Method for processing substrate

Abstract

A method for processing a substrate is disclosed. In one embodiment, a supercritical fluid is supplied to a processing space in a chamber to process a substrate in the processing space. The supercritical fluid is supplied to the processing space while the processing space is being vented. The temperature of the supercritical fluid supplied when the processing space is vented is higher than the temperature of the supercritical fluid supplied to the processing space for processing the substrate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application requests Korean Patent Application No. 10-2019-0085053 filed on July 15, 2019 in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the inventive concepts described herein relate to a method of treating a substrate, and more particularly, to a method of treating a substrate using a supercritical fluid. Background Art

[0004] Generally, semiconductor devices are manufactured from a substrate such as a wafer, and are manufactured by performing a deposition process, a photolithography process, an etching process, etc. to form a fine circuit pattern on the top surface of the substrate.

[0005] Since the top surface of the substrate on which the circuit pattern is formed may be contaminated by various foreign substances in the case where the above-mentioned process is performed, a cleaning process may be performed to remove the foreign substances.

[0006] Generally, the cleaning process includes a chemical treatment step of supplying chemicals to a substrate to remove foreign substances on the substrate, a cleaning step of supplying pure water to the substrate to remove the chemicals remaining on the substrate, and a drying step of removing the pure water remaining on the substrate.

[0007] The supercritical fluid is used to dry the substrate. In one embodiment, after replacing the pure water on the substrate with the organic solvent, the supercritical fluid is supplied to the top surface of the substrate in the high pressure chamber, so that the organic solvent remaining on the substrate is dissolved in the supercritical fluid, and the organic solvent is removed from the substrate. Isopropyl alcohol (IPA) is used as the organic solvent, and carbon dioxide (CO 2 ) is used as a supercritical fluid, IPA dissolves well in carbon dioxide, and the critical temperature and critical pressure of carbon dioxide are relatively low.

[0008] The substrate processing using supercritical fluid is as follows. Figure 1 The pressure P in the chamber and the temperature T in the chamber are shown when the substrate is processed using a supercritical fluid. When the substrate is brought into the high-pressure chamber, carbon dioxide in a critical state is supplied to the high-pressure chamber, thereby pressurizing the interior of the high-pressure chamber (S10). Then, the substrate is processed with the supercritical fluid while repeating the supply of the supercritical fluid and the discharge of the high-pressure chamber (S20). When the substrate processing is completed, the interior of the high-pressure chamber is discharged, and the pressure is thus reduced (S30).

[0009] like Figure 2As shown in FIG. 1 , the solubility of IPA in carbon dioxide decreases as the temperature decreases. Therefore, in the case of repeating the supply of carbon dioxide and the exhaust of the interior of the chamber, when the chamber is exhausted during the processing of the substrate, the temperature inside the chamber decreases due to adiabatic expansion. Although the temperature inside the chamber is not lower than the critical temperature t1 of carbon dioxide, as shown in FIG. Figure 2 As shown in FIG. 1 , the solubility of IPA in carbon dioxide decreases as the temperature inside the chamber decreases. Due to the decrease in solubility, the IPA in the chamber remains in the form of mist and falls on the substrate, resulting in cleaning defects.

[0010] When the interior of the high-pressure chamber is exhausted to achieve decompression of the chamber (S30), the pressure inside the chamber is reduced, and due to adiabatic expansion, the temperature inside the chamber drops to below 31 degrees Celsius, the critical temperature t1 of carbon dioxide. This causes the supercritical mixture inside the chamber to condense and drip onto the substrate from time t1.

[0011] The mixture between IPA and carbon dioxide that is not dissolved in the supercritical fluid remains on the substrate and is adsorbed into the substrate, causing pattern lining. Therefore, the processing time is increased to reduce the IPA remaining on the substrate. However, this may lead to an increase in semiconductor prices and a decrease in semiconductor yield. Summary of the invention

[0012] Embodiments of the inventive concept provide a substrate processing method that can improve processing efficiency when processing a substrate using a supercritical fluid.

[0013] Embodiments of the inventive concept provide a method of treating a substrate that can solve problems caused when a high pressure chamber is exhausted during a process of drying a substrate using a supercritical fluid.

[0014] The purpose of the present invention is not limited to this. For those skilled in the art, other purposes not mentioned will become apparent from the following description.

[0015] According to an exemplary embodiment, a method for processing a substrate includes: supplying a supercritical fluid to a processing space in a chamber to process the substrate in the processing space using the supercritical fluid, wherein the supercritical fluid at a first temperature and the supercritical fluid at a second temperature higher than the first temperature are supplied to the processing space to process the substrate using each supercritical fluid.

[0016] The method may include repeatedly supplying the supercritical fluid at the first temperature to the processing space to process the substrate, and exhausting the processing space to process the substrate in the processing space, wherein, in the case of processing the substrate, when exhausting the processing space, the supercritical fluid at the second temperature may be supplied to the processing space.

[0017] The method may further include depressurizing the processing space after completing the processing of the substrate, wherein the supercritical fluid at the second temperature may be supplied to the processing space when the processing space is depressurized. When the processing space is depressurized, the supply amount per unit time of the supercritical fluid at the second temperature supplied to the processing space may be less than the supply amount per unit time of the supercritical fluid at the first temperature supplied to the processing space during the processing of the substrate.

[0018] During processing of the substrate, when the processing space is exhausted, a supply amount per unit time of the supercritical fluid at the second temperature supplied to the processing space may be less than a supply amount per unit time of the supercritical fluid at the first temperature supplied to the processing space.

[0019] The method may further include depressurizing the processing space after completing the processing of the substrate, wherein the supercritical fluid at the second temperature may be supplied to the processing space when depressurizing the processing space.

[0020] When the processing space is depressurized, a supply amount per unit time of the supercritical fluid at the second temperature supplied to the processing space may be smaller than a discharge amount per unit time of the supercritical fluid from the processing space.

[0021] The treating of the substrate may include a process of dissolving an organic solvent on the substrate in a supercritical fluid to remove the organic solvent from the substrate.

[0022] The supercritical fluid may be carbon dioxide.

