Substrate processing method

Abstract

This invention relates to a substrate processing method, and more specifically to a substrate processing method using a substrate processing apparatus employing supercritical fluid, wherein supplying supercritical fluid into a chamber reduces damage or defects to the substrate. The substrate processing method includes: a pressurization step, pressurizing the fluid to a predetermined process pressure by supplying the fluid through the lower part of the chamber; an isobaric step, discharging the fluid while supplying it towards the chamber to maintain a constant pressure inside the chamber, and performing a processing procedure on the substrate; and a depressurization step, discharging the fluid from the chamber, and supplying the fluid to the chamber through the lower part of the chamber during at least a portion of the isobaric step.

Description

Technical Field

[0001] This invention relates to a substrate processing method, and more specifically to a substrate processing method using a substrate processing apparatus employing supercritical fluid, wherein supplying supercritical fluid into the chamber reduces damage or defects to the substrate. Prior Technology

[0002] Typically, when manufacturing large-scale / high-density semiconductor devices such as LSI (Large Scale Integration) on the surface of a semiconductor wafer, it is necessary to form extremely fine patterns on the wafer surface.

[0003] Such micro-patterns are formed by various processes of exposing, developing, cleaning, and patterning the photoresist-coated wafer, followed by etching the wafer, thereby transferring the photoresist pattern onto the wafer.

[0004] Furthermore, after such etching, a wafer cleaning process is performed to remove dust or natural oxide film from the wafer surface. The cleaning process is carried out by immersing the patterned wafer in a treatment solution such as a chemical solution or rinsing solution, or by supplying a treatment solution to the wafer surface.

[0005] However, with the increasing integration of semiconductor devices, pattern collapse occurs on the photoresist or wafer surface during the drying process after cleaning.

[0006] Such pattern collapse is equivalent to, as shown in Figure 12, when the cleaning process is completed and the residual processing liquid 10 on the surface of the substrate S is dried, if the processing liquid on the left and right sides of patterns 11, 12, and 13 is not dried evenly, the capillary force that stretches patterns 11, 12, and 13 from left to right will be uneven, resulting in the phenomenon that patterns 11, 12, and 13 collapse in the direction with more residual processing liquid.

[0007] In the case of Figure 12, it is shown that while the drying of the processing liquid in the left and right outer regions on the substrate S where no pattern is formed is completed, the processing liquid 10 remains in the gaps between the patterns 11, 12, and 13. As a result, the patterns 11 and 13 on the left and right sides collapse inwards due to the capillary force received from the processing liquid 10 remaining between the patterns 11, 12, and 13.

[0008] The capillary force that caused the aforementioned pattern collapse is due to the surface tension of the processing liquid acting in the liquid / gas interface placed between the atmospheric atmosphere surrounding the substrate S after cleaning and the processing liquid remaining between the patterns.

[0009] Therefore, a treatment method that utilizes a supercritical fluid (hereinafter referred to as "supercritical fluid") that does not form an interface with a gas or liquid to dry the treatment liquid is currently attracting attention.

[0010] In the pressure and temperature state diagram of Figure 13, in the existing drying method that only utilizes temperature regulation, as shown by the hidden line, it is necessary to pass through the gas-liquid equilibrium line. Therefore, capillary forces are generated at the gas-liquid interface at this time.

[0011] Conversely, in the case of drying via a supercritical state by entirely utilizing the temperature and pressure regulation of the fluid, without passing through the gas-liquid equilibrium line, it is essentially possible to dry the substrate in a state without capillary force.

[0012] Referring to Figure 13, in the drying process using supercritical fluid, if the liquid pressure is increased from A to B, and then the temperature is increased from B to C, it will not cross the gas-liquid equilibrium line and will be converted to the supercritical state C. Furthermore, at the end of the drying process, if the pressure of the supercritical fluid is reduced, it will not cross the gas-liquid equilibrium line and will be converted to gas D.

[0013] On the other hand, when using supercritical fluid, if the supercritical fluid is supplied into the chamber, the high pressure and flow rate of the supercritical fluid may cause damage to the substrate in the initial stage of supply. Therefore, in existing devices, the fluid is supplied from below the chamber in the pressurization step and from above the chamber in the isobaric step. However, supplying the fluid from above the chamber in the isobaric step does not reduce the damage to the substrate.

