Substrate processing apparatus, substrate processing method, and method of manufacturing article

Abstract

To provide a technology that is advantageous for drying a substrate coated with a plurality of types of solvents.SOLUTION: A substrate processing apparatus includes: a hermetically sealed container into which a substrate coated with a plurality of types of solvents having different saturated vapor pressures is conveyed; a depressurizing mechanism for depressurizing an interior of the hermetically sealed container; and a control unit capable of performing a drying treatment to evaporate the plurality of types of solvents coated on the substrate disposed in the interior of the hermetically sealed container under the depressurized environment in which the interior of the hermetically sealed container has been depressurized by the depressurizing mechanism. The control unit is configured to independently control a flow rate of a first gas introduced into the interior of the hermetically sealed container and a flow rate of a second gas which has a smaller molecular weight than the first gas, the second gas being introduced into the interior of the hermetically sealed container, during the drying treatment. The first gas and the second gas are both present as gases under conditions of 25°C and 1 atmosphere.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a technique for processing a substrate.

Background Art

[0002] When manufacturing an article such as a panel (organic EL panel) having an OLED (Organic Light Emitting Diode) which is an organic EL (Electro Luminescence) element, a method of applying a solvent film or a solution film to a desired location on a substrate using, for example, an inkjet device is known. A solvent film is a film composed of a solvent, and a solution film is a film composed of a solution containing a solute and a solvent. The substrate is processed by applying a solvent onto the substrate and drying the surface of the substrate. Further, by applying a solution onto the substrate and drying the solution film, the substrate is processed to form a film (layer) of the solute. For drying the solution film, a vacuum drying device which is a substrate processing device is used.

[0003] Patent Document 1 discloses controlling the drying rate of a solution film by supplying a gas containing the same solvent vapor as the solvent contained in the solution film around the substrate during substrate processing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The solvent applied onto the substrate, or the solvent contained in the solution applied onto the substrate, is not necessarily a single solvent as described in Patent Document 1, and may be a plurality of solvents having different saturated vapor pressures. However, Patent Document 1 does not disclose the case where a plurality of solvents are applied onto the substrate. When a plurality of solvents are applied onto the substrate, drying proceeds from the solvent having a high saturated vapor pressure, so the ratio of the solvent vapor in the ambient atmosphere around the substrate continues to change, and the drying rate of the solvent or solution changes. This change in the drying rate affects the quality of the surface of the substrate or the film formed on the substrate.

[0006] The present disclosure aims to provide a technique advantageous for drying a substrate coated with a plurality of solvents.

Means for Solving the Problems

[0007] One aspect of the present disclosure includes an airtight container into which a substrate coated with a plurality of solvents having different saturated vapor pressures is conveyed, a decompression mechanism for decompressing the inside of the airtight container, and a control unit capable of performing a drying process for evaporating the plurality of solvents applied to the substrate disposed inside the airtight container in a decompressed environment in which the inside of the airtight container is decompressed by the decompression mechanism. The control unit is configured to independently control the flow rate of a first gas introduced into the inside of the airtight container and the flow rate of a second gas introduced into the inside of the airtight container and having a smaller molecular weight than the first gas in the drying process, and both the first gas and the second gas exist as gases in an environment of 25°C and 1 atm. The substrate processing apparatus is characterized by this.

Effects of the Invention

[0008] According to the present disclosure, a technique advantageous for drying a substrate coated with a plurality of solvents is provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and overlapping explanations are omitted. In the following embodiments, the directions are indicated by an XYZ coordinate system which is an orthogonal coordinate system. In the XYZ coordinate system, the XY plane is a horizontal plane, the Z direction is the vertical direction, and the minus direction of the Z axis is the vertical direction (gravity direction).

[0011] <First Embodiment> FIG. 1 is a schematic cross-sectional view showing the configuration of a vacuum drying apparatus 100 which is an example of a substrate processing apparatus according to the first embodiment. The vacuum drying apparatus 100 is used in a part of the process of manufacturing an organic EL panel having an OLED which is an organic EL element. That is, the vacuum drying apparatus 100 forms an organic film on the substrate S by performing a drying process for drying the solution film F applied to the substrate S. Hereinafter, drying the solution film F is also expressed as drying the substrate S or drying the solvent. That is, the process of bringing the substrate S into a state in which almost no solvent remains is expressed as a drying process.

[0012] The solution film F is composed of, for example, a solution containing a solute and a solvent for forming an organic film. The solvent contained in the solution film F can exist as a liquid in an environment of normal temperature (25°C) and atmospheric pressure (1 atm). The solvent contained in the solution film F preferably has a property that evaporation is promoted in a reduced-pressure environment lower than atmospheric pressure (1 atm). The evaporation of the solvent is preferably promoted, for example, at a temperature higher than normal temperature (25°C).

[0013] In the first embodiment, the solvent contained in the solution film F is a mixed solvent containing two or more solvents. The two or more solvents include a plurality of solvents having different saturated vapor pressures from each other.

[0014] The solvent contained in the mixed solvent is preferably an organic solvent. Examples of the organic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, diethylene glycol monomethyl ether, cyclohexanone, N,N-dimethylisobutyramide, N-methylformamide, N-methylacetamide, N-diethylformamide, cyclohexanol, ethylene glycol, ethylene glycol diglycidyl ether, 1,3-octylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, 1,4-butanediol, propylene glycol, hexylene glycol, propylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diacetone alcohol, γ-butyrolactone, ethyl lactate, N-hexyl acetate, ethyl cellosolve acetate, cyclohexylbenzene, and the like.

[0015] The organic film is an organic layer, for example, any one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, or an electron injection layer of an OLED. The manufacture of the organic EL element includes a step of forming each organic film of the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer, and the electron injection layer on the substrate S. The solution film F is applied to necessary locations on the substrate S by a coating device before the substrate S is carried into the vacuum drying device 100.

[0016] The vacuum drying device 100 includes an airtight container 10, a decompression mechanism 30 for decompressing the inside of the airtight container 10, and a substrate holding part 20 which is a holding part arranged inside the airtight container 10 and capable of holding the substrate S. Further, the vacuum drying device 100 includes a cover unit 40 arranged at a position surrounding the substrate S held by the substrate holding part 20 inside the airtight container 10. The cover unit 40 is arranged at a position not in contact with the substrate S held by the substrate holding part 20.

