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

Abstract

The invention provides a substrate processing apparatus, a substrate processing method and an article manufacturing method, and provides a technology beneficial to drying processing of a substrate coated with a plurality of solvents. The substrate processing apparatus includes: an airtight container which conveys a substrate coated with a plurality of types of solvents having different saturated vapor pressures into the airtight container; 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 reduced-pressure environment in which the pressure reduction mechanism depressurizes the inside of the airtight container. The control unit is configured so as to independently control the flow rate of a first gas introduced into the airtight container and the flow rate of a second gas introduced into the airtight container and having a molecular weight smaller than that of the first gas during the drying process. The first gas and the second gas are both present as gases in an environment of 25 DEG C and one gas pressure.

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, for example, a method of applying a solvent film or a solution film to a desired portion on a substrate using a spraying device is known. The solvent film is a film composed of a solvent, and the solution film is a film composed of a solution containing a solute and a solvent. The substrate is processed by drying the surface of the substrate on which the solvent has been applied. Further, the solution film formed by applying a solution on the substrate is dried, whereby a substrate process for forming a film (layer) of the solute is performed. A reduced-pressure drying device is used as a substrate processing device in the drying of the solution film.

[0003] Patent Document 1 discloses the following configuration: In substrate processing, a gas containing a solvent vapor the same as the solvent contained in the solution film is supplied to the periphery of the substrate, thereby controlling the drying rate of the solution film.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-185939 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] The solvent applied to the substrate or the solvents contained in the solution applied to the substrate are not limited to a single solvent as described in Patent Document 1, and there are cases of multiple solvents having different saturated vapor pressures. However, Patent Document 1 does not disclose a case of applying multiple solvents to the substrate. When applying multiple solvents to the substrate, drying starts from the solvent having a high saturated vapor pressure, and thus, the ratio of the solvent vapor in the peripheral atmosphere of the substrate continuously changes, and the drying rate of the solvent or the solution changes. This change in the drying rate affects the quality of the surface of the substrate or the film formed on the substrate.

[0009] Means for Solving the Problems

[0010] One aspect of the present disclosure is a substrate processing apparatus, characterized in that the substrate processing apparatus includes: an airtight container for transporting a substrate coated with a plurality of solvents having different saturated vapor pressures into the interior of the airtight container; a decompression mechanism for decompressing the interior of the airtight container; a control unit that can perform a drying process in a decompressed environment in which the decompression mechanism decompresses the interior of the airtight container, the drying process evaporating the plurality of solvents coated on the substrate disposed in the interior of the airtight container, and 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 and having a molecular weight smaller than that of the first gas during the drying process, and both the first gas and the second gas exist as gases in an environment of 25 °C and 1 atmosphere. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 FIG. is a schematic cross-sectional view showing the configuration of a decompression drying apparatus as an example of the substrate processing apparatus according to the first embodiment.

[0012] Figure 2 (a) is a cross-sectional view of a part of the decompression drying apparatus according to the first embodiment. Figure 2 (b) is a cross-sectional view of a part of the decompression drying apparatus according to the first embodiment.

[0013] Figure 3 FIG. is a flowchart of the substrate processing method according to the first embodiment.

[0014] Figure 4 FIG. is an explanatory diagram of the drying process according to the first embodiment.

[0015] Figure 5 FIG. is an explanatory diagram of a part of the drying process according to the first embodiment.

[0016] Figure 6 FIG. is a schematic cross-sectional view showing the configuration of a decompression drying apparatus as an example of the substrate processing apparatus according to the second embodiment.

[0017] Figure 7 FIG. is an explanatory diagram of a part of the drying process according to the second embodiment.

[0018] Figure 8 FIG. is a schematic cross-sectional view showing the configuration of a decompression drying apparatus as an example of the substrate processing apparatus according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, in each figure, the same reference numerals are assigned to the same components, and repeated descriptions are omitted. In the following embodiments, the directions are represented by the XYZ coordinate system, which is an orthogonal coordinate system. In the XYZ coordinate system, the XY plane is the horizontal plane, the Z direction is the vertical direction, and the negative direction of the Z axis is the vertical direction (gravity direction).

[0020] <First Embodiment>

[0021] Figure 1 FIG. 1 is a schematic cross-sectional view showing the configuration of a reduced-pressure drying apparatus 100 as an example of a substrate processing apparatus according to the first embodiment. The reduced-pressure drying apparatus 100 is used in a part of the process for manufacturing an organic EL panel having an OLED as an organic EL element. That is, the reduced-pressure drying apparatus 100 forms an organic film on the substrate S by performing a drying process for drying the solution film F coated on 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 forming a state in which almost no solvent remains in the substrate S is expressed as a drying process.

[0022] 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 atmosphere). Preferably, the solvent contained in the solution film F has a property that evaporation is promoted in a reduced-pressure environment lower than atmospheric pressure (1 atmosphere). Preferably, the evaporation of the solvent is promoted, for example, at a temperature higher than normal temperature (25°C).

