Ultrahigh-temperature rapid thermal oxidation of 4H-SiC(0001) surfaces and oxidation temperature dependence of SiO2/SiC interface properties

Ultrahigh-temperature rapid thermal oxidation of 4H-SiC(0001) surfaces in dry O2 ambient was performed at temperatures up to 1700 °C. The temperature dependence of the reaction-limited linear growth rate of a thermal SiO2 layer revealed that not active but passive oxidation is dominant even at 1600 °C, and its activation energy was estimated to be 2.9 eV. We also found that high-temperature oxidation is beneficial in improving SiO2/SiC interface properties, but unintentional oxidation during the cooling down process causes interface degradation. By effectively suppressing the oxide growth during the cooling process, the lowest interface state density was obtained for the oxide formed at 1450 °C.