[0017] Inside the airtight container 10, the substrate S coated with a plurality of types of solvents having different saturated vapor pressures can be conveyed. The pressure of the external environment of the airtight container 10 is atmospheric pressure, for example, 1 atm. The airtight container 10 is a member that defines the internal space SP0. The internal space SP0 includes a space SP2 surrounded by the cover unit 40 and a space SP1 other than the space SP2. In the first embodiment, the space SP2 is a space surrounded by the substrate holding part 20 and the cover unit 40. The space SP2 inside the cover unit 40 and the space SP1 outside the cover unit 40 communicate with each other, but the pressure distribution of the space SP2 is adjusted to be as uniform as possible by surrounding the substrate S with the cover unit 40.

[0018] Further, the vacuum drying apparatus 100 includes a gate valve 11 provided in the airtight container 10 for opening and closing the inside of the airtight container 10. The substrate S coated with the solution film F to be subjected to the drying process is carried into the internal space SP0 of the airtight container 10 from the external space outside the airtight container 10 (for example, another airtight container) through the gate valve 11. Further, the substrate S that has undergone the drying process is carried out from the internal space SP0 to the external space (for example, another airtight container) through the gate valve 11. The loading and unloading of the substrate S are performed by a conveying device (not shown) placed outside the airtight container 10.

[0019] An exhaust port 12 is formed at the upper part of the airtight container 10. An exhaust duct is connected to the exhaust port 12. By operating the decompression mechanism 30, the gas in the internal space SP0 of the airtight container 10 can be exhausted through the exhaust duct, and the internal space SP0 of the airtight container 10 can be decompressed. The decompression mechanism 30 includes at least one pump, for example, a plurality of pumps. The plurality of pumps includes at least one of, for example, a dry pump and a diaphragm vacuum pump. Further, the plurality of pumps may include at least one of, for example, a turbo molecular pump, a cryopump, a soap solution pump, an oil diffusion pump, a mechanical booster pump, an ejector pump, and an oil rotary vacuum pump.

[0020] The vacuum drying apparatus 100 further includes a pressure gauge 50 for measuring the pressure in the internal space SP0. The pressure gauge 50 may include at least one of a diaphragm vacuum gauge, a Pirani vacuum gauge, a thermocouple vacuum gauge, a Penning vacuum gauge, and an ionization vacuum gauge.

[0021] The vacuum drying apparatus 100 further includes a temperature control unit 70. The temperature control unit 70 controls the temperature of the substrate S or the solution film F on the substrate S by controlling the temperature of the substrate holding unit 20. The temperature control unit 70 preferably includes a heater for heating the substrate holding unit 20. Further, the temperature control unit 70 may include a cooler for cooling the substrate holding unit 20. The temperature control unit 70 controls the temperature of the substrate holding unit 20 by performing at least one of heating and cooling on the substrate holding unit 20.

[0022] The temperature control unit 70 controls a plurality of regions of the substrate holding unit 20 to the same temperature or different temperatures from each other so that the substrate S has a uniform temperature distribution. Preferably, the temperature control unit 70 controls so that the temperature difference between a plurality of regions of the substrate S held by the substrate holding unit 20 is within 10°C. More preferably, the temperature control unit 70 controls so that the temperature difference between a plurality of regions of the substrate S held by the substrate holding unit 20 is within 5°C. The temperature control unit 70 controls the temperature of the substrate holding unit 20 so that the temperature of the substrate S becomes a predetermined temperature within the range from 0°C to 100°C. By heating the substrate holding unit 20, the drying rate of the solution film F applied on the substrate S can be improved.

[0023] The cover unit 40 is disposed, for example, on the substrate holding unit 20. The main material of the cover unit 40 is metal. As the metal, for example, stainless steel or aluminum is suitable. As the stainless steel, for example, austenitic stainless steel containing 0.045% or less of phosphorus and 0.030% or less of sulfur (that is, the stainless steel specified as SUS304 in Japanese Industrial Standard: JIS) is suitable.

[0024] FIGS. 2(a) and 2(b) are cross-sectional views of a partial configuration of the vacuum drying apparatus 100 according to the first embodiment. FIG. 2(a) is a view of a cross-section of the cover unit 40 and members around the cover unit 40 along the XY plane viewed in the negative Z-axis direction. FIG. 2(b) is a view of a cross-section of the cover unit 40 and members around the cover unit 40 along the YZ plane viewed in the negative X-axis direction.

[0025] The cover unit 40 includes an enclosure wall 41 and a cover 42. The cover 42 may be separate from the enclosure wall 41 or may be integral with the enclosure wall 41. In the first embodiment, the cover 42 is integral with the enclosure wall 41.

[0026] The surrounding wall 41 is an example of a side wall member. The surrounding wall 41 is a member that supports the cover 42, is placed on the substrate holding part 20, and is arranged at a position where it can face the side surface SS of the substrate S placed on the substrate holding part 20. Note that the surrounding wall 41 may be placed on another member.

[0027] The cover 42 is an example of a top plate. The cover 42 is arranged at a position facing the main surface MS of the substrate S in the direction perpendicular to the upper surface of the substrate holding part 20, that is, the Z direction. Specifically, the cover 42 is arranged at a position facing the solution film F applied on the main surface MS of the substrate S in the Z direction. The cover 42 is fixed on the surrounding wall 41. That is, the cover 42 is fixed to the upper end of the surrounding wall 41.

[0028] The vacuum drying device 100 further includes a lifting mechanism 80 which is an example of an opening / closing mechanism capable of opening and closing the space SP2. The cover unit 40 can be moved in the Z direction, which is the vertical direction, with respect to the substrate holding part 20 by the lifting mechanism 80. The lifting mechanism 80 can be used when transporting the substrate S to and from the substrate holding part 20. For example, the lifting mechanism 80 can move the cover unit 40 between a closed position where the cover unit 40 is placed on the substrate holding part 20 and an open position where the cover unit 40 is separated from the substrate holding part 20. Note that instead of the lifting mechanism 80, an opening through which the substrate S can be carried in and out may be provided in the surrounding wall 41, and a shutter for opening and closing the opening may be arranged.

[0029] The cover 42 has a plurality of openings 43. Each opening 43 is a through hole. The shape of the opening 43 may be circular or linear like a slit. The arrangement and dimensions of the openings 43 are determined so that the drying of the solution film F applied on the substrate S is performed uniformly. For example, by making the area of the opening 43 facing a part where the drying rate of the solution film F on the substrate S is high smaller than the area of the other openings 43, the drying rate of the solution film F can be adjusted to reduce the non-uniformity of the drying rate.

