BaTiO3/Al0.58Ga0.42N lateral heterojunction diodes with breakdown field exceeding 8 MV/cm

Abstract

In this Letter, we demonstrate a Pt/BaTiO3/Al0.58Ga0.42N lateral heterojunction diode with enhanced breakdown characteristics. By using BaTiO3, a high-k material, as a dielectric material between the anode and semiconductor, the peak electric field at the anode edge near the cathode was significantly reduced and an average breakdown field exceeding 8 MV/cm was achieved for devices with an anode to cathode spacing of <0.2 μm. In contrast, Pt/Al0.58Ga0.42N control Schottky diodes displayed an average breakdown field of ∼4 MV/cm for devices with similar dimensions. The use of a high-k dielectric can more effectively utilize the high breakdown fields in ultra-wide bandgap materials by proper management of the electric field. This demonstration thus provides a framework to realize ultra-scaled lateral devices with improved breakdown characteristics.