Impact of nitridation on the reliability of 4H-SiC(112̄0) MOS devices

Abstract

The leakage current and flat-band voltage (V FB) instability of NO-nitrided SiC(110) (a-face) MOS devices were systematically investigated. Although NO nitridation is effective in improving the interface properties, we found that it reduces the onset field of Fowler–Nordheim current by about 1 MV cm−1, leading to pronounced leakage current. Synchrotron radiation X-ray photoelectron spectroscopy revealed that the nitridation reduces the conduction band offset at the SiO2/SiC interface, corroborating the above finding. Furthermore, systematical positive and negative bias stress tests clearly indicated the enhancement of V FB instability of nitrided a-face MOS devices against electron and hole injection.