High-BFOM GaN p-channel MOSFETs enabled by ALD Ga2O3 gate dielectric

We report high-performance GaN p-channel MOSFETs enabled by atomic layer deposited (ALD) Ga2O3 as a high-k gate dielectric. The devices achieve a high Baliga's figure of merit of 0.43 MW/cm2 with a breakdown voltage exceeding 200 V. Minimal hysteresis (<100 mV) is observed in both I–V and C–V characteristics, indicating a high-quality Ga2O3/p-GaN interface with a low interface trapped charge density. Material characterization confirms the formation of a dense and uniform Ga2O3 dielectric with excellent interfacial integrity. The devices exhibit well-defined transfer and output characteristics with clear pinch-off and stable off-state leakage. Post-breakdown analysis and TCAD simulations reveal that electric-field crowding at the gate edge governs device failure. These results establish ALD Ga2O3 as a promising gate dielectric for high-voltage GaN complementary power electronics.