High Temperature Reactions in the Silicon-Hydrogen-Chlorine System

The partial pressures of the gaseous species in equilibrium with solid silicon in the Si‐H‐Cl system are presented as a function of temperature for different Cl/H ratios and total pressures. Computations were performed using our recently determined value of Δ Hf ° 298 ( SiHCl 3 , g ) = − 116.9 kcal / mol . Experimental data concerning the deposition and dissolution of silicon over a temperature range of 1200°–1700°K are compared to the equilibrium data and general conclusions drawn about the probable reaction mechanisms involved, especially for decomposition of the compounds SiCl 4 and SiHCl 3 . Particular emphasis is put on attempting to integrate the diverse body of experimental data that exists for silicon deposition from SiCl 4 ‐ H 2 and SiHCl 3 ‐ H 2 mixtures at high temperatures.