[0023] According to an exemplary embodiment, a method for processing a substrate includes: supplying a supercritical fluid to a processing space in a chamber to process the substrate in the processing space using the supercritical fluid, wherein the method further includes: a pressurizing step of pressurizing the processing space after the substrate is brought into the processing space; a processing step of supplying the supercritical fluid to the processing space to process the substrate using the supercritical fluid; and a decompression step of discharging the supercritical fluid from the processing space after completing the processing of the substrate, wherein the supercritical fluid is supplied to the processing space during the decompression step while the supercritical fluid is discharged from the processing space, wherein the temperature of the supercritical fluid supplied to the processing space in the decompression step is higher than the temperature of the supercritical fluid supplied to the processing space in the pressurizing step.

[0024] In the decompression step, supply of the supercritical fluid may be started simultaneously with the start of the decompression step.

[0025] In the decompression step, supply of the supercritical fluid may be started in the middle of the decompression step.

[0026] The supercritical fluid supplied in the depressurizing step may be supplied to the processing space before the depressurizing step.

[0027] In the depressurizing step, a supply amount per unit time of the supercritical fluid supplied to the processing space may be smaller than a discharge amount per unit time of the supercritical fluid from the processing space.

[0028] In the processing step, the supplying step of supplying the supercritical fluid to the processing space and the discharging step of discharging the supercritical fluid from the processing space can be repeated alternately for multiple times, wherein, in the discharging step, the supercritical fluid having a higher temperature than the temperature of the supercritical fluid supplied to the processing space in the supplying step can be supplied to the processing space.

[0029] In the depressurizing step, a supply amount per unit time of the supercritical fluid supplied to the processing space may be smaller than a supply amount per unit time of the supercritical fluid supplied to the processing space in the supplying step.

[0030] In the discharging step, a supply amount per unit time of the supercritical fluid supplied to the processing space may be smaller than a supply amount per unit time of the supercritical fluid supplied to the processing space in the supplying step.

[0031] According to an exemplary embodiment, a method for processing a substrate includes: supplying a supercritical fluid to a processing space in a chamber to process the substrate in the processing space using the supercritical fluid, wherein the method further includes: a pressurizing step of pressurizing the processing space after the substrate can be brought into the processing space; a processing step of supplying the supercritical fluid to the processing space to process the substrate using the supercritical fluid; and a decompression step of discharging the supercritical fluid from the processing space after completing the processing of the substrate, wherein in the processing step, a supply step of supplying the supercritical fluid to the processing space and a discharge step of discharging the supercritical fluid from the processing space are repeated alternately multiple times, wherein in the discharge step, the supercritical fluid having a temperature higher than the temperature of the supercritical fluid supplied to the processing space in the supply step is supplied to the processing space.

[0032] A supply amount per unit time of the supercritical fluid supplied to the processing space in the discharging step may be smaller than a supply amount per unit time of the supercritical fluid supplied to the processing space in the supplying step. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The above and other objects and features will become apparent from the following description with reference to the following drawings, wherein like reference numerals refer to like parts throughout the various drawings unless otherwise specified, and wherein:

[0034] Figure 1 is a diagram showing a conventional drying process using a supercritical fluid.

[0035] Figure 2 is a graph showing solubility of isopropyl alcohol in carbon dioxide according to temperature;

[0036] Figure 3 is a plan view schematically illustrating a substrate processing apparatus according to an embodiment of the present inventive concept;

[0037] Figure 4 It is schematically shown Figure 2 A diagram of an embodiment of a liquid handling device;

[0038] Figure 5 It is schematically shown Figure 2 A diagram of one embodiment of a supercritical device;

[0039] Figure 6 is a view schematically showing an embodiment of a fluid supply unit for supplying a supercritical fluid;

[0040] Figure 7is a diagram showing the conversion of a supercritical fluid of a first density or a second temperature from Figure 6 A view of a state in which a fluid supply unit supplies fluid to a chamber;

[0041] Figure 8 is a diagram showing the conversion of a supercritical fluid of a second density or a first temperature from Figure 6 A view of a state in which a fluid supply unit supplies fluid to a chamber;

[0042] Fig. 9 is a view schematically showing another embodiment of a fluid supply unit for supplying a supercritical fluid;

[0043] Fig.10 is a diagram showing the conversion of a supercritical fluid of a first density or a second temperature from Fig. 9 A view of a state in which a fluid supply unit supplies fluid to a chamber;

[0044] Fig.11 is a diagram showing the conversion of a supercritical fluid of a second density or a first temperature from Fig. 9 A view of a state in which a fluid supply unit supplies fluid to a chamber;

[0045] Fig.12 It is schematically shown Fig. 9 A view of a variation of a fluid supply unit;

[0046] Fig.13 is a view showing a flowchart of a substrate processing method according to an embodiment of the present inventive concept;

[0047] Fig.14 is a diagram showing changes in pressure within a chamber over time;

[0048] Figures 15 to 18 are views schematically showing the density of carbon dioxide supplied to the process chamber over time, respectively;

[0049] Figures 19 to 21 are diagrams schematically showing temperatures of carbon dioxide supplied to a process chamber over time, respectively; and

[0050] Fig. 22 is a graph showing a temperature T1 in a conventional chamber, and a temperature T2 and a pressure P inside a chamber according to the inventive concept. DETAILED DESCRIPTION

[0051] Hereinafter, the embodiments of the inventive concept will be described in more detail with reference to the accompanying drawings. The embodiments of the inventive concept can be modified in various forms. The scope of the inventive concept should not be interpreted as being limited to the following embodiments. Embodiments are provided to more fully explain the inventive concept to those skilled in the art. Therefore, for a clearer explanation, the shapes of the elements in the accompanying drawings are exaggerated.

[0052] Figure 3 is a plan view schematically illustrating a substrate processing system according to an embodiment of the present inventive concept. Figure 3 , the substrate processing system includes an index module 10, a processing module 20, and a controller (not shown). In one embodiment, the index module 10 and the processing module 20 are arranged in one direction. Hereinafter, the direction in which the index module 10 and the processing module 20 are arranged is referred to as a first direction 92. When viewed from above, the direction perpendicular to the first direction 92 is referred to as a second direction 94. The direction perpendicular to the first direction 92 and the second direction 94 is referred to as a third direction 96.

[0053] The index module 10 transfers the substrate W from the container 80 storing the substrate W to the processing module 20, and transfers the substrate W processed in the processing module 20 to the container 80. The length direction of the index module 10 is the second direction 94. The index module 10 has a loading port 12 and an index frame 14. The loading port 12 is opposite to the processing module 20 around the index frame 14. The container 80 containing the substrate W therein is placed on the loading port 12. A plurality of loading ports 12 may be provided. The plurality of loading ports 12 may be arranged along the second direction 94.