[0030] The aperture area per unit area in the cover 42 is referred to as the aperture ratio. The cover 42 is configured such that the aperture ratio near the outer periphery of the substrate S is smaller than the aperture ratio near the center of the substrate S by adjusting the area of each aperture 43. For example, in the cover 42, the aperture ratio of the portion facing the center of the substrate S may be defined as 40 to 70%, and the aperture ratio of the portion facing the outer periphery of the substrate S may be defined as 20 to 50%. Note that the cover 42 only needs to have a configuration that allows the space SP2 and the space SP1 to communicate with each other, and does not necessarily need to have the aperture 43. The surrounding wall 41 may also be configured to communicate the space SP2 and the space SP1.

[0031] The vacuum drying apparatus 100 further includes a gas introduction unit 60 that introduces a gas G1, which is a first gas, and a gas G2, which is a second gas, into the internal space SP0 (space SP1). In the first embodiment, the gas introduction unit 60 is configured to introduce an introduced gas G0 in a state where the gas G1 and the gas G2 are mixed into the internal space SP0 (space SP1). The gas G2 is a gas having a smaller molecular weight than the gas G1.

[0032] A gas supply source 61 for the gas G1 and a gas supply source 62 for the gas G2 are connected to the gas introduction unit 60. The supply source 61 is, for example, a gas cylinder filled with liquefied gas G1. The supply source 62 is, for example, a gas cylinder filled with liquefied gas G2. Both the gases G1 and G2 exist as gases in an environment of normal temperature (25°C) and atmospheric pressure (1 atm). That is, neither the gas G1 nor the gas G2 can exist as a liquid in an environment of normal temperature (25°C) and atmospheric pressure (1 atm).

[0033] The gas introduction unit 60 includes a pipe 63 to which the supply source 61 is connected, a pipe 64 to which the supply source 62 is connected, a pipe 65 connected to the airtight container 10, a mixer 66, a flow rate regulator 67 disposed in the pipe 63, and a flow rate regulator 68 disposed in the pipe 64. The mixer 66 has two input ports and one output port. The pipes 63 and 64 are respectively connected to the input ports, and the pipe 65 is connected to the output port. The flow rate regulator 67 is an example of a first flow rate regulator. The flow rate regulator 68 is an example of a second flow rate regulator.

[0034] The mixer 66 may be provided with a mechanism for stirring the input gas and uniformly mixing it. The gas G1 flowing through the pipe 63 and the gas G2 flowing through the pipe 64 are mixed in the mixer 66, and the introduced gas G0 is sent to the pipe 65. The pipe 65 is provided so as to penetrate the airtight container 10, and the introduced gas G0 is introduced into the airtight container 10. In the first embodiment, the gas introduction part 60 is configured such that the introduced gas G0 is introduced into the airtight container 10 from the lower part of the airtight container 10. Thus, in the first embodiment, the gas G1 and the gas G2 are mixed and introduced into the airtight container 10.

[0035] By introducing the introduced gas G0 into the internal space SP0 of the airtight container 10 through the gas introduction part 60, the pressure of the internal space SP0 of the airtight container 10, particularly the pressure of the space SP1, is adjusted. Also, the mixing ratio of the gas G1 and the gas G2 in the mixer 66 is adjusted by adjusting the flow rates of the gases G1 and G2 by the flow rate regulators 67 and 68. That is, the gas G1 whose flow rate is adjusted by the flow rate regulator 67 and the gas G2 whose flow rate is adjusted by the flow rate regulator 68 can be introduced into the airtight container 10.

[0036] Note that depending on the adjustment of the flow rates of the gases G1 and G2 in the flow rate regulators 67 and 68, the introduced gas G0 output from the mixer 66 can be not only a mixed gas of the gas G1 and the gas G2 but also the gas G1 or the gas G2 alone. Also, the gas introduction part 60 may be configured to directly introduce the gases G1 and G2 into the airtight container 10 without having a mixer 66. In this case, the gas G1 and the gas G2 are mixed inside the airtight container 10.

[0037] The pipe 65 is arranged to introduce the introduced gas G0 outside the space SP2, that is, into the space SP1. According to this, the introduced gas G0 introduced from the pipe 65 into the internal space SP0 can replace the atmospheric gas in the internal space SP0 without disturbing the flow of the solvent vapor in the space SP2.

[0038] Both gas G1 and gas G2 are gases with a saturated vapor pressure higher than atmospheric pressure (1 atm). Gas G1 and gas G2 can be, for example, any of clean dry air, noble gases such as helium gas, neon gas, argon gas, krypton gas, and xenon gas, and relatively stable gases such as nitrogen gas and carbon dioxide gas. These gases both exist as gases under the environment of normal temperature (25°C) and atmospheric pressure (1 atm).

[0039] For example, gas G1 is nitrogen gas and gas G2 is helium gas. Helium gas has a smaller molecular weight than nitrogen gas.

[0040] Note that although the above examples of gas G1 and G2 are preferred, they are not limited to the above examples. As long as the molecular weight of gas G2 is smaller than that of gas G1 and both gas G1 and G2 can exist as gases under the environment of normal temperature (25°C) and atmospheric pressure (1 atm), gases other than the above examples may be used.

[0041] In addition, the vacuum drying device 100 further includes a control device 90 that controls each part of the entire device. The control device 90 is an example of a control unit. The control device 90 is composed of, for example, a computer. The control device 90 includes a CPU which is an example of a processor, a RAM which is a temporary storage device, a ROM and an SSD which are non-temporary storage devices (recording media), an I / O which is an interface, etc. A control program for causing the CPU of the control device 90 to execute the control of each part of the entire device in the manufacturing process described later is stored in the non-temporary storage device.

[0042] The control device 90 controls the pressure inside the airtight container 10 by controlling the decompression mechanism 30. Also, the control device 90 controls the supply and stop of the introduced gas G0 to the inside of the airtight container 10 and the flow rate of the introduced gas G0 by controlling the flow rate regulators 67 and 68.

[0043] In the first embodiment, the control device 90 is configured to be capable of performing a drying process of evaporating a plurality of types of solvents contained in the solution film F applied to the substrate S disposed inside the airtight container 10 in a reduced-pressure environment in which the inside of the airtight container 10 is reduced in pressure by the decompression mechanism 30. The control device 90 is configured to independently control the flow rate of the gas G1 introduced into the airtight container 10 and the flow rate of the gas G2 introduced into the airtight container 10 in the drying process. Specifically, the control device 90 controls the respective flow rates of the gas G1 and the gas G2 introduced into the airtight container 10 by causing the flow rate regulator 67 to adjust the flow rate of the gas G1 and causing the flow rate regulator 68 to adjust the flow rate of the gas G2.

