Comparison of thermally oxidized metal–oxide–semiconductor interfaces on 4H and 6H polytypes of silicon carbide

Abstract

The 4H polytype of silicon carbide (SiC) has a wider band gap and higher electron mobility than either the 6H or 3C polytypes. We show here that similar oxidation rates and interfacial quality can be obtained on 4H-SiC and 6H-SiC by thermal oxidation. This makes the 4H polytype an attractive choice for developing SiC power metal–oxide–semiconductor field effect transistors. Postoxidation annealing in helium increases fixed charge and interface state densities in both 4H and 6H metal–oxide–semiconductor capacitors.