F. Brunner, E. Bahat-Treidel, M. Cho, C. Netzel, O. Hilt, J. Würfl, and M. Weyers

Published in:

phys. stat. sol. (c), vol. 8, no. 7-8, pp. 2427-2429 (2011).

Abstract:

A comparison of different epilayer concepts to achieve high breakdown voltage AlGaN-GaN HFETs is presented. A double heterostructure with a low Al-content Al_0.05Ga_0.95N back-barrier as well as a carbon-doped GaN buffer are investigated with regard to material and device properties. Material analysis reaffirms the incorporation of carbon on a nitrogen lattice site without creation of extended defects or causing memory effects. It is demonstrated that carrier trapping in the buffer using carbon deep acceptors reduces sub-threshold drain leakage currents in HFET devices enabling breakdown voltages above 1 kV. An undoped GaN channel layer is shown to suppress drain current reduction under pulsed transistor operation.

Keywords:

GaN, HFET, breakdown, carbon doping, back-barrier

© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Full version in pdf-format.