Catalytic conversion of carbon-containing impurity methyldichlorosilane to purify raw material trichlorosilane of polysilicon production

Abstract

In order to remove the main carbon impurity methyldichlorosilane from the raw material trichlorosilane used in the production of polysilicon, the catalytic reaction was used to convert it into methyltrichlorosilane...

Chlorination of trichlorosilane/chlorodimethylsilane using metal chlorides: experimental and mechanistic investigations

“…Typical chlorine sources for the chlorination reactions of CH 3 SiHCl 2 are chlorine gas, 8 chlorinated hydrocarbons 6,9 and chlorosilane. 4,10,11 Wan et al 8 proposed photochlorination of CH 3 SiHCl 2 with Cl 2 in a continuous microchannel reactor. The results showed that the removal rate of CH 3 SiHCl 2 was as high as 99.67% under the optimal reaction conditions.…”

“…Additionally, silicon tetrachloride, a byproduct of polysilicon production via a modified Siemens process, can also be used as a chlorine source for chlorination of CH 3 SiHCl 2 . 4 However, silicon powder is easily formed, blocking the pores of the activated carbon catalyst during this process. Therefore, the catalytic performance and stability of the activated carbon catalyst are poor.…”

“…The standard for solar-grade polysilicon requires the carbon atom concentration to be less than 5 × 10 18 atoms per cm 3 . 4 Currently, the main process used in producing polysilicon is the improved Siemens method. 1,5 Since the nal polysilicon product is obtained by reacting SiHCl 3 with H 2 in a bell jar furnace, 5 carbon impurities in SiHCl 3 should be strictly limited.…”