Substrate processing method and substrate processing device

Abstract

To shorten a drying time in a substrate processing method and a substrate processing device for drying a substrate having a liquid film of an organic solvent formed in a liquid-filled state on a surface by a processing fluid in a supercritical state.SOLUTION: During a step of boosting a processing chamber from an atmospheric pressure to a first pressure by supplying a processing fluid to the processing chamber, a subcritical state being reached at the first pressure; part of the processing fluid is dissolved into a liquid film. Thereby, a surface tension of the liquid film decreases and part of a mixture liquid (=organic solvent+processing fluid) constituting the liquid film drips down from a substrate and the liquid film becomes thinner. Here, if vibration is applied to the substrate when the surface tension decreases, part of the mixture liquid additionally drips down from the substrate and the liquid film is further thinned. After this film thinning processing, the substrate is dried by the processing fluid in a supercritical state.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a technique for drying a substrate in a processing chamber, and more particularly to a process in which a substrate covered with a liquid film is treated with a processing fluid in a supercritical state. [Background technology]

[0002] The processing of various substrates such as semiconductor substrates and glass substrates for display devices includes processing of the substrate surface 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 in order to dry the substrate after the wet processing. This is particularly useful in the drying processing of a substrate having a pattern-formed surface on which a fine pattern is formed. This is because the processing fluid in a supercritical state has a lower surface tension than a liquid and has the property of penetrating deep into the gaps of the pattern. By using the processing fluid, it is possible to perform the drying processing efficiently. It is also possible to reduce the risk of pattern collapse caused by surface tension during drying.

[0003] For example, in the substrate processing apparatus described in Patent Document 1, a substrate having a liquid film formed of IPA (isopropyl alcohol), which is an example of the "organic solvent" of the present invention, is dried with carbon dioxide (processing fluid) in a supercritical state. The liquid film is IPA piled up on the surface of the substrate. Therefore, the surface of the substrate is maintained in a wet state with IPA. Then, while the puddle state is maintained, the substrate is transported to a substrate drying apparatus, which is an example of the "substrate processing apparatus" of the present invention, and a drying process is performed using the processing fluid in a supercritical state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-103636 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above substrate processing apparatus, the processing chamber is filled with the processing fluid in a supercritical state, and the IPA covering the substrate is replaced by the processing fluid in a supercritical state. The IPA released from the surface of the substrate is dissolved in the processing fluid and discharged from the processing chamber together with the processing fluid. In this way, the substrate undergoes supercritical drying. Therefore, in order to shorten the time required for supercritical drying, it is considered to be beneficial to thin the liquid film before it comes into contact with the processing fluid in a supercritical state. However, there has been no conventional approach to shorten the processing time using the above approach.

[0006] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to shorten the drying time in a substrate processing method and substrate processing apparatus in which a substrate having a liquid film of an organic solvent formed in a puddle state on its surface is dried by a processing fluid in a supercritical state. [Means for solving the problem]

[0007] One aspect of the present invention is a substrate processing method in which a substrate having a puddle of a liquid film of an organic solvent formed on its surface is dried by a processing fluid in a supercritical state, the method comprising the steps of: (a) placing the substrate in a processing chamber; (b) supplying the processing fluid to the processing chamber to raise the pressure of the processing chamber from atmospheric pressure to a first pressure at which the processing chamber is in a subcritical state; (c) supplying the processing fluid to the processing chamber, which has been pressurized to the first pressure, to raise the pressure of the processing chamber to a second pressure at which the processing chamber is in a supercritical state; and (d) applying vibration to the substrate during the pressure raising period from the start of step (b) to when the processing chamber reaches the supercritical state, thereby reducing the thickness of the liquid film while maintaining the puddle state.

[0008] Another aspect of the present invention is a substrate processing apparatus that dries a substrate having a liquid film of an organic solvent formed on its surface in a puddle state using a processing fluid in a supercritical state, the processing apparatus comprising: a processing chamber that accommodates the substrate; a fluid supply unit that supplies the processing fluid to the processing chamber; a vibration imparting unit that imparts vibrations to the substrate accommodated in the processing chamber; and a control unit that controls the fluid supply unit to raise the pressure of the processing chamber from a first pressure that brings the processing chamber to a subcritical state to a second pressure that brings the processing chamber to a supercritical state by supplying the processing fluid to the processing chamber, which is at atmospheric pressure, and controls the vibration imparting unit to impart vibrations to the substrate while the processing chamber is being raised from atmospheric pressure to the first pressure by imparting vibrations to the substrate during the pressure increase period from the start of the supply of the processing fluid to the time when the processing chamber reaches the supercritical state.

[0009] In the invention thus configured, during the pressure increase period in which the processing fluid is supplied to the processing chamber and the pressure is increased, the processing fluid dissolves in the liquid film, and the surface tension of the liquid film decreases. Therefore, part of the liquid film flows off the substrate, and the thickness of the liquid film becomes somewhat thin. Here, vibration is applied to the substrate during the pressure increase period, so that the amount of film thickness reduction increases significantly, accelerating the thinning of the film. After that, the processing fluid in a supercritical state comes into contact with the thinned liquid film, thereby drying the substrate. Effect of the Invention

