Vacuum processing apparatus and method for removing oxidizing gas

Abstract

A vacuum treatment device according to one aspect of the present disclosure comprises: a treatment container in which the pressure can be reduced; a supply port which is formed in a lateral wall of the treatment container and through which an ionic liquid for absorbing an oxidizing gas is supplied into the treatment container; and a discharge port through which the ionic liquid supplied in the treatment container is discharged.

Description

[Technical Field]

[0001] The present disclosure relates to a vacuum processing apparatus and a method for removing an oxidizing gas. [Background technology]

[0002] BACKGROUND ART A technique is known in which a graphene structure is formed on the surface of a substrate accommodated in a processing chamber by remote microwave plasma CVD using a carbon-containing gas as a film-forming source gas (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-55887 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique capable of removing oxidizing gas remaining in a processing vessel. [Means for solving the problem]

[0005] A vacuum processing apparatus according to one aspect of the present disclosure includes a processing vessel capable of being depressurized, a supply port formed in a sidewall of the processing vessel for supplying an ionic liquid that absorbs an oxidizing gas to the processing vessel, and a discharge port for discharging the ionic liquid supplied to the processing vessel. The ionic liquid is supplied from the supply port to the inner wall of the processing vessel, and a spiral groove for allowing the ionic liquid to flow is formed on the inner wall of the processing vessel. . [Effects of the Invention]

[0006] According to the present disclosure, the oxidizing gas remaining in the processing vessel can be removed. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic view showing an example of a vacuum processing apparatus according to the first embodiment. [Figure 2]FIG. 2 is a schematic view showing an example of a vacuum processing apparatus according to the second embodiment. [Figure 3] FIG. 3 is a schematic view showing an example of a vacuum processing apparatus according to the third embodiment. [Figure 4] FIG. 4 is a schematic view showing an example of a vacuum processing apparatus according to the fourth embodiment. [Figure 5] FIG. 5 is an enlarged view of a joint between the processing vessel and the support member in the vacuum processing apparatus of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, non-limiting exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the accompanying drawings, the same or corresponding reference numerals are used to designate the same or corresponding members or components, and redundant descriptions will be omitted.

[0009] [Regarding oxidizing gas remaining in the processing vessel] When a substrate is placed in a processing vessel with oxidizing gases such as HO gas and O gas adsorbed on the inner wall thereof and a semiconductor process such as film formation or etching is performed, the oxidizing gas may be desorbed from the inner wall of the processing vessel, adversely affecting the semiconductor process.

[0010] For example, in a semiconductor process where a graphene film is formed on the surface of a wiring layer formed on the surface of a substrate, an oxidizing gas desorbed from the inner wall of a processing vessel oxidizes the surface of the wiring layer of the substrate before the graphene film is formed, and an oxide film is formed at the interface between the wiring layer and the graphene film. Since the oxide film formed at the interface between the wiring layer and the graphene film has insulating properties, the contact resistance between the wiring layer and the graphene film increases.

[0011] Therefore, the present disclosure provides a technology that can remove the oxidizing gas remaining in a processing vessel by supplying an ionic liquid to the processing vessel and causing the oxidizing gas remaining in the processing vessel to be absorbed by the ionic liquid.

[0012] [Vacuum Processing Apparatus] (First embodiment) An example of a vacuum processing apparatus according to the first embodiment will be described with reference to Fig. 1. A vacuum processing apparatus 1A shown in Fig. 1 is configured as a plasma processing apparatus using, for example, a RLSA (Radial Line Slot Antenna) microwave plasma method.

[0013] The vacuum processing apparatus 1A includes an apparatus main body 10 and a control unit 11 that controls the apparatus main body 10.

[0014] The apparatus main body 10 includes a chamber 101, a stage 102, a microwave introduction mechanism 103, a gas supply mechanism 104, an exhaust mechanism 105, a liquid supply mechanism 106, and the like.

[0015] The chamber 101 is formed in a substantially cylindrical shape. An opening 110 is formed in the approximate center of a bottom wall 101a of the chamber 101. An exhaust chamber 111 that communicates with the opening 110 and protrudes downward is provided in the bottom wall 101a. A load / unload port 117 through which the substrate W passes is formed in a side wall 101s of the chamber 101. The load / unload port 117 is opened and closed by a gate valve 118. The chamber 101, together with a part of the microwave introduction mechanism 103, constitutes a processing vessel whose interior can be depressurized.