[0044] In addition to the above-described configuration, the control device 90 may be configured by a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), an ASIC (abbreviation for Application Specific Integrated Circuit), a general-purpose or dedicated computer in which a program is incorporated, or a combination of all or part of these.

[0045] Hereinafter, among a plurality of steps of a method for manufacturing an organic EL panel, which is an example of an article, a part of the steps (substrate processing method) including a drying step (drying process) will be described. FIG. 3 is a flowchart of the substrate processing method (article manufacturing method) according to the first embodiment. The solution film F is applied to necessary portions on the main surface MS of the substrate S by an application device such as an inkjet device.

[0046] In step S1, the control device 90 controls the transfer device so as to transfer the substrate S to which the solution film F is applied into the airtight container 10. As a result, the substrate S is placed on the substrate holding portion 20.

[0047] Next, in step S2, the control device 90 controls the lifting mechanism 80 to move the cover unit 40 to the closed position.

[0048] Next, in step S3, the control device 90 executes a drying process for drying the solution film F on the substrate S, that is, evaporating the solvent contained in the solution film F. The drying process may include a plurality of drying steps. The control device 90 controls the pressure reducing mechanism 30 and the flow rate regulators 67, 68 in each drying step.

[0049] The vacuum drying device 100 is capable of executing a drying process for drying the solvent applied on the substrate S. Hereinafter, the drying process will be specifically described. FIG. 4 is an explanatory diagram of the drying process according to the first embodiment. FIG. 4 shows a graph illustrating an example of pressure control in the drying process. The horizontal axis shown in FIG. 4 is time, and the vertical axis is the pressure in the internal space SP0. In the example of FIG. 4, the plurality of drying steps are four drying steps D1 to D4, but the number of drying steps is not limited to four.

[0050] Also, in the first embodiment, the case where the solvent contained in the solution film F is two types of solvents A and B will be described as an example. The saturation vapor pressures of solvents A and B are both lower than the atmospheric pressure. And the saturation vapor pressure of solvent A is higher than the saturation vapor pressure of solvent B. That is, the saturation vapor pressure of solvent B is lower than the saturation vapor pressure of solvent A. Solvent A is an example of the first solvent. Solvent B is an example of the second solvent. Solvent A is the solvent having the highest saturation vapor pressure among the plurality of types of solvents contained in the solution film F. Also, solvent B is the solvent having the lowest saturation vapor pressure among the plurality of types of solvents contained in the solution film F. Note that the comparison of the magnitudes of the saturation vapor pressures of the plurality of types of solvents can be performed using, for example, the values of the saturation vapor pressures at room temperature (25°C).

[0051] First, in the drying step D1, the control device 90 controls the decompression mechanism 30 so that the pressure in the internal space SP0 of the airtight container 10, that is, the pressure indicated by the pressure gauge 50, decreases from atmospheric pressure (1 atm) to the first pressure P1. Thereby, the inside of the airtight container 10 is decompressed to the first pressure P1. The drying step D1 is a step in the process of decompressing from atmospheric pressure to the first pressure P1. The first pressure P1 is a pressure lower than atmospheric pressure and higher than the vapor pressure of any solvent contained in the solution film F. Even in the drying step D1 of reducing the pressure in the internal space SP0 from atmospheric pressure to the first pressure P1, the solvent contained in the solution film F on the substrate S evaporates. That is, even in the drying step D1, the drying of the solution film F on the substrate S proceeds.

[0052] The mixing ratio of the gases G1 and G2 in the introduced gas G0 is defined as the ratio of the volume flow rate of the gas G1 to the volume flow rate of the gas G2. In the first embodiment, the mixing ratio of the gases G1 and G2 in the introduced gas G0 is defined as the volume flow rate of the gas G2 / (the volume flow rate of the gas G1 + the volume flow rate of the gas G2). When the mixing ratio is 0, only the gas G1 is introduced into the inside of the airtight container 10, and when the mixing ratio is 1, only the gas G2 is introduced into the inside of the airtight container 10. In the drying step D1, the control device 90 controls the flow rate regulators 67 and 68 so that the mixing ratio is 0, that is, only the gas G1 is introduced into the inside of the airtight container 10. Note that both the gas G1 and the gas G2 are gases of types different from the vapors of the solvents A and B.

[0053] Next, in the drying step D2, after the pressure indicated by the pressure gauge 50 reaches the first pressure P1, the control device 90 controls the decompression mechanism 30 so that the pressure in the internal space SP0, that is, the pressure indicated by the pressure gauge 50, is maintained near the first pressure P1. For example, the control device 90 controls the decompression mechanism 30 and the flow rate regulators 67 and 68 so that the exhaust amount (volume flow rate) in the decompression mechanism 30 is constant and the air supply amount (volume flow rate) in the gas introduction unit 60 is constant.

[0054] Also, in the drying process D2, the control device 90 controls the flow rate regulators 67 and 68 so that the mixing ratio changes while the volume flow rate of the introduced gas G0 introduced into the inside of the airtight container 10 from the gas introduction unit 60 is kept constant at a predetermined volume flow rate. In this drying process D2, the solution film F of the substrate S is dried. The drying process D2 corresponds to the first treatment. That is, in the drying process D2, the control device 90 executes a first treatment for controlling the inside of the airtight container 10 to a first pressure P1 that is lower than 1 atm and higher than the saturated vapor pressure of the solvent A.

[0055] As described above, in the first embodiment, the control device 90 changes the ratio (mixing ratio) of the gases G1 and G2 introduced into the airtight container 10 according to the progress of the drying process. At that time, the control device 90 changes the mixing ratio of the gases G1 and G2 so that the ratio of the gas G2 contained in the introduced gas G0 increases according to the progress of the drying process. Specifically, the control device 90 controls the flow rates of the gases G1 and G2 so that the volume flow rate of the gas G2 increases with respect to the total volume flow rate of the volume flow rates of the gases G1 and G2 as the first treatment included in the drying process progresses.

[0056] FIG. 5 is an explanatory diagram of the drying processes D1 and D2 which are part of the drying process according to the first embodiment. In FIG. 5, graphs showing examples of pressure control and flow rate control of the gases G1 and G2 in the drying processes D1 and D2 are illustrated. The horizontal axis shown in FIG. 5 is time, and the vertical axis is the pressure of the internal space SP0 and the mixing ratio of the gases G1 and G2. In the first embodiment, the control device 90 determines the mixing ratio of the gases G1 and G2 based on the measurement result of the pressure gauge 50 that measures the pressure inside the airtight container 10.

