Vertical GaN and Vertical Ga2O3Power Transistors: Status and Challenges

Abstract

Wide bandgap (WBG) semiconductors such as gallium nitride (GaN) and silicon carbide (SiC) are rapidly making inroads into the power semiconductor markets dominated by the incumbent silicon (Si). However, the performance of these WBG semiconductors has not reached the ideal material limits and thus, leaves significant room for improvement. In this regard, for medium voltage (600–1700 V)/high current (>50 A) applications, with a high Baliga figure of merit (BFOM) and architectural advantages, vertical GaN offers a highly energy‐efficient solution. Similarly, for high‐voltage applications (>1700 V), ultrawide bandgap (UWBG) semiconductors with their high BFOM present a strong case. Gallium oxide (Ga2O3) has emerged as the UWBG material for next‐generation power electronics. Together vertical GaN and vertical Ga2O3have the potential to serve a large range of power switching applications. These technologies are both at different junctures and face different challenges to become commercially viable. Herein, a comprehensive review of all major vertical GaN and Ga2O3power transistors is provided while discussing their features, advantages, and challenges that need to be solved. Finally, the critical material and device advancements that are needed to push these technologies further are also discussed.