Thermodynamic Calculations for the Chemical Vapor Deposition of Silicon Carbide

A computer code, SOLGASMIX‐PV, was used to calculate CVD phase diagrams useful for the preparation of silicon carbide from commonly used precursors. The results show that in order to prepare single‐phase β‐SiC it is necessary to closely control thermodynamic parameters such as pressure, temperature, and the concentrations of the precursor and carrier gases. The system Si‐C‐H is substantially different from that of Si‐C‐H‐Cl, the latter being more complex, with single‐phase β‐SiC occurring under conditions very different from those of the former. The calculated CVD phase diagrams are compared with calculated and experimental data from the literature. The fundamental importance of a thermodynamic equilibrium description of the CVD system is emphasized.