Method for producing fluorocarbons

Abstract

To provide a production method with which a fluorohydrocarbon can be simply and inexpensively produced through a gas phase circulation system without using a catalyst.SOLUTION: A production method of a fluorohydrocarbon comprises continuously supplying a raw material gas which contains a compound represented by formula 1: CH3-R {here, R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom or an organic group (however, except for a hydrocarbon group)} and an inert gas in a thermal nonequilibrium region of a plasma device containing a solid active species derived from a fluorine-containing inorganic compound, and next continuously discharging the gas in the thermal nonequilibrium region to the outside of the plasma device.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a fluorohydrocarbon. [Background technology]

[0002] Fluorinated hydrocarbons such as monofluoromethane are widely used as etching gases for semiconductor microfabrication.

[0003] A known method for producing monofluoromethane involves reacting methyl chloride (CHCl) and hydrogen fluoride in the gas phase in the presence of a fluorination catalyst to obtain a mixed gas containing monofluoromethane, and then separating and purifying the monofluoromethane from the mixed gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-111611 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned methods for producing monofluoromethane have been difficult to carry out continuously, due to the large burden of preparing a fluorination catalyst, and the yield decreases as the activity of the catalyst decreases.

[0006] An object of the present invention is to provide a method for producing fluorohydrocarbons such as monofluoromethane simply and inexpensively by a gas-phase flow system without using a catalyst.

[0007] The present invention aims to advantageously solve the above-mentioned problems, and provides a method for producing a plasma device comprising the steps of: continuously supplying a compound represented by the formula 1: CH3-R (wherein R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or an organic group (excluding a hydrocarbon group)) and a raw material gas containing an inert gas to a thermal non-equilibrium region of a plasma device containing active species derived from a solid fluorine-containing inorganic compound; and then continuously discharging the gas in the thermally non-equilibrium region to the outside of the plasma device.

[0008] Here, thermal non-equilibrium refers to a state in which the temperature of ions and molecules is different from the temperature of electrons, and in a thermal non-equilibrium region within a plasma device, the temperature of electrons is higher than the temperature of ions and molecules. The discharge region in a plasma device is the space between opposing electrodes in a plasma device that generates plasma using electrodes, but in a method in which a flame is extracted outside the space between the electrodes, such as a plasma jet, it corresponds to the flame zone, and in a plasma device that generates plasma by means other than electrodes, it is the corresponding space. A solid fluorine-containing inorganic compound is a fluorine-containing inorganic compound that is solid under standard conditions (298 K, atmospheric pressure). Inorganic compounds include compounds that contain no carbon atoms and compounds that contain one carbon atom and no hydrogen atoms. The term "fluorohydrocarbon" refers to a compound in which at least one hydrogen atom of a hydrocarbon compound has been substituted with a fluorine atom, and includes compounds in which all hydrogen atoms of a hydrocarbon compound have been substituted with fluorine atoms.

[0009] According to the method for producing fluorocarbons of the present invention, it is presumed that fluorocarbons are produced as follows. When a compound represented by formula 1: CH3-R (wherein R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or an organic group (excluding a hydrocarbon group)) is supplied to a thermal non-equilibrium region of a plasma device, various active species are generated from the compound of formula 1 in this region. In the thermal non-equilibrium region of the plasma device, decomposition of the compound of formula 1 is appropriately suppressed, and the generated active species contain a sufficient amount of radicals and ions containing a partial structure of the compound of formula 1, such as CH3 radicals and CH3 ions (hereinafter also referred to as "CH3 radicals, etc."). At that time, active species derived from a solid fluorine-containing inorganic compound are allowed to exist in the thermal non-equilibrium region of the plasma device. The active species derived from a solid fluorine-containing inorganic compound contain at least one of fluorine ions and fluorine radicals (hereinafter also referred to as "fluorine source"). Then, the gas in the thermal non-equilibrium region of the plasma device, which contains active species (including CH3 radicals, etc.) generated from the compound of formula 1 and active species (including a fluorine source) derived from the solid fluorine-containing inorganic compound, is continuously discharged to the outside of the plasma device, whereby these active species combine to generate fluorohydrocarbons. In this way, by utilizing plasma, fluorohydrocarbons can be easily produced in the gas phase without using a catalyst. In this case, by using a solid fluorine-containing inorganic compound to generate the fluorine source, fluorohydrocarbons can be produced at low cost.