[0016] A substrate W to be processed is placed on the stage 102. The stage 102 has a substantially circular plate shape. The stage 102 is made of ceramics such as aluminum nitride (AlN). The stage 102 is supported by substantially cylindrical supports 112 made of ceramics such as AlN and extending upward from approximately the center of the bottom of the exhaust chamber 111. An edge ring 113 is provided on the outer edge of the stage 102 so as to surround the substrate W placed on the stage 102. Elevating pins (not shown) for raising and lowering the substrate W are provided inside the stage 102 so as to be protruding and retracting from the upper surface of the stage 102.

[0017] A resistance heater 114 is embedded inside the stage 102. The heater 114 heats the substrate W placed on the stage 102 in response to power supplied from a heater power supply 115. A thermocouple (not shown) is also inserted into the stage 102, and the temperature of the substrate W can be controlled to, for example, 350 to 850°C based on a signal from the thermocouple. An electrode 116 having a size approximately the same as that of the substrate W is embedded above the heater 114 in the stage 102. A bias power supply 119 is electrically connected to the electrode 116. The bias power supply 119 supplies power of a predetermined frequency and magnitude to the electrode 116. This attracts ions to the substrate W placed on the stage 102. The bias power supply 119 may not be provided depending on the characteristics of the plasma processing.

[0018] The microwave introduction mechanism 103 is provided at the top of the chamber 101. The microwave introduction mechanism 103 has an antenna 121, a microwave output unit 122, a microwave transmission mechanism 123, and the like. The antenna 121 has a large number of slots 121a that are through-holes. The microwave output unit 122 outputs microwaves. The microwave transmission mechanism 123 guides the microwaves output from the microwave output unit 122 to the antenna 121.

[0019] A dielectric window 124 made of a dielectric material is provided below the antenna 121. The dielectric window 124 is supported by a support member 132 provided in an annular shape at the top of the chamber 101. A target 140 made of a metal is disposed on the lower surface (the surface facing the stage 102) of the dielectric window 124. The target 140 contains at least one metal selected from the group consisting of titanium, cobalt, aluminum, yttrium, aluminum nitride, and titanium nitride. A shield member 125 and a slow-wave plate 126 are provided above the antenna 121. A coolant flow path (not shown) is provided inside the shield member 125. The shield member 125 cools the antenna 121, the dielectric window 124, the slow-wave plate 126, and the target 140 by a cooling fluid such as water flowing through the coolant flow path.

[0020] The antenna 121 is formed of, for example, a copper plate or an aluminum plate whose surface is plated with silver or gold. The antenna 121 has a plurality of slots 121a arranged in a predetermined pattern for radiating microwaves. The arrangement pattern of the slots 121a is appropriately set so that the microwaves are radiated uniformly. An example of a suitable pattern is a radial line slot, in which two slots 121a arranged in a T-shape form a pair, and multiple pairs of slots 121a are arranged concentrically. The length and arrangement interval of the slots 121a are appropriately set according to the effective wavelength (λg) of the microwaves. The slots 121a may also have other shapes, such as a circular shape or an arc shape. The arrangement of the slots 121a is not particularly limited, and may be arranged in a spiral or radial shape in addition to a concentric shape. The pattern of the slots 121a is appropriately set so that microwave radiation characteristics that obtain a desired plasma density distribution are achieved.

[0021] The slow-wave plate 126 is made of a dielectric material having a dielectric constant greater than that of a vacuum, such as quartz, ceramics (Al2O3), polytetrafluoroethylene, or polyimide. The slow-wave plate 126 has the function of shortening the wavelength of the microwaves compared to that in a vacuum, thereby reducing the size of the antenna 121. The dielectric window 124 is also made of a similar dielectric material.

[0022] The thicknesses of the dielectric window 124 and the slow-wave plate 126 are adjusted so that the equivalent circuit formed by the slow-wave plate 126, antenna 121, dielectric window 124, target 140, and plasma satisfies the resonance condition. The phase of the microwave can be adjusted by adjusting the thickness of the slow-wave plate 126. By adjusting the thickness of the slow-wave plate 126 so that the junction of the antenna 121 becomes the "antinode" of the standing wave, microwave reflection can be minimized and the radiated energy of the microwave can be maximized. Furthermore, by using the same material for the slow-wave plate 126 and the dielectric window 124, interface reflection of the microwave can be prevented.

