Method for improving quality of trichlorosilane

Abstract

The invention discloses a method for improving the quality of trichlorosilane, which comprises the following steps: mixing a trichlorosilane heavy component obtained by de-weighting when trichlorosilane is purified in synthetic rectification with a silicon tetrachloride product liquid, sequentially enabling the mixture to pass through a resin adsorption column and an anti-disproportionated resin column, and recycling the treated mixture as a synthetic rectification raw material so as to control the content of boron in the refined trichlorosilane material obtained by synthesis and rectification to be less than or equal to 0.06 ppb, the content of phosphorus to be 0.2-0.5 ppb, and the content of organic silicon to be 1-4 ppm. According to the method, the trichlorosilane heavy component circulated in synthesis rectification is mixed with silicon tetrachloride, boron, phosphorus and other impurities are removed, the mixture is repeatedly used for synthesis rectification to obtain refined trichlorosilane, and the purpose of improving the quality of refined trichlorosilane and polycrystalline silicon products is achieved.

Description

Technical field [0001] The present invention belongs to the field of polysilicon production, in particular, is a method of improving trichlorosily quality. Background technique [0002] With the development of the photovoltaic industry, especially the electronic industry, its requirements for polysilicon quality are continuously improved, and the quality of trichlorosilicon as the main raw material directly affects the quality and yield of polysilicon products. At present, due to the quality of raw material manufacturers, especially the amount of impurities such as boron tide and phosphorus trichloride in raw materials, the increase in mass production and quality of the enterprise has had a certain impact. In this case, the polysilicon enterprises seek new technical methods, and it is desirable to remove part of a part of trichloride, phosphorus phosphorus, etc., improve and stabilize the quality of the material, to ensure product quality. [0003] As a new type of adsorbent, the...

AI Technical Summary

Problems solved by technology

The boron and phosphorus impurities in the silicon powder participate in the reaction in the trichlorosilane synthesis furnace and the cold hydrogenation furnace to form borophosphorus compounds and methyl silane, which exist in the trichlorosilane liquid and can be removed by multi-stage rectification. However, in the high-purity rectification system, the light and heavy components of boron, phosphorus and methyl silane are still not easy to remove.

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