[0054] The container 80 may include a sealed container such as a FOUP (Front Open Unified Pod). The container 80 may be placed on the load port 12 by an operator, or a transfer means (not shown) such as an overhead conveyor, an overhead conveyor, or an automatic guided vehicle.

[0055] The index frame 14 has an index robot 120. The index frame 14 has a guide rail 140, and the length direction of the guide rail 140 is the second direction 94. The index robot 120 can be configured to be movable on the guide rail 140. The index robot 120 includes a hand 122, and the substrate W is placed on the hand 122. The hand 122 can be configured to be able to move forward and backward, rotate around the third direction 96, and move along the third direction 96. A plurality of hands 122 can be arranged, and the plurality of hands 122 can be spaced apart from each other in the vertical direction. The hands 122 can move forward and backward independently of each other.

[0056] The processing module 20 includes a buffer unit 200, a conveying device 300, a liquid processing device 400, and a supercritical device 500. The buffer unit 200 is a space in which the substrate W loaded into the processing module 20 and the substrate W loaded out of the processing module 20 temporarily stay. The liquid processing device 400 performs a liquid processing process of supplying liquid on the substrate W to process the substrate W with the liquid. The supercritical device 500 performs a drying process to remove the liquid remaining on the substrate W. The conveying device 300 transports the substrate W between the buffer unit 200, the liquid processing device 400, and the cleaning device 500.

[0057] The conveying device 300 may have a length direction of a first direction 92. The buffer unit 200 may be disposed between the index module 10 and the conveying device 300. The liquid handling device 400 and the supercritical device 500 may be disposed on a side of the conveying device 300. The liquid handling device 400 and the conveying device 300 may be arranged along a second direction 94. The supercritical device 500 and the conveying device 300 may be arranged along the second direction 94. The buffer unit 200 may be located at one end of the conveying device 300.

[0058] In one embodiment, the liquid treatment device 400 may be respectively arranged on both sides of the conveying device 300. The supercritical device 500 may be respectively arranged on both sides of the conveying device 300. The liquid treatment device 400 may be closer to the buffer unit 200 than the supercritical cleaning device 500. On one side of the conveying device 300, the liquid treatment device 400 may be arranged in a matrix of A×B (each of A and B is a natural number greater than 1) along the first direction 92 and the third direction 96, respectively. In addition, on one side of the conveying device 300, the supercritical device 500 may be arranged in a matrix of C×D (each of C and D is a natural number greater than 1) along the first direction 92 and the third direction 96, respectively. Alternatively, only the liquid treatment device 400 may be arranged on one side of the conveying device 300, and only the supercritical device 500 may be arranged on the other side of the conveying device 300.

[0059] The conveyor 300 has a conveyor robot 320. The conveyor 300 has a guide rail 340, and the length direction of the guide rail 340 is the first direction 92. The conveyor robot 320 can be configured to be movable on the guide rail 340. The conveyor robot 320 may include a hand 322, and the substrate W is placed on the hand 322. The hand 322 can be configured to be able to move forward and backward, rotate around a third direction 96, and move along the third direction 96. A plurality of hands 322 may be arranged, and the plurality of hands 322 may be spaced apart from each other in the vertical direction. The hands 322 can move forward and backward independently of each other.

[0060] The buffer unit 200 has a plurality of buffer areas 220 on which the substrate W is placed. The buffer areas 220 may be configured to be spaced apart from each other along the third direction 96. The buffer unit 200 has an open front surface and an open rear surface. The front surface faces the index module 10, and the rear surface faces the transfer device 300. The index robot 120 accesses the buffer unit 200 through the front surface. The transfer robot 320 may access the buffer unit 200 through the rear surface.

[0061] Figure 4 It is schematically shown Figure 3 FIG. 4 is a diagram of an embodiment of a liquid handling device 400. Figure 4 The liquid treatment device 400 has a housing 410, a cup 420, a support unit 440, a liquid supply unit 460, an ascending and descending unit 480, and a controller 40. The controller 40 controls the operation of each of the support unit 440, the liquid supply unit 460, and the ascending and descending unit 480. The housing 410 is generally formed in the shape of a rectangular parallelepiped. The cup 420, the support unit 440, and the liquid supply unit 460 are disposed in the housing 410.

[0062] The cup 420 has a processing space having an open top. In the processing space, the substrate W is processed with liquid. The support unit 440 supports the substrate W in the processing space. The liquid supply unit 460 supplies liquid to the substrate W supported by the support unit 440. The liquid has various types. The various types of liquids can be sequentially supplied to the substrate W. The lifting unit 480 adjusts the relative height between the cup 420 and the support unit 440.

[0063] In one embodiment, the cup 420 has a plurality of collection vessels 422, 424, and 426. Each collection vessel 422, 424, and 426 has a collection space to collect liquid for processing a substrate. Each collection vessel 422, 424, and 426 is formed in an annular shape around the support unit 440. As the liquid treatment process proceeds, the pre-treatment liquid scattered by the rotation of the substrate W enters the collection space through each inlet 422a, 424a, and 426a of the collection vessels 422, 424, and 426, respectively. In one embodiment, the cup 420 has a first collection vessel 422, a second collection vessel 424, and a third collection vessel 426. The first collection vessel 422 is configured to surround the support unit 440, the second collection vessel 424 is configured to surround the first collection vessel 422, and the third collection vessel 426 is configured to surround the second collection vessel 424. The second inlet 424a may be located above the first inlet 422a, through which the liquid is supplied to the second collection dish 424, and the liquid is supplied to the first collection dish 422 through the first inlet 422a. The third inlet 426a may be located above the second inlet 424a, through which the liquid is supplied to the third collection dish 426.

[0064] The support unit 440 has a support plate 442 and a driving shaft 444. The top surface of the support plate 442 may be generally formed in a circular shape and may have a diameter larger than the diameter of the substrate W. A support pin 442a is provided at the center of the support plate 442 to support the rear surface of the substrate W. The support pin 442a has a top protruding from the support plate 442 so that the substrate W is spaced a certain distance from the support plate 442. A chuck pin 442b is provided at the edge of the support plate 442.

[0065] The chuck pin 442b protrudes upward from the support plate 442 and supports the side of the substrate W so that the substrate W does not deviate from the support unit 440 when the substrate W rotates. The driving shaft 444 is driven by the actuator 446 and is connected to the center of the bottom surface of the substrate W, and rotates the support plate 442 about its central axis.