[0023] The microwave output unit 122 has a microwave oscillator. The microwave oscillator may be a magnetron type or a solid-state type. The frequency of the microwave generated by the microwave oscillator is, for example, 300 MHz to 10 GHz. As an example, the microwave output unit 122 outputs a microwave of 2.45 GHz using a magnetron type microwave oscillator. Microwaves are an example of electromagnetic waves.

[0024] The microwave transmission mechanism 123 includes a waveguide 127, a coaxial waveguide 128, a mode conversion mechanism 131, and the like. The waveguide 127 guides the microwaves output from the microwave output unit 122. The coaxial waveguide 128 includes an inner conductor 129 connected to the center of the antenna 121 and an outer conductor 130 located outside the inner conductor 129. The mode conversion mechanism 131 is provided between the waveguide 127 and the coaxial waveguide 128. The microwaves output from the microwave output unit 122 propagate through the waveguide 127 in TE mode and are converted from TE mode to TEM mode by the mode conversion mechanism 131. The microwaves converted to TEM mode propagate through the coaxial waveguide 128 to the slow-wave plate 126 and are radiated from the slow-wave plate 126 into the chamber 101 via the slot 121a of the antenna 121, the dielectric window 124, and the target 140. A tuner (not shown) is provided midway along the waveguide 127 to match the impedance of the load (plasma) in the chamber 101 with the output impedance of the microwave output part 122.

[0025] The gas supply mechanism 104 includes a shower ring 142. The shower ring 142 is annularly disposed along the inner wall of the chamber 101. The shower ring 142 has an annular flow path 166 disposed therein and a plurality of outlets 167 connected to the flow path 166 and opening to the inside of the flow path 166. A gas supply unit 163 is connected to the flow path 166 via a pipe 161. The gas supply unit 163 includes a plurality of gas sources, a plurality of flow rate controllers, and the like. The gas supply unit 163 is configured to supply at least one process gas from a corresponding gas source to the shower ring 142 via a corresponding flow rate controller. The gas supplied to the shower ring 142 is then supplied into the chamber 101 through the plurality of outlets 167.

[0026] When a metal film is formed on the substrate W, the gas supply unit 163 supplies an inert gas, the flow rate of which is controlled to a predetermined value, into the chamber 101 via the shower ring 142. The inert gas is, for example, a rare gas or nitrogen (N2) gas. Alternatively, when a metal film is formed on the substrate W, the gas supply unit 163 may supply a reducing gas, in addition to the inert gas, into the chamber 101 via the shower ring 142. The reducing gas is, for example, a hydrogen-containing gas or a halogen-containing gas.

[0027] Furthermore, when a graphene film is formed on the substrate W, the gas supply unit 163 supplies a carbon-containing gas, a hydrogen-containing gas, and a rare gas, each of which is controlled at a predetermined flow rate, into the chamber 101 via the shower ring 142. The carbon-containing gas is, for example, C2H2 gas, C2H4 gas, CH4 gas, C2H6 gas, C3H8 gas, C3H6 gas, or a combination thereof. The hydrogen-containing gas is, for example, hydrogen (H2) gas. However, instead of or in addition to H2 gas, a halogen-based gas such as fluorine (F2) gas, chlorine (Cl2) gas, or bromine (Br2) gas may be used. The rare gas is, for example, argon (Ar) gas or helium (He) gas.

[0028] The exhaust mechanism 105 includes an exhaust chamber 111, an exhaust pipe 181, an exhaust device 182, etc. The exhaust pipe 181 is provided on the side wall of the exhaust chamber 111. The exhaust device 182 is connected to the exhaust pipe 181. The exhaust device 182 includes a vacuum pump, a pressure control valve, etc.

[0029] The liquid supply mechanism 106 supplies an ionic liquid into the chamber 101 and recovers the ionic liquid supplied into the chamber 101. The ionic liquid is an ionic liquid that absorbs an oxidizing gas. Details of the ionic liquid that absorbs an oxidizing gas will be described later. The liquid supply mechanism 106 includes a supply port 191, a discharge port 192, a liquid circulation unit 193, etc.