[0023] 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.

[0024] The solvents contained in the mixed solvent are preferably organic solvents. Examples of the organic solvents 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-octanediol, 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, ethylene glycol ethyl ether acetate, cyclohexylbenzene, and the like.

[0025] The organic film is an organic layer, for example, any one of the hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer of an OLED. The manufacture of an organic EL element includes the steps of forming each organic film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer and an electron injection layer on a substrate S. Before the substrate S is carried into the reduced pressure drying device 100, a solution film F is applied to a necessary portion of the substrate S by a coating device.

[0026] The reduced pressure drying device 100 includes: an airtight container 10; a decompression mechanism 30 for decompressing the interior of the airtight container 10; and a substrate holding portion 20 disposed inside the airtight container 10 and serving as a holding portion capable of holding a substrate S. In addition, the reduced pressure drying device 100 includes a cover unit 40 disposed inside the airtight container 10 at a position surrounding the substrate S held by the substrate holding portion 20. The cover unit 40 is disposed at a position not in contact with the substrate S held by the substrate holding portion 20.

[0027] Inside the airtight container 10, a substrate S coated with a plurality of solvents having different saturated vapor pressures can be transported. The pressure of the external environment of the airtight container 10 is atmospheric pressure, for example, 1 atmosphere. The airtight container 10 is a component that partitions an 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 portion 20 and the cover unit 40. The space SP2 on the inner side of the cover unit 40 and the space SP1 on the outer side of the cover unit 40 are connected to each other, and by surrounding the substrate S with the cover unit 40, the pressure distribution of the space SP2 is adjusted to be as uniform as possible.

[0028] In addition, the reduced pressure drying device 100 is provided with a gate valve 11 provided on the airtight container 10 for opening and closing the interior of the airtight container 10. The substrate S coated with the solution film F to be dried is moved from the external space outside the airtight container 10 (for example, another airtight container) to the internal space SP0 of the airtight container 10 through the gate valve 11. In addition, the substrate S that has been dried is moved out from the internal space SP0 to the external space (for example, another airtight container) through the gate valve 11. The moving in and out of the substrate S is performed by a conveying device (not shown) placed outside the airtight container 10.

[0029] An exhaust port 12 is formed at the upper part of the airtight container 10. An exhaust pipe 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 is exhausted through the exhaust pipe, 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 include, for example, at least one of a dry pump and a diaphragm vacuum pump. In addition, the plurality of pumps may also include, for example, at least one of a turbomolecular pump, a cryopump, an adsorption pump, an oil diffusion pump, a mechanical booster pump, a jet pump, and an oil rotary vacuum pump.

[0030] The decompression drying apparatus 100 further includes a pressure gauge 50 for measuring the pressure of 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.

[0031] The decompression drying apparatus 100 further includes a temperature control unit 70. The temperature control unit 70 controls the temperature of the substrate holding unit 20 to control the temperature of the substrate S or the solution film F on the substrate S. Preferably, the temperature control unit 70 includes a heater for heating the substrate holding unit 20. In addition, the temperature control unit 70 may also 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.

[0032] The temperature control unit 70 controls a plurality of regions of the substrate holding unit 20 to have 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 the temperature difference between a plurality of regions of the substrate S held by the substrate holding unit 20 to be within 10 °C. More preferably, the temperature control unit 70 controls the temperature difference between a plurality of regions of the substrate S held by the substrate holding unit 20 to be 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 specified temperature within the range of 0 °C to 100 °C. By heating the substrate holding unit 20, the drying speed of the solution film F coated on the substrate S can be increased.

[0033] The cover unit 40 is disposed, for example, on the substrate holding unit 20. The main material of the cover unit 40 is metal. The metal is preferably, for example, stainless steel or aluminum. The stainless steel is preferably, 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 the Japanese Industrial Standard: JIS).

[0034] Figure 2 of (a) and Figure 2 of (b) are cross-sectional views of a part of the configuration of the decompression drying apparatus 100 according to the first embodiment. Figure 2Fig. (a) is a sectional view of the cover unit 40 along the XY plane and the components around the cover unit 40 as viewed in the negative Z-axis direction.

[0035] Figure 2 Fig. (b) is a sectional view of the cover unit 40 along the YZ plane and the components around the cover unit 40 as viewed in the negative X-axis direction.

[0036] The cover unit 40 includes a surrounding wall 41 and a cover 42. The cover 42 can be provided separately from the surrounding wall 41 or integrally with the surrounding wall 41. In the first embodiment, the cover 42 is provided integrally with the surrounding wall 41.

[0037] 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 portion 20, and is disposed at a position where it can face the side surface SS of the substrate S disposed on the substrate holding portion 20. Additionally, the surrounding wall 41 can also be placed on another member.

[0038] The cover 42 is an example of a top plate. The cover 42 is disposed at a position facing the main surface MS of the substrate S in the Z direction, which is perpendicular to the upper surface of the substrate holding portion 20. Specifically, the cover 42 is disposed at a position facing the solution film F coated on the main surface MS of the substrate S in the Z direction. The cover 42 is fixed to the surrounding wall 41. That is, the cover 42 is fixed to the upper end of the surrounding wall 41.