[0066] In one embodiment, the liquid supply unit 460 has a first nozzle 462, a second nozzle 464, and a third nozzle 466. The first nozzle 462 supplies a first liquid onto the substrate W. The first liquid may be a liquid for removing a film or foreign matter remaining on the substrate W. The second nozzle 464 supplies a second liquid onto the substrate W. The second liquid may be a liquid soluble in the third liquid. For example, the second liquid may be a liquid that is more soluble in the third liquid than the first liquid. The second liquid may be a liquid that neutralizes the first liquid supplied onto the substrate W. In addition, the second liquid may be a liquid that neutralizes the first liquid and is more soluble in the third liquid than the first liquid.

[0067] In one embodiment, the second liquid may be water. The third nozzle 466 supplies the third liquid onto the substrate W. The third liquid may be a liquid that can be well dissolved in the supercritical fluid used in the supercritical device 500. For example, the third liquid may be a liquid that is more soluble in the supercritical fluid used in the supercritical device 500 than the second liquid. In one embodiment, the third liquid may be an organic solvent. The organic solvent may be isopropyl alcohol (IPA). In one embodiment, the supercritical fluid may be carbon dioxide.

[0068] The first nozzle 462, the second nozzle 464 and the third nozzle 466 are supported on different arms 461. These arms 461 can move independently. Alternatively, the first nozzle 462, the second nozzle 464 and the third nozzle 466 can be mounted on the same arm and move simultaneously.

[0069] The lifting unit 480 moves the cup 420 in the vertical direction. The relative height between the cup 420 and the substrate W changes due to the vertical movement of the cup 420. Therefore, the collection dishes 422, 424, and 426 for collecting the pre-treatment liquid are changed according to the type of liquid supplied to the substrate W, so that the liquid can be collected separately. Alternatively, the cup 420 may be fixedly installed, and the lifting unit 480 may move the support unit 440 in the vertical direction.

[0070] Figure 5 It is schematically shown Figure 3 FIG. 5 is a simplified diagram of an embodiment of a supercritical device 500 of FIG. According to one embodiment, the supercritical device 500 uses a supercritical fluid to remove liquid on a substrate W. In one embodiment, the liquid on the substrate W may be IPA. The supercritical device 500 may supply the supercritical fluid to the substrate W to dissolve the IPA on the substrate W in the supercritical fluid to remove the IPA from the substrate W.

[0071] The supercritical apparatus 500 has a process chamber 520 , a fluid supply unit 560 , a support apparatus 580 , and a discharge line 550 .

[0072] The process chamber 520 provides a processing space 502 in which a cleaning process is performed. The process chamber 520 has an upper shell 522 and a lower shell 524. The upper shell 522 and the lower shell 524 are combined with each other to provide the processing space 502 as described above. The upper shell 522 is located above the lower shell 524.

[0073] The upper housing 522 has a fixed position. The lower housing 524 can be moved up and down by a driving member 590 such as a cylinder. When the lower housing 524 is separated from the upper housing 522, the processing space 502 is opened, so the substrate W is brought into or out of the processing space 502.

[0074] During the process, the lower housing 524 is in close contact with the upper housing 522, so the processing space 502 is sealed from the outside. The heater 570 is located inside the wall of the process chamber 520. The heater 570 heats the processing space 502 of the process chamber 520 so that the fluid supplied into the inner space of the process chamber 520 maintains a supercritical state. The inside of the processing space 502 has an atmosphere of a supercritical fluid.

[0075] The support device 580 supports the substrate W in the processing space 502 of the process chamber 520. The substrate W brought into the processing space 502 of the process chamber 520 is placed on the support device 580. In one embodiment, the substrate W is supported on the support device 580 with the pattern surface of the substrate W facing upward.

[0076] The fluid supply unit 560 supplies a supercritical fluid for processing a substrate into the processing space 502 of the process chamber 520. In one embodiment, the fluid supply unit 560 has a main supply line 562, an upper supply line 564, and a lower supply line 566. The upper supply line 564 and the lower supply line 566 are branched from the main supply line 562. The upper supply line 564 may be coupled to the center of the upper housing 522. In one embodiment, the lower supply line 566 may be coupled to the lower housing 524. Further, the exhaust line is coupled to the lower housing 524. The fluid in the processing space 502 of the process chamber 520 is exhausted to the outside of the process chamber 520 through the exhaust line.

[0077] Figure 6 Schematically illustrates a fluid supply unit 560 according to an embodiment of the present inventive concept. Figure 6 , the fluid supply unit 560 supplies the supercritical fluid to the processing space 502 .

[0078] Fluid supply unit 560 has a first reservoir 615, a second reservoir 625 and a fluid supply unit 560. The first reservoir 615 and the second reservoir 625 are connected to a fluid supply source (not shown) to receive carbon dioxide from the fluid supply source. The fluid supply source may include a circulation line connected to a tank or a process chamber. The first reservoir 615 is installed at the first supply line 610. The second reservoir 625 is installed at the second supply line 620. In one embodiment, the first supply line 610 and the second supply line 620 are connected to the main supply line 562. The first supply line 610 and the second supply line 620 are connected in parallel to each other. A heater for heating a supercritical fluid may be arranged at each first supply line 610 and the second supply line 620. The heater arranged in the first supply line 610 and the heater arranged in the second supply line 620 may have different outputs.

[0079] In one embodiment, each of the first storage 615 and the second storage 625 may store carbon dioxide in a supercritical state. The temperature, pressure or density of the supercritical fluid stored in the first storage 615 and the second storage 625 may be different from each other. For example, the first storage 615 may store a supercritical fluid of a first density, and the second storage 625 may store a supercritical fluid of a second density. The first density may be different from the second density. For example, the second density may be higher than the first density.

[0080] The first storage 615 and the second storage 625 have different internal temperatures and / or pressures. Therefore, the carbon dioxide density in the first storage 615 and the second storage 625 may be different from each other. For example, the carbon dioxide density in the supercritical state in the first storage 615 may be 200kg / m3 to 400kg / m3, and the carbon dioxide density in the supercritical state in the second storage 625 may be 600kg / m3 to 800kg / m3.

[0081] Alternatively, the first storage 615 may store carbon dioxide therein at a second temperature, and the second storage 625 may store carbon dioxide therein at a first temperature. The first temperature may be different from the second temperature. For example, the second temperature may be higher than the first temperature.