[0030] Supply port 191 is formed by penetrating side wall 101s of chamber 101. Supply port 191 supplies ionic liquid into chamber 101 from the side of chamber 101. The ionic liquid supplied into chamber 101 flows downward along the inner wall of chamber 101, as indicated by arrow A1 in FIG. 1. FIG. 1 shows a case in which supply port 191 is formed below load / unload port 117. However, supply port 191 may also be formed above load / unload port 117.

[0031] The exhaust port 192 is formed so as to penetrate the bottom of the exhaust chamber 111. The exhaust port 192 exhausts the ionic liquid supplied into the chamber 101 to the outside of the chamber 101. FIG. 1 shows a case where the exhaust port 192 is formed at the bottom of the exhaust chamber 111. However, the exhaust port 192 may be formed in a side wall of the exhaust chamber 111, or in the bottom wall 101a of the chamber 101. Furthermore, a plurality of exhaust ports 192 may be formed.

[0032] The liquid circulation unit 193 collects the ionic liquid discharged from the outlet 192 and circulates the ionic liquid by introducing the collected ionic liquid into the supply port 191. The liquid circulation unit 193 includes a tank 193a, a temperature adjustment mechanism 193b, a supply pipe 193c, a return pipe 193d, and the like.

[0033] The tank 193a is connected to the outlet 192 via a return pipe 193d. The tank 193a stores the ionic liquid discharged from the outlet 192.

[0034] The temperature adjustment mechanism 193b includes a heater, a temperature sensor (neither of which are shown), etc. The temperature adjustment mechanism 193b controls the heater based on the value detected by the temperature sensor, thereby controlling the temperature of the ionic liquid in the tank 193a.

[0035] Outlet pipe 193c connects supply port 191 and tank 193a. Outlet pipe 193c introduces the ionic liquid stored in tank 193a into supply port 191. Valve 193e is provided in outlet pipe 193c. When valve 193e is opened, the ionic liquid is introduced from tank 193a to supply port 191, and when valve 193e is closed, the introduction of the ionic liquid from tank 193a to supply port 191 is stopped.

[0036] Return pipe 193d connects outlet 192 and tank 193a. Return pipe 193d recovers the ionic liquid discharged from outlet 192 into tank 193a. Valve 193f is provided in return pipe 193d. When valve 193f is opened, the ionic liquid is recovered from outlet 192 into tank 193a, and when valve 193f is closed, the recovery of the ionic liquid from outlet 192 into tank 193a is stopped.

[0037] The control unit 11 has a memory, a processor, an input / output interface, etc. The memory stores programs to be executed by the processor and recipes including conditions for each process, etc. The processor executes the programs read from the memory and controls each part of the device main body 10 via the input / output interface based on the recipes stored in the memory.

[0038] For example, the control unit 11 performs the oxidizing gas removal method prior to placing a substrate in the processing vessel and performing a semiconductor process. Specifically, the control unit 11 controls the valves 193e and 193f to open prior to the semiconductor process. As a result, an ionic liquid is supplied into the chamber 101 from the supply port 191, and the ionic liquid absorbs the oxidizing gas remaining in the chamber 101. Furthermore, the ionic liquid that has absorbed the oxidizing gas is discharged to the outside of the chamber 101 from the discharge port 192. Note that the control unit 11 may perform the oxidizing gas removal method at a timing different from that prior to performing the semiconductor process.

[0039] As described above, the vacuum processing apparatus 1A of the first embodiment has supply port 191 formed in sidewall 101s of chamber 101, which supplies ionic liquid into chamber 101, and outlet 192 which discharges the ionic liquid supplied into chamber 101. As a result, ionic liquid can be supplied into chamber 101 from supply port 191, and the ionic liquid can absorb oxidizing gas remaining in chamber 101. Furthermore, the ionic liquid that has absorbed the oxidizing gas can be discharged to the outside of chamber 101 from outlet 192. As a result, the oxidizing gas remaining in chamber 101 can be removed.

[0040] In the first embodiment, the case where one supply port 191 is formed has been described, but this is not limiting. For example, a plurality of supply ports 191 may be formed. When a plurality of supply ports 191 are formed, the plurality of supply ports 191 are preferably formed at intervals along the circumferential direction of the side wall 101s of the chamber 101. This allows the ionic liquid to be discharged from a plurality of positions in the circumferential direction of the chamber 101. Therefore, the ionic liquid flows over a wide range of the inner wall of the chamber 101, and the surface area of ​​the ionic liquid flowing within the chamber 101 is increased. As a result, the efficiency of absorption of the oxidizing gas remaining in the chamber 101 is improved.