[0039] The vacuum drying device 100 includes a lifting mechanism 80 as an example of an opening / closing mechanism that can open and close the space SP2. The cover unit 40 can move relative to the substrate holding portion 20 in the Z direction, which is the up and down direction, by the lifting mechanism 80. The lifting mechanism 80 can be used when transporting the substrate S to the substrate holding portion 20 and when transporting the substrate S from the substrate holding portion 20. For example, the lifting mechanism 80 can move the cover unit 40 to a closed position where the cover unit 40 is placed on the substrate holding portion 20 and an open position where the cover unit 40 is separated from the substrate holding portion 20. Additionally, instead of the lifting mechanism 80, an opening for loading and unloading the substrate S can be provided in the surrounding wall 41, and a gate for opening and closing the opening can be configured.

[0040] The cover 42 has a plurality of openings 43. Each opening 43 is a through hole. The shape of the opening 43 can be a circular shape or a linear shape such as a slit. The arrangement and size of the openings 43 are determined to uniformly dry the solution film F coated on the substrate S. For example, by making the area of the opening 43 facing the portion with a high drying rate of the solution film F on the substrate S 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.

[0041] The opening area per unit area in the cover 42 is called the opening ratio. The areas of the respective openings 43 of the cover 42 are adjusted so that the opening ratio near the outer periphery of the substrate S is smaller than the opening ratio near the center of the substrate S. For example, in the cover 42, the opening ratio of the portion facing the center of the substrate S may be specified to be 40 to 70%, and the opening ratio of the portion facing the outer periphery of the substrate S may be specified to be 20 to 50%. In addition, the cover 42 only needs to have a configuration that allows the space SP2 to communicate with the space SP1, and does not necessarily have the openings 43. The surrounding wall 41 may also be configured to allow the space SP2 to communicate with the space SP1.

[0042] The reduced-pressure drying apparatus 100 further includes a gas introduction unit 60 that introduces a gas G1 as a first gas and a gas G2 as 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 in which the gas G1 and the gas G2 are mixed into the internal space SP0 (space SP1). The gas G2 is a gas having a molecular weight smaller than that of the gas G1.

[0043] The gas supply source 61 of the gas G1 and the gas supply source 62 of the gas G2 are connected to the gas introduction unit 60. The supply source 61 is, for example, a gas cylinder filled with the liquefied gas G1. The supply source 62 is, for example, a gas cylinder filled with the liquefied gas G2. The gases G1 and G2 exist as gases in an environment of normal temperature (25°C) and atmospheric pressure (1 atmosphere). That is, the gases G1 and G2 cannot exist as liquids in an environment of normal temperature (25°C) and atmospheric pressure (1 atmosphere).

[0044] The gas introduction unit 60 includes: a pipe 63 connected to the supply source 61; a pipe 64 connected to the supply source 62; a pipe 65 connected to the airtight container 10; a mixer 66; a flow regulator 67 disposed in the pipe 63; and a flow regulator 68 disposed in the pipe 64. The mixer 66 has two input orifices and one output orifice. The pipes 63 and 64 are respectively connected to the input orifices, and the pipe 65 is connected to the output orifice. The flow regulator 67 is an example of a first flow regulator. The flow regulator 68 is an example of a second flow regulator.

[0045] The mixer 66 may include a mechanism that stirs the input gases and mixes them uniformly. 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 is configured to introduce the introduced gas G0 into the airtight container 10. In the first embodiment, the gas introduction unit 60 is configured to introduce the introduced gas G0 into the airtight container 10 from the lower part of the airtight container 10. Thus, in the first embodiment, the gases G1 and G2 are mixed and introduced into the airtight container 10.

[0046] By introducing the introduced gas G0 into the internal space SP0 of the airtight container 10 via 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. In addition, 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 adjusters 67 and 68. That is, the gas G1 with the flow rate adjusted by the flow rate adjuster 67 and the gas G2 with the flow rate adjusted by the flow rate adjuster 68 can be introduced into the interior of the airtight container 10.

[0047] In addition, during the adjustment of the flow rates of the gases G1 and G2 by the flow rate adjusters 67 and 68, the introduced gas G0 output from the mixer 66 can be not only the mixed gas of the gas G1 and the gas G2, but also the single gas of the gas G1 or the gas G2. In addition, the gas introduction part 60 may not have the mixer 66, but may be configured to directly introduce the gases G1 and G2 from the supply sources 61 and 62 into the interior of the airtight container 10. In this case, the gases G1 and G2 are mixed inside the airtight container 10.

[0048] The pipe 65 is arranged to introduce the introduced gas G0 into the space SP1, which is the outside of the space SP2. Thereby, the flow of the solvent vapor in the space SP2 is not disturbed by the introduced gas G0 introduced into the internal space SP0 from the pipe 65, and the atmosphere gas in the internal space SP0 can be replaced with the introduced gas G0.