[0082] Alternatively, the first storage 615 may store carbon dioxide therein at a first pressure, and the second storage 625 may store carbon dioxide therein at a second pressure. The first pressure and the second pressure are different from each other. For example, the second pressure may be higher than the first pressure.

[0083] Alternatively, the first storage 615 and the second storage 625 store carbon dioxide therein at the same density, and / or the same temperature, and / or the same pressure. The output of the first heater 618 provided in the first supply line 610 and the output of the second heater 628 provided in the second supply line 620 may be different from each other, so that the density and / or temperature of the carbon dioxide flowing through the first supply line 610 and the density and / or temperature of the carbon dioxide flowing through the second supply line 620 may be different from each other.

[0084] The first supply line 610 has a first pump 612, a first front valve 614, a first rear valve 616, and a first filter 619 installed thereon. The first pump 612 is installed at the front end of the first reservoir 615 to discharge carbon dioxide to the first reservoir 615. The first front valve 614 controls the flow rate of carbon dioxide discharged from the first pump 612 to the first reservoir 615. The first rear valve 616 controls the flow rate of carbon dioxide supplied from the first reservoir 615 to the first heater 618. The first filter 619 exists downstream of the first heater 618 to remove impurities flowing in the first supply line 610. The first regulating valve 617 regulates the flow rate of the supercritical fluid supplied from the first supply line 610 to the processing space 502.

[0085] The second supply line 620 has a second pump 622, a second front valve 624, a second rear valve 626, and a second filter 629 installed thereon, and the second pump 622, the second front valve 624, the second rear valve 626, and the second filter 629 are arranged in the same manner as the first pump 612, the first front valve 614, the first rear valve 616, and the first filter 619. The second pump 622 is installed at the front end of the second reservoir 625 to discharge carbon dioxide to the second reservoir 625. The second front valve 624 controls the flow rate of carbon dioxide discharged from the second pump 622 to the second reservoir 625. The second rear valve 626 controls the flow rate of carbon dioxide supplied from the second reservoir 625 to the second heater 628. The second filter 629 exists downstream of the second heater 628 to remove impurities flowing in the second supply line 620. The second regulating valve 627 regulates the flow rate of the supercritical fluid supplied from the second supply line 620 to the processing space 502.

[0086] The controller controls the composition of the fluid supply unit 560. When carbon dioxide is intended to be supplied to the processing space 502 at a relatively low density as the first density, or at a relatively high temperature as the second temperature, as Figure 7 As shown, the controller opens the first front valve 614 , the first rear valve 616 and the first regulating valve 617 , and closes the second front valve 624 , the second rear valve 626 and the second regulating valve 627 , so that the carbon dioxide stored in the first storage 615 is supplied to the processing space 502 through the first supply line 610 .

[0087] When carbon dioxide is intended to be supplied to the processing space 502 at a relatively high density as the second density, or at a relatively low temperature as the second temperature, as Figure 8 As shown, the controller opens the second front valve 624 , the second rear valve 626 and the second regulating valve 627 , and closes the first front valve 614 , the first rear valve 616 and the first regulating valve 617 , so that the carbon dioxide stored in the second storage 625 is supplied to the processing space 502 through the second supply line 620 .

[0088] Fig. 9 Schematically shows another embodiment of the fluid supply unit 560. Fig. 9 , the fluid supply unit 560 has a reservoir 645, a main supply line 562, and a bypass line 630. The reservoir 645 is connected to a fluid supply source to receive carbon dioxide from the fluid supply source. The fluid supply source may include a circulation line connected to a tank or a process chamber. A second reservoir 645 is installed at the main supply line 562.

[0089] In one embodiment, the bypass line 630 allows the fluid flowing through the reservoir 645 to bypass the second heater 648. The bypass line 630 is connected to the main supply line 562 at a first point 631 and a second point 633. The first point 631 is located further upstream of the main supply line 562 than the second point 633. The first heater 668 and the second heater 648 are disposed at the main supply line 562. The first heater 668 is installed between the reservoir 645 and the first point 631. The second heater 648 is installed between the first point 631 and the second point 633. In one embodiment, the second heater 648 may have a higher output than the output of the first heater 668.

[0090] The main supply line 562 has a pump 642, valves 643, 646 and 647, and a filter 649 installed thereon. The pump 642 is installed at the front end of the reservoir 645 to discharge carbon dioxide to the reservoir 645. The front valve 643 controls the flow rate of carbon dioxide discharged from the pump 642 to the reservoir 645. The rear valve 646 controls the flow rate of carbon dioxide supplied from the reservoir 645 to the first heater 668. The bypass valve 632 is installed at the bypass line 630. The filter 649 is provided downstream of the second point 633 to remove impurities from the main supply line 562. The regulating valve 647 regulates the flow rate of the supercritical fluid supplied from the main supply line 562 to the processing space 502.

[0091] The operation of the fluid supply unit 560 is controlled by the controller. When carbon dioxide is intended to be supplied to the processing space 502 at a relatively low density as the first density, or at a relatively high temperature as the second temperature, as Fig.10 As shown, the controller opens the front valve 643 , the rear valve 646 , and the regulating valve 647 , and closes the bypass valve 632 , so that the carbon dioxide is supplied to the processing space 502 via the first heater 668 and the second heater 648 .

[0092] When carbon dioxide is intended to be supplied to the processing space 502 at a second density of relatively high density, or at a first temperature of relatively low temperature, such as Fig.11As shown, the controller opens the front valve 643 , closes the rear valve 646 , opens the regulating valve 647 and opens the bypass valve 632 , so that carbon dioxide is supplied to the processing space 502 via the first heater 668 while bypassing the second heater 648 .

[0093] In the above-described embodiment, it is shown that each of the first heater 668 and the second heater 648 is installed at the supply line. Fig.12 As shown, the heater 648 may be disposed between the first point 631 and the second point 633 in the supply line, while no heater may be disposed between the reservoir and the first point 631 .

[0094] Fig.13 is a view schematically illustrating a method of processing a substrate in a drying chamber according to an embodiment. Fig.14 The pressure state in the process space is shown over time. Fig.13 and Fig.14 , the method for processing a substrate may include a pressurizing step S100, a processing step S200, a decompressing step S300, and an opening step S400. When the substrate is brought into the processing space 502, the pressurizing step S100 is performed. In the pressurizing step S100, a supercritical fluid is supplied to the processing space 502 to pressurize the processing space 502. The pressurization is performed until the inside of the processing space 502 is at or above a critical pressure at which carbon dioxide becomes a supercritical fluid.

