THIN OXIDE-GROWTH ON 6H-SILICON CARBIDE

A marked difference is observed for the initial oxidation rates of GR- SiC (silicon face) obtained with oxygen and argon as carrier gases in a wet oxidation process. A modified Deal-Grove model with surface and bulk reaction constants is presented to model the early oxidation proc ess at the SiO2-SiC interface in the case of oxygen as the carrier gas . In the early phase of oxidation there is rapid growth with the oxyge n carrier gas, in contrast with the argon carrier gas. This is a surpr ising result, since silicon oxidation does not demonstrate a dependenc e on the carrier gas. After a time of approximately 150 minutes, a lin ear growth rate of 1.2 Angstrom/min. occurs for both carrier gases. Th ermal oxides on p-type (doping=4x10(16)/cm(3)) GB-SIC using oxygen and argon as the carrier gases have interface trap densities (D-it) of 2. 5x10(11)/cm(2)eV and 5x10(11)/cm(2)eV respectively. Fixed charge (Q(f) ) was determined to be 4x10(11)/cm(2) and 8x10(11)/cm(2) for the oxyge n and argon carrier gas case respectively. Electrical breakdown measur ements indicated oxide breakdown field strengths on fabricated MOS cap acitors to be 8.5 MV/cm.