[0057] When the solution film F contains a plurality of solvents, drying proceeds from the solvent with the higher saturated vapor pressure among the plurality of solvents. For this reason, as the drying of the solution film F progresses, the saturated vapor pressure of the mixed solvent contained in the solution film F will decrease, and the pressure in the internal space SP0 will decrease from the first pressure P1 as shown in FIG. 5. In this case, due to the decrease in the saturated vapor pressure of the mixed solvent contained in the solution film F, the drying rate of the solution film F will also decrease. That is, as the drying of the solution film F progresses, the solvents contained in the solution film F become less likely to evaporate, and since the exhaust rate in the decompression mechanism 30 is adjusted to be constant, the pressure in the internal space SP0 decreases from the first pressure P1.

[0058] Here, when the pressure measured by the pressure gauge 50 decreases from the first pressure P1, the control device 90 controls the flow rate regulator 67 so that the volume flow rate of the gas G1 decreases according to the amount of pressure decrease from the first pressure P1, and controls the flow rate regulator 68 so that the volume flow rate of the gas G2 increases. That is, the control device 90 determines the mixing ratio so that the ratio of the gas G2 in the introduced gas G0 increases according to the amount of pressure decrease per unit time of the pressure value indicated by the pressure gauge 50. Thereby, the control device 90 controls the mixing ratio so as to increase the concentration of the gas G2 introduced into the airtight container 10 while keeping the total flow rate (volume flow rate) of the gas G1 and the gas G2 introduced from the gas introduction part 60 into the airtight container 10 constant.

[0059] According to the above control, in the gas forming the atmosphere around the substrate S, the concentration of the gas G2 with a low molecular weight will increase. Generally, the diffusion coefficient of gas molecules is inversely proportional to the square root of the molecular weight. For this reason, the higher the concentration of the gas G2 with a low molecular weight in the atmosphere around the substrate S, the higher the diffusion coefficient of the entire atmosphere, and the more active the diffusion of the solvent vapor becomes.

[0060] Here, the lower the concentration of the solvent vapor directly above the gas-liquid interface of the solvent, the easier it is for the solvent to vaporize and the greater the drying rate. Therefore, by activating the diffusion of the solvent vapor, the solvent vapor directly above the gas-liquid interface decreases, and the drying rate increases. In the first embodiment, this property is utilized, and the control device 90 controls the mixing ratio of the gas G1 and the gas G2 according to the amount of pressure drop. As a result, during the drying process D2, the drying rate of the solution film F is controlled to be constant, and the variation in the drying rate of the solution film F with respect to the elapsed time of the drying process D2 is reduced.

[0061] In addition, in the control of the drying processes D1 and D2, although the case of adjusting the volume flow rates of the respective gases G1 and G2 has been described as an example, the present invention is not limited thereto, and the mass flow rates of the respective gases G1 and G2 may be adjusted.

[0062] The shape of the solution film F is approximately determined by the end of the drying process D2. Therefore, after the drying process D3, control for making the drying rate constant is not performed, and the pressure inside the airtight container 10 is set to a pressure lower than the saturation vapor pressure of the solvent having the lowest saturation vapor pressure among the plurality of solvents contained in the solution film F.

[0063] In the drying process D3, the control device 90 controls the flow rate regulators 67 and 68 to stop the introduction of the gas from the gas introduction unit 60, and controls the decompression mechanism 30 so that the pressure in the internal space SP0 of the airtight container 10, that is, the pressure indicated by the pressure gauge 50, decreases from the first pressure P1 to the second pressure P2. As a result, the inside of the airtight container 10 is decompressed to the second pressure P2. The drying process D3 is a process of decompressing from the first pressure P1 to the second pressure P2. The second pressure P2 is a pressure lower than the first pressure P1 and lower than the saturation vapor pressure of the solvent having the lowest saturation vapor pressure. Thereby, the solution film F on the substrate S is dried.

[0064] After the pressure indicated by the pressure gauge 50 reaches the second pressure P2, in the drying process D4, the control device 90 controls the decompression mechanism 30 so that the pressure in the internal space SP0, that is, the pressure indicated by the pressure gauge 50, is maintained at the second pressure P2. Thereby, the solution film F on the substrate S is dried. The drying process D4 corresponds to the second treatment. That is, in the drying process D4, the control device 90 executes a second treatment for controlling the inside of the airtight container 10 to the second pressure P2, which is lower than the saturated vapor pressure of the solvent B.

[0065] As described above, after the drying process D3, the solution film F on the substrate S is further dried while reducing the pressure inside the airtight container 10 to the second pressure P2. In particular, in the drying process D4, the solution film F on the substrate S is further dried while maintaining the pressure in the internal space SP0 at the second pressure P2. Thus, in order to quickly dry the solution film F on the substrate S, it is preferable that the pressure is low.

[0066] Here, as illustrated in FIG. 4, in the plurality of drying processes D1 to D4 included in the drying process, the pressures in the internal space SP0 may be different from each other. Note that among the plurality of drying processes included in the drying process, two or more drying processes in which the pressures in the internal space SP0 are the same as each other may be included.

[0067] In step S4, the control device 90 determines whether or not all the drying processes have been completed, that is, whether or not the drying process has been completed. Whether or not the drying process has been completed is determined based on the output value of the pressure gauge 50 or a preset processing time. When the drying process includes a plurality of drying processes, the control device 90 may perform the determination process in step S4 after the start of the last drying process among the plurality of drying processes.

[0068] If step S4 is YES, that is, if the drying process has been completed, the control device 90 executes the next step S5. If step S4 is NO, that is, if the drying process has not been completed, the control device 90 returns to the process of step S3 again and continues the drying process.

[0069] In step S5, the control device 90 controls the lifting mechanism 80 to move the cover unit 40 to the open position. Then, in step S6, the control device 90 controls the transfer device so that the substrate S held by the substrate holding unit 20 is carried out of the airtight container 10.

[0070] As described above, according to the first embodiment, in the drying process, particularly in the drying step D2, since the gas G1 and the gas G2 having a molecular weight smaller than that of the gas G1 are introduced into the airtight container 10, the drying rate of the solution film F (a plurality of solvents) on the substrate S is stabilized, and the quality of the film formed on the substrate S is improved.

[0071] Further, in the drying step D2, since the mixing ratio of the gases G1 and G2 introduced into the airtight container 10 is adjusted, the drying rate of the solution film F (a plurality of solvents) on the substrate S is stabilized, and the quality of the film formed on the substrate S is further improved. In particular, since the ratio of the gas G2 in the introduced gas G0 introduced into the airtight container 10 is increased as the drying step D2 progresses, the quality of the film formed on the substrate S is further improved.

