China Nonferrous Metallurgy

Methylchlorosilane in trichlorosilane is an important cause of excessive carbon impurities in polysilicon. In order to deeply remove methylchlorosilane in chlorosilane, this paper detects and analyzes the content of methylchlorosilane in each process of trichlorosilane hydrogen reduction method, and studies the conversionrules of methylchlorosilane impurities. The results show that there is a conversion equilibrium relationship between MDCSand MTCS in the hydrogenation system; In the reduction system, MDCS will be converted into MTCS, and the relative conversion amount is basically the same according to the content of MDCS in the incoming and outgoing streams;in the anti disproportionation system, methylchlorosilane will not be converted, and it can be inferred that methylchlorosilane needs to be converted under appropriate temperature and pressure;the purification system is the transfer and separation process of methylchlorosilane components,and properly organizing the purification tower to purify the methylchlorosilane is beneficial to the convertion of MDCS in TCS.