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

The impact of excimer ultraviolet (UV) light irradiation on SiO 2 /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 SiO 2 /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 SiO 2 /SiC interface was less sensitive to UV light, indicating the instability of the nitrided SiC MOS structure.