[0041] (Second embodiment) An example of a vacuum processing apparatus 1B according to the second embodiment will be described with reference to Fig. 2. The vacuum processing apparatus 1B according to the second embodiment differs from the vacuum processing apparatus 1A according to the first embodiment in that grooves 101g that allow the ionic liquid to flow along the circumferential direction of the inner wall of the chamber 101 are formed on the inner wall. The following description will focus on the differences from the vacuum processing apparatus 1A.

[0042] Groove 101g is formed in a spiral shape on the inner wall of chamber 101 along the circumferential direction of the inner wall. The upper end of groove 101g is connected to supply port 191, and causes the ionic liquid supplied from supply port 191 to flow along the circumferential direction of the inner wall of chamber 101. This allows the ionic liquid to flow over a wide range of the inner wall of chamber 101, increasing the surface area of ​​the ionic liquid flowing within chamber 101. As a result, the efficiency of absorption of oxidizing gas remaining in chamber 101 is improved.

[0043] As described above, the vacuum processing apparatus 1B of the second embodiment has supply port 191 formed in sidewall 101s of chamber 101, which supplies ionic liquid into chamber 101, and outlet 192 which discharges the ionic liquid supplied into chamber 101. As a result, ionic liquid can be supplied into chamber 101 from supply port 191, and the ionic liquid can absorb oxidizing gas remaining in chamber 101. Furthermore, the ionic liquid that has absorbed the oxidizing gas can be discharged to the outside of chamber 101 from outlet 192. As a result, the oxidizing gas remaining in chamber 101 can be removed.

[0044] Furthermore, according to the vacuum processing apparatus 1B of the second embodiment, grooves 101g are formed in the inner wall of the chamber 101, which allow the ionic liquid to flow along the circumferential direction of the inner wall. This causes the ionic liquid to flow within the chamber 101 along the grooves 101g. As a result, the ionic liquid flows over a wide range of the inner wall of the chamber 101, increasing the surface area of ​​the ionic liquid flowing within the chamber 101. Furthermore, since the path from the supply port 191 to the exhaust port 192 is longer, the time it takes for the ionic liquid to flow within the chamber 101 is longer. As a result, the efficiency of absorbing the oxidizing gas remaining in the chamber 101 is improved.

[0045] In the second embodiment, the case where one supply port 191 is formed has been described, but this is not limiting. For example, a plurality of supply ports 191 may be formed. When a plurality of supply ports 191 are formed, the plurality of supply ports 191 are preferably formed at intervals along the circumferential direction of the side wall 101s of the chamber 101, and grooves 101g are preferably formed corresponding to each of the plurality of supply ports 191. This allows the ionic liquid to flow over a wide range of the inner wall of the chamber 101, thereby increasing the surface area of ​​the ionic liquid flowing within the chamber 101. As a result, the efficiency of absorption of the oxidizing gas remaining in the chamber 101 is improved.

[0046] (Third embodiment) An example of a vacuum processing apparatus 1C according to a third embodiment will be described with reference to Fig. 3. The vacuum processing apparatus 1C according to the third embodiment differs from the vacuum processing apparatus 1A according to the first embodiment in that the vacuum processing apparatus 1C has a liquid supply mechanism 306 including a supply port 391 provided in a ring shape along the inner wall of the chamber 101, instead of the supply port 191. The following description will focus on the differences from the vacuum processing apparatus 1A.

[0047] The liquid supply mechanism 306 supplies the ionic liquid into the chamber 101 and recovers the ionic liquid supplied into the chamber 101. The ionic liquid is an ionic liquid that absorbs oxidizing gases. The liquid supply mechanism 306 includes a supply port 391, an outlet 192, a liquid circulation unit 193, and the like.

[0048] Supply port 391 is provided in a ring shape along the inner wall of chamber 101. Supply port 391 includes an annular liquid flow path 391a provided therein and multiple liquid discharge ports 391b connected to liquid flow path 391a and opening inward. Liquid flow path 391a is connected to tank 193a via feed pipe 193c. The ionic liquid introduced into supply port 391 flows circumferentially around chamber 101 along liquid flow path 391a, and is then supplied into chamber 101 through multiple liquid discharge ports 391b as indicated by arrow A3 in FIG. 3, and flows downward along the inner wall of chamber 101. This allows the ionic liquid to flow over a wide area of ​​the inner wall of chamber 101, increasing the surface area of ​​the ionic liquid flowing within chamber 101. As a result, the efficiency of absorbing oxidizing gas remaining in chamber 101 is improved.

