Degradation of NO-nitrided SiC MOS interfaces by excimer ultraviolet light irradiation

Abstract

Abstract The impact of excimer ultraviolet (UV) light irradiation on SiO2/SiC(0001) and (112̄0) interfaces was examined to get insight into the effect of NO nitridation. While NO nitridation appears to be effective in passivating the electron traps at the SiO2/SiC interfaces, we found that the nitridation induces additional traps that are not active until UV light is irradiated. The traps include those causing hysteresis and frequency dispersion in the C–V characteristics and those affecting the long-term reliability of MOS devices. A non-nitrided SiO2/SiC interface was less sensitive to UV light, indicating the instability of the nitrided SiC MOS structure.