Temperature dependence and postirradiation annealing response of the 1/f noise of 4H-SiC MOSFETs

The temperature dependence of the low-frequency noise of 4H-silicon carbide (SiC) MOSFETs with nitrided oxides is reported over the temperature range 85-510 K. The 1f noise decreases significantly with increasing measurement temperature. This decrease in noise results primarily from a decrease in the density of interface traps at increasing temperatures. The 1f noise is also characterized after total ionizing dose irradiation and postirradiation annealing. No significant change in the 1f noise is observed after the devices are irradiated to 1 Mrad (SiO2) and then annealed under bias at elevated temperature. These results show that the 1f noise in 4H-SiC MOSFETs is dominated by the interaction of channel carriers with slow interface traps at temperatures \u3c360 K and with border traps \u3e360 K. This result contrasts with most experience with Si SiO2-based MOSFETs, and results from the wider bandgap and greater density of slow interface traps in SiC/SiO 2-based MOSFETs than in SiSiO2-based MOSFETs. © 1963-2012 IEEE