Influence of low temperature oxidation and nitrogen passivation on the MOS interface of C-face 4H-SiC

摘要

Wet and dry thermal oxidations on carbon (C)-face 4H-SiC samples were carried out at temperatures of 850 ℃, 900 ℃, 950 ℃, and 1000 ℃ at different durations, followed by Ar anneals at the same temperature as the oxidations and NO anneals at 1175℃ for different durations. The Fowler-Nordheim tunneling exhibits between 2 and 4 MV cm~(-1), respectively, and then the breakdown occurs at around 6-8 MV cm~(-1). The wet oxidation at 950 ℃ provides the lowest interface trap density of 4-6 × 10~(11) cm~(-2) eV~(-1) at 0.24 eV below the conduction band. Experiments also demonstrate that the oxide breakdown field for an N-implanted sample is lower than that of the non-implanted samples. However, the oxide breakdown field for an Al-implanted sample is even lower than that of the N-implanted sample, only 1.5 MV cm~(-1), mainly due to damage caused by ion implantation.