Increase in silicon film deposition rate in a SiHCl3-SiHx-H2 system

The silicon film deposition rate at 850 °C using trichlorosilane gas was increased by adding SiHx gas which was in situ produced by the thermal decomposition of monomethylsilane gas in ambient hydrogen. With the increasing monomethylsilane gas concentration, the amounts of the chlorosilanes in the gas phase and the by-product deposited at the exhaust decreased. The influence of CHx on the deposition rate was negligible, because the carbon concentration contained in the silicon film obtained in this study was comparable to that formed only by the trichlorosilane gas.