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 °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 °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.