MORPHOLOGICAL STRUCTURE OF SILICON-CARBIDE GROWN BY CHEMICAL-VAPOR-DEPOSITION ON TITANIUM CARBIDE USING SILANE AND ETHYLENE

the morphologies of polycrstalline SiC layers and beta-SiC layers and beta-SiC epilayers deposited onto TiC(x) by pyrolysis of SiH4 and C2H4 in diluent atmospheres of Ar, He, H-2, Ar + He, Ar + H-2, and He + H-2 were studied. The fraction of the TiC(x) surface covered by SiC was dependent on the diluent atmosphere and the TiC(x) temperature (T(s)). The morphology and growth rate were dependent on T(s), at a fixed C:Si ratio. Epilayer morphologies, similar to those reported for beta-SiC on Si were obtained in Ar + H-2, and He + H-2 atmospheres, without thermal ramping, and in H-2 with thermal ramping; where, the optimum C:Si ratio was a function of T(s). Ratios of C:Si from 0.16 to 7.0 yielded beta-SiC epitaxial growth in Ar and He diluent atomospheres. The occurrence of homogeneous nucleation was strongly influenced by diluent to reactant ratios and T(s).