[0010] As described above, according to the present invention, the drying time can be shortened by applying vibration to the substrate during the pressure increase period. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing a schematic configuration of a substrate processing system equipped with a first embodiment of a substrate processing apparatus according to the present invention. [Figure 2A] FIG. 2 is a side view showing the overall configuration of the wet treatment apparatus. [Figure 2B] FIG. 4 is a diagram for explaining the operation of the wet treatment apparatus. [Diagram 3] FIG. 2 is a side view showing the configuration of a supercritical processing apparatus. [Figure 4] FIG. 2 is a perspective view showing a structure of a support tray. [Diagram 5] 5A to 5C are diagrams illustrating the configuration and operation of a support pin. [Figure 6] 2 is a flowchart showing an outline of a process executed by the substrate processing system according to the first embodiment. [Figure 7] 1A to 1C are diagrams showing pressure changes in a processing chamber, the operation of a support pin, and the state inside a pattern. [Figure 8A] 1A to 1C are diagrams illustrating problems that occur in a liquid film after a liquid film formation process. [Figure 8B] 10A to 10C are diagrams illustrating the solution of the above problem by applying vibration. [Figure 9] FIG. 4 is a view showing a second embodiment of the substrate processing apparatus according to the present invention. [Figure 10] FIG. 13 is a view showing a third embodiment of a substrate processing apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1 is a diagram showing a schematic configuration of a substrate processing system equipped with a first embodiment of a substrate processing apparatus according to the present invention. The substrate processing system 1 is a processing system for supplying a processing liquid to the upper surface of various substrates, such as semiconductor wafers, to wet process the substrates and then drying the substrates, and has a system configuration suitable for carrying out a substrate processing method according to the present invention. The substrate processing system 1 mainly comprises a wet processing apparatus 2, a substrate transport apparatus 3, a supercritical processing apparatus 4, and a control apparatus 9.

[0013] The wet processing device 2 receives the substrate to be processed and performs a predetermined wet processing. The type of processing is not particularly limited. The wet processing includes a developing process and a cleaning process, and after the developing process, a puddle state of an organic solvent such as an 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) using a processing fluid in a supercritical state on the substrate that has been transported. These are installed in a clean room. Therefore, the substrate transport device 3 transports the substrate S in the air atmosphere and under atmospheric pressure.

[0014] The control device 9 controls the operation of each of these devices to realize 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 a user and external devices. The operation of the devices described below is realized by the CPU 91 executing the control programs written in advance in the storage 93 and causing each part of the devices to perform a predetermined operation.

[0015] As a result of the CPU 91 executing a predetermined control program, functional blocks such as a wet processing control unit 95 for controlling the operation of the wet processing device 2, a transport control unit 96 for controlling the operation of the substrate transport device 3, and a supercritical processing control unit 97 for controlling the operation of the supercritical processing device 4 are realized in the form of software in the control device 9. Note that each of these functional blocks may be at least partially configured with dedicated hardware.

[0016] As the "substrate" in this embodiment, various substrates such as 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 can be applied. In the following, a substrate processing apparatus used mainly for processing disc-shaped semiconductor wafers will be described with reference to the drawings. However, the present invention can be applied to the processing of the various substrates exemplified above. Various substrate shapes can also be applied.

[0017] In the following description, a substrate having a pattern formed only on one main surface is used as an example. Here, the side of the main surface on which the pattern is formed is referred to as the "front surface," and the opposite main surface on which no pattern is formed is referred to as the "rear surface." The main surface of the substrate facing downward is referred to as the "lower surface," and the main surface of the substrate facing upward is referred to as the "upper surface." In the following description, the upper surface is referred to as the front surface.

[0018] 2A and 2B are diagrams showing an example of the configuration of a wet-type processing apparatus. More specifically, FIG. 2A is a side view showing the overall configuration of the wet-type processing apparatus, and FIG. 2B is a diagram for explaining the operation of the wet-type processing apparatus. This wet-type processing apparatus 2 is an apparatus for processing a substrate by supplying a processing liquid to the upper surface of a substrate S. The operation of the wet-type processing apparatus 2 is controlled by a wet processing control unit 95 of a control apparatus 9.

[0019] The wet processing device 2 supplies a processing liquid to a surface (pattern-formed 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 device 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 a diameter substantially equal to that of 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, so that the spin chuck 211 can hold the substrate S in a horizontal position while being spaced apart from the upper surface of the substrate S.

[0020] The spin chuck 211 is supported by a rotation support shaft 213 extending downward from the center of its bottom 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 about a rotation axis AX indicated by a dashed dotted line. In FIG. 2, the up-down direction is the vertical direction. As a result, the substrate S is rotated about the rotation axis AX while remaining in a horizontal position.

[0021] 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. 2A, 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. 2B.

[0022] 2A, 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, for example, when the substrate S is loaded onto or unloaded from the spin chuck 211.

[0023] 2B, when the cup 221 is in the upper position, it surrounds the peripheral portion of the substrate S held by the spin chuck 211. This prevents the processing liquid shaken off from the peripheral portion of the substrate S during liquid supply, which will be described later, from scattering inside the chamber 200, and makes it possible to reliably collect the processing liquid. That is, droplets of the processing liquid shaken off from the peripheral portion 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.

[0024] The processing liquid supply unit 23 has a structure in which a nozzle 234 is attached to the tip of an arm 233 extending horizontally from a pivot shaft 232 that is rotatably provided with respect to a base 231 fixed to the processing chamber 200. The pivot shaft 232 rotates in response to a control command from the control device 9, whereby the arm 233 swings, and the nozzle 234 at the tip of the arm 233 moves between a retracted position retracted to the side from above the substrate S as shown in Fig. 2A and a processing position above the substrate S as shown in Fig. 2B.

