Defect Reduction by Post-Oxidation Annealing of Oxides on P- and N-Type 6H-SiC

We report on the influence of post-oxidation annealing (POA) on electrical properties of MOS-(Metal Oxide Semiconductor)-capacitors on n- and p-type 6H-SiC. The samples were oxidized in dry and wet oxygen at 1150°C. POA at the same temperature can significantly reduce the densities of fixed oxide charges and interface states. High temperature H2 annealing experiments show that hydrogen plays a critical role in the SiO2-SiC system. Oxide defects on p-type SiC, which are believed to result from dopant (Al) incorporation into SiO2, could be passivated by forming-gas anneals.