Patent ID: 6060021
Filing Date: 2000-05-09
Classification: C01B

Abstract:
A process for producing polycrystal silicon comprising:the step (1) of forming polycrystal silicon by reacting trichlorosilane with hydrogen;the step (2) of forming trichlorosilane by reacting silicon tetrachloride, by-produced in the polycrystal silicon-forming step (1), with hydrogen and silicon; andthe step of supplying trichlorosilane, containing at least part of the trichlorosilane obtained in the trichlorosilane-forming step (2), to the polycrystal silicon-forming step (1), whereintrichlorosilane used in the polycrystal silicon-forming step (1) and/or silicon tetrachloride used in the trichlorosilane-forming step (2) are stored in storage tank(s) using a hydrogen gas as a sealing gas to control the pressure inside the tank at a higher level than that of the outside air and supplied to the respective steps from the tank(s).