Thermodynamic prediction of SiC deposition in C3H 8-SiCl4-H2 system

Abstract

In order to deposit a homogeneous and uniform β-SiC films by chemical vapor deposition, we demonstrated the phase stability of β-SiC over graphite and silicon via computational thermodynamic calculation considering pressure, temperature and gas composition as variables. The β-SiC predominant region over other solid phases like carbon and silicon was changed gradually and consistently with temperature and pressure. Practically these maps provide necessary conditions for homogeneous β-SiC deposition of single phase. With the thermodynamic analyses, the CVD apparatus for uniform coating was modeled and simulated with computational fluid dynamics to obtain temperature and flow distribution in the CVD chamber. It gave an inspiration for the uniform temperature distribution and low local flow velocity over the deposition chamber. These calculation and model simulation could provide milestones for improving the thickness uniformity and phase homogeneity.