Abstract: A tungsten hexafluoride manufacturing method of the present invention includes a reaction step of reacting tungsten containing arsenic or an arsenic compound with a gas of a fluorine element-containing compound so as to obtain a mixture containing tungsten hexafluoride and a trivalent arsenic compound, and a distillation step of distilling and purifying the mixture so as to separate and remove a fraction containing the trivalent arsenic compound and to obtain tungsten hexafluoride.

Abstract: Disclosed is a method for forming lithium hexafluorophosphate by reacting together phosphorus trichloride, chlorine and lithium chloride in a nonaqueous organic solvent and then making the reaction product formed in the solvent react with hydrogen fluoride. This method is characterized by that a lithium hexafluorophosphate concentrated liquid is obtained by conducting a filtration after making the reaction product formed in the solvent react with hydrogen fluoride and then subjecting the filtrate to a concentration by degassing. By this method, it is possible to easily produce a high-purity, lithium hexafluorophosphate concentrated liquid at a low cost.

Abstract: Disclosed is a method for forming lithium hexafluorophosphate by reacting together phosphorus trichloride, chlorine and lithium chloride in a nonaqueous organic solvent and then making the reaction product formed in the solvent react with hydrogen fluoride. This method is characterized by that a lithium hexafluorophosphate concentrated liquid is obtained by conducting a filtration after making the reaction product formed in the solvent react with hydrogen fluoride and then subjecting the filtrate to a concentration by degassing. By this method, it is possible to easily produce a high-purity, lithium hexafluorophosphate concentrated liquid at a low cost.

Abstract: A modifier for lowering relative dielectric constant of a low dielectric constant film used in semiconductor devices, the modifier of the low dielectric constant film being characterized in that it contains as an effective component a silicon compound represented by formula (1) R3-nHnSiN3??(1) in which R is a C1-C4 alkyl group, and n is an integer from 0 to 3.

Abstract: There is provided a modifier for lowering relative dielectric constant of a low dielectric constant film used in semiconductor devices, the modifier of the low dielectric constant film being characterized in that it contains as an effective component a silicon compound represented by formula (1) R3-nHnSiN3??(1) (R is a C1-C4 alkyl group, and n is an integer of 0-3).

Abstract: The invention relates to a gas for removing deposits by a gas-solid reaction. This gas includes a hypofluorite that is defined as being a compound having at least one OF group in the molecule. Various deposits can be removed by the gas, and the gas can easily be made unharmful on the global environment after the removal of the deposits, due to the use of a hypofluorite. The gas may be a cleaning gas for cleaning, for example, the inside of an apparatus for producing semiconductor devices. This cleaning gas comprises 1-100 volume % of the hypofluorite. Alternatively, the gas of the invention may be an etching gas for removing an unwanted portion of a film deposited on a substrate. The unwanted portion can be removed by this etching gas as precisely as originally designed, due to the use of a hypofluorite. The invention further relates to a method for removing a deposit by the gas.

Abstract: The invention relates to a process for producing carbonyl difluoride. This process includes the steps of (a) reacting carbon monoxide with a first metal fluoride in a reactor, thereby obtaining carbonyl difluoride and a second metal fluoride having in the molecule a fluorine atom number less than that of the first metal fluoride; and (b) reacting the second metal fluoride with fluorine in the reactor, thereby obtaining the first metal fluoride. The steps (a) and (b) are alternately repeated in the reactor, thereby repeatedly producing carbonyl difluoride.

Abstract: By reducing an organosilane represented by the formula (1), SiXnR4-n??(1) (wherein X represents a halogen or alkoxide, n represents an integer of 1-3, and R represents an alkyl group or aryl group), there is produced a corresponding organosilane represented by the formula (2), SiHnR4-n??(2) (wherein n represents an integer of 1-3, and R represents an alkyl group or aryl group). In this production method, an aromatic hydrocarbon series organic solvent is used as a reaction solvent, and aluminum lithium hydride is used as a hydrogenating agent.

Abstract: By reducing an organosilane represented by the formula (1), SiXnR4-n ??(1) (wherein X represents a halogen or alkoxide, n represents an integer of 1-3, and R represents an alkyl group or aryl group), there is produced a corresponding organosilane represented by the formula (2), SiHnR4-n ??(2) (wherein n represents an integer of 1-3, and R represents an alkyl group or aryl group). In this production method, an aromatic hydrocarbon series organic solvent is used as a reaction solvent, and aluminum lithium hydride is used as a hydrogenating agent.

