EFFECTS OF PROPANE AND METHANE ON CARBONIZATION AND SURFACE-MORPHOLOGY IN HETEROEPITAXIAL GROWTH OF BETA-SIC FILMS ON (100) SI VIA CHEMICAL-VAPOR-DEPOSITION

Epitaxial beta-SiC films have been produced on Si(100) substrates by chemical vapor deposition (CVD) with 90% of the carbon supplied by methane and 10% by propane as compared to 100% by propane (or 100% by any carbon source more reactive than methane). These films, grown at 1350-degrees-C in a CVD reactor, are single crystalline with a three-dimensional surface morphology and have similar growth rates but lower carrier concentrations than films grown from propane and silane. The interplay of the chemistry of methane and evaporative loss of the Si substrate at approximately 1100-1300-degrees-C provide a reasonable explanation of our observations.