Vertical β-Ga₂O₃ Power Transistors: A Review

With projected performance advantages over silicon and incumbent wide-bandgap compound semiconductors, gallium oxide (Ga ₂ O ₃ ) has garnered worldwide attention as an ultrawide-bandgap semiconductor material suitable for high-voltage, high-temperature, and radiation-hard electronics. Thanks to recent breakthroughs in crystal growth and device processing technologies, the research and development of vertically oriented Ga ₂ O ₃ power transistors has made rapid strides. In this article, we review the important engineering achievements and performance milestones of the two major types of vertical Ga ₂ O ₃ transistors-current aperture vertical metal-oxide-semiconductor field-effect transistors (MOSFETs) and vertical fin-channel MOSFETs. Challenges underlying the unique processing approaches to these devices and their implications on device reliability are also discussed.