Effects of CH₃Cl Gas on Heteroepitaxial Growth of β-SiC on Si(111) by Chemical Vapor Deposition

Abstract

β-SiC epitaxial films were grown on Si(111) substrate by two-step chemical vapor deposition (CVD) using CH₃Cl as a C-source gas. Carbonized buffer layers were investigated by means of structural analyses. The buffer layers were formed with large voids underneath. This fact suggests that the Si atoms diffused out to the surface through the boundaries and defects in the buffer layer. Cl active species, which were produced by the decomposition of CH₃Cl, enhanced the supply of the Si atoms in the carbonization process. Furthermore, Cl active species enhanced two-dimensional growth of SiC nuclei on Si(111).