Recent Progress of β-Ga2O3 Power Diodes: A Comprehensive Review

Ultra-bandgap semiconductor material, β-gallium oxide (β-Ga2O3), has great potential for fabricating the next generation of high-temperature, high-voltage power devices due to its superior material properties and cost competitiveness. In addition, β-Ga2O3 has the advantages of high-quality, large-size, low-cost, and controllable doping, which can be realized by the melt method. It has a wide bandgap of 4.7–4.9 eV, a large breakdown field strength of 8 MV/cm, and a Baliga figure of merit (BFOM) as high as 3000, which is approximately 10 and 4 times that of SiC and GaN, respectively. These properties enable β-Ga2O3 to be strongly competitive in power diodes and metal-oxide-semiconductor field-effect transistor (MOSFET) applications. Most of the current research is focused on electrical characteristics of those devices, including breakdown voltage (VBR), specific on-resistance (RON,SP), power figure of merit (PFOM), etc. Considering the rapid development of β-Ga2O3 diode technology, this review mainly introduces the research progress of different structures of β-Ga2O3 power diodes, including vertical and lateral structures with various advanced techniques. A detailed analysis of Ga2O3-based high-voltage power diodes is presented. This review will help our theoretical understanding of β-Ga2O3 power diodes as well as the development trends of β-Ga2O3 power application schemes.