[0010] In the method for producing fluorocarbons of the present invention, a device for generating atmospheric pressure low-temperature plasma or vacuum plasma can be used as the plasma device. The discharge region in such a plasma device corresponds to a thermal non-equilibrium plasma region.

[0011] Specifically, a solid fluorine-containing inorganic compound is placed in an apparatus for forming atmospheric pressure low-temperature plasma or vacuum plasma, and then an oxygen-containing compound is introduced to generate active species derived from the solid fluorine-containing inorganic compound, and a raw material gas containing the compound of formula 1 and an inert gas can be continuously supplied to the apparatus. This advantageously enables the solid fluorine-containing inorganic compound to be activated in the apparatus for supplying the compound of formula 1.

[0012] The generation of a fluorine source from a solid fluorine-containing inorganic compound can be achieved by introducing an oxygen-containing compound into the discharge region in a plasma device, generating oxygen-containing active species (e.g., various ions (oxygen ions, carbonate ions, etc.), various radicals (carbon monoxide radicals, carbon dioxide radicals), etc.), which are then collided with the solid fluorine-containing inorganic compound to knock out the fluorine source. For example, when the starting material is CaF2 or the like, a stable compound (e.g., carbonate (CaCO3, etc.)) close to its standard formation energy can be expected to be generated in the region by the collision of oxygen-containing active species (e.g., various ions (oxygen ions, carbonate ions, etc.), various radicals (carbon monoxide radicals, carbon dioxide radicals), etc.), which is advantageous for generating a fluorine source from the viewpoint of Gibbs free energy.

[0013] In the method for producing fluorohydrocarbons of the present invention, a device for generating atmospheric pressure thermal plasma can be used as the plasma device. The area around the discharge region in such a plasma device reaches a high temperature (approximately 1000 to 3000 K) due to plasma radiation, and this temperature region corresponds to a thermal non-equilibrium region, where chemical species may undergo excitation or dissociation reactions.

[0014] When using a device for generating atmospheric pressure thermal plasma, a solid fluorine-containing inorganic compound can be activated in the discharge region of the plasma device to generate a fluorine source. The activated species derived from the solid fluorine-containing inorganic compound can be supplied to a temperature region of 1000 to 3000K around the discharge region of the same plasma device, which is advantageous in that it is expected to produce fluorohydrocarbons simply and efficiently.

[0015] In the method for producing fluorohydrocarbons of the present invention, the solid fluorine-containing inorganic compound is preferably at least one type of compound represented by formula 2: M-Fx (wherein M is Li, Na, Mg, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Al, B, Cs, Ba, Pb or Sn, and x is the valence of M). These compounds can easily generate a fluorine source. Furthermore, by using these compounds, costs can be easily reduced compared to conventional methods for producing fluorohydrocarbons.

[0016] In the method for producing a fluorohydrocarbon of the present invention, the inert gas is N 2、 It may be at least one selected from the group consisting of Ar and He.

[0017] Furthermore, in the method for producing fluorohydrocarbons of the present invention, the content of the compound represented by formula 1 in the raw material gas is preferably 1 volume % or more and 85 volume % or less. If the content is within the above range, the target fluorohydrocarbons can be efficiently produced.

[0018] The process for producing a fluorohydrocarbon of the present invention can produce monofluoromethane as the target substance. Effect of the Invention

[0019] According to the present invention, there is provided a method for producing fluorohydrocarbons such as monofluoromethane simply and inexpensively by a gas phase flow system without using a catalyst. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a schematic diagram of a plasma device used in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, embodiments of the present invention will be described in detail.

