ATOMIC LEVEL EPITAXY OF 3C-SIC BY LOW-PRESSURE VAPOR-DEPOSITION WITH ALTERNATING GAS-SUPPLY

The heteroepitaxial growth of 3C SiC on Si substrates has been studied in a hot-wall-type, low pressure, chemical vapour deposition reactor with an alternating supply of SiH2Cl2 and C2H2 in the temperature range of 750-1050-degrees-C. SiC films have been grown only at temperatures above 800-degrees-C. The growth rate of the SiC films increases with temperature above 900-degrees-C, while a constant growth rate (4.4 angstrom cycle-1) is obtained in the temperature range between 800 and 900-degrees-C. The characteristics of the growth rate of the SiC films can be understood by taking into account the decomposition of adsorbed SiCl2 on the surface of the substrates. The crystallinity of the SiC layers was affected by the orientation of the Si substrates and the growth temperature. Monocrystalline 3C-SiC has been obtained on the Si(111) face at temperatures above 1000-degrees-C, while polycrystalline 3C-SiC deposits on the (00 1) face over the range of growth temperature studied.