Chemical vapor deposition of SiC at different molar ratios of hydrogen to methyltrichlorosilane

Abstract

Chemical vapor deposition (CVD) of SiC from methyltrichlorosilane (MTS) was studied at two different molar ratios of H2 to MTS (n(H2)/n(MTS)). The total pressure was kept as 100 kPa and the temperature was varied from 850 to 1 100 °C at a total residence time of 1 s. Steady-state deposition rates as functions of reactor length and of temperature, investigated at different n(H2)/n(MTS) values, show that hydrogen exhibits strongly influences on the deposition rate. Especially, the deposition of Si co-deposit can be obtained in broader substrate length and at higher temperatures with increasing hydrogen partial pressure. Influence of hydrogen on the deposition process was also studied using gas phase composition and deposit composition analysis at various n(H2)/n(MTS). SEM micrographs directly show the variation of surface morphologies at various n(H2)/n(MTS). It can be found that the crystal grain of the deposit at 1 100 °C is better developed and the crystallization is also improved with increasing n(H2)/n(MTS).