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 process 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 oxygen carrier gas, in contrast with the argon carrier gas. This is a surprising result, since silicon oxidation does not demonstrate a dependence on the carrier gas. After a time of approximately 150 minutes, a linear growth rate of 1.2 Angstrom/min. occurs for both carrier gases. Thermal 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 oxygen and argon carrier gas case respectively. Electrical breakdown measurements indicated oxide breakdown field strengths on fabricated MOS capacitors to be 8.5 MV/cm.