PRIMARY DISTILLATION BORON REDUCTION

摘要

The present invention relates to an apparatus and a method for producing polycrystalline silicon having a reduced amount of boron compound impurities. Especially, the boron compounds are removed from the process for producing polycrystalline silicon, while the trichlorosilane is purified by distillation. The invention feeds condensed liquid trichlorosilane into a primary distillation tower below the liquid level inside the primary distillation tower thereby scrubbing the boron impurities upon contact inside the primary distillation tower. There result is trichlorosilane leaving the primary distillation tower with total amount of boron at least 10 times less.

主权项

1. An apparatus for manufacturing polycrystalline silicon having a reduced amount of boron compounds, comprising:
a fluidized-bed reactor for reacting metallurgical grade silicon with hydrogen chloride gas for producing trichlorosilane and other compounds; a condenser for condensing trichlorosilane and other compounds produced in the fluidized-bed reactor into a liquid; a distillation unit for purifying the trichlorosilane wherein the liquid trichlorosilane and other compounds enters the distillation unit below a liquid level in the distillation unit; and a reactor for depositing polycrystalline silicon on a surface of silicon seed rods.