[0095] The pressurizing step S100 includes a first pressurizing step S101 and a second pressurizing step S103. In the first pressurizing step S101, carbon dioxide in a supercritical state is supplied to the processing space 502, so that the processing space 502 is pressurized to a preset pressure P1. Then, in the second pressurizing step S103, carbon dioxide in a supercritical state is supplied to the processing space 502, so that the processing space 502 is pressurized to a target pressure P2. In one embodiment, the preset pressure P1 to which the processing space 502 is pressurized in the first pressurizing step S101 may be 70 bar, and the target pressure P2 to which the processing space 502 is pressurized in the second pressurizing step S103 may be 150 bar. Carbon dioxide may be supplied at a higher density in the first pressurizing step S101 than in the second pressurizing step S103.

[0096] The processing step S200 supplies a supercritical fluid to the processing space 502 to process the substrate using the supercritical fluid. The processing step S200 includes a supplying step S201 and an exhausting step S203. The supplying step S201 and the exhausting step S203 are sequentially and repeatedly performed. In the supplying step S201, carbon dioxide is supplied to the processing space 502. In the exhausting step S203, the processing space 502 is exhausted.

[0097] When the substrate processing is completed, a decompression step S300 is performed to allow exhaust of the processing space 502. In one embodiment, the decompression is performed until the pressure inside the processing space 502 reaches normal pressure or a pressure similar thereto. When the decompression step S300 is completed, an opening step S400 for opening the chamber is performed. Therefore, when the chamber is opened, the substrate is taken out of the processing space 502.

[0098] Figures 15 to 18 Schematically showing the density of carbon dioxide supplied to the process chamber over time. Fig.15 , the carbon dioxide in the first pressurizing step has a higher density than the carbon dioxide in the second pressurizing step. For example, in the first pressurizing step S101, carbon dioxide of the second density D2 is supplied to the processing space 502. In the second pressurizing step S103, carbon dioxide of the first density D1 is supplied to the processing space 502, and the first density D1 is lower than the density of the carbon dioxide supplied in the first pressurizing step S101. In one embodiment, the first density D1 may be 200 kg / m 3 Up to 400kg / m 3 , the second density D2 can be 600kg / m 3 Up to 800kg / m 3 .

[0099] In the second pressurizing step S103, carbon dioxide is supplied at a relatively low density, so that the diffusion rate of carbon dioxide in the processing space 502 increases. The carbon dioxide diffused in the processing space 502 effectively dissolves IPA. Further, over time, the relatively high-density carbon dioxide supplied for the first time moves from the bottom to the top of the substrate in the processing space 502, so that the mixture of carbon dioxide and IPA occurs in a reliable manner.

[0100] In one embodiment, in the first pressurizing step S101, carbon dioxide is supplied to the processing space 502 at a second density D2. In the first pressurizing step S101, carbon dioxide is supplied at a relatively high density, so that at the beginning of the pressurizing step S100, a large amount of carbon dioxide is supplied to the processing space 502 in a short time. Thereafter, in the second pressurizing step S103, carbon dioxide is supplied to the processing space 502 at a first density D1, which is lower than the second density D2.

[0101] In one embodiment, the density of carbon dioxide supplied to the processing space 502 in one step of the supplying step S201 may be different from the density of carbon dioxide supplied to the processing space 502 in another step of the supplying step S201. In one embodiment, the density of carbon dioxide supplied to the processing space 502 in the supplying step S201 is the first density D1 or the second density D2. In one embodiment, the supply of the supercritical fluid of the first density D1 and the supply of the supercritical fluid of the second density D2 may be alternately performed once in the continuous supplying step S201.

[0102] In the supplying step S201 , carbon dioxide having different densities may be repeatedly injected to obtain a stirring effect, thereby increasing the solubility of IPA in the carbon dioxide.

[0103] When a certain amount of IPA has been dissolved in the carbon dioxide in a supercritical state, IPA no longer dissolves in the carbon dioxide. Therefore, the discharge step S203 is performed to discharge a certain amount of IPA dissolved in the carbon dioxide from the processing space 502. Subsequently, the supply step S201 is performed to supply new carbon dioxide in a supercritical state to the processing space 502, so that IPA is continuously dissolved in the carbon dioxide. The discharge step S203 and the supply step S201 are repeatedly performed.

[0104] In one embodiment, in each supply step S201, carbon dioxide may be supplied until the pressure in the processing space 502 reaches the target pressure P2. In each exhaust step S203, exhaust of the processing space 502 is performed so that the pressure in the processing space 502 is maintained at a pressure higher than the critical pressure.

[0105] During the supplying step S201, the supercritical fluid of the first density D1 may be supplied continuously N times, and the supercritical fluid of the second density D2 may be supplied continuously M times. In one embodiment, at least one of M and N may be 2 or greater. In one embodiment, M and N may be different numbers. In one embodiment, M may be a number greater than N. Fig.16 , during the continuous supplying step S201, the supercritical fluid of the second density D2 may be supplied twice, and subsequently, in the supplying step S201, the supercritical fluid of the first density may be supplied once.

[0106] According to the inventive concept, alternately supplying carbon dioxide having different densities to the processing space 502 can obtain advantages of increasing drying efficiency, minimizing the residual amount of IPA, and reducing the process time of the processing step S200.

[0107] The embodiment in which supercritical carbon dioxide is supplied to the processing space at different densities of carbon dioxide in each of the pressurizing step and the processing step has been described above. Fig.17 As shown, in the pressurizing step S100, the supercritical carbon dioxide may be supplied at the same density, and only in the processing step S200, the supercritical carbon dioxide may be supplied at different densities. Fig.18 As shown, in the processing step S200, the supercritical carbon dioxide may be supplied with the same density, and only in the pressurizing step S100, the supercritical carbon dioxide may be supplied with different densities.

[0108] The above has described an embodiment in which the supercritical fluid is supplied at a first density and a second density. However, the supercritical fluid may be supplied at the first density, a second density higher than the first density, and a third density higher than the first density and lower than the second density. In one embodiment, the first density may be 200 kg / m 3 Up to 400kg / m 3 The second density can be 600kg / m 3 Up to 800kg / m 3 The third density can be 400kg / m 3 Up to 600kg / m 3 .

