Time-dependent-dielectric-breakdown measurements of thermal oxides on n-type 6H-SiC

Time-dependent-dielectric-breakdown (TDDB) measurements are reported on n-type 6H-SiC MOS capacitors formed by thermal oxidation. Failure distributions are obtained at 145, 240, and 305/spl deg/C, and intrinsic mean-time-to-failure (MTTF) is plotted as a function of oxide field at each temperature. The results indicate that oxide reliability will not be a significant limitation to MOS-based power switching devices at temperatures up to 150/spl deg/C. However, long-term operation of SiC MOS devices at temperatures higher than 250/spl deg/C may not be practical.