Time-Dependent Dielectric Breakdown of Thermal Oxides on 4H-SiC
Thermal oxides on 4H-SiC are characterized using time-dependent dielectric breakdown techniques at electric fields between 6 and 10 MV/cm. At 250°C, oxides thermally-grown using N2O with NO annealing achieve a mean time to failure (MTTF) of 2300 hours at 6 MV/cm. Oxides grown in steam with NO annealing show approximately four times longer MTTF than N2O-grown oxides. At electric fields greater than 8 MV/cm, Fowler-Nordheim tunneling significantly reduces the expected failure times. For this reason, extrapolation of mean-time to failure at low fields must be performed by datapoints measured at lower electric fields.
N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall
K. Matocha and R. Beaupre, "Time-Dependent Dielectric Breakdown of Thermal Oxides on 4H-SiC", Materials Science Forum, Vols. 556-557, pp. 675-678, 2007