[0014] In the pressurization step, after the isobaric step following the supply below the chamber, if the organic solvent fails to form sufficient replacement (mixing) due to the supercritical fluid, and is supplied from above the chamber, in the region where the two phases (liquid-supercritical) coexist, the organic solvent rapidly mixes due to the flow of the supercritical fluid, and at the same time, the organic solvent flows off. Therefore, more damage may occur, especially in the central region of the substrate where the supercritical fluid is supplied. Summary of the Invention

[0015] In order to solve the problems described above, the present invention aims to provide a substrate processing method that can reduce damage to the substrate caused by the high pressure and flow rate of the supercritical fluid when supplying a supercritical fluid to a chamber.

[0016] The objective of the present invention, as described above, can be achieved through a substrate processing method comprising a substrate processing apparatus having a chamber for performing a substrate processing process using a supercritical fluid, the substrate processing method comprising: a pressurization step, pressurizing the fluid to a predetermined process pressure by supplying the fluid through the lower part of the chamber; an isobaric step, discharging the fluid while supplying the fluid toward the chamber, thereby maintaining the pressure inside the chamber at a constant pressure and performing the substrate processing process; and a depressurization step, discharging the fluid from the interior of the chamber, and supplying the fluid to the chamber through the lower part of the chamber during at least a portion of the isobaric step.

[0017] Here, the isobaric step may include: a first supply step, supplying the fluid to the chamber from below; and a second supply step, supplying the fluid to the chamber from above.

[0018] Furthermore, the first supply step may be configured within a predetermined interval during the isobaric step.

[0019] Alternatively, in the isobaric step, the first supply step and the second supply step may be repeated alternately.

[0020] Alternatively, during the isobaric step, the fluid may be supplied to the chamber only through the lower part of the chamber.

[0021] Alternatively, during the isobaric step, a pulse wave caused by the fluid may be generated inside the chamber. In this case, during the isobaric step, an exhaust step may be performed to reduce the fluid inside the chamber to a predetermined pressure, followed by a first supply step to supply the fluid to the chamber from below to repressurize the pressure inside the chamber back to the process pressure.

[0022] According to the present invention having the aforementioned structure, when supplying supercritical fluid to the chamber, a pressurization step can be followed by supplying fluid through the lower part of the chamber in at least a portion of the isobaric step, thereby reducing damage to the substrate. Simple Explanation of the Diagram

[0023] [Figure 1] is a block diagram showing the structure of a substrate processing apparatus utilizing a supercritical fluid according to an embodiment of the present invention. [Figure 2] is a side cross-sectional view showing the structure of the chamber in Figure 1. [Figure 3] is a graph showing the pressure change inside the chamber according to the existing substrate processing method. [Figure 4] is a diagram illustrating that in each step of the substrate processing process, the first valve and the discharge valve of the substrate processing apparatus are in the closed state, and the second valve is in the open state. [Figure 5] is a diagram illustrating that in each step of the substrate processing process, the first valve and the discharge valve of the substrate processing apparatus are in the open state, and the second valve is in the closed state. [Figure 6] is a diagram illustrating that in each step of the substrate processing process, the first and second valves of the substrate processing apparatus are in the closed state, and the discharge valve is in the open state. [Figure 7] is a graph showing the pressure change inside the chamber when the first supply step and the second supply step are performed once each according to the substrate processing method of the present invention. [Figure 8] is a graph showing the pressure change inside the chamber when the first supply step and the second supply step are alternately repeated twice according to the substrate processing method of the present invention. [Figure 9] is a graph showing the pressure change inside the chamber when fluid is supplied to the chamber only from the bottom direction according to the substrate processing method of the present invention. [Figure 10] is a graph showing the pressure change inside the chamber when the venting step and the first supply step are repeatedly performed according to the substrate processing method of the present invention. [Figure 11] is a diagram showing the degree of damage to the substrate when the substrate is processed according to the conventional substrate processing method and the substrate processing method of the present invention. [Figure 12] is a schematic diagram illustrating the state of pattern collapse when the pattern on the substrate is dried according to the prior art. [Figure 13] is a state diagram showing the pressure and temperature changes of the fluid in a processing technology utilizing supercritical fluid. Implementation

[0024] Hereinafter, the structure of the substrate processing apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0025] Figure 1 is a block diagram showing the structure of a substrate processing apparatus 1000 according to the prior art, and Figure 2 is a side cross-sectional view showing the structure of the chamber 400.