[0109] Figures 19 to 21 2 are graphs schematically showing the temperature of carbon dioxide supplied to a process chamber over time.

[0110] Reference Fig.19 In this embodiment, supercritical carbon dioxide is supplied while the processing space is exhausted. In one embodiment, the temperature of the carbon dioxide supplied to the processing space 502 in the pressurizing step S100 is a first temperature T1.

[0111] In the discharge step S203, the carbon dioxide supplied to the processing space 502 has a relatively high temperature. The temperature of the carbon dioxide supplied to the processing space 502 in the discharge step S203 may be higher than the temperature of the carbon dioxide supplied to the processing space 502 in the pressurizing step S100. In one embodiment, the temperature of the carbon dioxide supplied to the processing space 502 in the discharge step S203 is a second temperature T2.

[0112] The temperature of carbon dioxide supplied to the processing space 502 in the decompression step S300 may be higher than the temperature of carbon dioxide supplied to the processing space 502 in the pressurization step S100. In one embodiment, the temperature of carbon dioxide supplied to the processing space 502 in the decompression step S300 is a second temperature T2.

[0113] In the pressurizing step, the processing step, and the first decompression step S301, carbon dioxide in a supercritical state is supplied to the processing space 502. In one embodiment, carbon dioxide is supplied at a supply amount Q1 per unit time in the first pressurizing step S101, and carbon dioxide is supplied at a supply amount Q2 per unit time in the second pressurizing step S103. Q1 may be greater than Q2.

[0114] The amount of carbon dioxide supplied per unit time in the supply step S201 is less than the amount of carbon dioxide supplied per unit time in the pressurizing step S100. In one embodiment, the amount of carbon dioxide supplied per unit time in the supply step S201 is Q3. Q3 is less than Q2. In the discharge step S203, carbon dioxide may be supplied to the processing space 502. The supply amount of carbon dioxide supplied to the processing space 502 per unit time in the discharge step S203 is less than the supply amount of carbon dioxide supplied to the processing space 502 per unit time in the supply step S201. In one embodiment, the supply amount of carbon dioxide supplied per unit time in the discharge stage is Q4. In the discharge step S203, the emission amount of carbon dioxide per unit time is greater than the supply amount of carbon dioxide per unit time. In one embodiment, the emission amount per unit time in the discharge step S203 is V3. A relationship of V3>Q4 is established.

[0115] In the first decompression step S300, the supply amount per unit time of the supercritical fluid supplied to the processing space 502 is less than the supply amount per unit time of the supercritical fluid supplied to the processing space 502 in the pressurization step S100 or the supply step S201. In one embodiment, in the first decompression step S301, the supply amount per unit time of carbon dioxide is Q4, and Q4 is lower than Q3. In the first decompression step S301, the supply amount per unit time of carbon dioxide supplied to the processing space 502 is less than the emission amount per unit time of carbon dioxide in the processing space 502. In one embodiment, the emission amount of carbon dioxide per unit time in the first decompression step S300 is V2 which is higher than V3. A relationship of V2>Q4 is established.

[0116] In the second depressurizing step S303, the processing space 502 is exhausted without supplying carbon dioxide into the processing space 502. In one embodiment, in the second depressurizing step S303, the exhaust amount of carbon dioxide per unit time is V1 which is higher than V2.

[0117] Fig. 22 is a diagram showing a temperature T1 in a conventional chamber, and a temperature T2 and a pressure P inside a chamber according to the inventive concept. Fig. 20When the decompression step S300 discharges the processing space 502, the temperature T1 inside the conventional process chamber drops rapidly due to the sudden pressure drop. Therefore, the solubility of IPA in carbon dioxide decreases as the temperature inside the processing space 502 decreases. When the temperature inside the processing space 502 drops below 31 degrees Celsius, the supercritical carbon dioxide changes to a subcritical state. In the subcritical state of carbon dioxide, the solubility of IPA in carbon dioxide decreases significantly. Therefore, the subcritical carbon dioxide forms a mixture with IPW and contaminates the substrate.

[0118] According to the present invention, the temperature T2 inside the chamber can be maintained at a high temperature by supplying relatively high temperature carbon dioxide in the discharge step S203 and the decompression step S300, and the pressure drops in the discharge step S203 and the decompression step S300. Therefore, it has the advantage of maintaining the solubility of IPA in carbon dioxide at a high level. Further, due to temperature compensation, the carbon dioxide in the chamber is maintained in a supercritical state. Therefore, the solubility of IPA in carbon dioxide is maintained. Therefore, when the processing space 502 is decompressed, the IPA dissolved in the carbon dioxide in the supercritical state is discharged to the outside of the chamber. In one embodiment, the lower limit of the second temperature is set to a value higher than the critical temperature of carbon dioxide, so that the carbon dioxide in the chamber is maintained in a supercritical state.

[0119] An embodiment has been described above in which the carbon dioxide at the second temperature T2 is continuously supplied to the processing space 502 in the case of performing the decompression step S300. However, the carbon dioxide at the second temperature T2 may be supplied only in the first decompression step S301.

[0120] The above has described an embodiment in which the supply of carbon dioxide in the decompression step S300 is started at the same time as the decompression step S300 is started. However, in another embodiment, the supply of carbon dioxide in the decompression step S300 may be started in the middle of the decompression step S300. In another embodiment, the supply of carbon dioxide in the decompression step S300 may be started in the middle of the processing step S200.

[0121] The embodiment in which carbon dioxide at a relatively high temperature is supplied to the processing space 502 in the exhaust step S203 and the decompression step S300 has been described above. Fig. 20 As shown, carbon dioxide at the second temperature, which is a relatively high temperature, may be supplied to the processing space 502 only in the decompression step S300. Fig.21 As shown, the carbon dioxide at the second temperature may be supplied to the processing space 502 only in the exhaust step S203.

[0122] The embodiment in which the temperature of the carbon dioxide supplied to the processing space 502 in the decompression step S300 is the second temperature has been described above. However, the temperature of the carbon dioxide supplied to the processing space 502 in the decompression step S300 is higher than the second temperature as the temperature of the carbon dioxide supplied to the processing space 502 in the supply step S201.

[0123] According to an embodiment of the inventive concept, when a substrate is processed using a supercritical fluid, processing efficiency of the substrate is improved.