[0049] As described above, vacuum processing apparatus 1C of the third embodiment has supply port 391 formed in sidewall 101s of chamber 101, which supplies ionic liquid into chamber 101, and outlet 192 which discharges the ionic liquid supplied into chamber 101. As a result, ionic liquid can be supplied into chamber 101 from supply port 391, and the ionic liquid can absorb oxidizing gas remaining in chamber 101. Furthermore, the ionic liquid that has absorbed the oxidizing gas can be discharged to the outside of chamber 101 from outlet 192. As a result, oxidizing gas remaining in chamber 101 can be removed.

[0050] Furthermore, according to the vacuum processing apparatus 1C of the third embodiment, the supply port 391 includes an annular liquid flow path 391a provided therein and a plurality of liquid discharge ports 391b connected to the liquid flow path 391a and opening inward. This allows the ionic liquid to be discharged from a plurality of positions in the circumferential direction of the chamber 101. This allows the ionic liquid to flow over a wide range of the inner wall of the chamber 101, increasing the surface area of ​​the ionic liquid flowing within the chamber 101. As a result, the efficiency of absorption of the oxidizing gas remaining in the chamber 101 is improved.

[0051] In the third embodiment, vacuum processing apparatus 1C is described as having liquid supply mechanism 306 including supply port 391 provided in a ring shape along the inner wall of chamber 101, instead of supply port 191 of vacuum processing apparatus 1A. However, the present invention is not limited to this. For example, vacuum processing apparatus 1C may have both supply port 191 and supply port 391.

[0052] (Fourth embodiment) An example of a vacuum processing apparatus 1D according to a fourth embodiment will be described with reference to Figures 4 and 5. The vacuum processing apparatus 1D according to the fourth embodiment differs from the vacuum processing apparatus 1A according to the first embodiment in that a recess 101h for allowing the ionic liquid to flow is formed at the joint between the members constituting the processing vessel. The following description will focus on the differences from the vacuum processing apparatus 1A.

[0053] The seal material 151 is provided at the joint between the chamber 101 and the support member 132 to seal the joint. The seal material 151 is, for example, an O-ring.

[0054] The recessed portion 101h is formed in a ring shape along the sealant 151 on the vacuum side of the sealant 151 at the joint between the chamber 101 and the support member 132. The recessed portion 101h communicates with a supply port 491, and the ionic liquid is supplied to the recessed portion 101h through the supply port 491. The ionic liquid supplied to the recessed portion 101h flows in the circumferential direction of the chamber 101 along the recessed portion 101h.

[0055] The recess 101h is preferably formed so that the ionic liquid flowing through the recess 101h comes into contact with both the chamber 101 and the support member 132. This allows the ionic liquid flowing through the recess 101h to function as an annular conductive seal, typified by a spiral seal. That is, the ionic liquid flowing through the recess 101h ensures electrical continuity between the chamber 101 and the support member 132 and keeps the support member 132 at ground potential. The ionic liquid flowing through the recess 101h also prevents leakage of high frequency waves or plasma from between the chamber 101 and the support member 132. When the ionic liquid flowing through the recess 101h is used instead of a spiral seal, the ionic liquid flowing through the recess 101h is recovered by opening the valve 193f when the chamber 101 is opened to the atmosphere for maintenance or the like. Furthermore, when depressurizing chamber 101 after maintenance or the like is completed, valve 193f is closed and valve 193e is opened, filling recess 101h with ionic liquid, and then depressurizing chamber 101. As a result, the ionic liquid filled in recess 101h absorbs the oxidizing gas in chamber 101, so that chamber 101 can be placed at a high vacuum and an environment with little oxidizing gas can be created.

[0056] 5, the depth of the recessed portion 101h on the vacuum side is greater than the depth on the sealing material 151 side. This prevents the ionic liquid filled in the recessed portion 101h from flowing out to the vacuum side, so that the state in which the ionic liquid is filled in the recessed portion 101h can be maintained.

