Numerical Evaluation of Silicon-Thin Film Growth from SiHCl3-H2 Gas Mixture in a Horizontal Chemical Vapor Deposition Reactor.

An evaluation of silicon epitaxial thin film growth using the SiHCl3-H2 system in a horizontal chemical vapor deposition (CVD) reactor is discussed. The transport equations for gas velocity, temperature and concentration of chemical species are solved, taking account of the dependence of gas properties on temperature and composition. By comparing the measured and predicted growth rates under atmospheric pressure, the increase in growth rate with temperature and SiHCl3 concentration can be explained by assuming an Arrhenius-type expression for the chemical reaction of SiHCl3 and H2 on a substrate. The calculated growth rate of the Si film increases nonlinearly with SiHCl3 concentration because the flow, temperature, and concentration distributions in the reactor depend on the SiHCl3 concentration. Suppression of the growth rate due to thermal diffusion, which transports SiHCl3 gas away from the hot surface, is found to become significant as the SiHCl3 concentration in the reactor increases.