[0022] [Solid fluorine-containing inorganic compounds] The solid fluorine-containing inorganic compound may be any solid inorganic compound that contains one or more fluorine atoms, typically six or fewer fluorine atoms.

[0023] Examples of solid fluorine-containing inorganic compounds include compounds represented by formula 2: M-Fx (wherein M is Li, Na, Mg, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Al, B, Cs, Ba, Pb, or Sn, and x is the valence of M), such as NaF, KF, and Ca2F, with Ca2F being preferred from the standpoints of economy and safety. These may be used alone or in any combination of two or more.

[0024] [Compound of Formula 1] The compound of formula 1 is a compound represented by formula 1: CH3-R (wherein R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or an organic group (excluding hydrocarbon groups). The compound of formula 1 may be used alone or in combination of two or more kinds.

[0025] Here, the organic group (excluding hydrocarbon groups) refers to a functional group containing at least one carbon atom (excluding those consisting only of carbon atoms and hydrogen atoms), as well as a functional group containing at least one element selected from oxygen, nitrogen, and sulfur, but containing no carbon atoms, and examples of such a functional group include an oxygen-containing organic group, a nitrogen-containing organic group, and a sulfur-containing organic group.

[0026] The oxygen-containing organic groups include hydroxyl (-OH), carboxyl (-COOH), formyl (-CHO), formyloxy (-O-CH(=O)), acyl (-CR 1 (=O)), acyloxy (-O-CR 1 (=O)), alkoxy (-OR 1 ), alkoxycarbonyl (-C(=O)-OR 1 ) etc. Here, R 1 is alkyl, preferably C1 to C4 alkyl, more preferably methyl or ethyl.

[0027] Nitrogen-containing organic groups include unsubstituted amino (-NH2), substituted amino (-NR 2 R 3 ), nitro (-NO2), cyano (-CN), etc. 2 and R 3 are independently hydrogen or alkyl, but at least one of them is alkyl, and the alkyl is preferably C1 to C4 alkyl, more preferably methyl or ethyl.

[0028] Sulfur-containing organic groups include mercapto (-SH), sulfo (-SO3H), alkylthio (-SR 4 ) etc. Here, R 4 is alkyl, preferably C1 to C4 alkyl, more preferably methyl.

[0029] R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl (-OH), an alkoxy (-OR 1 ), acyl (-CR 1 (=O)), substituted amino (-NR 2 R 3 ) (where R 1 , R 2 and R 3 is as defined above.) is preferred, and a hydrogen atom, a chlorine atom, hydroxy, methoxy, acetyl, and dimethylamino are more preferred.

[0030] Compounds of formula 1 include CH4, CH3OH, CH3Cl, CH3Br, CH3I, CH3CHO, HCOOCH3, CH3COOCH3, CH3COOC2H5, CH3NH2, (CH3)2NH, (CH3)3N, CH3CN, CH3NO2, CH3SH, CH3SCH3, CH3OCH3, CH3OC2H5, CH3COCH3, CH3COC2H5, etc., of which CH4, CH3OH, CH3Cl, CH3COCH3, CH3OCH3, and (CH3)3N are preferred from the standpoint of ease of handling, with CH3OH being more preferred.

[0031] [Inert gas] Examples of inert gases include N2, He, Ne, Ar, Xe, Kr, and CO2. 2 , Ar, He, and CO2 are preferred, and N2 and Ar are more preferred. The inert gas may be used alone or in combination of two or more kinds.

[0032] [Raw material gas] The source gas contains the compound of formula 1 and an inert gas. The compound of formula 1 may be in any of a gas, liquid, and solid state under standard conditions (atmospheric pressure, 298 K), but is in a gas state when the source gas is introduced into the thermally non-equilibrium region.

