LCS-FY2020-PP-11
Survey of Technological Issues in Device Fabrications Processes for Gallium Oxide as a Next-Generation Widegap Semiconductor (Vol. 2):
Clarification of Energy Band Diagram of Single-Crystalline Gallium Oxides
Summary
Gallium oxide (Ga2O3), which is attracting attention as a next-generation wide-band-gap semiconductor device material, is expected to find application in power devices that can operate with lower energy losses. However, its fundamental physical properties have not been fully elucidated.
On the other hand, thanks to the rapid progress in single crystal wafer growth technology in recent years, it has become feasible to obtain highquality crystal samples for the accurate evaluation of physical properties such as band structure. In this study, the energy band diagram referenced to the vacuum level was clarified by applying ultraviolet photoelectron spectroscopy to the β-Ga2O3 single crystal surface, and it was demonstrated that this band diagram information has an important role in the accurate evaluation of MOS device characteristics. Research aimed at clarifying the fundamental physical properties of next-generation wide-band-gap semiconductors should be promoted to accelerate the development of devices using those materials, since it is essential for engineers and researchers to share an understanding of fundamental physical properties that will form the basis for accurate device characterization and device design.