Fabrication of Anodic Oxidation Films on 4H–SiC at Room Temperature Using HNO3-Based Electrolytes

Abstract

Oxidation of 4H–SiC substrates by anodic methods using HNO3 and HF+HNO3 electrolytes was carried out at room temperature. Oxide layers with a thickness of 1 µm were formed in 5 min, which is 100 times faster than by a conventional dry thermal oxidation method. The consumed SiC layer is 1/3 of the oxide thickness. The oxide layer was found to be SiO2 including carbon by XPS analysis. The carbon atomic concentration in the oxide layers could be reduced by thermal annealing in a gas mixture of H2/Ar=1:9.