Passivation of Very Fast Near-Interface Traps at the 4H-SiC/SiO₂ Interface Using Sodium Enhanced Oxidation

Silicon carbide (SiC) metal-oxide semiconductor (MOS) power devices such as metaloxide semiconductor field-effect transistors (MOSFETs) require a stable and low defect-density interface, and a high-quality dielectric, for good device performance and reliability. Notably, the interface and dielectric properties determine the threshold voltage stability, the field-effect channel mobility, and the device lifetime as limited by dielectric breakdown in both the forward on-state and reverse blocking conditions. Here we discuss the present state of SiC MOS processing and properties and point to directions for future development. Important items to address are: 1) interface passivation approaches; 2) dielectrics; 3) device design; and 4) in-depth measurements of the interface quality and reliability.