[0033] The content ratio of the compound of formula 1 and the inert gas in the raw material gas is not particularly limited and can be adjusted to any ratio. The content ratio of the compound of formula 1 in the raw material gas is preferably 1 volume % or more, more preferably 5 volume % or more, and is preferably 85 volume % or less, more preferably 80 volume % or less. The remainder of the raw material gas other than the compound of formula 1 and the inert gas is preferably impurities that are inevitably mixed in from the surrounding environment.

[0034] The source gas may contain the compound of formula 1 and an inert gas in a thermally non-equilibrium region of the plasma device. The compound of formula 1 and the inert gas may be separately supplied as gases to the thermally non-equilibrium region of the plasma device to be used as the source gas, or the entirety of the compound of formula 1 and the inert gas may be supplied as a premixed gas to be used as the source gas, or a portion of the compound of formula 1 and the inert gas may be supplied as a premixed gas separately from the remaining gas to be used as the source gas.

[0035] When the compound of formula 1 is a gas under standard conditions or a liquid with a sufficiently high vapor pressure that can be easily vaporized by heating, etc., the compound of formula 1 can be supplied as a gas to the thermally non-equilibrium region without providing a separate vaporization chamber, etc. The supply flow rate can be controlled using a mass flow controller, etc.

[0036] When the compound of formula 1 is a liquid or solid with a low vapor pressure under standard conditions, the compound of formula 1 can be vaporized in a separately provided vaporization chamber and then fed to the gas-phase flow reactor. When the compound of formula 1 is a solid, it can be heated to become a liquid and then introduced into the vaporization chamber.

[0037] For example, the compound of formula 1 can be vaporized by introducing it in a liquid state into a vaporization chamber maintained at a temperature and pressure at which the compound of formula 1 is sufficiently vaporized. The temperature and pressure of the vaporization chamber are preferably maintained at a temperature and pressure at which the compound of formula 1 can be vaporized instantly. By using such a vaporization chamber, the compound of formula 1 can be continuously introduced into the vaporization chamber as a liquid, instantly vaporized in the vaporization chamber, and continuously supplied as a gas to the thermally non-equilibrium region of the plasma device. The supply flow rate can be controlled by controlling the gas vaporized in the vaporization chamber with a mass flow controller or the like, or by controlling the compound of formula 1 when it is continuously introduced into the vaporization chamber in a liquid state with a liquid mass flow controller or the like. When the vaporized compound of formula 1 is introduced into the thermally non-equilibrium region of the plasma device, it may be diluted with an inert gas.

[0038] [Thermal nonequilibrium region] In the manufacturing method of the present invention, the raw material gas is introduced into a thermal non-equilibrium region of a plasma device. In the thermal non-equilibrium region of the plasma device, the compound of formula 1 is brought into a thermal non-equilibrium state, and various active species can be generated. In the thermal non-equilibrium region, decomposition of the compound of formula 1 is moderately suppressed, which is advantageous in terms of generating CH3 radicals.

[0039] The thermal non-equilibrium region of the plasma device can be a discharge region by atmospheric pressure low temperature plasma or vacuum plasma. An electrical method can be used to generate the atmospheric pressure low temperature plasma or vacuum plasma. Examples of atmospheric pressure low-temperature plasma include systems in which dielectric barrier discharge, glow discharge, and pulse discharge are performed under low temperature and atmospheric pressure, while examples of vacuum plasma include systems in which glow discharge and high-frequency discharge are performed under low temperature and low pressure.

[0040] The thermal non-equilibrium region of the plasma device can also be a reaction field that creates atmospheric pressure thermal plasma, and typically, the temperature region of 1000 to 3000 K around the discharge region of the device that creates atmospheric pressure thermal plasma corresponds to the thermal non-equilibrium region.

[0041] In the production method of the present invention, the raw material gas is continuously circulated through the thermal non-equilibrium region of the plasma device. The space velocity at that time is not particularly limited, and is preferably 0.01 h -1 More than 0.1h is preferable. -1 More preferably, 0.3h -1 More preferably, 100,000 h -1 Less than 50000h is preferable. -1 The space velocity is preferably 10,000 h-1 or less, and more preferably 10,000 h-1 or less. If the space velocity is within the above range, it is possible to avoid difficulties in discharging, and to efficiently produce fluorocarbons without reducing productivity.

