unit used in the first filter section to handle the liquid, thereby achieving cost benefits through the use of common parts.

[0121] In addition, in the present invention, for example, the supply unit may be configured to include a gas supply source that outputs a gaseous processing fluid and a liquefaction mechanism that pressurizes or cools the processing fluid output from the gas supply source to liquefy it, and the liquefaction mechanism outputs the liquid processing fluid to the flow path. With this configuration, processing can be performed using, for example, a commercially available gas cylinder as the gas supply source. This reduces the cost of processing substrates.

[0122] In this case, it is desirable to connect the gas supply source and the liquefaction mechanism via a third filter unit that filters the gaseous processing fluid. This allows contaminants such as particles contained in the gas to be removed before liquefaction. Furthermore, the cleanliness level required for the gas supply source can be lowered, making it possible to reduce procurement costs. [Industrial Applicability]

[0123] The present invention can be applied to any technique for processing a substrate with a processing fluid in a supercritical state in a processing chamber. [Explanation of symbols]

[0124] 4. Supercritical processing equipment (substrate processing equipment) 412 Processing Chamber 457 Fluid supply section (supply section) 700 Fluid supply source (gas supply source) 710 Purification Unit (Liquefaction Mechanism) 712 Filter (third filter section) 715 Pressure pump (pressurizing part) 721,722 Filter (filter unit, first filter part) 725,726 Heater (heating part) 727,728 Filter (Second Filter Section) 730,740 Piping group (flow path forming section) 747,748 Piping (branch) S board SP Processing space (internal space)

Claims

1. 1. A substrate processing apparatus for processing a substrate with a processing fluid in a supercritical state, a processing chamber having an interior space capable of accommodating the substrate; a supply unit capable of supplying the treatment fluid as a liquid; a heating unit that heats the liquid treatment fluid supplied from the supply unit to a critical temperature of the treatment fluid or higher to transition it to a supercritical state; a flow path forming unit that forms a flow path for the processing fluid from the supply unit to the processing chamber via the heating unit; a first filter unit interposed in the flow path between the supply unit and the heating unit to filter the liquid treatment fluid; a second filter unit interposed in the flow path between the heating unit and the processing chamber to filter the processing fluid in a supercritical state; A substrate processing apparatus comprising:

2. 2 . The substrate processing apparatus according to claim 1 , wherein the flow path branches into a plurality of branch paths, each of the branch paths being connected to the processing chamber, and the heating unit and the second filter unit being individually provided for each of the branch paths.

3. The substrate processing apparatus according to claim 2 , wherein the flow path branches on an output side of the first filter unit.

4. The substrate processing apparatus according to claim 2 , wherein the first filter unit is provided for each of the branch paths.

5. The substrate processing apparatus according to claim 1 , wherein the first filter section includes a plurality of filter units having the same structure and connected in parallel to each other.

6. The substrate processing apparatus according to claim 5 , wherein the filter unit has a structure in which a filter element is accommodated in a metal housing.

7. The substrate processing apparatus according to claim 5 , wherein the second filter section has a filter unit having the same structure as the filter unit.

8. the supply unit includes a gas supply source that outputs the gaseous processing fluid, and a liquefaction mechanism that pressurizes or cools the processing fluid output from the gas supply source to liquefy it; 8. The substrate processing apparatus according to claim 1, wherein the liquefaction mechanism outputs the processing fluid in a liquid state to the flow path.

9. The substrate processing apparatus according to claim 8 , wherein the gas supply source and the liquefaction mechanism are connected via a third filter unit that filters the gaseous processing fluid.

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