Patent ID: 9156705
Filing Date: 2015-10-13
Classification: B01J,C01B,C23C

Abstract:
1. A process for producing polycrystalline silicon by the thermal decomposition of dichlorosilane in a fluidized bed reactor having a core region and a peripheral region, the process comprising: introducing a first feed gas comprising dichlorosilane into the core region of the fluidized bed reactor, the fluidized bed reactor containing silicon particles and the temperature of the first feed gas being less than about 600° C., the dichlorosilane thermally decomposing in the fluidized bed reactor to deposit an amount of silicon on the silicon particles; and introducing a second feed gas into the peripheral region of the fluidized bed reactor, wherein the concentration of dichlorosilane in the first feed gas exceeds the concentration in the second feed gas and the pressure in the fluidized bed reactor is at least about 3 bar, the fluidized bed reactor operating at a conversion of less than about 80% of a conversion at equilibrium.