[0025] The nozzle 234 is connected to a processing liquid supply source 238, and when an appropriate processing liquid is sent from the processing liquid supply source 238, the processing liquid is discharged from the nozzle 234 toward the substrate S. As shown in FIG. 2B, while the spin chuck 211 rotates at a relatively slow speed to rotate the substrate S, a processing liquid L1 is supplied from the nozzle 234 positioned above the center of rotation of the substrate S, and the surface Sa of the substrate S is processed with the processing liquid L1. As the processing liquid L1, liquids having various functions such as a developer, an etching liquid, a cleaning liquid, a rinsing liquid, etc. can be used, and the composition thereof is arbitrary. In addition, a plurality of types of processing liquids may be combined to perform processing.

[0026] The other processing liquid supply unit 24 also has a configuration corresponding to that of the above-mentioned first processing liquid supply unit 23. That is, the second processing liquid supply unit 24 has a base 241, a rotating support 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 rotating support shaft 242 rotates in response to a control command from the control device 9, thereby swinging the arm 243. The nozzle 244 at the tip of the arm 243 supplies the processing liquid to the surface Sa of the substrate S.

[0027] 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 the wet processing. That is, the substrate S after the wet processing is transported to the supercritical processing device 4 and subjected to a supercritical drying process, 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 in a state where the surface is covered with a paddle-shaped liquid film.

[0028] The liquid that constitutes the liquid film is a material having a smaller surface tension than 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. These organic solvents are supplied from an organic solvent supply source 248.

[0029] 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. Also, one processing liquid supply unit may have multiple nozzles. For example, multiple nozzles may be provided at the tip of one arm. Also, in addition to the above-mentioned mode in which the nozzle is positioned at a predetermined position and the processing liquid is discharged, for example, the nozzle may be moved in a scanning manner along the surface Sa of the substrate S and the processing liquid is discharged.

[0030] Returning to FIG. 1, the description will be continued. The substrate transport device 3 is provided with a transport robot 30 having a hand 31 attached to the tip of a telescopic and rotatable arm. The hand 31 can support the substrate by partially contacting the lower surface of the substrate, and can move forward and backward relative to both the wet treatment device 2 and the supercritical treatment device 4 as shown by the dotted line in FIG. 1. This allows the substrate to be carried in and out of both the wet treatment device 2 and the supercritical treatment device 4. The operation of the transport robot 30 is controlled by a transport control unit 96 of the control device 9. There are many known techniques for this type of transport robot, and since these can be appropriately selected and used in this embodiment, detailed explanations will be omitted.

[0031] 3 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.

[0032] 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 body that executes the supercritical drying process. The transfer unit 43 receives the substrate S after the wet process 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 the process to the processing unit 41 and the transfer unit 43. These operations are controlled by the control device 9, in particular the supercritical processing control unit 97.

[0033] The processing unit 41 has a structure in which a processing chamber 412 is attached on a pedestal 411. The processing chamber 412 is configured by combining several metal blocks, and its interior is hollow to form 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 and extends 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.

[0034] A lid member 413 is provided on the (-Y) side surface of the processing chamber 412 so as to close the opening 421. The lid member 413 closes the opening 421 of the processing chamber 412 to form an airtight processing container. This allows processing of 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 serves as 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 horizontally movable in the Y direction.

[0035] The lid member 413 can be moved forward and backward with respect to the processing chamber 412 by an advance / retract mechanism 453 provided in the supply unit 45. Specifically, the advance / retract mechanism 453 has a linear motion mechanism such as a linear motor, a linear motion guide, a ball screw mechanism, a solenoid, an air cylinder, or the like. Such a linear motion mechanism moves the lid member 413 in the Y direction. The advance / retract mechanism 453 operates in response to a control command from the control device 9.

[0036] 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 to the outside 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 the 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.

[0037] 4 is a perspective view showing the structure of the support tray. The support tray 415 has a tray member 416 and a plurality of support pins 417. The tray member 416 has a structure in which a depression 418 having a diameter corresponding to the planar size of the substrate S, more specifically, a diameter slightly larger than the diameter of the circular substrate S, is provided on the horizontal and flat upper surface of, for example, a flat plate-like structure.

[0038] The recess 418 partially extends to the side surface of the tray member 416. In other words, the side wall surface of the recess 418 is not circular, but is partially cut out. Therefore, at this cutout portion, part of the bottom surface 418a of the recess 418 is directly connected to the side surface. In this example, such cutout portions are provided at both ends on the X side and the (+Y) side end of the support tray 415, and at these locations, the bottom surface 418a is directly connected to the side surface.

[0039] Further, through holes 419 for inserting the lift pins 437 are formed in the bottom surface 418a at positions corresponding to the lift pins 437 of the transfer unit 43. The lift pins 437 are raised and lowered through the through holes 419, whereby the substrate S is accommodated in the recess 418 and is lifted upward therefrom.

[0040] A plurality of support pins 417 are arranged on the periphery of the recess 418. The number of support pins 417 to be arranged is arbitrary, but it is preferable that the number be three or more in terms of stably supporting the substrate S. In this embodiment, three support pins 417 are attached to the tray member 416 so as to surround the bottom surface 418a in a plan view from above.

