We report the first observation of ferroelectric gating in AlScN barrier wide-bandgap nitride transistors. These FerroHEMT devices realized by direct epitaxial growth represent a new class of ferroelectric transistors in which the semiconductor is itself polar, and the crystalline ferroelectric barrier is lattice-matched to the substrate. The FerroHEMTs reported here use the thinnest nitride high K and ferroelectric barriers to date to deliver the highest on currents at 4 A/mm, and highest speed AlScN transistors with fmax larger than 150 GHz observed in any ferroelectric transistor. The FerroHEMTs exhibit hysteretic Id Vgs loops with subthreshold slopes below the Boltzmann limit. A control AlN barrier HEMT exhibits neither hysteretic, nor sub Boltzmann behavior. While these results introduce the first epitaxial high K and ferroelectric barrier technology to RF and mm wave electronics, they are also of interest as a new material platform for combining memory and logic functionalities in digital electronics.
@article{arxiv.2302.14209,
title = {FerroHEMTs: High-Current and High-Speed All-Epitaxial AlScN/GaN Ferroelectric Transistors},
author = {J. Casamento and K. Nomoto and T. S. Nguyen and H. Lee and C. Savant and L. Li and A. Hickman and T. Maeda and J. Encomendero and V. Gund and A. Lal and J. C. M. Hwang and H. G. Xing and D. Jena},
journal= {arXiv preprint arXiv:2302.14209},
year = {2023}
}
Comments
4 pages, 8 figures, appeared in IEEE IEDM, December 2022