[0049] Both the gas G1 and the gas G2 are gases with a saturated vapor pressure higher than the atmospheric pressure (1 atm). The gas G1 and the gas G2 can be, for example, any one of clean dry air, helium, neon, argon, krypton, and xenon as noble gases, and nitrogen and carbon dioxide gas as relatively stable gases. These gases exist as gases under the environment of normal temperature (25°C) and atmospheric pressure (1 atm).

[0050] For example, the gas G1 is nitrogen and the gas G2 is helium. The molecular weight of helium is smaller than that of nitrogen.

[0051] In addition, the gases G1 and G2 are preferably the above examples, but are not limited to the above examples. If the molecular weight of the gas G2 is smaller than that of the gas G1 and the gases 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 can also be used.

[0052] In addition, the pressure-reducing drying apparatus 100 further includes a control device 90 that controls each part of the entire apparatus. The control device 90 is an example of a control unit. The control device 90 is constituted by a computer, for example. The control device 90 includes a CPU as an example of a processor, a RAM as a temporary storage device, a ROM and an SSD as non-temporary storage devices (storage media), an I / O as an interface, and the like. In the non-temporary storage device, a control program for causing the CPU of the control device 90 to control each part of the entire apparatus in the manufacturing process described later is stored.

[0053] The control device 90 controls the pressure inside the airtight container 10 by controlling the pressure-reducing mechanism 30. In addition, 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 adjusters 67 and 68.

[0054] In the first embodiment, the control device 90 is configured to be able to perform a drying process of evaporating a plurality of solvents contained in the solution film F coated on the substrate S disposed inside the airtight container 10 in a pressure-reducing environment in which the pressure-reducing mechanism 30 reduces the pressure inside the airtight container 10. The control device 90 is configured to independently control the flow rate of the gas G1 introduced into the inside of the airtight container 10 and the flow rate of the gas G2 introduced into the inside of the airtight container 10 during the drying process. Specifically, the control device 90 controls the flow rates of the gas G1 and the gas G2 introduced into the inside of the airtight container 10 by causing the flow rate adjuster 67 to adjust the flow rate of the gas G1 and causing the flow rate adjuster 68 to adjust the flow rate of the gas G2.

[0055] In addition to the above configuration, the control device 90 may be constituted 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 stored, or a combination of all or a part of them.

[0056] Hereinafter, a process (substrate processing method) including a part of a drying process (drying treatment) among a plurality of processes of a method for manufacturing an organic EL panel as an example of an article will be described. Figure 3 It is a flowchart of the substrate processing method (article manufacturing method) according to the first embodiment. A solution film F is coated on a necessary part on the main surface MS of the substrate S by a coating device such as a spraying device.

[0057] In step S1, the control device 90 controls the transfer device to transfer the substrate S coated with the solution film F into the interior of the airtight container 10. Thereby, the substrate S is placed on the substrate holding portion 20.

[0058] Next, in step S2, the control device 90 controls the lifting mechanism 80 to move the cover unit 40 to the closed position.

[0059] Next, in step S3, the control device 90 performs a drying process of 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 decompression mechanism 30 and the flow regulators 67, 68 in each drying step.

[0060] The decompression drying device 100 can perform a drying process of drying the solvent coated on the substrate S. Hereinafter, the drying process will be specifically described. Figure 4 It is an explanatory diagram of the drying process according to the first embodiment. In Figure 4 it, a graph showing an example of pressure control in the drying process is illustrated. Figure 4 The horizontal axis shown is time, and the vertical axis is the pressure in the internal space SP0. In Figure 4 the example, the plurality of drying steps are four drying steps D1 to D4, but the number of drying steps is not limited to four.

[0061] In addition, in the first embodiment, the case where the solvent contained in the solution film F is two solvents A and B is taken as an example for explanation. The saturated vapor pressures of both solvents A and B are lower than the atmospheric pressure. And, the saturated vapor pressure of solvent A is higher than the saturated vapor pressure of solvent B. That is, the saturated vapor pressure of solvent B is lower than the saturated 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 saturated vapor pressure among the various solvents contained in the solution film F. In addition, solvent B is the solvent having the lowest saturated vapor pressure among the various solvents contained in the solution film F. In addition, the comparison of the magnitudes of the saturated vapor pressures of the various solvents can be performed using, for example, the values of the saturated vapor pressures at room temperature (25°C).

[0062] 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, i.e., 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 of 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. 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 also evaporates. That is, in the drying step D1, the drying of the solution film F on the substrate S also progresses.

[0063] The mixing ratio of the gases G1 and G2 in the introduced gas G0 is defined by 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 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. In addition, both the gas G1 and the gas G2 are gases of different types from the vapors of the solvents A and B.

