Temperature Dependence and Postirradiation Annealing Response of the $1/f$ Noise of 4H-SiC MOSFETs

摘要

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 $1/{{{f}}}$ 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 $1/{{{f}}}$ noise is also characterized after total ionizing dose irradiation and postirradiation annealing. No significant change in the $1/{{{f}}}$ noise is observed after the devices are irradiated to 1 Mrad (${rm SiO}_{2}$) and then annealed under bias at elevated temperature. These results show that the $1/{{{f}}}$ noise in 4H-SiC MOSFETs is dominated by the interaction of channel carriers with slow interface traps at temperatures ${<}{rm 360}~{rm K}$ and with border traps ${>}{rm!360}~{rm K}$. This result contrasts with most experience with ${rm Si}/{rm SiO}_{2}$-based MOSFETs, and results from the wider bandgap and greater density of slow interface traps in ${rm SiC/SiO}_{2}$-based MOSFETs than in ${rm Si}/{rm SiO}_{2}$ -based MOSFETs.