[0072] The progress of drying of the solution film F (a plurality of solvents) on the substrate S in the drying step D2 is estimated by the pressure inside the airtight container 10. In the first embodiment, since the measurement result of the pressure gauge 50 is acquired by the control device 90, the progress of drying can be accurately estimated. Then, since the ratio of the gases G1 and G2 is adjusted using the measurement result of the pressure gauge 50, the quality of the film formed on the substrate S is further improved.

[0073] As described above, according to the first embodiment, a technique advantageous for drying the substrate S coated with a plurality of solvents is provided.

[0074] <Second Embodiment> The second embodiment will be described. Hereinafter, elements denoted by the same reference numerals as those in the first embodiment have substantially the same configuration and operation as those described in the first embodiment unless otherwise particularly described, and the parts different from the first embodiment will be mainly described.

[0075] FIG. 6 is a schematic cross-sectional view showing the configuration of a vacuum drying apparatus 100A, which is an example of a substrate processing apparatus according to the second embodiment. The vacuum drying apparatus 100A of the second embodiment is obtained by adding a gas analyzer 95 to the vacuum drying apparatus 100 of the first embodiment. In the vacuum drying apparatus 100A of the second embodiment, the same components as those of the vacuum drying apparatus 100 are denoted by the same reference numerals, and detailed description thereof is omitted. Note that, as in the first embodiment, the case where the mixed solvent contained in the solution film F contains two solvents A and B will be described as an example.

[0076] The gas analyzer 95 is used to measure the partial pressure of each solvent vapor of a plurality of solvents evaporated from above the substrate S. The gas analyzer 95 can be, for example, a mass spectrometer. The gas analyzer 95 has a probe inserted into the space SP2 and is configured to be able to analyze the evaporated solvent evaporated from the substrate S.

[0077] The progress of drying of the solution film F (a plurality of solvents) on the substrate S in the drying step D2 is estimated from the partial pressure of the solvent A and the partial pressure of the solvent B inside the airtight container 10. The control device 90 can estimate the mixing ratio of the mixed solvent in the solvent film and the decrease in the drying rate accompanying the change in the mixing ratio of the mixed solvent by measuring the partial pressure ratio of the mixed solvent in the solvent vapor using the gas analyzer 95.

[0078] Hereinafter, a substrate processing method using the vacuum drying apparatus 100A according to the second embodiment will be described. The method for manufacturing an article (substrate processing method) in the second embodiment is the same as that described in the flowchart of FIG. 3 in the first embodiment, but is partly different from the first embodiment.

[0079] In the first embodiment, in the drying step D2, the control device 90 measures the amount of pressure drop using the pressure gauge 50 and changes the mixing ratio of the gases G1 and G2 according to the measurement result. In the second embodiment, in the drying step D2, the control device 90 analyzes the solvent species of the solvent vapor directly above the substrate S in the space SP2 using the gas analyzer 95 and changes the mixing ratio of the gases G1 and G2 according to the analysis result. Note that since the drying steps other than the drying steps D1 and D2 are the same as those in the first embodiment, the description thereof is omitted.

[0080] FIG. 7 is an explanatory diagram of the drying steps D1 and D2 which are part of the drying process according to the second embodiment. FIG. 7 shows graphs illustrating examples of the partial pressure control of the solvent vapors of the solvents A and B and the flow rate control of the gases G1 and G2 in the drying steps D1 and D2. The horizontal axis shown in FIG. 7 is time, and the vertical axis is the partial pressure ratio of the vapors of the solvents A and B in the internal space SP0 and the mixing ratio of the gases G1 and G2 introduced into the internal space SP0.

[0081] In the drying step D2, the control device 90 determines the mixing ratio of the gases G1 and G2 based on the measurement results of the gas analyzer 95 that measures the partial pressure of each solvent vapor of the plurality of types of solvents evaporated from the substrate S.

[0082] Specifically, the control device 90 obtains the partial pressure of the vapor of the solvent A and the partial pressure of the vapor of the solvent B respectively based on the measurement results by the gas analyzer 95, and obtains the partial pressure ratio between the partial pressure of the vapor of the solvent A and the partial pressure of the vapor of the solvent B from the calculation result. The partial pressure ratio is represented by, for example, the partial pressure of the vapor of the solvent A with respect to the sum of the partial pressure of the vapor of the solvent A and the partial pressure of the vapor of the solvent B. That is, the partial pressure ratio is represented by partial pressure ratio = partial pressure of vapor of solvent A / (partial pressure of vapor of solvent A + partial pressure of vapor of solvent B). Then, the control device 90 determines the mixing ratio of the gases G1 and G2 based on the partial pressure ratio.

[0083] In the second embodiment, the solvent A has a higher saturated vapor pressure than the solvent B. During the drying process, the solvent A with a higher saturated vapor pressure evaporates more easily than the solvent B with a lower saturated vapor pressure. Therefore, at the start of the drying step D2, which is measured using the gas analyzer 95, in the space SP2, the partial pressure of the solvent vapor of the solvent A is higher than the partial pressure of the solvent vapor of the solvent B, and as the drying process progresses, the partial pressure of the solvent vapor of the solvent A decreases. That is, the partial pressure ratio decreases from the start of the drying step D2.

[0084] When the partial pressure ratio of the vapor of the solvent A and the vapor of the solvent B measured using the gas analyzer 95 changes from the value at the start of the drying step D2, the control device 90 controls the mixing ratio so as to increase the concentration of the gas G2 in the gas introduction section 60 according to the decrease amount of the partial pressure of the vapor of the solvent A.

[0085] According to the second embodiment, among the gases forming the atmosphere in the internal space SP0, the concentration of the gas G2 with a low molecular weight increases, so the diffusion of the solvent vapor in the space SP2 is promoted, the decrease in the drying rate in the drying step D2 is suppressed, and during the drying step D2, the drying rate of the solution film F can be maintained constant, that is, the unevenness of the drying rate of the solution film F can be reduced.

[0086] Note that also in the drying step D1, when a change in the partial pressure ratio of the solvent vapor is detected, the control device 90 may change the mixing ratio of the gases G1 and G2.

[0087] <Third Embodiment> The third embodiment will be described. Hereinafter, elements denoted by the same reference numerals as those in the first embodiment have substantially the same configuration and operation as those described in the first embodiment unless otherwise specified, and the parts different from the first embodiment will be mainly described.