[0064] 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 to maintain the pressure in the internal space SP0, i.e., the pressure indicated by the pressure gauge 50, near the first pressure P1. For example, the control device 90 controls the decompression mechanism 30 and the flow regulators 67 and 68 so that the exhaust gas volume (volume flow rate) in the decompression mechanism 30 becomes constant and the gas supply volume (volume flow rate) in the gas introduction unit 60 becomes constant.

[0065] In addition, in the drying step D2, the control device 90 controls the flow regulators 67 and 68 so that the mixing ratio changes while maintaining the volume flow rate of the introduced gas G0 introduced into the inside of the airtight container 10 from the gas introduction unit 60 at a constant prescribed volume flow rate. In this drying step D2, the solution film F on the substrate S is dried. The drying step D2 corresponds to the first treatment. That is, in the drying step D2, the control device 90 executes the first treatment, which controls the inside of the airtight container 10 to the first pressure P1 that is lower than 1 atm and higher than the saturated vapor pressure of the solvent A.

[0066] Thus, in the first embodiment, the control device 90 changes the ratio (mixing ratio) of the gas G1 and the gas G2 introduced into the inside of the airtight container 10 according to the progress of the drying process. At this time, the control device 90 changes the mixing ratio of the gases G1 and G2 according to the progress of the drying process so that the proportion of the gas G2 contained in the introduced gas G0 becomes higher. Specifically, as the first process included in the drying process progresses, 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 flow rate of the volume flow rates of the gas G1 and the gas G2.

[0067] Figure 5 FIG. 4 is an explanatory diagram of the drying steps D1 and D2 which are part of the drying process according to the first embodiment. In Figure 5 FIG. 4, graphs showing examples of pressure control and flow rate control of the gases G1 and G2 in the drying steps D1 and D2 are illustrated. Figure 5 In FIG. 4, the horizontal axis represents time, and the vertical axis represents the pressure in 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.

[0068] When the solution film F contains a plurality of solvents, drying progresses starting from the solvent having a high saturated vapor pressure among the plurality of solvents. Therefore, as the drying of the solution film F progresses, the saturated vapor pressure of the mixed solvent contained in the solution film F decreases, and the pressure in the internal space SP0 decreases from the first pressure P1 as Figure 5 shown. 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 also decreases. That is, as the drying of the solution film F progresses, the solvent contained in the solution film F is difficult to evaporate, and the exhaust speed in the decompression mechanism 30 is adjusted to be constant. Therefore, the pressure in the internal space SP0 decreases from the first pressure P1.

[0069] Here, when the pressure measured by the pressure gauge 50 decreases from the first pressure P1, the control device 90 controls the flow rate adjuster 67 so that the volume flow rate of the gas G1 decreases and controls the flow rate adjuster 68 so that the volume flow rate of the gas G2 increases according to the amount of decrease in pressure from the first pressure P1. That is, the control device 90 determines the mixing ratio based on the amount of decrease in the pressure value shown by the pressure gauge 50 per unit time so that the proportion of the gas G2 in the introduced gas G0 increases. Thereby, the control device 90 controls the total flow rate (volume flow rate) of the gases G1 and G2 introduced from the gas introduction unit 60 into the inside of the airtight container 10 to be constant, and controls the mixing ratio to increase the concentration of the gas G2 introduced into the inside of the airtight container 10.

[0070] 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 increases. Generally speaking, the diffusion coefficient of gas molecules is inversely proportional to the 1 / 2 power of the molecular weight. Therefore, in the atmosphere around the substrate S, the higher the concentration of the gas G2 with a low molecular weight, the higher the diffusion coefficient of the whole atmosphere, and the more active the diffusion of the solvent vapor.

[0071] Here, the lower the concentration of the solvent vapor directly above the gas-liquid interface of the solvent, the easier the solvent vaporizes, and the greater the drying speed. Therefore, by making the diffusion of the solvent vapor more active, the solvent vapor directly above the gas-liquid interface decreases, and the drying speed increases. In the first embodiment, using this property, the control device 90 controls the mixing ratio of the gas G1 and the gas G2 corresponding to the amount of pressure reduction. Thereby, during the drying process D2, the drying speed of the solution film F is controlled to be constant, and the deviation of the drying speed of the solution film F with respect to the elapsed time of the drying process D2 is reduced.

[0072] In addition, although the case where the volume flow rates of the respective gases G1 and G2 are adjusted in the control of the drying processes D1 and D2 has been described as an example, it is not limited thereto, and the mass flow rates of the respective gases G1 and G2 may also be adjusted.

[0073] The shape of the solution film F is substantially determined before the end of the drying process D2. Therefore, from the drying process D3 onward, control for making the drying speed constant is not performed, and the pressure inside the airtight container 10 is set to a pressure lower than the saturated vapor pressure of the solvent having the lowest saturated vapor pressure among the multiple solvents contained in the solution film F.

[0074] In the drying process D3, the control device 90 controls the flow rate adjusters 67 and 68 to stop the gas introduction 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, drops from the first pressure P1 to the second pressure P2. Thereby, 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 saturated vapor pressure of the solvent having the lowest saturated vapor pressure. Thereby, the solution film F on the substrate S is dried.

