Highly reliable AlSiO gate oxides formed through post-deposition annealing for GaN-based MOS devices

The electrical stabilities of AlSiO gate oxides formed through post-deposition annealing (PDA) and intended for GaN-based power devices were assessed. No degradation of the interface properties of AlSiO/n-type GaN or the oxide breakdown voltage was observed, even after PDA up to 1050 degrees C. Furthermore, higher temperature PDA drastically reduced the trap density in the oxide, as indicated by current-voltage and positive bias temperature instability data. Time-to-breakdown characteristics showed sufficient lifetimes above 20 years at 150 degrees C in an equivalent field of 5 MV cm(-1). Therefore, AlSiO films fabricated by high-temperature PDA are reliable gate oxide films for GaN-based devices. (C) 2020 The Japan Society of Applied Physics