[0026] The substrate processing apparatus 1000 utilizing supercritical fluids performs processing on a substrate S using a supercritical fluid. Here, a supercritical fluid refers to a substance reaching a critical state, that is, exceeding the critical temperature and critical pressure, and is equivalent to a fluid with a formed phase. Such supercritical fluids possess properties where the molecular density is close to that of a liquid and the viscosity is close to that of a gas. Therefore, supercritical fluids exhibit excellent diffusion, penetration, and dissolving power, facilitating chemical reactions, and have almost no surface tension, thus avoiding the application of surface tension to fine structures. Consequently, they are highly useful in the drying process of semiconductor devices, not only providing excellent drying efficiency but also preventing pattern collapse.

[0027] In this invention, carbon dioxide (CO2) can be used as a supercritical fluid. Carbon dioxide has a relatively low critical temperature of approximately 31.1°C and a critical pressure of 7.38 MPa, thus it is easy to achieve a supercritical state, its state can be easily controlled by adjusting temperature and pressure, and it is inexpensive.

[0028] Furthermore, carbon dioxide is non-toxic, harmless to humans, and possesses non-flammable and inert properties. Moreover, compared to water or other organic solvents, supercritical carbon dioxide has a diffusion coefficient approximately 10 to 100 times higher, exhibiting excellent permeability. This allows for rapid replacement of organic solvents and almost no surface tension, making it advantageous for drying processes. In addition, carbon dioxide used in drying processes can be converted into a gaseous state, allowing for the separation of organic solvents for reuse, thus minimizing environmental pollution.

[0029] Referring to Figures 1 and 2, the substrate processing apparatus 1000 may include: a chamber 400, a processing space 412 providing a supercritical fluid for performing a processing process on a substrate S coated with a processing liquid or an organic solvent 10 (hereinafter referred to as "organic solvent"); and a fluid supply unit 600 for supplying fluid to the chamber 400.

[0030] The fluid supply unit 600 can adjust at least one of the fluid temperature and pressure to supply fluid to the chamber 400 via the main supply line 120.

[0031] For example, the fluid supply unit 600 may include: a fluid storage unit 100 for storing the fluid; and a main supply line 120 for connecting the fluid storage unit 100 and the chamber 400.

[0032] In this case, a pressure regulating unit 200 and a temperature regulating unit 300 can be configured along the main supply line 120. At this time, the pressure regulating unit 200 can be composed of, for example, a pressure pump, and the temperature regulating unit 300 can be composed of, for example, a heater or heat exchanger for heating the fluid.

[0033] Furthermore, the main supply line 120 may also include a sensing unit (not shown) for sensing at least one of the pressure and temperature of the fluid. The pressure and temperature of the fluid flowing in the main supply line 120 can be adjusted based on the pressure and temperature sensed in the sensing unit. Therefore, a substrate processing apparatus 1000 according to an embodiment of the present invention may include a control unit (not shown) for controlling the pressure regulating unit 200 and the temperature regulating unit 300. The control unit can control the pressure regulating unit 200 and the temperature regulating unit 300 based on the pressure and temperature sensed in the sensing unit.

[0034] On the other hand, when performing a processing process on the substrate S, the temperature and pressure of the processing space 412 of the chamber 400 must be maintained above the critical temperature and critical pressure so that the fluid supplied to the interior of the chamber 400 can be converted to a supercritical state.

[0035] Therefore, when the fluid moves along the main supply line 120, the pressure regulating unit 200 can pressurize the fluid to a critical pressure or higher, and the temperature regulating unit 300 can heat the fluid to a critical temperature or higher.

[0036] On the other hand, the main supply line 120 may be configured to include: a first supply line 150 connected to the upper part of the chamber 400; and a second supply line 160 connected to the lower part of the chamber 400. The first supply line 150 may be connected to the approximately central portion of the upper part of the chamber 400, and similarly, the second supply line 160 may be connected to the approximately central portion of the lower part of the chamber 400. A supply valve 122 may be provided on the main supply line 120 before it branches into the first supply line 150 and the second supply line 160.

[0037] In addition, the first supply line 150 may be equipped with a first valve 152 that controls the flow of fluid by opening / closing, and the second supply line 160 may also be equipped with a second valve 162 that controls the flow of fluid by opening / closing.

[0038] Furthermore, although not shown in the accompanying drawings, the first supply line 150 can be equipped with a first screening program for filtering foreign objects in the fluid, and similarly, the second supply line 160 can be equipped with a second screening program for filtering foreign objects in the fluid. In this case, the first screening program can be arranged in the direction of fluid flow in the first supply line 150 at the front end of the first valve 152. Additionally, the second screening program can also be arranged in the direction of fluid flow in the second supply line 160 at the front end of the second valve 162.