[0088] FIG. 8 is a schematic cross-sectional view showing the configuration of a vacuum drying apparatus 100B which is an example of a substrate processing apparatus according to the third embodiment. The vacuum drying apparatus 100B of the first embodiment is obtained by adding an imaging device 110 to the vacuum drying apparatus 100 of the first embodiment. In the vacuum drying apparatus 100B of the third embodiment, for the components having the same configuration as those of the vacuum drying apparatus 100, the detailed description thereof will be omitted by using the same reference numerals.

[0089] As a means for observing the progress of drying of the substrate S disposed inside the airtight container 10, the case where the pressure gauge 50 is used in the first embodiment and the gas analyzer 95 is used in the second embodiment has been described as an example. In the third embodiment, an imaging device 110 such as a video camera or a still camera is used as a means for observing the progress of drying of the substrate S disposed inside the airtight container 10. The imaging device 110 is disposed at a position where the substrate S disposed inside the airtight container 10 can be imaged.

[0090] In the third embodiment, the control device 90 causes the imaging device 110 to image the substrate S, acquires an imaging image which is the imaging result of the imaging device 110, and determines the mixing ratio of the gases G1 and G2 based on the imaging image. For example, the control device 90 estimates the shape or thickness of the film surface on the substrate S from the imaging image.

[0091] <Embodiment of the method for manufacturing an article> In this embodiment, an article is manufactured by using the above-described vacuum drying apparatus (substrate processing apparatus). The article may be an intermediate product or a final product. In the method for manufacturing an article according to this embodiment, for example, it is suitable for manufacturing an article such as an organic EL (OLED) panel using an inkjet printing apparatus. The method for manufacturing an article of this embodiment includes a step (coating step) of disposing or applying a solution film (a solution containing a solute and a solvent for forming an organic film) on a substrate by a printing method or the like using an inkjet printing apparatus to obtain a coated substrate. Further, it includes a step (drying step) of drying the solution film on the coated substrate by the above-described vacuum drying apparatus to obtain a dried substrate on which a dried film is formed. Furthermore, such a manufacturing method includes other well-known steps (such as firing, cooling, dehumidification, dry cleaning, formation of electrodes, formation of a sealing film, etc.). The method for manufacturing an article of this embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

[0092] In the above-described embodiment, the case where the control device 90 determines the mixing ratio of the gases G1 and G2 based on the result of observing the progress of drying has been described, but it is not limited thereto. For example, the control device 90 may determine the mixing ratio of the gases G1 and G2 based on the processing time.

[0093] Also, in the above-described embodiment, the case where there are two types of solvents contained in the mixed solvent has been described as an example, but it is not limited thereto. The solvents contained in the mixed solvent may be three or more types. In this case, among the solvents contained in the mixed solvent, the solvent having the highest saturated vapor pressure is solvent A, and the solvent having the lowest saturated vapor pressure is solvent B.

[0094] Also, in the above-described embodiment, the case of applying a solution to the substrate S has been described as an example, but it is not limited thereto. For example, even when only a solvent is applied to the substrate to process the surface of the substrate, the above-described embodiment is applicable.

[0095] In the above-described embodiments, the case where a mixed solvent is applied to the substrate has been described as an example. However, the present invention is not limited thereto. For example, after applying the first solvent to the substrate, the second solvent may be applied to the substrate, and a plurality of types of solvents may be applied separately so that a mixed solvent is formed on the substrate.

[0096] Also, different types of solvents, or solutions containing different types of solvents, may be applied for each area on the substrate. For example, the first solvent may be applied to the first area of the substrate S, and the second solvent may be applied to the second area of the substrate S, or the first solution containing the first solvent may be applied to the first area of the substrate S, and the second solution containing the second solvent may be applied to the second area of the substrate S.

[0097] In the above-described embodiments, the case where the vacuum drying apparatus has the gas introduction unit 60 has been described. However, the present invention is not limited thereto. For example, the gas introduction unit 60 may be a facility such as a factory, and the gas introduction unit 60 may be connectable to the vacuum drying apparatus.

[0098] [Other Modification Examples] The present disclosure is not limited to the embodiments described above, and many modifications are possible within the technical idea of the present disclosure. For example, at least two of the above-described multiple embodiments and multiple modification examples may be combined. Also, the effects described in the present embodiments merely list the most preferable effects resulting from the embodiments of the present disclosure, and the effects according to the embodiments of the present disclosure are not limited to those described in the present embodiments.

[0099] The disclosure of the above embodiments includes the following items.

[0100] (Item 1) An airtight container into which a substrate coated with a plurality of types of solvents having different saturated vapor pressures is conveyed, A decompression mechanism for decompressing the inside of the airtight container, A control unit capable of performing a drying process for evaporating the plurality of types of solvents applied to the substrate disposed inside the airtight container in a decompressed environment in which the inside of the airtight container is decompressed by the decompression mechanism. In the drying process, the control unit is configured to independently control the flow rate of a first gas introduced into the interior of the airtight container and the flow rate of a second gas introduced into the interior of the airtight container, the second gas having a molecular weight smaller than that of the first gas. Both the first gas and the second gas exist as gases in an environment of 25°C and 1 atm. A substrate processing apparatus, characterized by the above.

[0101] (Item 2) The control unit changes the ratio of the first gas and the second gas introduced into the interior of the airtight container according to the progress of the drying process. The substrate processing apparatus according to Item 1, characterized by the above.

[0102] (Item 3) The control unit changes the ratio so that the proportion of the second gas increases according to the progress of the drying process. The substrate processing apparatus according to Item 2, characterized by the above.

[0103] (Item 4) The control unit determines the ratio based on the measurement result of a pressure gauge that measures the pressure inside the airtight container. The substrate processing apparatus according to Item 2 or 3, characterized by the above.

[0104] (Item 5) The control unit determines the ratio so that the proportion of the second gas increases according to the amount of decrease per unit time of the pressure value indicated by the pressure gauge. The substrate processing apparatus according to Item 4, characterized by the above.

[0105] (Item 6) The control unit determines the ratio based on the measurement result of a gas analyzer that measures the partial pressure of each solvent vapor of the plurality of types of solvents evaporated from the substrate. The substrate processing apparatus according to Item 2 or 3, characterized by the above.

[0106] (Item 7) The control unit determines the ratio based on an imaging result of an imaging device that images the substrate. The substrate processing apparatus according to claim 2 or 3, characterized in that.

[0107] (Item 8) The ratio is a ratio of a volume flow rate of the first gas to a volume flow rate of the second gas. The substrate processing apparatus according to any one of claims 2 to 7, characterized in that.