[0041] The support pins 417 all have the same configuration. Therefore, in the following, the configuration of one support pin 417 will be described, and the other support pins 417 will be denoted by the same reference numerals and their description will be omitted. As shown in FIG. 5, the support pin 417 has a tray contact surface 417a. This tray contact surface 417a is movable along the radial direction D on the upper surface of the tray member 416. The support pin 417 has a lower contact surface 417b above the tray contact surface 417a. The lower contact surface 417b is inclined downward as it proceeds in the direction (+D) toward the center line BX. Here, the "center line BX" means a vertical line passing through the center of the recess 418 as shown in FIG. 4, and passes through the center of the substrate S when the substrate S is chucked by the support pins 417 as described later.

[0042] A curved abutment surface 417c is provided upward from the end of the lower abutment surface 417b on the (-D) direction side. The curved abutment surface 417c is finished into a curved surface facing the center line BX side. Furthermore, an upper abutment surface 417d is provided extending upward from the upper end of the curved abutment surface 417c. The upper abutment surface 417d is inclined upward as it proceeds in the direction (+D) toward the center line BX side. More specifically, as shown in FIG. 5, the curved abutment surface 417c is disposed between the upper abutment surface 417d and the lower abutment surface 417b, and directly continues to the upper abutment surface 417d and the lower abutment surface 417b. Therefore, when a substrate abutment portion 417e where the upper abutment surface 417d, the curved abutment surface 417c, and the lower abutment surface 417b are connected and abut against the substrate S, is viewed from a horizontal direction perpendicular to the radial direction D, the substrate abutment portion 417e has a substantially C-shape. In other words, the support pin 417 is capable of reciprocating movement along the radial direction D with the substrate abutment portion 417e facing the center line BX.

[0043] The support pin 417 is connected to a pin driver 417f. The pin driver 417f moves the support pin 417 in the radial direction D in response to a command from the supercritical process control unit 97. For example, when transferring the substrate S to and from the substrate transport device 3, as shown in FIG. 5(b), the pin driver 417f moves the support pin 417 in the direction (-D) and positions it at a non-chuck position (corresponding to an example of the "release position" of the present invention). At this time, the curved contact surface 417c and the upper contact surface 417d are slightly farther away from the center line BX than the radius of the substrate S. On the other hand, the lower contact surface 417b is located below the substrate S. Therefore, as shown in FIG. 5(b), the substrate S is supported only by the lower contact surface 417b, and moreover, at a position of the lower contact surface 417b that is farther away from the curved contact surface 417c in the (+D) direction.

[0044] On the other hand, when chucking the substrate S, as shown in Fig. 5(a), the pin driving unit 417f moves the support pin 417 in the direction (+D) and positions it at the chuck position (corresponding to an example of the "clamping position" of the present invention). By moving the support pin 417 from the non-chuck position to the chuck position in this manner, the support position of the substrate S on the lower contact surface 417b shifts in the (-D) direction. When the movement of the support pin 417 to the chuck position is completed, the substrate S is supported by the lower contact surface 417b, the curved contact surface 417c, and the upper contact surface 417d. In other words, substrate chucking is completed.

[0045] When the substrate S is released from the chuck, the support pins 417 move in the reverse order to that described above, and the support position of the substrate S on the lower contact surface 417b shifts in the (+D) direction.

[0046] Furthermore, the support position of the substrate S on the lower contact surface 417b moves in the radial direction D, and thus the height position of the substrate S in the vertical direction Z is displaced by a distance dz. Therefore, when the supercritical processing control unit 97 gives a reciprocating movement command to the pin driving unit 417f, the support pins 417 move reciprocatingly in the radial direction D, and the substrate S is repeatedly raised and lowered in synchronization therewith. In other words, it is possible to apply vibrations in the vertical direction to the substrate S. In this embodiment, the object of the present invention is achieved by utilizing this application of vibrations. This point will be described in detail later together with the operation of the substrate processing system 1.

[0047] 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 to keep the processing space SP airtight. The seal member 422 is made of rubber, for example. The lid member 413 is fixed to the processing chamber 412 by a locking mechanism (not shown). Thus, in this embodiment, the lid member 413 can be switched between a closed state (solid line) in which the opening 421 is closed to seal the processing space SP, and a separated state (dotted line) in which the lid member 413 is significantly separated from the opening 421 to allow the substrate S to be inserted and removed.

[0048] With the airtight state of the processing space SP ensured, processing of the substrate S is performed in the processing space SP. In this embodiment, the fluid supply unit 457 provided in the supply unit 45 delivers a processing fluid of a substance usable for supercritical processing, such as carbon dioxide, as the processing fluid, and the processing fluid is pressurized in the processing chamber 412 to bring it into a supercritical state. The processing fluid is supplied to the processing unit 41 in a gaseous or liquid state. Carbon dioxide is a chemical substance suitable for supercritical drying processing in that it reaches a supercritical state at a relatively low temperature and low pressure, and has the property of dissolving organic solvents that are often used in substrate processing well. 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.

[0049] When the processing space SP is filled with the processing fluid and the inside of 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 supercritical state in the processing chamber 412. The supply unit 45 is provided with a fluid recovery part 455, and the fluid after processing 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.

[0050] The processing space SP has a shape and volume capable of receiving 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 capable of receiving the support tray 415. In this manner, the processing space SP has a shape and volume sufficient to receive 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.

[0051] The fluid supply unit 457 supplies the processing fluid to the processing space SP on the (+Y) side of the (+Y) side end of the substrate S. Meanwhile, the fluid recovery unit 55 discharges the processing fluid flowing through the space above the substrate S and the space below the support tray 415 in the processing space SP on the (-Y) side of the (-Y) side of 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.