[0057] The supply port 491 is formed to penetrate the support member 132. The supply port 491 communicates with the recessed portion 101h and supplies the ionic liquid to the recessed portion 101h in the processing vessel from the side of the processing vessel.

[0058] The outlet 492 is formed by penetrating the side wall 101s of the chamber 101 and communicates with the recessed portion 101h. The outlet 492 discharges the ionic liquid flowing in the recessed portion 101h to the outside of the chamber 101.

[0059] As described above, the vacuum processing apparatus 1D of the fourth embodiment has a supply port 491 formed in the sidewall (support member 132) of the processing vessel, which supplies ionic liquid to the recessed portion 101h, and a discharge port 492 which discharges the ionic liquid supplied to the recessed portion 101h. As a result, the ionic liquid can be supplied from the supply port 491 to the recessed portion 101h, and the ionic liquid can absorb the oxidizing gas remaining in the chamber 101. Furthermore, the ionic liquid that has absorbed the oxidizing gas can be discharged from the discharge port 492 to the outside of the chamber 101. As a result, the oxidizing gas remaining in the chamber 101 can be removed.

[0060] Furthermore, according to the vacuum processing apparatus 1D of the fourth embodiment, the ionic liquid flowing in the recessed portion 101h comes into contact with both the chamber 101 and the support member 132. As a result, the ionic liquid flowing in the recessed portion 101h functions as an annular conductive sealant instead of a spiral seal. That is, the ionic liquid flowing in the recessed portion 101h ensures electrical continuity between the chamber 101 and the support member 132, and keeps the support member 132 at ground potential. Furthermore, the ionic liquid flowing in the recessed portion 101h prevents high frequency waves and plasma from leaking between the chamber 101 and the support member 132.

[0061] In the fourth embodiment, the depth of the recess 101h on the vacuum side is greater than the depth on the sealing material 151 side. However, the present disclosure is not limited to this. For example, the depth of the recess 101h on the vacuum side may be the same as the depth on the sealing material 151 side. In this case, part of the ionic liquid flowing in the recess 101h also flows into the inner wall of the chamber 101, increasing the surface area of ​​the ionic liquid flowing in the chamber 101. As a result, the absorption efficiency of the oxidizing gas remaining in the chamber 101 is improved. In this case, by providing an outlet formed through the bottom of the exhaust chamber 111 in addition to the outlet 492 communicating with the recess 101h, the ionic liquid flowing into the inner wall of the chamber 101 can be discharged to the outside of the chamber 101.

[0062] In the fourth embodiment, vacuum processing apparatus 1D is described as having liquid supply mechanism 406 including supply port 491 formed through support member 132 instead of supply port 191 of vacuum processing apparatus 1A, but the present invention is not limited to this. For example, vacuum processing apparatus 1D may have both supply port 191 and supply port 491. Furthermore, for example, vacuum processing apparatus 1D may have groove portion 101g of vacuum processing apparatus 1B, or may have supply port 391 of vacuum processing apparatus 1C.

[0063] [Ionic Liquid] An example of an ionic liquid that can be suitably used in the vacuum processing apparatuses 1A to 1D will be described. The ionic liquid is an ionic liquid that absorbs oxidizing gases. Examples of oxidizing gases include H2O gas and O2 gas.

[0064] When the oxidizing gas to be absorbed by an ionic liquid is HO gas, an ionic liquid with a highly polar molecular structure can be used. By using an ionic liquid with a highly polar molecular structure, the ionic liquid can efficiently absorb the polar molecule HO. Examples of such ionic liquids include DEME-BF (N,N-Diethyl-N-methyl-N-(2-methoxyethyl)ammonium tetrafluoroborate) and EMI-AcO (1-Ethyl-3-methylimidazolium acetate). Other examples include halide-based ionic liquids such as [BPy]Cl represented by chemical formula I1, [B2MPY]Cl represented by chemical formula I2, [B3MPy]Cl represented by chemical formula I3, and [B4MPY]Cl represented by chemical formula I4.

