Patent ID: 9114997
Filing Date: 2015-08-25
Classification: C01B,F23G

Abstract:
1. A process for depositing polycrystalline silicon on polycrystalline silicon particles by the thermal decomposition of silane in a fluidized bed reactor having a reaction chamber, the reaction chamber having a cross-section through which feed gases pass, the fluidized bed reactor producing at least about 100 kg/hr of polycrystalline silicon per square meter of reaction chamber cross-section, the process comprising introducing one or more feed gases into the reaction chamber with one or more of the feed gases comprising silane, the overall concentration of silane in the feed gases fed into the reaction chamber being less than about 15% by volume, the pressure in the reaction chamber being at least about 4 bar, and the average residence time of feed gases introduced into the reaction chamber is less than about 20 seconds; wherein silane thermally decomposes in the reaction chamber to deposit at least about 100 kg/hr of polycrystalline silicon per square meter of reaction chamber cross-section on the polycrystalline silicon particles.