[0052] The supercritical processing control unit 97 of the control device 9 identifies the pressure and temperature in the processing space SP based on the detection result from a detection unit (not shown), and controls the fluid supply unit 457 and the fluid recovery unit 455 based on the result. 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.

[0053] 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 a plurality of 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 upper portion of the lifting member 433. A plurality of 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 portion against 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.

[0054] 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, an air cylinder, etc., and such a 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.

[0055] The base member 435 moves up and down by the lifting member 433 moving up and down, and the multiple 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 in a state in which the support tray 415 is pulled out 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 reach a position higher than the upper surface of the support tray 415 through the through holes 419. 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 taken out by reversing the above procedure. In this embodiment, the support pins 417 are positioned at the open position when the substrate S is loaded and unloaded. On the other hand, the support pins 417 are positioned at the clamping position at other times. However, in the thinning process described next, the support pins 417 are repeatedly switched between the open position and the clamping position.

[0056] 6 is a flow chart showing an outline of the processing performed by the substrate processing system according to the first embodiment. The substrate processing system 1 receives a substrate S to be processed, and sequentially performs a wet processing using a processing liquid and a supercritical drying processing using a supercritical processing fluid. Specifically, the following steps S101 to S111d are performed. The substrate S to be processed is accommodated in a wet processing device 2 constituting the substrate processing system 1 (step S101). The substrate S may be carried in directly by an external transfer device, or may be carried in from the external transfer device via a transfer robot 30.

[0057] The wet processing device 2 performs wet processing on the substrate S using a predetermined processing liquid (step S102). In this wet processing, a developer, a cleaning liquid, etc. are supplied to perform a predetermined processing, and then a rinse liquid such as DIW (de-ionized water) is supplied to the surface Sa of the substrate S. Therefore, immediately after the completion of the wet processing, the rinse liquid adheres to the surface Sa of the substrate S as an example of the "liquid" of the present invention. Therefore, by supplying an organic solvent such as IPA to the substrate S after the wet processing, the rinse liquid adhering to the surface Sa of the substrate S is replaced with the organic solvent, and a liquid mound state in which the organic solvent is piled up is created. In other words, a liquid film LF is formed on the surface Sa of the substrate S (step S103: liquid film forming processing).

[0058] The technical significance of the liquid film forming process is as follows. For example, if DIW is present inside the pattern PT formed on the surface Sa of the substrate S, the pattern PT may collapse due to the surface tension of the DIW. In addition, watermarks may remain on the surface Sa of the substrate S due to incomplete drying. Furthermore, the surface Sa of the substrate S may be altered, such as by oxidation, when exposed to the outside air. In order to prevent such problems, the surface Sa of the substrate S is covered with an organic solvent. As the organic solvent, it is preferable to use a liquid that has a lower surface tension than DIW and is less corrosive to the substrate S, such as IPA or acetone, which is compatible with DIW. In the following, a case will be described in which DIW is used as the rinse liquid and IPA is used as the organic solvent.

[0059] By the liquid film forming process, a liquid film LF is formed on the surface Sa of the substrate S. The substrate S, in the liquid-pile state, is transported by the substrate transport device 3 from the wet processing device 2 to the supercritical processing device 4 (step S104).

[0060] The substrate S transported to the supercritical processing apparatus 4 is accommodated in the processing chamber 412 in a puddle state. Specifically, the substrate S is transported with the pattern-formed surface (surface Sa) facing up and covered with a thin liquid film LF. As shown by the dotted line in FIG. 3, the lift pins 437 rise while the cover member 413 moves to the (-Y) side and the support tray 415 is pulled out. The transport device transfers the substrate S to the lift pins 437. The lift pins 437 are lowered, so that the substrate S is placed on the support pins 417 positioned at the open position. Subsequently, the support pins 417 move to the clamping position to hold the substrate S. In this way, the support tray 415 completes receiving the substrate S (step S105).

[0061] When the support tray 415 and the lid member 413 move integrally in the (+Y) direction, the support tray 415 supporting the substrate S is accommodated in the processing space SP in the processing chamber 412 and the opening 421 is closed by the lid member 413 .

[0062] When it is confirmed that the substrate S has been accommodated ("YES" in step S106), carbon dioxide as a processing fluid is introduced in a gaseous state into the processing space SP while still in a liquid mound state. That is, introduction of the processing fluid into the processing chamber 412 is started (step S107). When the substrate S is loaded, outside air enters the processing space SP, but this can be replaced by introducing the gaseous processing fluid. Furthermore, by injecting the gaseous processing fluid, the pressure inside the processing chamber 412 increases from atmospheric pressure, and the inside of the processing chamber 412 becomes atmospheric pressure.

[0063] During the process of introducing the processing fluid, the processing fluid is continuously discharged from the processing space SP. That is, even while the processing fluid is being introduced by the fluid supply unit 457, the processing fluid is discharged from the processing space SP by the fluid recovery unit 455. This allows the processing fluid used for processing to be discharged without remaining in the processing space SP, and prevents impurities such as residues that have been taken in the processing fluid from adhering again to the substrate S.

