Reliability-aware design of metal/high-k gate stack for high-performance SiC power MOSFET

Abstract

Advanced metal/high-k gate stack technology for SiC-based power MOSFET was demonstrated. We found that the Hf incorporation into aluminum oxynitride (HfAlON gate insulator) combined with TIN electrode effectively improves the stability of threshold voltage under both negative and positive bias temperature stresses. Since the relative permittivity of HfAlON increases with increasing Hf content, peak transconductance enhancement up to 3.4 times with acceptable reliability margin was achieved in the state-of-the-art trench MOSFET by implementing TiN/HfAlON(Hf50%) gate stack.