Apparatus and process for the preparation of low-iron single crystal silicon substantially free of agglomerated intrinsic point defects

摘要

A method and apparatus for producing silicon single crystals with reduced iron contamination is disclosed. The apparatus contains at least one structural component constructed of a graphite substrate and a silicon carbide protective layer covering the surface of the substrate that is exposed to the atmosphere of the growth chamber. The graphite substrate has a concentration of iron no greater than about 1.5*10¹² atoms/cm³and the silicon carbide protective layer has a concentration of iron no greater than about 1.0*10¹² atoms/cm³.