[0064] If the supply amount of the processing fluid is greater than the discharge amount, the density of the processing fluid in the processing space SP increases, and the pressure inside the chamber increases. Conversely, if the supply amount of the processing fluid is less than the discharge amount, the density of the processing fluid in the processing space SP decreases, and the pressure inside the chamber is reduced. The supply of the processing fluid to the processing chamber 412 and the discharge of the processing fluid from the processing chamber 412 are performed based on a supply and discharge recipe created in advance. That is, the control device 9 controls the fluid supply unit 457 and the fluid recovery unit 455 based on the supply and discharge recipe, thereby adjusting the supply and discharge timing and the flow rate of the processing fluid. Furthermore, the support pins 417 are reciprocated in response to the pressure change inside the processing chamber 412, and the thin film processing is performed.

[0065] 7 shows the pressure change in the processing chamber, the operation of the support pins, and the state inside the pattern. When the processing fluid is carbon dioxide, its critical temperature is not much different from room temperature, so the temperature change during processing is not so great. Here, the phenomenon will be explained by focusing on the pressure inside the chamber, where the change is more noticeable. When the processing space SP is opened to the atmosphere and the internal pressure is atmospheric pressure Pa, the introduction of the processing fluid begins at time T1 after the processing space SP is sealed, and the internal pressure begins to rise.

[0066] The pressure of the processing fluid increases in the processing space SP. In this embodiment, the pressure in the processing chamber 412 continues to be pressurized until it exceeds the critical pressure Pc via a pressure (hereinafter referred to as "subcritical pressure") Ps at which the pressure is in a subcritical state. Carbon dioxide, which is the processing fluid, is supplied, and the carbon dioxide is mixed with the IPA constituting the liquid film LF. As a result, the liquid film LF increases, but the surface tension of the mixed liquid (=IPA+carbon dioxide) decreases. For example, when the pressure in the processing chamber 412 reaches the vicinity of the subcritical pressure Ps, a part of the mixed liquid constituting the liquid film LF drips from the substrate S, and the film thickness of the liquid film LF becomes thinner. Here, if vibration is applied to the substrate S at the stage where the surface tension becomes smaller, a part of the mixed liquid additionally drips from the substrate S, and the liquid film LF can be further thinned.

[0067] Therefore, in this embodiment, when the pressure in the processing chamber 412 reaches the subcritical pressure Ps ("YES" in step S108: time T2), the supercritical processing control unit 97 issues a reciprocating movement command to the pin driving unit 417f. Then, as shown in the middle graph of FIG. 7, the pin driving unit 417f reciprocates the support pins 417 in the radial direction D. In response to this, the substrate S repeatedly rises and falls, and vibrations are applied to the substrate S in the up-down direction. This causes the liquid film LF to be thinned by a thickness dz while maintaining the liquid film LF in a puddle state (step S109: thinning process). Note that when the pressure in the processing chamber 412 exceeds time T3 at which the pressure reaches the subcritical pressure Ps, the processing fluid becomes supercritical in the chamber. Therefore, the period during which vibration is applied, that is, the end of the vibration application period, needs to be set before time T3. On the other hand, the start of the vibration application period is not limited to time T2, and may be set at a timing when the surface tension of the liquid film LF is sufficiently reduced. Furthermore, the number of times that the support pin 417 reciprocates during the vibration application period, that is, the number of vibrations, is arbitrary.

[0068] Even after the thinning process is performed in this manner, the pressure increase process continues. Therefore, at time T3 when the pressure inside the chamber reaches the critical pressure Pc, the processing fluid becomes supercritical in the chamber. That is, the processing fluid transitions from the gas phase to the supercritical state due to a phase change in the processing space SP. When the processing space SP is filled with the processing fluid in the supercritical state, the IPA covering the substrate S is replaced by the processing fluid in the supercritical state. The IPA and the like liberated from the surface of the substrate S are discharged from the processing chamber 412 together with the processing fluid in a state dissolved in the processing fluid, and are removed from the substrate S. That is, the processing fluid in the supercritical state has the function of replacing the IPA adhering to the substrate S as the replacement target liquid, and discharging it out of the processing chamber 412.

[0069] After time T3 when the processing fluid has definitely transitioned to the supercritical state, the processing space SP is kept filled with the processing fluid in the supercritical state for a predetermined time (steps S110, S111), whereby the liquid to be replaced adhering to the substrate S can be completely replaced and discharged outside the chamber. Note that, in Fig. 7, the pressure Pm in the chamber in the supercritical state is shown as being constant after the pressure increase continues until time T4, which is beyond time T3, but the pressure may fluctuate within a range not falling below the critical pressure Pc.

[0070] At time T4, when replacement of the liquid to be replaced with the processing fluid in the supercritical state in the processing chamber 412 is completed (step S112), the processing fluid in the processing space SP is discharged to dry the substrate S. Specifically, the amount of fluid discharged from the processing space SP is increased to reduce the pressure in the processing chamber 12 filled with the processing fluid in the supercritical state (step S113).

[0071] In the depressurization process, the supply of the processing fluid may be stopped, or a small amount of the processing fluid may be continuously supplied. When the processing space SP is depressurized from a state filled with the processing fluid in a supercritical state, the processing fluid changes phase from the supercritical state to a gas phase. By discharging the vaporized processing fluid to the outside, the substrate S becomes a dry state. At this time, the depressurization speed is adjusted so that a solid phase and a liquid phase are not generated due to a sudden drop in temperature. That is, after the depressurization is started at time T5, the depressurization is performed at a relatively low depressurization speed until time T6 when the pressure falls reliably below the critical pressure Pc. As a result, the processing fluid in the processing space SP is directly vaporized from the supercritical state and discharged to the outside.

