SGSilicon's Silicon Production Plant Begins Operation

March 18, 2003 by Jeff Shepard

Solar Grade Silicon LLC (SGSilicon, Moses Lake, WA), a joint venture of Advanced Silicon Materials LLC, a subsidiary of Komatsu Ltd. and Silicon Technologies AS, and a subsidiary of Renewable Energy Corp., has begun full production of polycrystalline silicon at its Moses Lake facility. The initial startup has been successful with all polysilicon chemical vapor deposition (CVD) reactors available modified to produce 2,000 metric tons annually of solar-grade polysilicon for the photovoltaics industry.

The project includes development of a new rod-breaking process and bulk packaging for products. Five standard solar-grade products, including chip-form, chunk-form and rod-form polysilicon, have been developed for solar silicon ingot producers. SGSilicon manufactures polysilicon in two steps at the 100-acre Moses Lake plant. Silane (SiH4) is produced by a patented process, reacting metallurgical-grade silicon with hydrogen and silicon tetrachloride to form trichlorosilane, which is then converted to silane in redistribution reactors. The continuous-flow process recycles all hydrogen and chloride materials to the initial reactors, achieving a low waste, low-impact, environmentally friendly process. The silane is then decomposed in hot-filament, CVD reactors, modified to produce lower-cost, solar-grade polysilicon. The CVD reactors yield large diameter rods at 2m in length, which are then broken and sized into standard chip, chunk and rod forms.