Monosilane-based Polysilicon Technology
Polysilicon Production Reaches Full Operation
The successful start of production at the hydrochlorination plant for synthesis of trichlorosilane completes the commissioning of Schmid Silicon Technology’s own monosilane-based polysilicon production facility.
This closes the entire production cycle, starting from metallurgical silicon and ending with high-purity polysilicon. The company’s monosilane-based silicon technology differs from conventional production methods through a lean process with extremely low power and raw material consumption. Besides the resulting cost advantage of about 40 % over conventional polysilicon production and the high product quality, this production method also exhibits a better environmental balance. The hydrochlorination reactor is operated at a pressure of about only 10 to 12 bar. This substantially reduces energy consumption and also has favourable implications for equipment design. At the same time, a lower operating pressure significantly reduces deposits of metal chlorides, for example. The new technology allows use of both silicon tetrachloride and hydrogen chloride gas as feedstock, depending on the market situation. Intermediates such as silicon tetrachloride, hydrogen chloride gas, and hydrogen, which emerge from the conventional Siemens CVD process, can also be directly processed to trichlorosilane and hence recycled in the this hydrochlorination process.