Growth and Properties of Intentionally Carbon-Doped GaN Layers

E. Richter1, F.C. Beyer2, F. Zimmermann2, G. Gärtner3, K. Irmscher4, I. Gamov4, J. Heitmann2, M. Weyers1, and G. Tränkle1

Published in:

Cryst. Res. Technol., vol. 55, no. 2, pp. 1900129, DOI: 10.1002/crat.201900129 (2020).

Copyright © 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.


Carbon-doping of GaN layers with thickness in the mm-range is performed by hydride vapor phase epitaxy. Characterization by optical and electrical measurements reveals semi-insulating behavior with a maximum of specific resistivity of 2 × 1010 Ω cm at room temperature found for a carbon concentration of 8.8 × 1018 cm-3. For higher carbon levels up to 3.5 × 1019 cm-3, a slight increase of the conductivity is observed and related to self-compensation and passivation of the acceptor. The acceptor can be identified as CN with an electrical activation energy of 0.94 eV and partial passivation by interstitial hydrogen. In addition, two differently oriented tri-carbon defects, CN-a-CGa-a-CN and CN-a-CGa-c-CN, are identified which probably compensate about two-thirds of the carbon which is incorporated in excess of 2 × 1018 cm-3.

1 Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str.&nbsp:4, 12489 Berlin, Germany
2 Institute of Applied Physics, TU Bergakademie Freiberg, 09599 Freiberg, Germany
3 Institute of Experimental Physics, TU Bergakademie Freiberg, 09599 Freiberg, Germany
4 Leibniz-Institut für Kristallzüchtung, Max-Born-Strasse 2, 12489 Berlin, Germany


carbon, GaN, HVPE, self-compensation, tri-carbon-defect