CHARACTERIZATION OF THE BUFFER LAYER IN SIC HETEROEPITAXY

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