Lateral Heterojunction BaTiO3/AlGaN Diodes with >8MV/cm Breakdown Field

TL;DR

This paper demonstrates that using BaTiO3 as a dielectric in lateral heterojunction diodes significantly enhances breakdown voltage, achieving over 8 MV/cm, which surpasses traditional Schottky diodes and benefits ultra-wide bandgap device scaling.

Contribution

The study introduces a novel BaTiO3/AlGaN heterojunction diode structure that significantly improves breakdown strength compared to standard Schottky diodes, enabling better electric field management in ultra-wide bandgap devices.

Findings

Breakdown field exceeds 8 MV/cm with BaTiO3 dielectric.

Control Schottky diodes show around 4 MV/cm breakdown.

Enhanced electric field management for ultra-wide bandgap devices.

Abstract

In this paper, we report enhanced breakdown characteristics of Pt/BaTiO3/Al0.58Ga0.42N lateral heterojunction diodes compared to Pt/Al0.58Ga0.42N Schottky diodes. BaTiO3, an extreme dielectric constant material, has been used, in this study, as dielectric material under the anode to significantly reduce the peak electric field at the anode edge of the heterojunction diode such that the observed average breakdown field was higher than 8 MV/cm, achieved for devices with anode to cathode spacing less than 0.2 microns. Control Schottky anode devices (Pt/Al0.58Ga0.42N) fabricated on the same sample displayed an average breakdown field around 4 MV/cm for devices with similar dimensions. While both breakdown fields are significantly higher than those exhibited by incumbent technologies such as GaN-based devices, BaTiO3 can enable more effective utilization of the higher breakdown fields available in ultra-wide bandgap materials by proper electric field management. This demonstration thus lays the groundwork needed to realize ultra-scaled lateral devices with significantly improved breakdown characteristics.