Density functional theory calculation for carrier scattering at 4H-SiC(0001)/SiO2 interface

Electronic structure and charrier scattering property of the 4H-SiC(0001)/SiO 2 interface are investigated by the density functional theory calculations. It is found that the bonding structure with SiO 2 affects the electronic structure of the interface. In addition, there are two conduction channels at the interface. The carriers flowing the channel immediately below the interface are significantly scattered at the step edge and those flowing the channel 5 Å away from the interface are insensitive to the existence of the step edges. These results indicate that on-current will increase when the on-axis SiC substrates are used for metal-oxide-semiconductor field-effect transistors because the density of the step edges is low at the on-axis substrates.