Electric properties of La2O3/SiO2/4H-SiC MOS capacitors with different annealing temperatures

In this work, we describe a rapid thermal annealing (RTA) process for the La2O3/SiO2/4H-SiC interface and investigate its effect on the material’s electrical properties. Our results indicate that the trap charge density and interface state density (Dit) are reduced as the RTA temperature increases due to the termination of residual carbon and dangling bonds. We demonstrate that the sample obtained after RTA at 500 °C has the highest breakdown electric field (Efb) (7 MV/cm) due to a decrease in the trap charge density and an improvement in the interfacial properties. However, when the RTA temperature reaches 600 °C or higher, a lower Efb value (1.2 MV/cm) is obtained due to leakage routes generated by the crystallization of La2O3. Based on our results, we conclude that the ideal choice for the RTA temperature is 500 °C.