[0042] [Fluorine source] In the production method of the present invention, the active species derived from the solid fluorine-containing inorganic compound is present in a thermal non-equilibrium region. The active species derived from the solid fluorine-containing inorganic compound contains a fluorine source.

[0043] A solid fluorine-containing inorganic compound can be activated in the thermal non-equilibrium region of a plasma device, and the activated species can be present in the thermal non-equilibrium region. For example, a method can be used in which a solid fluorine-containing inorganic compound is placed in the thermal non-equilibrium region of a plasma device, and then an oxygen-containing compound is introduced. By introducing an oxygen-containing compound into the thermal non-equilibrium region, oxygen ions or oxygen radicals are generated in the region, and the oxygen ions or oxygen radicals are caused to collide with the solid fluorine-containing inorganic compound, thereby driving out the fluorine source.

[0044] For example, the solid fluorine-containing inorganic compound can be applied to a silicon wafer or the like and placed in a plasma device. In this case, the amount of the solid fluorine-containing inorganic compound is 0.2 mg / cm. 2The coating thickness is preferably 1 μm or more. Examples of oxygen-containing compounds that are supplied to the thermal non-equilibrium region to generate the fluorine source include O2 and SO2. The oxygen-containing compound may be introduced into the thermal non-equilibrium region of the plasma device together with the raw material gas. When the inert gas or the compound of formula 1 contains oxygen, they can also be the oxygen-containing compound. For example, the inert gas can be CO2, and the compound of formula 1 can be CH3OH or CH3CHO. The amount of the oxygen-containing compound is preferably adjusted so that the ratio of the number of oxygen atoms to the number of carbon atoms supplied into the system (number of oxygen atoms / number of carbon atoms) is 0.5 or more and 10 or less.

[0045] A source gas containing the compound of formula 1 and an inert gas can be continuously supplied into the plasma device in which the fluorine source is generated as described above. Alternatively, the generated active species may be supplied to another plasma device for atmospheric pressure low-temperature plasma or vacuum plasma, and a raw material gas containing the compound of formula 1 and an inert gas may be continuously supplied to the other plasma device.

[0046] The activation of the solid fluorine-containing inorganic compound can be achieved, for example, by introducing the solid fluorine-containing inorganic compound into the discharge region in the case of an apparatus for forming atmospheric pressure thermal plasma. In this case, it is preferable to continuously supply the solid fluorine-containing inorganic compound, and a quantitative feeder, a disk feeder, a micron feeder, a mono pump, or the like can be used for supplying the solid fluorine-containing inorganic compound. The amount of the solid fluorine-containing inorganic compound is preferably such that the number of fluorine atoms relative to the number of carbon atoms supplied into the system is 0.25 or more and 25 or less. The generated active species can be supplied to a temperature region of 1000 to 3000 K around the discharge region in the same plasma device. Specifically, the active species generated in the discharge region can be transferred to a temperature region of 1000 to 3000 K around the discharge region. Alternatively, the generated active species may be supplied to a plasma device for atmospheric pressure low-temperature plasma or vacuum plasma, and a raw material gas containing the compound of formula 1 and an inert gas may be continuously supplied to the plasma device for atmospheric pressure low-temperature plasma or vacuum plasma.

[0047] [Fluorocarbons] Fluorocarbons can be obtained by continuously releasing the gas in the thermal non-equilibrium region of the plasma device to the outside of the plasma device. The gas in the thermal non-equilibrium region contains various active species, including the CH3 radical generated from the fluorine source and the compound of formula 1. By continuously releasing these to the outside of the region, the fluorine source and the active species combine to generate fluorocarbons. The continuous release can be performed at a space velocity corresponding to the continuous flow of the source gas.

