Implementation of a 900 V Switching Circuit for High Breakdown Voltage β-Ga2O3 Schottky Diodes

Yen-Ting Chen,Jiancheng Yang,S J Pearton,Marko J Tadjer,Yu-Te Liao,Jenshan Lin,Akito Kuramata,Chin-Wei Chang,Fan Ren

doi:10.1149/2.0421907jss

Abstract

This paper presents a switching circuit for high breakdown-voltage Ga2O3 vertical Schottky rectifiers. Field-plated edge-terminated (FPET) vertical Schottky diodes were fabricated on a 20-μm thick Si-doped n-type Ga2O3 drift layer which was grown on the 650-μm thick β-Ga2O3 substrate via halide vapor phase epitaxy (HVPE). The measured reverse recovery time of the proposed Ga2O3 Schottky diode was 81 ns when switched to a reverse bias voltage of −900 V. The implementation of a switching circuit with the novel Ga2O3 diode is the first demonstrated at such a high switching voltage. This paper also provides insights for the practical implementation of the Ga2O3 vertical Schottky rectifiers from device fabrication to circuit design.

Highlights

With the increasing demands of switching power electronics, widebandgap materials such as silicon carbide (SiC), gallium nitride (GaN), and gallium oxide (Ga2O3) have attracted intensive research and development
Among various wide-bandgap materials, Ga2O3 has been considered a potential candidate for next-generation power electronics because of its ultra-wide bandgaps (Eg) of 5.3 eV (α-phase) and 4.9 eV (β-phase),[1–3] which translate to around 5–9 MV/cm of a critical electric field
Compared with SiC and GaN, the larger bandgap and melt growth options with Ga2O3 offers the potential for higher breakdown fields, high Baliga’s Figure of Merit (BFoM), and potentially lower costs in materials and fabrication processes.[1–17]

Summary

Introduction

With the increasing demands of switching power electronics, widebandgap materials such as silicon carbide (SiC), gallium nitride (GaN), and gallium oxide (Ga2O3) have attracted intensive research and development. Since p-type doping, which would improve the breakdown voltage of devices with guard rings, has not yet been demonstrated for Ga2O3, the focus has been on field-plated vertical rectifiers to achieve high reverse blocking capability characteristics at high current density. Ga2O3 diodes for high-current switching applications have been demonstrated.[24–26]

Results

Conclusion