Hydrogen in InN: A ubiquitous phenomenon in molecular beam epitaxy grown material

Authors

V. Darakchieva, Instituto Tecnológico e Nuclear, 2686-953 Sacavém, Portugal
K. Lorenz, Instituto Tecnológico e Nuclear, Sacavém, Portugal
N. P. Barradas, Instituto Tecnológico e Nuclear, 2686-953 Sacavém, Portugal
E. Alves, Instituto Tecnológico e Nuclear, 2686-953 Sacavém, Portugal
B. Monemar, Department of Physics, Chemistry and Biology, Linköping University
Mathias Schubert, University of Nebraska-LincolnFollow
N. Franco, Instituto Tecnológico e Nuclear, 2686-953 Sacavém, Portugal
C. L. Hsiao, Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan
L. C. Chen, Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan
W. J. Schaff, Cornell University, Ithaca, New York
L. W. Tu, National Sun Yat-Sen University
T. Yamaguchi, Ritsumeikan University
Y. Nanishi, Ritsumeikan University

Date of this Version

2010

Comments

Published in Appl. Phys. Lett. 96, 081907 (2010). Copyright © 2010 American Institute of Physics. Used by permission.

Abstract

We study the unintentional H impurities in relation to the free electron properties of state-of-the-art InN films grown by molecular beam epitaxy (MBE). Enhanced concentrations of H are revealed in the near surface regions of the films, indicating postgrowth surface contamination by H. The near surface hydrogen could not be removed upon thermal annealing and may have significant implications for the surface and bulk free electron properties of InN. The bulk free electron concentrations were found to scale with the bulk H concentrations while no distinct correlation with dislocation density could be inferred, indicating a major role of hydrogen for the unintentional conductivity in MBE InN.