Thermodynamic Analysis and Kinetic Implications of Chemical Vapor Deposition of Sic from Si‐C‐C1‐H Gas Systems

Experimental results compiled from the literature were compared to thermodynamic calculations of the most stable proportion of condensed phases to deposit from gas mixtures of Si‐C‐Cl‐H. The calculations indicated that the predominant gas molecules participating in a deposition process are chlorides and chlorosilanes for silicon and methane and acetylene for carbon. The mismatch of the calculated and experimentally determined phase boundaries at 1473 and 1600 K led to the conclusion that silicon deposition occurs faster than carbon deposition in proportion to their partial pressures. The probable reason is that silicon‐bearing gas molecules have a greater sticking probability on polar Si and Sic surfaces because of their asymmetric geometries.