[0065] [ka] When the oxidizing gases to be absorbed by an ionic liquid are HO gas and O gas, for example, an ionic liquid with a molecular structure containing a nonpolar moiety can be used as the ionic liquid. Generally, many ionic liquids, which are combinations of anions and cations, are polar, and therefore it is thought that nonpolar O molecules are difficult to absorb in polar ionic liquids. Therefore, by using an ionic liquid with a molecular structure containing a nonpolar moiety, O gas can be efficiently absorbed by the nonpolar moiety contained in the ionic liquid. An example of such an ionic liquid is MEMP (N-(2-methoxyethyl)-N-methyl-pyrrolidinium)-TFSI (bis(tri-fluoro-methane-sulfonyl)imide).

[0066] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0067] In the above embodiment, a liquid circulation unit is provided to introduce the ionic liquid discharged from the outlet into the supply port and circulate it, but the present disclosure is not limited to this. For example, the ionic liquid may be introduced from the ionic liquid supply source into the supply port without providing a liquid circulation unit.

[0068] In the above embodiment, the vacuum processing apparatus is configured as a cold-wall type apparatus, but the present disclosure is not limited to this. Ionic liquids do not volatilize even in a vacuum and are heat-resistant. Therefore, the vacuum processing apparatus may be a hot-wall type apparatus in which the wall surface of the processing vessel is heated to a high temperature.

[0069] In the above embodiment, the vacuum processing apparatus is configured as a plasma processing apparatus, but the present disclosure is not limited to this. The vacuum processing apparatus is not limited to a plasma processing apparatus as long as it is an apparatus that performs a predetermined process (e.g., film formation, etching) on ​​a substrate. For example, the vacuum processing apparatus may be an ALD (Atomic Layer Deposition) apparatus, a CVD (Chemical Vapor Deposition) apparatus, a PVD (Physical Vapor Deposition) apparatus, etc.

[0070] This international application claims priority to U.S. Application No. 17 / 350125, filed June 17, 2021, with the U.S. Patent and Trademark Office, the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0071] 1A~1D Vacuum processing equipment 101 Chamber 191,391,491 supply outlets 192,492 outlet

Claims

1. a processing container that can be decompressed; a supply port formed in a side wall of the processing vessel for supplying an ionic liquid that absorbs an oxidizing gas into the processing vessel; an outlet for discharging the ionic liquid supplied to the treatment vessel; and the ionic liquid is supplied from the supply port to the inner wall of the processing vessel; a spiral groove portion for allowing the ionic liquid to flow is formed on the inner wall of the treatment vessel; Vacuum processing equipment.

2. The outlet is provided through the bottom of the processing vessel. The vacuum processing apparatus according to claim 1 .

3. a processing container that can be decompressed; a supply port formed in a side wall of the processing vessel for supplying an ionic liquid that absorbs an oxidizing gas into the processing vessel; an outlet for discharging the ionic liquid supplied to the treatment vessel; a seal material that seals a joint between members that configure the processing vessel; a recessed portion provided in communication with the supply port on a vacuum side of the sealing material at the joint portion, the recessed portion allowing the ionic liquid supplied from the supply port to flow along the sealing material; A vacuum processing apparatus comprising:

4. The outlet is provided in communication with the recessed portion. The vacuum processing apparatus according to claim 3 .

5. The ionic liquid flowing through the recessed portion comes into contact with both of the components constituting the processing vessel. The vacuum processing apparatus according to claim 3 .

6. a valve for stopping the discharge of the ionic liquid from the outlet; The vacuum processing apparatus according to claim 1 .

7. The oxidizing gas is H ２ Contains O gas, The vacuum processing apparatus according to claim 1 .

8. a liquid circulation unit that introduces the ionic liquid discharged from the outlet into the supply port and circulates the ionic liquid; The vacuum processing apparatus according to claim 1 .

9. The liquid circulation unit includes: a tank for storing the ionic liquid discharged from the discharge port; a temperature control mechanism for controlling the temperature of the ionic liquid in the tank; Including, The vacuum processing apparatus according to claim 8 .

10. A process for forming a graphene film is performed in the process container. The vacuum processing apparatus according to claim 1 .

11. supplying an ionic liquid that absorbs an oxidizing gas into a processing vessel through a supply port formed in a side wall of the processing vessel, the ionic liquid absorbing the oxidizing gas remaining in the processing vessel; Discharging the ionic liquid supplied to the treatment vessel; and the ionic liquid is supplied from the supply port to the inner wall of the processing vessel; a spiral groove portion for allowing the ionic liquid to flow is formed on the inner wall of the treatment vessel; Method for removing oxidizing gases.

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