| 摘要 |
The invention provides a process for producing polysilicon, comprising a) deposition of polycrystalline silicon on filaments in a deposition reactor by means of a reaction gas containing a silicon-containing component comprising trichloro--silane, and hydrogen, wherein a molar saturation of the silicon- containing component based on hydrogen is at least 25%; b) feeding an offgas from the deposition into an apparatus for cooling the offgas, i) wherein components of the offgas which condense as a result of the cooling and contain silicon tetrachloride are conducted to an apparatus which enables distillative purification of the condensate, and ii) components which do not condense in the course of cooling are conducted to an adsorption or desorption unit; c) to obtain a first stream of those non-condensing components which has been purified by adsorption and contains hydrogen; and d) to obtain, during a regeneration of the adsorption unit by means of desorption and purging with purge gas, a second stream of those non-condensing components, which contains silicon tetrachloride and is preferably supplied to a converter for conversion of silicon tetrachloride to trichlorosilane. The present invention also provides a process for depositing polysilicon on filaments in a deposition reactor by means of a reaction gas including a silicon--containing component and hydrogen, wherein a molar saturation of the silicon-containing component based on the hydrogen is at least 25%. |
