We report on the design and demonstration of ultra-wide bandgap (UWBG) AlGaN-channel metal-insulator heterostructure field effect transistors (HEFTs) for high-power, high-frequency applications. We find that the integration of gate dielectrics and field plates greatly improves the breakdown field in these devices, with state-of-art average breakdown field of 5.3 MV/cm (breakdown voltage > 260 V) with an associated maximum current density of 342 mA/mm, and cut-off frequency of 9.1 GHz. Furthermore, low trap-related impact was observed from minimal gate and drain lag estimated from pulsed I-V characteristics. The reported results provide the potential of UWBG AlGaN HEFTs for the next generation high-power radio frequency applications.
@article{arxiv.2504.12685,
title = {High Breakdown Electric Field (> 5 MV/cm) in UWBG AlGaN Transistors},
author = {Seungheon Shin and Hridibrata Pal and Jon Pratt and John Niroula and Yinxuan Zhu and Chandan Joishi and Brianna A. Klein and Andrew Armstrong and Andrew A. Allerman and Tomás Palacios and Siddharth Rajan},
journal= {arXiv preprint arXiv:2504.12685},
year = {2025}
}