[0075] 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 to maintain the pressure in the internal space SP0, that is, the pressure indicated by the pressure gauge 50, 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 performs the second treatment, which controls the inside of the airtight container 10 to the second pressure P2 lower than the saturated vapor pressure of the solvent B.

[0076] As described above, from the drying process D3 onwards, while reducing the pressure inside the airtight container 10 to the second pressure P2, the solution film F on the substrate S is further dried. Particularly 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 dry the solution film F on the substrate S quickly, it is preferable to perform drying under low-pressure conditions.

[0077] Here, as Figure 4 illustrated, in the plurality of drying processes D1 to D4 included in the drying treatment, the pressure in the internal space SP0 can be different from each other. In addition, among the plurality of drying processes included in the drying treatment, there may also be included two or more drying processes in which the pressures in the internal space SP0 are the same.

[0078] In step S4, the control device 90 determines whether all the drying processes have ended, that is, whether the drying treatment has ended. Whether the drying treatment has ended is determined based on the output value of the pressure gauge 50 or a preset treatment time. In addition, when the drying treatment includes a plurality of drying processes, the control device 90 may also perform the determination process of step S4 after the start of the last drying process among the plurality of drying processes.

[0079] When step S4 is yes, that is, when the drying treatment has ended, the control device 90 performs the next step S5. When step S4 is no, that is, when the drying treatment has not ended, the control device 90 returns to the process of step S3 again and continues the drying treatment.

[0080] In step S5, the control device 90 controls the lifting mechanism 80 to move the cover unit 40 to the open position. And in step S6, the control device 90 controls the transfer device to carry out the substrate S held by the substrate holding portion 20 to the outside of the airtight container 10.

[0081] As described above, according to the first embodiment, in the drying process, particularly in the drying step D2, the gas G1 and the gas G2 having a molecular weight smaller than that of the gas G1 are introduced into the inside of the airtight container 10. Therefore, the drying rate of the solution film F (a variety of solvents) on the substrate S becomes stable, and the quality of the film formed on the substrate S is improved.

[0082] In addition, since the mixing ratio of the gases G1 and G2 introduced into the inside of the airtight container 10 is adjusted in the drying step D2, the drying rate of the solution film F (a variety of solvents) on the substrate S becomes stable, and the quality of the film formed on the substrate S becomes higher. In particular, as the drying step D2 progresses, the ratio of the gas G2 in the introduced gas G0 introduced into the inside of the airtight container 10 increases, and therefore, the quality of the film formed on the substrate S becomes higher.

[0083] The progress of the drying of the solution film F (a variety of solvents) on the substrate S in the drying step D2 is estimated based on 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 the drying can be accurately estimated. And 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 becomes higher.

[0084] Thus, according to the first embodiment, a technique advantageous for the drying process of the substrate S coated with a variety of solvents can be provided.

[0085] <Second Embodiment>

[0086] 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 function as the elements described in the first embodiment unless otherwise specified, and mainly the parts different from the first embodiment will be described.

[0087] Figure 6 FIG. is a schematic cross-sectional view showing the configuration of a reduced-pressure drying apparatus 100A which is an example of a substrate processing apparatus according to the second embodiment. The reduced-pressure drying apparatus 100A of the second embodiment adds a gas analyzer 95 to the reduced-pressure drying apparatus 100 of the first embodiment. In the reduced-pressure drying apparatus 100A of the second embodiment, for the same configuration as that of the reduced-pressure drying apparatus 100, the same reference numerals are used and the detailed description is omitted. In addition, as in the first embodiment, the case where the mixed solvent contained in the solution film F includes two solvents A and B will be described as an example.

[0088] The gas analyzer 95 is used to measure the partial pressure of the solvent vapor of each of the various solvents evaporated from the substrate S. The gas analyzer 95 can be, for example, a mass spectrometer. The gas analyzer 95 has a probe 96 inserted into the space SP2 and is configured to analyze the evaporated solvent evaporated from the substrate S.

[0089] The progress of drying the solution film F (a variety of solvents) on the substrate S in the drying process D2 is estimated from the partial pressures of the solvent A and the solvent B inside the airtight container 10. By measuring the partial pressure ratio of the mixed solvents in the solvent vapor using the gas analyzer 95, the control device 90 can estimate the mixing ratio of the mixed solvents in the solvent film and the decrease in the drying rate accompanying the change in the mixing ratio of the mixed solvents.

[0090] Hereinafter, a substrate processing method using the reduced-pressure drying device 100A according to the second embodiment will be described. In addition, the article manufacturing method (substrate processing method) in the second embodiment is partially different from the first embodiment as described in the flowchart in Figure 3 as described.

[0091] In the first embodiment, the following method was described: in the drying process D2, the control device 90 measures the amount of pressure reduction 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, the following method will be described: in the drying process 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. In addition, since the drying processes other than the drying processes D1 and D2 are the same as those in the first embodiment, the description thereof is omitted.

