HETEROEPITAXIAL GROWTH OF BETA-SIC FILMS ON TIC SUBSTRATES - INTERFACE STRUCTURES AND DEFECTS

Thin epitaxial films of beta - SiC were grown by CVD on (100), (111), and (112) TiC substrates. TEM observations of the resulting interfaces revealed that island nucleation prevailed in the early stages of depo sition for all three substrate orientations. Films grown on (111) and (112) TiC were monocrystalline, while SiC films deposited on (100) sub strates were polycrystalline and not epitaxial, a phenomenon attribute d to the poor match of atomic positions in SiC and TiC on their respec tive (100) planes. The (111) interface was abrupt and atomically flat, while the (112) interface exhibited {111} facets and steps. Simulated images of the stable (111) interface were calculated based on several possible atomic configurations, and the atomic structure of the inter face was deduced from comparisons between the simulated images and pha se-contrast TEM images.