CHARACTERIZATION OF THE BUFFER LAYER IN SIC HETEROEPITAXY

Buffer layers of SiC for heteroepitaxy of SiC were grown on Si(100) substrates by pyrolysis of C3H8 diluted in H-2 as carrier gas, at atmospheric pressure. The composition profile and the interphase morphology have been studied by AES, TEM (XTEM, HREM) and ellipsometric spectroscopy. The buffer layer grown at 1200-degrees-C presents a steep composition gradient and allows the growth of a high-quality epitaxial film. The buffer layer grown at 1340-degrees-C reveals a more spread and irregular profile, with the formation of SiC inclusions in the Si substrate. It leads to an epitaxial film of poorer crystalline quality.