Characterization of Ba-Introduced Thin Gate Oxide on 4H-SiC

A thickness of Ba-introduced gate oxide was controlled with the oxygen concentration and a barrier layer thickness at a post-deposition annealing. The oxidation rate becomes slower with the low oxygen concentration and the thick barrier layer, and the thin oxide of 12 nm was realized with O2 5% and 9 nm of the barrier layer. This Ba-introduced thin gate oxide resulted in the field effect mobility of 13 cm2/Vs and the interface state density of 2×1011 cm-2eV-1 at 0.25 eV below the conduction band edge of 4H-SiC.