[0092] Figure 7 is an explanatory diagram of the drying processes D1 and D2, which are part of the drying process according to the second embodiment. In Figure 7 a graph showing an example of the control of the partial pressures of the solvent vapors of the solvents A and B and the control of the flow rates of the gases G1 and G2 in the drying processes D1 and D2 is shown. Figure 7 In the shown horizontal axis 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.

[0093] In the drying process 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 pressures of the solvent vapors of the various solvents evaporated from the substrate S.

[0094] Specifically, the control device 90 calculates the partial pressure of the vapor of solvent A and the partial pressure of the vapor of solvent B respectively based on the measurement results of the gas analyzer 95, and calculates the partial pressure ratio of the partial pressure of the vapor of solvent A to the partial pressure of the vapor of solvent B from the calculation results. The partial pressure ratio is expressed, for example, as the partial pressure of the vapor of solvent A with respect to the total pressure of the partial pressure of the vapor of solvent A and the partial pressure of the vapor of solvent B. That is, the partial pressure ratio is expressed as partial pressure ratio = partial pressure of the vapor of solvent A / (partial pressure of the vapor of solvent A + partial pressure of the vapor of solvent B). And the control device 90 determines the mixing ratio of the gases G1 and G2 based on the partial pressure ratio.

[0095] In the second embodiment, the saturated vapor pressure of solvent A is higher than that of solvent B. In the drying process, solvent A with a higher saturated vapor pressure evaporates more easily than solvent B with a lower saturated vapor pressure. Therefore, at the start of the drying step D2 measured using the gas analyzer 95, in the space SP2, the partial pressure of the solvent vapor of solvent A is higher than the partial pressure of the solvent vapor of solvent B, and as the drying process progresses, the partial pressure of the solvent vapor of solvent A decreases. That is, the partial pressure ratio decreases from the start of the drying step D2.

[0096] When the partial pressure ratio of the vapor of solvent A and the vapor of 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 to increase the concentration of the gas G2 in the gas introduction part 60 according to the decrease amount of the partial pressure of the vapor of solvent A.

[0097] According to the second embodiment, since the concentration of the gas G2 with a lower molecular weight among the gases forming the atmosphere in the internal space SP0 increases, the diffusion of the solvent vapor can be promoted in the space SP2, the decrease in the drying rate can be suppressed in the drying step D2, and the drying rate of the solution film F can be constantly maintained during the drying step D2, that is, the unevenness of the drying rate of the solution film F can be reduced.

[0098] In addition, 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.

[0099] <The Third Embodiment>

[0100] The third embodiment will be described. Hereinafter, elements marked with the same reference numerals as those in the first embodiment have substantially the same configuration and function as the elements described in the first embodiment in the case where there is no special description, and the parts different from the first embodiment will be mainly described.

[0101] Figure 8It is a schematic cross-sectional view showing the configuration of a reduced-pressure drying apparatus 100B which is an example of a substrate processing apparatus according to the third embodiment. The reduced-pressure drying apparatus 100B of the first embodiment is obtained by adding a photographing device 110 to the reduced-pressure drying apparatus 100 of the first embodiment. In the reduced-pressure drying apparatus 100B of the third embodiment, the same reference numerals are used for the configurations similar to those of the reduced-pressure drying apparatus 100, and the detailed description thereof is omitted.

[0102] As an example of a mechanism for observing the progress of drying of the substrate S disposed inside the airtight container 10, the case where a pressure gauge 50 is used in the first embodiment and a gas analyzer 95 is used in the second embodiment has been described. In the third embodiment, as a means for observing the progress of drying of the substrate S disposed inside the airtight container 10, a photographing device 110 such as a video camera or a still camera is used. The photographing device 110 is disposed at a position where it can photograph the substrate S disposed inside the airtight container 10.

[0103] In the third embodiment, the control device 90 causes the photographing device 110 to photograph the substrate S, obtains a photographed image which is the photographing result of the photographing device 110, and determines the mixing ratio of the gases G1 and G2 based on the photographed image. For example, the control device 90 estimates the shape or thickness of the film surface on the substrate S from the photographed image.

[0104] <Embodiment of article manufacturing method>

[0105] In the present embodiment, an article is manufactured by using the above-described reduced-pressure drying apparatus (substrate processing apparatus). The article may be an intermediate product or a final product. In the article manufacturing method according to the present embodiment, for example, it is preferable to manufacture an article such as an organic EL (OLED) panel by using an inkjet printing apparatus. The article manufacturing method of the present embodiment includes the following steps (coating step): a solution film (a solution containing a solute and a solvent for forming an organic film) is disposed or coated on a substrate by a printing method or the like using an inkjet printing apparatus to obtain a coated substrate. Further, it includes the following step (drying step): the solution film on the coated substrate is dried by the above-described reduced-pressure drying apparatus to obtain a dried substrate on which a dried film is formed. Furthermore, the manufacturing method includes other well-known steps (firing, cooling, dehumidification, dry cleaning, electrode formation, sealing film formation, etc.). Compared with the conventional method, the article manufacturing method of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article.

