Recent advances in vertical <i>β</i> -Ga ₂ O ₃ power devices: epitaxy, processing, and performance

Abstract The growing demand for higher power density and operational frequency in power conversion systems is driving the development of devices that exceed the limits of conventional silicon. Beta-phase gallium oxide ( β -Ga 2 O 3 ) has emerged as a highly promising ultra-wide-bandgap semiconductor for next-generation high-voltage and high-efficiency power electronics. This promise stems from its exceptional material properties, including a large bandgap (∼4.9 eV), a high theoretical critical electric field (8 MV cm −1 ), and the availability of large-area, low-cost melt-grown substrates. These intrinsic characteristics facilitate vertical device architectures that can achieve unprecedented breakdown voltages while minimizing conduction losses. However, several key challenges currently limiting the application of vertical β -Ga 2 O 3 devices must be addressed, including epitaxial quality, device degradation, low p-type doping efficiency, and inadequate thermal management. Overall, this review highlights the significant potential of vertical β -Ga 2 O 3 power devices, which is being realized through rapid advancements in epitaxial growth, device fabrication, and defect control. Furthermore, achieving the full potential of β -Ga 2 O 3 in high-power applications will require continued advances in p-type conductivity and thermal dissipation. The methodologies outlined may have broader applicability to other emerging semiconductor materials.