Application Of 3-Dimensional Phase-Diagram Using Factsage In C3h8-Sici4-H-2 System

In order to deposit a homogeneous and uniform beta-SiC films by chemical vapor deposition, we constructed the phase-diagram of beta-SiC over graphite and silicon via computational thermodynamic calculation considering pressure(P), temperature(T) and gas composition(C) as variables in C3H8-SiCl4-H-2 system. During the calculation, the ratio of Cl/Si and C/Si is maintained to be 4 and 1, respectively, and H/Si ratio is varied from 2.67 to 15,000. The P-T-C diagram showed very steep phase boundary between SiC+C and SiC region perpendicular to H/Si axis and also showed SiC+Si region with very large H/Si value of similar to 6700. The diagram can be applied not only to the prediction of the deposited phase composition but to compositional variation due to the temperature distribution in the reactor. The P-T-C diagram could provide the better understanding of chemical vapor deposition of silicon carbide.