2004 Volume 45 Issue 7 Pages 2395-2402
The vapor-phase homoepitaxy of monocrystalline silicon by reduction of chlorosilanes is modeled using a novel approach. With digital computer calculation, the growth rate of silicon is predicted under ambient pressure (1.0 atm or 101.325 kPa) in the high-temperature regime 1200—1600 K, where silicon growth is expected to be mass-transport limited. This study considers four different initial stoichiometries, namely, 0.1% SiH4 + 0.4% HCl + H2, 0.1% SiCl4 + H2, 0.5% SiCl4 + H2, and 0.2% SiHCl3 + H2 in the Si-Cl-H system in order to make comparisons between the predicted and the experimentally determined growth rates. By combining the iterative equilibrium constant method with the Stefan-Maxwell relations for diffusion in a multi-component gas-phase, the respective molar fluxes of nine gaseous species that include SiCl4, SiHCl3, SiH2Cl2, SiH3Cl, SiH4, SiCl2, SiCl, SiCl3, and Si(g) were computed for steady-state condition; and the data on fluxes enabled the determination of the net silicon flux to the surface of the substrate. The computed rates were compared to the measured deposition rates of silicon.