[0048] After the gas is discharged outside the plasma device, it may be further introduced into a heat exchanger for cooling. The type of heat exchanger is not particularly limited, and examples thereof include air-cooling and water-cooling. The discharged material may contain hydrocarbons and the like in addition to the target substance, fluorohydrocarbons, and therefore may be subjected to a separation and purification step. Examples of the separation and purification method include distillation, absorption by a solution, membrane separation, and the like.

[0049] According to the production method of the present invention, various fluorohydrocarbons can be produced, and in particular, fluorohydrocarbons having one carbon atom can be produced. Specific examples include CH3F, CH2F2, CHF3, and CF4. Applications of monofluoromethane (CH3F) include etching gas, and applications of difluoromethane (CH2F2) and trifluoromethane (CHF3) include alternative fluorocarbon materials and etching gas. The production method of the present invention is suitable for producing monofluoromethane. EXAMPLES

[0050] The present invention will be described in more detail below with reference to examples. Not limited to this.

[0051] Example 1 CaF2 was injected into the parallel plate type high frequency plasma device 1 (upper electrode 11 (60 MHz), lower electrode 13 (2 MHz), capacity 35 L) shown in FIG. 2 A silicon wafer (4 inches) 2 coated with a thickness of about 1 μm was introduced. CH4 as a raw material and Ar as an inert gas were introduced into the plasma device 1 at flow rates of 25 sccm and 270 sccm, and O2 was introduced into the plasma device at a flow rate of 5 sccm as a mixed gas G for generating a fluorine source.

[0052] In the plasma device 1, while the mixed gas G was kept at 10 PaA (absolute pressure), plasma excitation was performed with an upper electrode supply power of 1800 W, and silicon wafer etching was simultaneously performed with a lower electrode supply power of 300 W. The gas P discharged out of the system was cooled only by continuously exhausting it with a vacuum pump at room temperature (298 K), and the gas P was collected in an aluminum bag.

[0053] The collected gas P was analyzed by gas chromatography-mass spectrometry (GC-MS) (Agilent 7890A, manufactured by Agilent) and flame ionization gas chromatography (GC-FID) (Agilent 6890N, manufactured by Agilent). The yield of fluorocarbons was calculated from the area values ​​of each component obtained by GC-MS and GC-FID analysis. The results are shown in Table 1. After the reaction was completed, the silicon wafer 2 was removed from the plasma device 1, and the plasma-irradiated surface was observed with a microscope infrared spectrophotometer (Nicolet iS10 Fourier transform infrared spectrophotometer manufactured by Thermo Fisher Scientific Co., Ltd.). - The peaks are at 870 and 1450 cm -1 It was observed nearby, and it was confirmed that oxygen-containing active species collided with CaF2, knocking out the fluorine source.

[0054] Example 2 The flow rates of CH4, O2, and Ar were changed to 20 sccm, 10 sccm, and 270 sccm, respectively, and the other factors were the same as in Example 1. The results are shown in Table 1.

[0055] Example 3 The flow rates of CH4, O2, and Ar were changed to 15 sccm, 15 sccm, and 270 sccm, respectively, and the other factors were the same as in Example 1. The results are shown in Table 1.

[0056] Example 4 The flow rates of CH4, O2, and Ar were changed to 10 sccm, 20 sccm, and 270 sccm, respectively, and the other factors were the same as in Example 1. The results are shown in Table 1.

[0057] Example 5 The flow rates of CH4, O2, and Ar were changed to 15 sccm, 15 sccm, and 270 sccm, respectively, and the upper electrode was changed to 500 W, but the same procedure was followed as in Example 1. The results are shown in Table 1.

[0058] Example 6 The flow rates of CH4, O2, and Ar were changed to 15 sccm, 15 sccm, and 270 sccm, respectively, and the upper electrode was changed to 1150 W, but the same procedure was followed as in Example 1. The results are shown in Table 1.

