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

Abstract

This work acquires a vertical β-Ga2O3 Schottky barrier diode (SBD) with the advanced termination structure of p-type NiOx 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-NiOx/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-NiOx/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.