[0106] In addition, 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 also determine the mixing ratio of the gases G1 and G2 based on the processing time.

[0107] In addition, in the above-described embodiments, the case where there are two solvents in the mixed solvent is taken as an example for explanation, but it is not limited thereto. The solvents contained in the mixed solvent may also be three or more. In this case, among the solvents contained in the mixed solvent, the solvent with the highest saturated vapor pressure is solvent A, and the solvent with the lowest saturated vapor pressure is solvent B.

[0108] In addition, in the above-described embodiments, the case of coating a solution on the substrate S is taken as an example for explanation, but it is not limited thereto. For example, in the case of treating the surface of the substrate by coating only a solvent on the substrate, the above-described embodiments can also be applied.

[0109] In addition, in the above-described embodiments, the case of coating a mixed solvent on the substrate is taken as an example for explanation, but it is not limited thereto. It is also possible to coat a second solvent on the substrate after coating a first solvent on the substrate, etc., and coat a plurality of solvents separately to form a mixed solvent on the substrate.

[0110] In addition, different types of solvents can be coated on each region of the substrate, or a solution containing different types of solvents can be coated on each region. For example, a first solvent can be coated on the first region of the substrate S, a second solvent can be coated on the second region of the substrate S, or a first solution containing the first solvent can be coated on the first region of the substrate S, and a second solution containing the second solvent can be coated on the second region of the substrate S.

[0111] In addition, in the above-described embodiments, the case where the reduced-pressure drying apparatus has the gas introduction part 60 is taken as an example for explanation, but it is not limited thereto. For example, the gas introduction part 60 can be a facility such as a factory, and the gas introduction part 60 can also be connected to the reduced-pressure drying apparatus.

[0112] As described above, according to the present disclosure, a technique advantageous for drying a substrate coated with a plurality of solvents can be provided.

[0113] [Other Modification Examples]

[0114] The present disclosure is not limited to the embodiments described above, and the embodiments can be variously modified within the technical concept of the present disclosure. For example, at least two of the above-described multiple embodiments and multiple modification examples can be combined. In addition, the effects described in the present embodiments are merely examples of the best effects produced by the embodiments of the present disclosure, and the effects obtained by the embodiments of the present disclosure are not limited to the effects described in the present embodiments.

[0115] Description of Reference Numerals

[0116] G1... gas (first gas), G2... gas (second gas), S... substrate, 10... airtight container, 90... control device (control unit), 100... vacuum drying device (substrate processing device).

Claims

1. A substrate processing device, characterized in that: The substrate processing device comprises: 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 interior of the airtight container; and a control unit capable of performing a drying process under a reduced pressure environment in which the decompression mechanism decompresses the interior of the airtight container, wherein the drying process evaporates the plurality of solvents applied to the substrate disposed in the interior of the airtight container, The control unit is configured to independently control the flow rate of the first gas introduced into the interior of the airtight container and the flow rate of the second gas introduced into the interior of the airtight container and having a smaller molecular weight than the first gas during the drying process. The first gas and the second gas both exist as gases under an environment of 25° C. and 1 atmospheric pressure.

2. The substrate processing apparatus according to claim 1, wherein: The control unit changes a ratio of the first gas and the second gas introduced into the interior of the airtight container according to progress of the drying process.

3. The substrate processing apparatus according to claim 2, wherein: The control unit changes the ratio such that the ratio of the second gas increases according to the progress of the drying process.

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

5. The substrate processing apparatus according to claim 4, wherein: The control unit determines the ratio based on an amount of decrease per unit time of the pressure value indicated by the pressure gauge so that the ratio of the second gas increases.

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

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

8. The substrate processing apparatus according to claim 2, wherein: The ratio is a ratio of the volume flow rate of the first gas to the volume flow rate of the second gas.

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

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

11. The substrate processing apparatus according to claim 9, wherein: The control unit executes a second process of controlling the interior of the airtight container to a second pressure lower than a saturated vapor pressure of the second solvent during the drying process.

12. The substrate processing apparatus according to claim 9, wherein: The first solvent is a solvent having the highest saturated vapor pressure among the plurality of solvents. The second solvent is a solvent having the lowest saturated vapor pressure among the plurality of solvents.

13. The substrate processing apparatus according to claim 9, wherein: The control unit controls the flow rates of the first gas and the second gas as the first process included in the drying process progresses so that the volume flow rate of the second gas increases relative to the volume flow rates of the first gas and the second gas.

14. The substrate processing apparatus according to claim 1, wherein: The first gas whose flow rate is adjusted by the first flow regulator and the second gas whose flow rate is adjusted by the second flow 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 causing the first flow rate regulator to adjust the flow rate of the first gas and causing the second flow rate regulator to adjust the flow rate of the second gas.

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

16. A substrate processing method, characterized in that: The substrate processing method includes 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, characterized in that: The article manufacturing method includes the 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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