Progress and challenges in the development of ultra-wide bandgap semiconductor α-Ga2O3 toward realizing power device applications

Ultra-wide-bandgap (UWBG) semiconductors, such as Ga2O3 and diamond, have been attracting increasing attention owing to their potential to realize high-performance power devices with high breakdown voltage and low on-resistance beyond those of SiC and GaN. Among numerous UWBG semiconductors, this work focuses on the corundum-structured alpha-Ga2O3, which is a metastable polymorph of Ga2O3. The large bandgap energy of 5.3 eV, a large degree of freedom in band engineering, and availability of isomorphic p-type oxides to form a hetero p-n junction make alpha-Ga2O3 an attractive candidate for power device applications. Promising preliminary prototype device structures have been demonstrated without advanced edge termination despite the high dislocation density in the epilayers owing to the absence of native substrates and lattice-matched foreign substrates. In this Perspective, we present an overview of the research and development of alpha-Ga2O3 for power device applications and discuss future research directions.

Automated summary

Ultra-wide-bandgap (UWBG) semiconductors, including alpha-Ga2O3, have attracted attention for high-performance power devices. Alpha-Ga2O3 shows promise due to its large bandgap energy, band engineering flexibility, and ability to form hetero p-n junctions. Despite high dislocation density, preliminary prototype devices have been demonstrated. This Perspective provides an overview of alpha-Ga2O3 research for power devices and discusses future directions.