A kind of hydrogenation method of silicon tetrachloride

Abstract

The invention provides a hydrogenation method for silicon tetrachloride, and belongs to the technical field of polycrystalline silicon production. The hydrogenation method for silicon tetrachloride ischaracterized in that silicon tetrachloride and hydrogen are introduced into a gas discharge reactor filled with an electromagnetic field adjusting material and a supported metal catalyst, and a reaction is performed under the action of the electromagnetic field. The method can improve the low-temperature hydrogenation efficiency of the silicon tetrachloride and reduce the temperature of a reaction system.

Description

technical field [0001] The invention relates to the technical field of polysilicon production, in particular to a method for hydrogenating silicon tetrachloride. Background technique [0002] Polysilicon is the cornerstone of photovoltaic industry and microelectronics industry, and is an important industrial material. At present, the modified Siemens method is the mainstream method for producing polysilicon, and more than 95% of polysilicon in the world is prepared by the modified Siemens method. According to statistics, when the improved Siemens method is used to produce polysilicon, about 16 tons of silicon tetrachloride will be produced for every ton of polysilicon produced. [0003] Silicon tetrachloride thermal hydrogenation method is the main technology for processing silicon tetrachloride. Silicon tetrachloride and hydrogen are passed into a thermal hydrogenation furnace to react at a temperature of about 1500K to form trichlorosilane. Due to the high energy consumpt...

AI Technical Summary

Problems solved by technology

The cold hydrogenation method of silicon tetrachloride is an emerging silicon tetrachloride treatment technology. Silicon tetrachloride, hydrogen and metal-grade silicon powder are passed into a large fluidized bed reactor and react at a temperature of about 850K. The main product is trichlorohydrogen. Silicon, dichlorodihydrosilane and polychlorosilane, because metal-grade silicon powder is added to the reaction material, which increases the impurity base during the reaction, so the reaction product contains C, B, P and other impurities that affect the quality of polysilicon. The physical properties of compounds containing such impurities are similar to those of the main product trichlorosilane or the main raw material hydrogen, so it is difficult to remove them from the system, and will cause fluctuations in product quality when the system circulates

[0004] The low boiling point substances in the equipment are easy to volatilize at high temperature, which will pollute the reaction materials and ultimately affect the product quality

The reaction temperature of silicon tetrachloride thermal hydrogenation technology and silicon tetrachloride cold hydrogenation technology exceeds 800K. At this temperature, the reactor furnace wall and reactor internals will volatilize impurities such as B and P, and then pollute the materials. Reduce material purity

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