Abstract: The invention relates to a gas for removing deposits by a gas-solid reaction. This gas includes a hypofluorite that is defined as being a compound having at least one OF group in the molecule. Various deposits can be removed by the gas, and the gas can easily be made unharmful on the global environment after the removal of the deposits, due to the use of a hypofluorite. The gas may be a cleaning gas for cleaning, for example, the inside of an apparatus for producing semiconductor devices. This cleaning gas comprises 1-100 volume % of the hypofluorite. Alternatively, the gas of the invention may be an etching gas for removing an unwanted portion of a film deposited on a substrate. The unwanted portion can be removed by this etching gas as precisely as originally designed, due to the use of a hypofluorite. The invention further relates to a method for removing a deposit by the gas.

Abstract: The invention relates to a gas for removing deposits by a gas-solid reaction. This gas includes a hypofluorite that is defined as being a compound having at least one OF group in the molecule. Various deposits can be removed by the gas, and the gas can easily be made unharmful on the global environment after the removal of the deposits, due to the use of a hypofluorite. The gas may be a cleaning gas for cleaning, for example, the inside of an apparatus for producing semiconductor devices. This cleaning gas comprises 1–100 volume % of the hypofluorite. Alternatively, the gas of the invention may be an etching gas for removing an unwanted portion of a film deposited on a substrate. The unwanted portion can be removed by this etching gas as precisely as originally designed, due to the use of a hypofluorite. The invention further relates to a method for removing a deposit by the gas.

Abstract: The invention relates to a gas for removing deposits by a gas-solid reaction. This gas includes a hypofluorite that is defined as being a compound having at least one OF group in the molecule. Various deposits can be removed by the gas, and the gas can easily be made unharmful on the global environment after the removal of the deposits, due to the use of a hypofluorite. The gas may be a cleaning gas for cleaning, for example, the inside of an apparatus for producing semiconductor devices. This cleaning gas comprises 1-100 volume % of the hypofluorite. Alternatively, the gas of the invention may be an etching gas for removing an unwanted portion of a film deposited on a substrate. The unwanted portion can be removed by this etching gas as precisely as originally designed, due to the use of a hypofluorite. The invention further relates to a method for removing a deposit by the gas.

Abstract: The invention relates to a gas for removing deposits by a gas-solid reaction. This gas includes a hypofluorite that is defined as being a compound having at least one OF group in the molecule. Various deposits can be removed by the gas, and the gas can easily be made unharmful on the global environment after the removal of the deposits, due to the use of a hypofluorite. The gas may be a cleaning gas for cleaning, for example, the inside of an apparatus for producing semiconductor devices. This cleaning gas comprises 1-100 volume % of the hypofluorite. Alternatively, the gas of the invention may be an etching gas for removing an unwanted portion of a film deposited on a substrate. The unwanted portion can be removed by this etching gas as precisely as originally designed, due to the use of a hypofluorite. The invention further relates to a method for removing a deposit by the gas.

Abstract: A cleaning gas includes HF gas whose concentration is greater than or equal to 1 vol % and oxygen containing gas whose concentration ranges from 0.5 to 99 vol %. The oxygen containing gas includes at least one of O2 gas, O3 gas, N2O gas, NO gas, CO gas and CO2 gas. The cleaning gas is employed to remove a deposited material generated in a vacuum treatment apparatus for producing a thin film of at least one of Ti, W, Ta, Ru, Ir, a compound thereof and an alloy thereof.

Abstract: The invention relates to a process for producing carbonyl difluoride. This process includes the steps of (a) reacting carbon monoxide with a first metal fluoride in a reactor, thereby obtaining carbonyl difluoride and a second metal fluoride having in the molecule a fluorine atom number less than that of the first metal fluoride; and (b) reacting the second metal fluoride with fluorine in the reactor, thereby obtaining the first metal fluoride. The steps (a) and (b) are alternately repeated in the reactor, thereby repeatedly producing carbonyl difluoride.

Abstract: A cleaning gas which is employed to remove an unnecessary deposited material formed in a thin film forming apparatus by thermal decomposition of pentaethoxytantalum or tetraethoxysilane without damaging a reactor, tools, parts and piping of a silicon oxide film-forming apparatus or a tantalum oxide film-forming apparatus. The cleaning gas comprises HF gas and at least one of an oxygen-containing gas, a fluorine gas, a chlorine fluoride gas, a bromine fluoride gas and an iodine fluoride gas.

Abstract: A method of refining tungsten hexafluoride containing molybdenum hexafluoride as an impurity includes the step of contacting the tungsten hexafluoride with at least one metal selected from the group consisting of Mo, W, Cu, Ni, Fe, Co, Zn, Ti, Al, Ca and Mg at a temperature ranging from 100.degree. to 500.degree. C. Molybdenum hexafluoride is efficiently removed from the tungsten hexafluoride by the method.