Work

Ultrahigh Breakdown Field in Gallium (III) Oxide Dielectric Structure Fabricated by Novel Aerosol Deposition Method

Year: 2024

Type: article

Abstract: With the increasing demand for modern high‐voltage electronic devices in electric vehicles and renewable‐energy systems, power semiconductor devices with high breakdown fields are becoming essential. β‐Gallium oxide (Ga 2 O 3 ), which has a theoretical breakdown field of 8 MV cm −1 , is being studied as a next‐generation power‐switch material. However, realizing a breakdown field close to this theoretical value remains challenging. In this study, an aerosol deposition‐manufactured Ga 2 O 3 film boasting an extremely high breakdown field, achieved through thickness optimization, heat treatment, and a unique nozzle‐tilting method, is developed. This study explores the effect of oxygen vacancies on the dielectric constant, breakdown field, and microstructure of Ga 2 O 3 films. Through these methods, Ga 2 O 3 films with a denser (98.88%) and uniform surface, made less affected by oxygen vacancies through nozzle tilting and post‐annealing at 800 °C, are produced, resulting in appropriate dielectric constants (9.3 at 10 kHz), low leakage currents (5.8 × 10 −11 A cm −2 at 20 kV cm −1 ), and a very high breakdown field of 5.5 MV cm −1 . The results of this study suggest that aerosol‐deposited Ga 2 O 3 layers have great potential to enable power switches with reliable switching.

Source: Small Structures

DOI: 10.1002/sstr.202400321