[0108] (Item 9) The plurality of types of solvents include a first solvent and a second solvent having a lower saturated vapor pressure than the first solvent. In the drying process, the control unit executes a first process of controlling the inside of the airtight container to a first pressure lower than 1 atm and higher than the saturated vapor pressure of the first solvent. The substrate processing apparatus according to any one of claims 1 to 8, characterized in that.

[0109] (Item 10) In the first process, the control unit controls the total flow rate of the first gas and the second gas to be constant. The substrate processing apparatus according to claim 9, characterized in that.

[0110] (Item 11) In the drying process, the control unit executes a second process of controlling the inside of the airtight container to a second pressure lower than the saturated vapor pressure of the second solvent. The substrate processing apparatus according to claim 9 or 10, characterized in that.

[0111] (Item 12) The first solvent is a solvent having the highest saturated vapor pressure among the plurality of types of solvents. The second solvent is a solvent having the lowest saturated vapor pressure among the plurality of types of solvents. The substrate processing apparatus according to any one of claims 9 to 11, characterized in that.

[0112] (Item 13) As the first process included in the drying process progresses, the control unit controls the flow rates of the first gas and the second gas so that the volume flow rate of the second gas with respect to the volume flow rate of the first gas increases. The substrate processing apparatus according to any one of claims 9 to 12, characterized in that.

[0113] (Claim 14) The first gas whose flow rate is adjusted by a first flow rate adjuster and the second gas whose flow rate is adjusted by a second flow rate adjuster are introduced into the inside of the airtight container. The control unit controls the flow rates of the first gas and the second gas introduced into the inside of the airtight container by causing the first flow rate adjuster to adjust the flow rate of the first gas and causing the second flow rate adjuster to adjust the flow rate of the second gas. The substrate processing apparatus according to any one of claims 1 to 13, characterized in that.

[0114] (Claim 15) The first gas and the second gas are mixed and introduced into the inside of the airtight container. The substrate processing apparatus according to any one of claims 1 to 14, characterized in that.

[0115] (Claim 16) A substrate processing method, comprising a step of drying a plurality of types of solvents applied on a substrate using the substrate processing apparatus according to any one of claims 1 to 15.

[0116] (Claim 17) A method for manufacturing an article, comprising a step of drying a plurality of types of solvents applied on a substrate using the substrate processing apparatus according to any one of claims 1 to 15.

Explanation of reference numerals

[0117] G1... gas (first gas), G2... gas (second gas), S... substrate, 10... airtight container, 90... control device (control unit), 100... vacuum drying device (substrate processing apparatus)

Claims

1. An airtight container into which a substrate coated with a plurality of types of solvents having different saturated vapor pressures is conveyed inside, A decompression mechanism for decompressing the inside of the airtight container, A control unit capable of performing a drying process for evaporating the plurality of types of solvents applied to the substrate disposed inside the airtight container in a decompressed environment in which the inside of the airtight container is decompressed by the decompression mechanism, comprising: The control unit is configured to independently control the flow rate of a first gas introduced into the inside of the airtight container and the flow rate of a second gas introduced into the inside of the airtight container and having a molecular weight smaller than that of the first gas in the drying process, Both the first gas and the second gas exist as gases in an environment of 25°C and 1 atm, A substrate processing apparatus characterized by the above.

2. The control unit changes the ratio of the first gas and the second gas introduced into the inside of the airtight container according to the progress of the drying process, The substrate processing apparatus according to claim 1, characterized by the above.

3. The control unit changes the ratio so that the proportion of the second gas increases according to the progress of the drying process, The substrate processing apparatus according to claim 2, characterized by the above.

4. The control unit determines the ratio based on the measurement result of a pressure gauge that measures the pressure inside the airtight container, The substrate processing apparatus according to claim 2, characterized by the above.

5. The control unit determines the ratio so that the proportion of the second gas increases according to the amount of decrease per unit time of the pressure value indicated by the pressure gauge, The substrate processing apparatus according to claim 4, characterized by the above.

6. The control unit determines the ratio based on the measurement result of a gas analyzer that measures the partial pressure of each solvent vapor of the plurality of types of solvents evaporated from the substrate, The substrate processing apparatus according to claim 2, characterized by the above.

7. The control unit determines the ratio based on the imaging result of an imaging device that images the substrate, The substrate processing apparatus according to claim 2, characterized by the above.

8. The ratio is the ratio of the volume flow rate of the first gas to the volume flow rate of the second gas, The substrate processing apparatus according to claim 2, characterized by the above.

9. The plurality of types of solvents include a first solvent and a second solvent having a saturated vapor pressure lower than that of the first solvent, In the drying process, the control unit executes a first process of controlling the interior of the airtight container to a first pressure that is lower than 1 atm and higher than the saturation vapor pressure of the first solvent. The substrate processing apparatus according to claim 1, characterized in that.

10. In the first process, the control unit controls the total flow rate of the first gas and the second gas to be constant. The substrate processing apparatus according to claim 9, characterized in that.

11. In the drying process, the control unit executes a second process of controlling the interior of the airtight container to a second pressure that is lower than the saturation vapor pressure of the second solvent. The substrate processing apparatus according to claim 9, characterized in that.

12. The first solvent is the solvent having the highest saturation vapor pressure among the plurality of solvents. The second solvent is the solvent having the lowest saturation vapor pressure among the plurality of solvents. The substrate processing apparatus according to claim 9, characterized in that.

13. As the first process included in the drying process progresses, the control unit controls the flow rates of the first gas and the second gas such that the volume flow rate of the second gas with respect to the volume flow rate of the first gas and the volume flow rate of the second gas increases. The substrate processing apparatus according to claim 9, characterized in that.

14. The first gas whose flow rate is adjusted by a first flow rate regulator and the second gas whose flow rate is adjusted by a second flow rate regulator are introduced into the interior of the airtight container. The control unit controls the flow rates of the first gas and the second gas introduced into the interior of the airtight container by adjusting the flow rate of the first gas to the first flow rate regulator and adjusting the flow rate of the second gas to the second flow rate regulator. The substrate processing apparatus according to claim 1, characterized in that.

15. The first gas and the second gas are mixed and introduced into the interior of the airtight container. The substrate processing apparatus according to claim 1, characterized in that.

16. A substrate processing method, comprising a step of drying a plurality of solvents applied on a substrate using the substrate processing apparatus according to any one of claims 1 to 15.

17. A method for manufacturing an article, comprising a step of drying a plurality of solvents applied on a substrate using the substrate processing apparatus according to any one of claims 1 to 15.

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