[0039] Additionally, a discharge line 146 may be provided in the chamber 400 to discharge fluid from the processing space 412 to the outside. During or after the processing of the substrate S, fluid can be discharged from the inside of the chamber 400 to the outside through the discharge line 146. A discharge valve 540 may be provided in the discharge line 146, for example, it may be a proportional valve.

[0040] Additionally, the discharge line 146 can be configured separately from the central portion below the chamber 400. As shown previously, the second supply line 160 is connected to the central portion below the chamber 400, therefore the discharge line 146 can be configured separately from the central portion below the chamber 400 to avoid interference with the second supply line 160.

[0041] On the other hand, the chamber 400 can provide a processing space 412 for performing processing processes such as drying on the substrate S using a supercritical fluid. The chamber 400 may have an opening (not shown) on one side and be made of a material suitable for handling high-pressure processes on the substrate S.

[0042] The processing space 412 of the chamber 400 can be kept in a sealed state, and the pressure of the fluid supplied to the processing space 412 can be maintained above the critical pressure.

[0043] Additionally, the chamber 400 may also include a heating element (not shown) to maintain the temperature of the processing space 412 at or above a predetermined temperature. This heating element allows the temperature of the processing space 412, or the temperature of the fluid contained within the processing space 412, to be maintained at or above a critical temperature during the process for the substrate S.

[0044] On the other hand, a tray 450 supporting the substrate S may be provided in the chamber 400.

[0045] The tray 450 can be fed into the processing space 412 of the aforementioned chamber 400 through the opening of the chamber 400 or sent out of the processing space 412 through the opening of the chamber 400.

[0046] Figure 3 is a graph showing the pressure change inside the chamber 400 in the substrate processing apparatus 1000 according to the conventional substrate processing method and the process for the substrate S. Figures 4 to 6 are diagrams illustrating the operation of the substrate processing apparatus 1000 in each step of the substrate processing process. Hereinafter, the processing process for the substrate S in the substrate processing apparatus 1000 will be observed with reference to the accompanying drawings.

[0047] Referring to FIG3, in the preparation step (D1:0~T1) where the tray 450 is inserted into and docked with the chamber 400 at the start of the process for the substrate S, the pressure inside the chamber 400 can be equivalent to atmospheric pressure.

[0048] Next comes the pressurization step (D2:T1~T3) to increase the pressure inside the chamber 400.

[0049] During the pressurization step, high-pressure fluid is supplied into the chamber 400, and no fluid is discharged from the chamber 400 to the outside. Therefore, the pressure inside the chamber 400 rises and exceeds a critical pressure Pc, reaching a preset pressure.

[0050] For example, as shown in FIG4, the supply valve 122 of the main supply line 120 can be opened, the first valve 152 of the first supply line 150 and the discharge valve 540 of the discharge line 146 can be closed, and the second valve 162 of the second supply line 160 can be opened so that fluid can be supplied through the lower part of the chamber 400.

[0051] When the pressure in the chamber 400 reaches the preset process pressure P1, fluid can be supplied to the interior of the chamber 400 through the aforementioned second supply line 160.

[0052] If fluid is supplied from above the chamber 400 during the pressurization step, the fluid can be supplied directly from above the chamber 400 toward the substrate S. In this case, the high-speed fluid can destabilize the organic solvent on the substrate S, and furthermore, the pattern (not shown) formed above the substrate S may be damaged due to the high-speed fluid.

[0053] Therefore, during the pressurization step, fluid is supplied from below the chamber 400 via the second supply line 160. When supplied from below the chamber 400, the fluid is not supplied directly toward the substrate S due to blockage caused by the tray 450, thereby preventing damage to the patterns on the substrate S.

[0054] Referring to Figure 3, following the pressurization step D2, the isobaric step (or pressure holding step) D3 is then performed.

[0055] In the isobaric step D3, as shown in FIG5, the fluid can be supplied through the top of the chamber 400 with the supply valve 122 of the main supply line 120 open, the first valve 152 of the first supply line 150 and the discharge valve 540 of the discharge line 146 open, and the second valve 162 of the second supply line 160 closed.

