Method for preparing trichlorosilane and dichlorosilane by hydrogenating silicon tetrachloride through microwave plasma

Abstract

The invention provides a method for preparing trichlorosilane and dichlorosilane by hydrogenating silicon tetrachloride through microwave plasma, which aims to solve the problems of high energy consumption, low single-pass conversion rate and high equipment investment in the catalytic hydrogenation of the silicon tetrachloride by a Siemens method and problems of high energy consumption and material consumption and difficult industrialization in hydrogenating the silicon tetrachloride by a conventional thermal plasma method and a radio-frequency induction plasma method in the conventional polysilicon industry. The method comprises the following steps: forming a stable cold plasma through arced hydrogen, argon or a mixture of the two under excitation of microwaves; forming a plasma jet flow by a plasma torch under the condition of the flow of the arced gas; and ejecting feed gas into a specific area of the plasma jet flow to form an active particle consumption zone in which the silicon tetrachloride is hydrogenated into trichlorosilane. The single-pass conversion rate of the silicon tetrachloride of the method reaches about 60 percent; and the method has the advantages of simple subsequent treatment of a product, low requirement on equipment and operation control, and easy realization of industrialization.

Description

technical field

[0001] The invention relates to a method for producing trichlorosilane, in particular to a method for producing trichlorosilane and dichlorosilane by using microwave plasma hydrogenation technology. Background technique

[0002] In the current industrial production of polysilicon at home and abroad, most production plants adopt the Siemens method, using trichlorosilane chemical vapor deposition of polysilicon. Trichlorosilane is produced by catalytic reaction of hydrogen chloride and metallurgical silicon under the conditions of 300°C and 0.45MPa, and silicon tetrachloride is the main by-product of the reaction. Among the synthetic products, trichlorosilane accounts for about 80%, and silicon tetrachloride accounts for about 20%. The synthesis gas is separated by cold distillation, silicon tetrachloride is separated as a by-product, and the purified trichlorosilane enters the next step of polysilicon vapor deposition reaction.

[0003] The gas-phase deposit...

Examples

Embodiment 1

[0046] SiCl 4 For raw materials, refer to figure 1 The system and technological process of the present invention are introduced in detail to produce SiHCl 3 Methods.

[0047]This embodiment produces SiHCl 3 The system consists of the following parts: the first gas control system for arcing gas hydrogen and argon gas intake 1, the adjustment of raw material gas hydrogen and SiCl 4 The second gas control system for intake air 2, plasma reactor 3, condensation separation system for separation of chlorosilane and other gases 4, tail gas treatment system for separation of hydrogen, argon and hydrogen chloride gas 5, various chlorosilanes Separated fractionation separation system 6, microwave generator 7 providing microwaves for the plasma generator, waveguide 8 for microwave transmission and microwave resonator 9, the above-mentioned equipment is conventional equipment used in this profession; apply this figure 1 The system shown is SiCl 4 Production of SiHCl as raw material ...

technical field

[0001] The invention relates to a method for producing trichlorosilane, in particular to a method for producing trichlorosilane and dichlorosilane by using microwave plasma hydrogenation technology. Background technique

[0002] In the current industrial production of polysilicon at home and abroad, most production plants adopt the Siemens method, using trichlorosilane chemical vapor deposition of polysilicon. Trichlorosilane is produced by catalytic reaction of hydrogen chloride and metallurgical silicon under the conditions of 300°C and 0.45MPa, and silicon tetrachloride is the main by-product of the reaction. Among the synthetic products, trichlorosilane accounts for about 80%, and silicon tetrachloride accounts for about 20%. The synthesis gas is separated by cold distillation, silicon tetrachloride is separated as a by-product, and the purified trichlorosilane enters the next step of polysilicon vapor deposition reaction.

[0003] The gas-phase deposit...

Examples

Embodiment 1

[0046] SiCl 4 For raw materials, refer to figure 1 The system and technological process of the present invention are introduced in detail to produce SiHCl 3 Methods.

[0047]This embodiment produces SiHCl 3 The system consists of the following parts: the first gas control system for arcing gas hydrogen and argon gas intake 1, the adjustment of raw material gas hydrogen and SiCl 4 The second gas control system for intake air 2, plasma reactor 3, condensation separation system for separation of chlorosilane and other gases 4, tail gas treatment system for separation of hydrogen, argon and hydrogen chloride gas 5, various chlorosilanes Separated fractionation separation system 6, microwave generator 7 providing microwaves for the plasma generator, waveguide 8 for microwave transmission and microwave resonator 9, the above-mentioned equipment is conventional equipment used in this profession; apply this figure 1 The system shown is SiCl 4 Production of SiHCl as raw material ...

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