Modeling of Silicon Vapor Phase Epitaxy Using Stefan-Maxwell Formalism

摘要

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 (l.0 atm or 101.325kPa) 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 percent SIR, + 0.4 percent HC1 + H_2, 0.1 percent SiCl_4 + H_2, 0.5 percent SiCl_4 + H_2, and 0.2 percent SiHCl_3 + H_2 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 SiCl_4, SiHCl_3, SiH_2Cl_2, SiH_3Cl, SiH_4, SiCl_2, SiCl, SiCl_3, 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.