Polarization Enhanced GaN SBDs with p-NiO/LiNiO Junction Termination Extensions Achieving 1 kV Breakdown Voltage

In this work, we propose a polarization enhanced GaN vertical Schottky barrier diode (PE-SBD) with p-NiO/LiNiO junction termination extensions (JTEs). A thin, fully depleted p-InGaN layer is implemented at the metal/semiconductor interface to induce an opposite polarization field to reduce reverse leakage current. Furthermore, a junction termination structure is included based on high-quality conductive p-NiO/LiNiO, grown via low-temperature deposition processes, to decrease the electric field crowding at anode edges. The fully vertical GaN PE-SBD with p-NiO/LiNiO JTEs exhibited a very low specific on-state resistance ( RON, sp) of 0.61 m Ω⋅ cm2 with a considerably high breakdown voltage (BV) of 1055 V, resulting in a Baliga’s figure of merit of 1.82 GW/cm2, one of the highest among the state-of-the-art vertical GaN Schottky barrier diodes (SBDs). These results highlight the power of polarization engineering and the strategic implementation of localized p-type oxide regions to provide superior electric field management for high-performance GaN vertical diodes.