We demonstrate high-performance UWBG AlGaN PolFETs exhibiting a state-of-the-art combination of nearly 1 A/mm on-state current (~ 960 mA/mm) and large breakdown field (> 4.8 MV/cm) in high carrier density (1.15 x 1013 cm-2). Multi-kV robustness is successfully demonstrated exhibiting 1.28 and 2.17 kV by utilizing a gate-connected field plate structures in 3.9 and 6.8 {\mu}m LGD, corresponding to the extremely low specific on-resistance of 1.25 and 2.86 m{\Omega}cm2, respectively. High RF performance is also achieved, providing fT and fMAX, of 8.5 and 15 GHz, respectively, for 3.9 {\mu}m LGD. These results highlight UWBG AlGaN as a platform for both high-voltage RF and power applications.
@article{arxiv.2604.06372,
title = {High Breakdown Field Multi-kV UWBG AlGaN Transistors},
author = {Seungheon Shin and Kyle Liddy and Jon Pratt and Can Cao and Yinxuan Zhu and Brianna A. Klein and Andrew Armstrong and Andrew A. Allerman and Siddharth Rajan},
journal= {arXiv preprint arXiv:2604.06372},
year = {2026}
}