【Member Papers】The Research Insights of Mr. Kohei Sasaki, CTO and Director of NCT, on Gallium Oxide from 2010 to 2024——Prospects for β-Ga₂O₃: now and into the future

      Kohei Sasaki was born in Sendai, Japan, in 1981. In 2006, he received an M.Eng. degree from Nagaoka University of Technology and joined the Tamura Corporation. He developed the Ga₂O₃ homoepitaxial growth technique by using ozone-MBE and an ion-implantation doping technique. He also developed Ga₂O₃ trench MOSSBDs, JBS diodes, and trench MOSFETs. He received a PhD degree in Engineering from Kyoto University in 2016. In 2018, he joined Novel Crystal Technology, Inc. He developed 100 A-class large-size Ga₂O₃ SBDs by using low killer defect density Ga₂O₃ homoepitaxial films grown by halide vapor phase epitaxy. He is the CTO and director of Novel Crystal Technology, Inc.

      This review describes the progress of research on gallium oxide as a material for power devices, covering the development of bulk crystal growth through to epitaxial growth, defect evaluations, device processes, and development, all based on the author's research experiences. During the last decade or so, the epi-wafer size has been expanded to 4–6 inches, and Schottky barrier diodes and field-effect transistors capable of ampere-class operations and with breakdown voltages of several kV have been demonstrated. On the other hand, challenges to the practical application of gallium oxide power devices, such as the cost of epi-wafers, killer defects, purity of epitaxial layer, etc., have also become apparent. This paper provides a comprehensive summary of the history of these developments, including not only papers but also patents and conference presentations, and gives my personal views on the prospects for this material's continued development.

DOI：https://doi.org/10.35848/1882-0786/ad6b73