EPITAXIAL-GROWTH OF BETA-SIC ON SILICON-ON-SAPPHIRE SUBSTRATES BY CHEMICAL VAPOR-DEPOSITION

Cubic (beta) silicon carbide films have been grown epitaxially on silicon-on-sapphire (SOS) substrates by chemical vapor deposition. The beta-SiC films were grown between 1340-1370-degrees-C on SOS substrates which have a layer of silicon deposited in situ or were grown directly on the as-is SOS substrate. In both cases, the silicon surface was carbonized prior to growth of the beta-SiC epilayer. With a growth rate of approximately 3.5-mu-m/h, 7-mu-m beta-SiC films have been obtained. The films have been characterized by infrared reflectance spectroscopy, optical and scanning electron microscopy. Specular films are obtained which have growth columns and pits. Electrical transport properties of the films were measured by the Van der Pauw-Hall method. The films are p type with carrier concentrations between 1 X 10(18) and 2 X 10(18) cm-3 and Hall mobilities of approximately 30 cm2/V s.