The Equilibrium Behavior of the Silicon-Hydrogen-Chlorine System

The composition of the gas phase is calculated for various temperatures, pressures, and chlorine-to-hydrogen ratios for the two-phase system consisting of solid silicon in equilibrium with the gas phase. It is shown that in the range of variables most frequently used for vapor growth of silicon, the principal species under equilibrium conditions are H2, HCl, SiHCl3, and SiCl2.