【International Papers】Progress in α-Ga₂O₃ for practical device applications

      Researchers from the Ritsumeikan University, Kyoto University, and FLOSFIA Inc. published a dissertation titled "Progress in α-Ga₂O₃ for practical device applications" in IOP Science.

Abstract

      Recent progress in α-phase gallium oxide (α-Ga₂O₃) grown on sapphire for low-cost and practical device applications is reviewed. This review focuses on (i) dislocations formed by heteroepitaxy, (ii) p-type conductivity (a common issue with β-Ga₂O₃), and (iii) thermal instability due to the metastable phase of α-Ga₂O₃, and discusses efforts aimed at overcoming these issues. The results reveal guidelines for the dislocation density (<1 × 10⁸ cm⁻²) so that the dislocation scattering is veiled in the electron transport, and for this purpose we mentioned buffer layers and epitaxial lateral overgrowth. Quasi-vertical Schottky barrier diodes (SBDs) show defect-insensitive behavior in current–voltage characteristics under a low current density. We also demonstrate the heterojunction pn diodes with α-phase iridium oxide (α-Ir₂O₃) or α-(Ir,Ga)₂O₃ and the ways to improve thermal stability of α-Ga₂O₃. The up-to-date device characteristics, that is, low on-resistance and large current SBDs, and high reverse voltage of 1400 V of a pn junction suggest promising development in α-Ga₂O₃-based devices.

Paper Link：https://doi.org/10.35848/1347-4065/acd125