Low density of interface trap states and temperature dependence study of Ga₂O₃ Schottky barrier diode with p-NiO_x termination

This work acquires a vertical β-Ga₂O₃ Schottky barrier diode (SBD) with the advanced termination structure of p-type NiO_x and n-type β-Ga₂O₃ heterojunctions and coupled field plate structures to alleviate the crowding electric field. A Ga₂O₃ SBD delivers an average breakdown voltage of 1860 V and a specific on-resistance of 3.12 mΩ cm², yielding a state-of-the-art direct-current Baliga's power figure of merit of 1.11 GW/cm² at an anode area of 2.83 × 10⁻⁵ cm². In addition, the Ga₂O₃ SBD with the same fabrication process at a large area of 1.21 × 10⁻² cm² also presents a high forward current of 7.13 A, a breakdown voltage of 1260 V, and a power figure-of-merit of 235 MW/cm². According to dynamic pulse switching and capacitance-frequency characteristics, an optimized p-NiO_x/Ga₂O₃ interface with a maximum trap density of 4.13 × 10¹⁰ eV⁻¹ cm⁻² is delivered. Moreover, based on the forward current-voltage measurement at various temperatures, the physics behind a forward conduction mechanism is illustrated. Ga₂O₃ SBDs with p-NiO_x/n-Ga₂O₃ heterojunction termination, field plate, high power figure of merit, and high quality interface as well as suppressed resistance increase after dynamic pulse switching, verifying their great promise for future high power applications.