[0124] According to an embodiment of the inventive concept, when exhausting a process space in a chamber, formation of a mixture that occurs when a supercritical fluid becomes a subcritical state and condenses as the temperature in the process space decreases may be suppressed, thereby preventing contamination of a substrate.

[0125] According to one embodiment of the inventive concept, when the supercritical fluid is supplied to or discharged from a processing space in a chamber, a phenomenon in which the solubility of an organic solvent in a supercritical fluid decreases due to a decrease in the temperature of the processing space can be suppressed.

[0126] The effects of the present inventive concept are not limited to the above-mentioned effects. Those skilled in the art to which the present inventive concept pertains may clearly understand unmentioned effects from the present specification and the accompanying drawings.

[0127] Although the present invention has been described with reference to exemplary embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. Therefore, it should be understood that the above embodiments are not restrictive, but illustrative.

[0128] Reference numerals

[0129] 502: Processing Space

[0130] 520: Chamber

[0131] 560: Fluid supply unit

Claims

1. A method for processing a substrate, the method comprising: supplying a supercritical fluid to a processing space in a chamber to process the substrate in the processing space using the supercritical fluid, wherein the supercritical fluid at a first temperature and the supercritical fluid at a second temperature higher than the first temperature are supplied into the processing space to process the substrate using each supercritical fluid, wherein the method includes repeatedly supplying the supercritical fluid at the first temperature to the processing space to process the substrate, and exhausting the processing space to process the substrate in the processing space, wherein the supercritical fluid having different densities is repeatedly injected while repeatedly supplying the supercritical fluid at the first temperature to the processing space, wherein, in the case of processing the substrate, when exhausting the processing space, the supercritical fluid at the second temperature is supplied to the processing space, The method further comprises depressurizing the processing space after completing the processing of the substrate. wherein, when the processing space is depressurized, the supercritical fluid at the second temperature is supplied to the processing space, Wherein, when the processing space is depressurized, the supply amount per unit time of the supercritical fluid at the second temperature supplied to the processing space is less than the supply amount per unit time of the supercritical fluid at the first temperature supplied to the processing space during the processing of the substrate.

2. The method according to claim 1, wherein: During processing of the substrate, when the processing space is exhausted, a supply amount per unit time of the supercritical fluid at the second temperature supplied to the processing space is less than a supply amount per unit time of the supercritical fluid at the first temperature supplied to the processing space.

3. The method according to claim 1, wherein: The method further includes depressurizing the processing space after completing the processing of the substrate, wherein, when the processing space is depressurized, the supercritical fluid at the second temperature is supplied to the processing space.

4. The method according to claim 3, wherein: When the processing space is depressurized, a supply amount per unit time of the supercritical fluid at the second temperature supplied to the processing space is smaller than a discharge amount per unit time of the supercritical fluid from the processing space.

5. The method according to any one of claims 1 to 4, wherein: The processing of the substrate includes a process of dissolving an organic solvent on the substrate in the supercritical fluid to remove the organic solvent from the substrate.

6. The method according to any one of claims 1 to 4, wherein: The supercritical fluid is carbon dioxide.

7. A method for processing a substrate, wherein: The method comprises: supplying a supercritical fluid to a processing space in a chamber to process the substrate in the processing space using the supercritical fluid, Wherein, the method further comprises: a pressurizing step of pressurizing the processing space after the substrate is brought into the processing space; a processing step of supplying the supercritical fluid to the processing space to process the substrate using the supercritical fluid; and a decompression step of discharging the supercritical fluid from the processing space after completing the processing of the substrate, wherein, during the depressurizing step, the supercritical fluid is supplied to the processing space while the supercritical fluid is discharged from the processing space, wherein the temperature of the supercritical fluid supplied to the processing space in the decompression step is higher than the temperature of the supercritical fluid supplied to the processing space in the pressurization step; wherein, in the processing step, a supplying step of supplying the supercritical fluid to the processing space and a discharging step of discharging the supercritical fluid from the processing space are repeated multiple times alternately, wherein the supercritical fluid having different densities is repeatedly injected when the supercritical fluid is supplied to the processing space multiple times in an alternating manner; wherein, in the discharging step, the supercritical fluid having a higher temperature than the supercritical fluid supplied to the processing space in the supplying step is supplied to the processing space, wherein, in the depressurizing step, a supply amount per unit time of the supercritical fluid supplied to the processing space is smaller than a discharge amount per unit time of the supercritical fluid from the processing space.

8. The method according to claim 7, wherein: In the decompression step, supply of the supercritical fluid is started simultaneously with the start of the decompression step.

9. The method according to claim 7, wherein: In the decompression step, supply of the supercritical fluid is started in the middle of the decompression step.

10. The method according to claim 7, wherein: In the discharging step, a supply amount per unit time of the supercritical fluid supplied to the processing space is smaller than a supply amount per unit time of the supercritical fluid supplied to the processing space in the supplying step.

11. The method according to any one of claims 7 to 10, wherein: The processing of the substrate includes a process of dissolving an organic solvent on the substrate in a supercritical fluid to remove the organic solvent from the substrate.

12. The method according to any one of claims 7 to 10, wherein: The supercritical fluid is carbon dioxide.

13. A method for processing a substrate, wherein: The method comprises: supplying a supercritical fluid to a processing space in a chamber to process the substrate in the processing space using the supercritical fluid, Wherein, the method further comprises: a pressurizing step of pressurizing the processing space after the substrate is brought into the processing space; a processing step of supplying the supercritical fluid to the processing space to process the substrate using the supercritical fluid; and a decompression step of discharging the supercritical fluid from the processing space after completing the processing of the substrate, wherein, in the processing step, a supplying step of supplying the supercritical fluid to the processing space and a discharging step of discharging the supercritical fluid from the processing space are repeated multiple times alternately, wherein the supercritical fluid having different densities is repeatedly injected when the supercritical fluid is supplied to the processing space multiple times in an alternating manner; wherein, in the discharging step, the supercritical fluid having a higher temperature than the supercritical fluid supplied to the processing space in the supplying step is supplied to the processing space, wherein a supply amount per unit time of the supercritical fluid supplied to the processing space in the discharging step is smaller than a supply amount per unit time of the supercritical fluid supplied to the processing space in the supplying step.

14. The method according to claim 13, wherein: The processing of the substrate includes a process of dissolving an organic solvent on the substrate in a supercritical fluid to remove the organic solvent from the substrate.

15. The method according to any one of claims 13 to 14, wherein: The supercritical fluid is carbon dioxide.

Images