Structure and Surface Morphology of Thermal SiO_2 Grown on 4H-SiC by Metal-Enhanced Oxidation Using Barium

摘要

Surface morphology and electrical properties of silicon dioxide (SiO_2) on 4H-SiC substrates formed by metal-enhanced oxidation (MEO) using barium (Ba) atoms were systematically investigated. It was found that severe surface roughening caused by Ba-MEO can be suppressed by using SiO_2 capping prior to MEO. The Ba atoms at the SiO_2/SiC interface were found to diffuse to the oxide surface through the deposited SiO_2 capping layer, and then the Ba density reduced to ~10~(14) cm~(-2) before stable MEO. The resulting SiO_2/SiC interface showed the reduced interface state density but the insulating property of the oxides was significantly degraded.