A method for producing an oligosilane including a reaction step of introducing a fluid containing a hydrosilane into a continuous reactor provided with a catalyst layer inside to produce an oligosilane from the hydrosilane and discharging a fluid containing the oligosilane from the reactor. The reaction step satisfies all of the following conditions (i) to (iii): (i) a temperature of the hydrosilane-containing fluid at an inlet of the catalyst layer is higher than a temperature of the oligosilane-containing fluid at an outlet of the catalyst layer; (ii) the temperature of the hydrosilane-containing fluid at the inlet of the catalyst layer is from 200 to 400 C.; and (iii) the temperature of the oligosilane-containing fluid at the outlet of the catalyst layer is from 50 to 300 C.

The invention relates to a method for purifying halogenated oligosilanes in the form of a pure compound or a mixture of compounds with respectively at least one direct SiSi bond, the substituents thereof being exclusively made from halogen or from halogen and hydrogen and in the composition thereof, the atomic ratio of the substituents:silicon is at least 3:2, by the action of at least one purification agent on the halogenated oligosilane and by isolating the halogenated oligosilanes with improved purity. According to prior art, halogenated monosilanes such as HSiCl.sub.3 are purified by treating with organic compounds, preferably polymers, containing amino groups, and are separated from said mixtures. Based on the contained amino groups, said method can not be used for halogenated oligosilanes as the secondary reactions lead to a decomposition of the products. The novel method is used to provide the desired products in a high yield and purity without using the amino groups.

The invention relates to a method for purifying halogenated oligosilanes in the form of a pure compound or a mixture of compounds with respectively at least one direct SiSi bond, the substituents thereof being exclusively made from halogen or from halogen and hydrogen and in the composition thereof, the atomic ratio of the substituents:silicon is at least 3:2, by the action of at least one purification agent on the halogenated oligosilane and by isolating the halogenated oligosilanes with improved purity. According to prior art, halogenated monosilanes such as HSiCl.sub.3 are purified by treating with organic compounds, preferably polymers, containing amino groups, and are separated from said mixtures. Based on the contained amino groups, said method can not be used for halogenated oligosilanes as the secondary reactions lead to a decomposition of the products. The novel method is used to provide the desired products in a high yield and purity without using the amino groups.

There is provided a highly conductive and good silicon thin film which is obtained by applying a coating-type polysilane composition prepared by use of a polysilane having a large weight average molecular weight to a substrate, followed by baking. A polysilane having a weight average molecular weight of 5,000 to 8,000. The polysilane may be a polymer of cyclopentasilane. A silicon film obtained by applying a polysilane composition in which the polysilane is dissolved in a solvent to a substrate, and baking the substrate at 100 C. to 425 C. The cyclopentasilane may be polymerized in the presence of a palladium catalyst supported on a polymer. The palladium catalyst supported on a polymer may be a catalyst in which palladium as a catalyst component is immobilized on a functional polystyrene. The palladium may be a palladium compound or a palladium complex. The palladium-immobilized catalyst may be formed by microencapsulating a zero-valent palladium complex or a divalent palladium compound with a functional polystyrene. The zero-valent palladium complex may be a tetrakis(triphenylphosphine)palladium (0) complex.

There is provided a highly conductive and good silicon thin film which is obtained by applying a coating-type polysilane composition prepared by use of a polysilane having a large weight average molecular weight to a substrate, followed by baking. A polysilane having a weight average molecular weight of 5,000 to 8,000. The polysilane may be a polymer of cyclopentasilane. A silicon film obtained by applying a polysilane composition in which the polysilane is dissolved in a solvent to a substrate, and baking the substrate at 100 C. to 425 C. The cyclopentasilane may be polymerized in the presence of a palladium catalyst supported on a polymer. The palladium catalyst supported on a polymer may be a catalyst in which palladium as a catalyst component is immobilized on a functional polystyrene. The palladium may be a palladium compound or a palladium complex. The palladium-immobilized catalyst may be formed by microencapsulating a zero-valent palladium complex or a divalent palladium compound with a functional polystyrene. The zero-valent palladium complex may be a tetrakis(triphenylphosphine)palladium (0) complex.

A method of producing a silicon hydride oxide-containing organic solvent (coating solution) is provided with which a silicon hydride oxide coating film can be formed on a substrate. Using the silicon hydride oxide-containing organic solvent makes it unnecessary to place a coating solution in non-oxidizing atmosphere at the time of coating or to heat the substrate after coating because the silicon hydride oxide is formed in the coating solution before it is coated. The method includes blowing an oxygen-containing gas through an organic solvent containing a silicon hydride or a polymer thereof. The silicon hydride oxide may contain a proportion of (residual Si-H groups)/(Si-H groups before oxidation) of 1 to 40 mol %. The silicon hydride can be obtained by reacting a cyclic silane with a hydrogen halide in the presence of an aluminum halide, and reducing the obtained cyclic halosilane.

A method of producing a silicon hydride oxide-containing organic solvent (coating solution) is provided with which a silicon hydride oxide coating film can be formed on a substrate. Using the silicon hydride oxide-containing organic solvent makes it unnecessary to place a coating solution in non-oxidizing atmosphere at the time of coating or to heat the substrate after coating because the silicon hydride oxide is formed in the coating solution before it is coated. The method includes blowing an oxygen-containing gas through an organic solvent containing a silicon hydride or a polymer thereof. The silicon hydride oxide may contain a proportion of (residual Si-H groups)/(Si-H groups before oxidation) of 1 to 40 mol %. The silicon hydride can be obtained by reacting a cyclic silane with a hydrogen halide in the presence of an aluminum halide, and reducing the obtained cyclic halosilane.

Provided is an oligosilane production method with which a target oligosilane can be selectively produced. A reaction-produced mixture fluid which contains an oligosilane obtained by the dehydrogenative coupling of a hydrosilane is supplied to a membrane separator under specific conditions and/or brought into contact with an adsorbent under specific conditions.

Provided is an oligosilane production method with which a target oligosilane can be selectively produced. A reaction-produced mixture fluid which contains an oligosilane obtained by the dehydrogenative coupling of a hydrosilane is supplied to a membrane separator under specific conditions and/or brought into contact with an adsorbent under specific conditions.

An object of the present invention is to provide an oligosilane production method with which a target oligosilane can be selectively produced. Oligosilanes can be efficiently produced at an improved selectivity for a target oligosilane by using, as a raw material, not only monosilane but also an oligosilane with a smaller number of silicon atoms than the target oligosilane or conversely an oligosilane with a larger number of silicon atoms than the target oligosilane.

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