Subcritical barrier AlN/GaN E/D-mode HFETs and inverters
Article first published online: 3 JUN 2011
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
physica status solidi (a)
Volume 208, Issue 7, pages 1620–1622, July 2011
How to Cite
Zimmermann, T., Cao, Y., Li, G., Snider, G., Jena, D. and Xing, H. (2011), Subcritical barrier AlN/GaN E/D-mode HFETs and inverters. Phys. Status Solidi A, 208: 1620–1622. doi: 10.1002/pssa.201001178
- Issue published online: 7 JUL 2011
- Article first published online: 3 JUN 2011
- Manuscript Accepted: 26 JAN 2011
- Manuscript Revised: 9 JAN 2011
- Manuscript Received: 18 OCT 2010
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Enhancement- and depletion-mode AlN/GaN HFETs have been fabricated with a subcritical barrier design: a two-dimensional electron gas (2DEG) is induced in the highly resistive as-grown heterostructure when a suitable capping material is deposited over the ultrathin AlN barrier. In this bottom-up approach 2DEGs can be locally induced by patterned cap layers on subcritical barrier AlN/GaN heterostructures, which can enable the monolithic integration of enhancement- and depletion-mode HFETs. An inverter circuit with 1.5 nm ultrathin AlN barrier E- and D-mode HFETs was successfully demonstrated with reasonable voltage transfer characteristics, noise margin, and gain. To our best knowledge this is the first reported inverter based on subcritical barrier III–V nitride heterostructures.
Integration of E- and D-mode HFETs in a subcritical barrier AlN/GaN heterostructure, where n2DEG ∼ 0 in the as-grown structure. A patterned cap locally enhances 2DEG at the AlN/GaN hetero-interface due to barrier lowering. It is an additive approach in contrast to the conventional gate recessing technique.