[0072] After time T6 when the processing fluid is completely vaporized, the depressurization speed is increased, and thus it is possible to quickly depressurize the chamber to atmospheric pressure Pa. In this way, the processing fluid is not liquefied during the entire period from time T4 when depressurization begins to time T7 when the pressure inside the chamber is lowered to atmospheric pressure Pa, and the formation of a gas-liquid interface on the substrate S with the exposed surface after drying is avoided.

[0073] As described above, in the supercritical drying process of this embodiment, the processing space SP is filled with a processing fluid in a supercritical state, and then the processing fluid is changed into a gas phase and discharged, thereby efficiently replacing the liquid adhering to the substrate S and preventing it from remaining on the substrate S. Moreover, the substrate can be dried while avoiding problems caused by the formation of a gas-liquid interface, such as contamination of the substrate due to the adhesion of impurities and pattern collapse.

[0074] After processing, the substrate S is discharged to a subsequent process (step S114). That is, the support tray 415 is drawn out from the processing chamber 412 to the outside by moving the cover member 413 in the (-Y) direction, and the substrate S is delivered to an external transport device via the transfer unit 43. At this time, the substrate S is in a dry state. The content of the subsequent process is arbitrary. In this way, the processing for one substrate S is completed. If there is another substrate to be processed, the process returns to step S101 to receive the new substrate S, and the above processing is repeated.

[0075] As described above, according to the first embodiment, after the liquid film LF is thinned, the substrate is dried by the processing fluid in a supercritical state, and therefore the drying time can be shortened.

[0076] Furthermore, the application of vibration provides the following effects, which will be described below with reference to Figures 8A and 8B.

[0077] FIG. 8A is a diagram showing a problem that occurs in the liquid film after the liquid film forming process. FIG. 8B is a diagram showing a solution to the problem by applying vibration. After the liquid film forming process (step S103), as shown in FIG. 8A, a part of the rinse liquid (DIW) may remain on the inner bottom surface of the pattern PT. If the drying process is performed on the substrate S with the remaining liquid (hereinafter referred to as "residual liquid") remaining, the following problem may occur. That is, the replacement of the liquid components constituting the liquid film with the processing fluid in the supercritical state is likely to be incomplete. Therefore, in order to cover this, a countermeasure of increasing the amount of processing fluid used may be considered. However, this leads to an increase in running costs and imposes a large environmental burden on society.

[0078] In contrast, in this embodiment, vibration is applied to the substrate S by performing the thinning process. Therefore, the liquid (DIW) remaining in the pattern PT is advected and diffused, and mixed into the mixed liquid (=IPA+carbon dioxide) that constitutes the liquid film LF. Therefore, the drying process is performed with the processing fluid in a supercritical state in a state where there is no residual liquid on the inner bottom surface of the pattern PT, that is, in a so-called residual liquid free state. As a result, it is possible to improve the yield while reducing the consumption of the processing fluid.

[0079] Furthermore, a portion of the mixed liquid that drips from the substrate S during pressure increase may adhere to the through-hole 419, which may adversely affect the drying performance. However, in this embodiment, the mixed liquid adhering to the through-hole 419 can be caused to fall and removed by applying vibration to the substrate S during the thinning process. As a result, the drying performance can be improved.

[0080] Furthermore, in the first embodiment, the reciprocating movement of the support pins 417 in the radial direction D is utilized to impart vibration to the substrate S. That is, the support pins 417 exert a vibration imparting function in addition to the function of holding the substrate S by pinching the side end portion of the substrate S. Therefore, since there is no need to add a configuration that specializes in the vibration imparting function, the cost of the device can be reduced.

[0081] As described above, in the first embodiment, DIW and IPA correspond to an example of the "liquid" and "organic solvent" of the present invention, respectively. Moreover, the subcritical pressure Ps and the critical pressure Pc correspond to an example of the "first pressure" and "second pressure" of the present invention, respectively. Moreover, the surface Sa of the substrate S corresponds to the "pattern formation surface" of the present invention. Moreover, steps S105 and S106 correspond to an example of the "step (a)" of the present invention, steps S107 and S108 correspond to an example of the "step (b)" of the present invention, steps S110 and S111 correspond to an example of the "step (c)" of the present invention, and step S109 corresponds to an example of the "step (d)" of the present invention. Moreover, the liquid film forming process (step S103) corresponds to an example of the "liquid film forming step" of the present invention, and step S109 corresponds to an example of the "step (d)" of the present invention. Moreover, the period from time T1 to time T4 corresponds to an example of the "pressure increase period" of the present invention. Moreover, the supercritical processing control unit 97 corresponds to an example of the "control unit" of the present invention.

[0082] In the first embodiment, the support pins 417 are reciprocated in the direction D to perform the thinning process. That is, the support pins 417 and the pin drive unit 417f function as the "vibration applying unit" of the present invention, but the configuration of the vibration applying unit is not limited to this. For example, vibration may be applied to the substrate S by a separately added configuration without applying vibration along the vertical direction Z by the support pins 417 (hereinafter referred to as "up-down vibration application"). For example, the support tray 415 may be directly or indirectly vibrated by a vibrator 415a (FIG. 9) or an ultrasonic vibrator (FIG. 10), and the substrate S may be vibrated by the vibration of the support tray 415.

