Generation of Amorphous SiO2/SiC Interface Structure by the First-Principles Molecular Dynamics Simulation

Abstract

The performance of SiC MOSFET devices to date is below theoretically expected performance levels. This is widely considered to be attributed to defect at the SiO2/SiC interface that degrade the electrical performance of the device. To analyze the relationship between defect structures near the interface and electrical performances, advanced computer simulations were performed. A slab model using 444 atoms for an amorphous oxide layer on a 4H-SiC (0001) substrate was made by using first-principles molecular dynamic simulation code optimized for the Earth-Simulator. Simulated heating and rapid quenching was performed for the slab model in order to obtain a more realistic structure and electronic geometry of a-SiO2/4H-SiC interface. The heating temperature, the heating time and the speed of rapid quenching were 4000 K, 3.0 ps and -1000 K/ps, respectively. The interatomic distance and the bond angles of SiO2 layers after the calculation are agree well with the most probable values of bulk a-SiO2 layers, and no coordination defects were observed in the neighborhood of SiC substrate.