[0056] In this case, while continuously supplying fluid into the chamber 400 through the first supply line 150, an amount of fluid equivalent to the supplied fluid is discharged to the outside of the chamber 400 through the discharge line to maintain a constant pressure inside the chamber 400.

[0057] Following the aforementioned isobaric step D3, as shown in Figure 3, the pressure reduction step D4 is executed. In the pressure reduction step D4, as shown in Figure 6, the first valve 152 of the first supply line 150 and the second valve 162 of the second supply line 160 may be completely closed, and the discharge valve 540 of the discharge line 146 may be opened to discharge the fluid inside the chamber 400.

[0058] That is, the pressure inside the chamber 400 is reduced by not supplying fluid to the inside of the chamber 400 and discharging fluid to the outside of the chamber 400 through the discharge line 146.

[0059] On the other hand, as mentioned above, in the pressurization step D2, in order to reduce damage to the substrate S, fluid is supplied through the lower part of the chamber 400, and in the isobaric step D3, in which the process pressure P1 is reached inside the chamber 400, fluid is supplied through the upper part of the chamber 400.

[0060] However, according to the inventors' tests, it can be confirmed that during the isobaric step D3, when fluid is supplied through the top of the chamber 400, damage mostly occurs on the substrate S even after the process pressure P1 is reached inside the chamber 400.

[0061] The explanation is that even if the process pressure P1 is reached inside the chamber 400, damage to the substrate S may still occur due to the high pressure and high speed of the fluid supplied from above the chamber 400.

[0062] Therefore, the present invention aims to provide a substrate processing method that can reduce damage to the substrate S caused by the fluid when supplying fluid to the interior of the chamber 400.

[0063] The substrate processing method according to the present invention includes: a pressurization step D2, pressurizing the fluid to a predetermined process pressure P1 by supplying the fluid from below the chamber 400; an isobaric step D3, maintaining the pressure inside the chamber 400 at a constant pressure while supplying the fluid toward the chamber 400, and performing a processing process for the substrate S; and a depressurization step D4, discharging the fluid from inside the chamber 400, wherein, in at least a portion of the isobaric step D3, the fluid can be supplied to the chamber 400 from below.

[0064] Figures 7 to 10 are graphs illustrating the pressure changes inside the chamber 400 according to the substrate processing method of the present invention. In the figures, dashed lines represent fluid supplied from the bottom of the chamber 400 (bottom flow), dotted lines represent fluid supplied from the top of the chamber 400 (top flow), and double-dotted lines represent fluid discharged from the chamber 400 (Vent).

[0065] As shown in Figure 7, the isobaric step D3 may include: a first supply step D31, supplying the fluid to the chamber 400 from below; and a second supply step D32, supplying the fluid to the chamber 400 from above. The operation of the chamber 400 and the substrate processing apparatus 1000 in the first supply step D31 and the second supply step D32 has been detailed in Figures 4 and 5, and therefore, repeated descriptions are omitted.

[0066] For example, the first supply step D31 can be performed following the aforementioned pressurization step D2, and the second supply step D32 can be performed after a predetermined conversion time Tt has been reached. The second supply step D32 can then execute the aforementioned depressurization step D4. In this embodiment, the first supply step D31 and the second supply step D32 can each be executed once.

[0067] That is, in the present invention, in the isobaric step D3, the fluid is supplied from below the chamber 400 for a slower time than in the prior art, thereby minimizing damage to the substrate S, instead of supplying fluid directly to the chamber 400 from above.

[0068] Alternatively, the conversion time Tt can be determined from the start time T3 of the isobaric step D3 to a predetermined time or determined taking into account various process conditions for the substrate S.

[0069] Additionally, although not shown in the accompanying drawings, in the isobaric step D3, the first supply step D31 can be configured to be executed within a predetermined interval.

[0070] That is, Figure 7 illustrates the state in which the first supply step D31 is configured in the initial region of the isobaric step D3, but it is not limited thereto. The first supply step D31 can also be configured in the middle or later region of the isobaric step D3.

[0071] Furthermore, as shown in Figure 8, in the isobaric step D3, the first supply step D31 and the second supply step D32 can be executed alternately and repeatedly.

[0072] For example, the aforementioned first supply step D31 and second supply step D32 can be alternately repeated twice. That is, the first supply step D31 can be performed after the aforementioned pressurization step D2, and the second supply step D32 can be performed when the first transition time Tt1 is reached, the first supply step D31 can be performed when the second transition time Tt2 is reached, and the second supply step D32 can be performed when the third transition time Tt3 is reached.