[0083] 9 is a diagram showing a second embodiment of a substrate processing apparatus according to the present invention. In this second embodiment, an oscillator 415a is attached to a support tray 415. The oscillator 415a vibrates in response to a vibration command from a supercritical processing control unit 97. Thus, in the second embodiment, the oscillator 415a corresponds to an example of the "vibration applying unit" of the present invention. Here, the attachment position of the oscillator 415a is not limited to the support tray 415, and it may be attached to the cover member 413.

[0084] 10 is a diagram showing a third embodiment of a substrate processing apparatus according to the present invention. In this third embodiment, an ultrasonic transducer 412a is attached to a processing chamber 412 so as to face the lower surface of a support tray 415. The ultrasonic transducer 412a vibrates in response to a vibration command from a supercritical processing control unit 97. Thus, in the second embodiment, the ultrasonic transducer 412a corresponds to an example of the "vibration applying unit" of the present invention.

[0085] As described above, in the second and third embodiments, the thin film processing (step S109) is performed prior to the drying processing using the processing fluid in a supercritical state, as in the first embodiment, and therefore, advantageous effects such as shortening the drying time can be obtained.

[0086] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Although the thinning process is performed only once when performing the supercritical drying process on one substrate S, the thinning process may be performed multiple times.

[0087] In addition, the various chemical substances used in the treatment of the above-mentioned embodiments are only some examples, and various substances can be used instead as long as they are in accordance with the technical concept of the present invention described above. [Industrial Applicability]

[0088] The present invention can be applied to any technique for drying a substrate using a processing fluid in a supercritical state in a chamber. [Explanation of symbols]

[0089] 4...Supercritical processing equipment (substrate processing equipment) 97...Supercritical processing control unit (control unit) 412... Processing chamber 412a...Ultrasonic vibrator (vibration applying unit) 415…Support tray 415a...Vibrator (vibration applying part) 417...Support pin (vibration applying part) 417f...Pin drive unit (vibration applying unit) LF…Liquid film PT…Pattern S...Substrate Sa: Top surface (pattern formation surface) Z: Vertical direction

Claims

1. 1. A substrate processing method for drying a substrate having a liquid film of an organic solvent formed on a surface thereof by using a processing fluid in a supercritical state, comprising the steps of: (a) placing the substrate in a processing chamber; (b) supplying a processing fluid to the processing chamber to increase the pressure in the processing chamber from atmospheric pressure to a first pressure that is a subcritical pressure; (c) supplying the processing fluid to the processing chamber pressurized to the first pressure to pressurize the processing chamber to a second pressure at which the processing chamber is in the supercritical state; (d) applying vibration to the substrate during a pressure increase period from the start of the step (b) until the processing chamber reaches the supercritical state, thereby reducing a thickness of the liquid film while maintaining the puddle state; A substrate processing method comprising:

2. 2. The substrate processing method according to claim 1, The step (a) (a-1) supporting a peripheral portion of the substrate from below with a plurality of support pins provided on a support tray, and then moving the plurality of support pins toward the substrate while continuing to support the substrate with the plurality of support pins, thereby sandwiching and holding the substrate with the plurality of support pins from a horizontal direction; (a-2) moving the support tray into the processing chamber while the substrate is held by the plurality of support pins; having In the step (d), the vibration is applied to the substrate by moving the plurality of support pins back and forth between a clamping position where the substrate is clamped and an open position spaced apart from the clamping position, thereby forming a substrate processing method.

3. 2. The substrate processing method according to claim 1, The step (a) (a-3) placing the substrate on a support tray; (a-4) moving the support tray with the substrate thereon into the processing chamber; having In the step (d), the application of vibration to the substrate is performed by activating a vibrator attached to the support tray.

4. 2. The substrate processing method according to claim 1, The step (a) (a-3) placing the substrate on a support tray; (a-4) moving the support tray with the substrate thereon into the processing chamber; having In the step (d), the application of vibration to the substrate is performed by activating an ultrasonic vibrator attached to the processing chamber.

5. 5. The substrate processing method according to claim 1 , further comprising the steps of: The substrate processing method, wherein the application of vibration to the substrate in the step (d) is performed in the subcritical state.

6. 5. The substrate processing method according to claim 1 , further comprising the steps of: the surface of the substrate is a pattern-formed surface on which a pattern is formed, before carrying out the step (a), a liquid film forming step is carried out in which the liquid adhering to the pattern-forming surface is replaced with the organic solvent by supplying the organic solvent to the pattern-forming surface to which the liquid has been adhering, and then the liquid film is formed on the pattern-forming surface; In the step (d), the liquid remaining in the pattern is mixed with the organic solvent while the liquid film is being thinned by applying the vibration to the substrate.

7. 1. A substrate processing apparatus for drying a substrate having a liquid film of an organic solvent formed on a surface thereof by using a processing fluid in a supercritical state, comprising: a processing chamber housing the substrate; a fluid supply section for supplying a processing fluid to the processing chamber; a vibration applying unit that applies vibration to the substrate accommodated in the processing chamber; a control unit that controls the fluid supply unit to supply the processing fluid to the processing chamber, which is in an atmospheric pressure state, to increase the pressure of the processing chamber via a first pressure that is in a subcritical state to a second pressure that is in the supercritical state, and controls the vibration applying unit to apply vibration to the substrate during a pressure increase period from the start of supply of the processing fluid to the processing chamber reaching the supercritical state, thereby applying vibration to the substrate while the processing chamber is being increased from atmospheric pressure to the first pressure; A substrate processing apparatus comprising:

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