[0059] Example 7 The flow rates of CH3OH and Ar were changed to 10 sccm and 290 sccm, respectively, and O2 was not used, but the other factors were the same as in Example 1. The results are shown in Table 1.

[0060] Example 8 The flow rates of CH4, CO2, and Ar were changed to 15 sccm, 15 sccm, and 270 sccm, respectively, and the other factors were the same as in Example 1. The results are shown in Table 1.

[0061] Example 9 The flow rates of CH4, CO2, and Ar were changed to 15 sccm, 45 sccm, and 240 sccm, respectively, and the other factors were the same as in Example 1. The results are shown in Table 1.

[0062] Example 10 The flow rates of CH4, O2, and N2 were changed to 15 sccm, 15 sccm, and 270 sccm, respectively, and the upper electrode was changed to 500 W, but the same procedure was followed as in Example 1. The results are shown in Table 1.

[0063] [Table 1]

[0064] From Table 1, it is understood that in the examples, fluorohydrocarbons (monofluoromethane, difluoromethane) can be produced without using a catalyst. [Industrial Applicability]

[0065] According to the present invention, fluorohydrocarbons can be produced in a gas phase without using a catalyst. The production method of the present invention can avoid a situation in which the yield is reduced due to a decrease in catalyst activity, and can continuously produce fluorohydrocarbons, and thus has industrial applicability. expensive. [Explanation of symbols]

[0066] 1. Parallel plate type high frequency plasma device 2. CaF2-coated silicon wafer 11 Upper electrode 12 Matching Box 13 Lower electrode 14 Matching Box 20 Cooling gas inlet G Mixed gas P Gas

Claims

1. In a thermally non-equilibrium region of a plasma device containing active species derived from a solid fluorine-containing inorganic compound, a fluorine-containing gas having the formula 1: CH ３ -R (wherein R is a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or an organic group (excluding a hydrocarbon group)) and a raw material gas containing an inert gas are continuously supplied, and then continuously discharging the gas in the thermally non-equilibrium region out of the plasma device. Method for producing fluorocarbons.

2. 2. The method for producing a fluorohydrocarbon according to claim 1, wherein the plasma device is a device for generating atmospheric pressure low-temperature plasma or vacuum plasma, and the thermally non-equilibrium region is a discharge region within the device for generating atmospheric pressure low-temperature plasma or vacuum plasma.

3. 3. The method for producing fluorohydrocarbon according to claim 2, wherein the solid fluorine-containing inorganic compound is placed in an apparatus for forming the atmospheric pressure low-temperature plasma or vacuum plasma, and then an oxygen-containing compound is introduced to generate active species derived from the solid fluorine-containing inorganic compound.

4. 2. The method for producing fluorohydrocarbon according to claim 1, wherein the plasma device is a device for generating atmospheric pressure thermal plasma, and the thermal non-equilibrium region is a temperature region of 1000 to 3000 K around a discharge region in the device for generating atmospheric pressure thermal plasma.

5. The method for producing fluorohydrocarbon according to claim 4, wherein active species derived from the solid fluorine-containing inorganic compound are generated in a discharge region in an apparatus for forming the atmospheric pressure thermal plasma.

6. The method for producing a fluorohydrocarbon according to any one of claims 1 to 5, wherein the solid fluorine-containing inorganic compound is at least one type of compound represented by Formula 2: M-Fx (wherein M is Li, Na, Mg, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Al, B, Cs, Ba, Pb or Sn, and x is a valence of M).

7. The inert gas is N ２、 7. The method for producing a fluorohydrocarbon according to claim 1, wherein the gas is at least one selected from the group consisting of Ar and He.

8. 8. The method for producing a hydrocarbon fluoride according to claim 1, wherein the content of the compound represented by formula 1 in the source gas is 1 vol % or more and 85 vol % or less.

9. The method for producing a fluorohydrocarbon according to any one of claims 1 to 8, wherein the fluorohydrocarbon is monofluoromethane.

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