[0073] The number of repetitions of the first supply step D31 and the second supply step D32 is an example and can be modified as appropriate.

[0074] Furthermore, when the first supply step D31 and the second supply step D32 are alternately and repeatedly executed as shown in Figure 8, the fluid flow inside the chamber 400 is continuously varied, which can reduce the dead zone on the substrate S where the aforementioned organic solvent 10 is not replaced.

[0075] On the other hand, as shown in FIG9, in the isobaric step D3, the fluid may also be supplied to the chamber 400 only through the lower direction of the chamber 400.

[0076] In this case, fluid is supplied only through the lower part of the chamber 400, thus having the advantage of minimizing damage to the substrate S.

[0077] Furthermore, as shown in Figure 10, in the isobaric step D3, it can also be driven by generating a pulse wave caused by the fluid inside the chamber 400.

[0078] For example, referring to FIG10, in the isobaric step D3, firstly, an exhaust step D41 can be performed to reduce the fluid inside the chamber 400 to a constant pressure P2, and then a first supply step D51 can be performed to supply the fluid to the chamber 400 from below to repressurize the pressure inside the chamber 400 to the process pressure P1.

[0079] In this case, the aforementioned exhaust steps D42 and D43 and the first supply steps D52 and D53 can be repeated.

[0080] Figure 11 is essentially a diagram showing the degree of damage to the substrate S when it is processed according to the conventional substrate processing method and the substrate processing method of the present invention. Figure 11(A) shows the degree of damage to the substrate S according to the conventional substrate processing method, and Figure 11(B) shows the degree of damage to the substrate S according to the substrate processing method of the present invention.

[0081] As shown in Figure 11, it can be seen that when substrate S is processed according to the existing substrate processing method, damage occurs concentrated in the central part of substrate S, and furthermore, more damage occurs throughout the substrate.

[0082] Conversely, it can be seen that when the substrate S is processed by the substrate processing method according to the present invention, the damage to the central part of the substrate S is significantly reduced, and furthermore, the overall damage is relatively reduced compared to the existing method.

[0083] The above description refers to preferred embodiments of the present invention. However, those skilled in the art can make various modifications and alterations to the present invention without departing from the concept and scope of the invention as described in the appended claims. Therefore, if any modified implementation substantially includes the constituent elements of the claims of the present invention, it should be considered to fall entirely within the technical scope of the present invention.

[0084] S:Substrate 100: Fluid Storage Section 120: Main Supply Line 122: Supply valve 146: Exit line 150: First Supply Line 152: First valve 160: Second Supply Line 162: Second valve 200: Temperature Control Unit 300: Pressure Regulation Section 400: Chamber 412: Processing Space 450: Pallet 540: Discharge valve 600: Fluid Supply Department 1000: Substrate processing apparatus

Claims

1. A substrate processing method, which is a substrate processing apparatus comprising a chamber for performing a processing procedure on a substrate using a supercritical fluid, wherein, The substrate processing method includes: a pressurization step, pressurizing the fluid to a predetermined process pressure by supplying the fluid through the lower part of the chamber; an isobaric step, discharging the fluid while supplying the fluid toward the chamber, thereby maintaining a constant pressure inside the chamber and performing a processing procedure for the substrate; and a depressurization step, discharging the fluid from inside the chamber, wherein, in at least a portion of the isobaric step, the fluid is supplied to the chamber from the lower part of the chamber instead of from the upper part.

2. The substrate processing method as described in claim 1, wherein, The isobaric step includes: a first supply step, supplying the fluid to the chamber from below; and a second supply step, supplying the fluid to the chamber from above.

3. The substrate processing method as described in claim 2, wherein, The first supply step is configured within a predetermined interval in the isobaric step.

4. The substrate processing method as described in claim 2, wherein, In the isobaric step, the first supply step and the second supply step are repeated alternately.

5. The substrate processing method as described in claim 1, wherein, In the isobaric step, the fluid is supplied to the chamber only through the lower part of the chamber.

6. The substrate processing method as described in claim 1, wherein, In the isobaric step, a pulse wave caused by the fluid is generated inside the chamber.

7. The substrate processing method as described in claim 6, wherein, In the isobaric step, an exhaust step is performed to reduce the fluid inside the chamber to a predetermined pressure, followed by a first supply step to supply the fluid to the chamber from below to repressurize the pressure inside the chamber back to the process pressure.

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