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Title: Relaxation of compressively strained AlGaN by inclined threading dislocations.

Abstract

Transmission electron microscopy and x-ray diffraction were used to assess the microstructure and strain of Al{sub x}Ga{sub 1?x}N(x = 0.61-0.64) layers grown on AlN. The compressively-strained AlGaN is partially relaxed by inclined threading dislocations, similar to observations on Si-doped AlGaN by P. Cantu, F. Wu, P. Waltereit, S. Keller, A. E. Romanov, U. K. Mishra, S. P. DenBaars, and J. S. Speck [Appl. Phys. Lett. 83, 674 (2003) ]; however, in our material, the dislocations bend before the introduction of any Si. The bending may be initiated by the greater lattice mismatch or the lower dislocation density of our material, but the presence of Si is not necessarily required. The relaxation by inclined dislocations is quantitatively accounted for with the model of A. E. Romanov and J. S. Speck [Appl. Phys. Lett. 83, 2569 (2003)], and we demonstrate the predicted linear dependence of relaxation on layer thickness. Notably, such relaxation was not found in tensile strained AlGaN grown on GaN [J. A. Floro, D. M. Follstaedt, P. Provencio, S. J. Hearne, and S. R. Lee, J. Appl. Phys. 96, 7087 (2004)], even though the same mechanism appears applicable.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
USDOE
OSTI Identifier:
973648
Report Number(s):
SAND2005-3941J
Journal ID: ISSN 0003-6951; APPLAB; TRN: US201006%%1042
DOE Contract Number:
AC04-94AL85000
Resource Type:
Journal Article
Resource Relation:
Journal Name: Proposed for publication in Applied Physics Letters.; Journal Volume: 87; Journal Issue: 12
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BENDING; DISLOCATIONS; MICROSTRUCTURE; RELAXATION; STRAINS; THICKNESS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION

Citation Formats

Follstaedt, David Martin, Lee, Stephen Roger, Crawford, Mary Hagerott, Provencio, Paula Polyak, Allerman, Andrew Alan, and Floro, Jerrold Anthony. Relaxation of compressively strained AlGaN by inclined threading dislocations.. United States: N. p., 2005. Web. doi:10.1063/1.2056582.
Follstaedt, David Martin, Lee, Stephen Roger, Crawford, Mary Hagerott, Provencio, Paula Polyak, Allerman, Andrew Alan, & Floro, Jerrold Anthony. Relaxation of compressively strained AlGaN by inclined threading dislocations.. United States. doi:10.1063/1.2056582.
Follstaedt, David Martin, Lee, Stephen Roger, Crawford, Mary Hagerott, Provencio, Paula Polyak, Allerman, Andrew Alan, and Floro, Jerrold Anthony. Wed . "Relaxation of compressively strained AlGaN by inclined threading dislocations.". United States. doi:10.1063/1.2056582.
@article{osti_973648,
title = {Relaxation of compressively strained AlGaN by inclined threading dislocations.},
author = {Follstaedt, David Martin and Lee, Stephen Roger and Crawford, Mary Hagerott and Provencio, Paula Polyak and Allerman, Andrew Alan and Floro, Jerrold Anthony},
abstractNote = {Transmission electron microscopy and x-ray diffraction were used to assess the microstructure and strain of Al{sub x}Ga{sub 1?x}N(x = 0.61-0.64) layers grown on AlN. The compressively-strained AlGaN is partially relaxed by inclined threading dislocations, similar to observations on Si-doped AlGaN by P. Cantu, F. Wu, P. Waltereit, S. Keller, A. E. Romanov, U. K. Mishra, S. P. DenBaars, and J. S. Speck [Appl. Phys. Lett. 83, 674 (2003) ]; however, in our material, the dislocations bend before the introduction of any Si. The bending may be initiated by the greater lattice mismatch or the lower dislocation density of our material, but the presence of Si is not necessarily required. The relaxation by inclined dislocations is quantitatively accounted for with the model of A. E. Romanov and J. S. Speck [Appl. Phys. Lett. 83, 2569 (2003)], and we demonstrate the predicted linear dependence of relaxation on layer thickness. Notably, such relaxation was not found in tensile strained AlGaN grown on GaN [J. A. Floro, D. M. Follstaedt, P. Provencio, S. J. Hearne, and S. R. Lee, J. Appl. Phys. 96, 7087 (2004)], even though the same mechanism appears applicable.},
doi = {10.1063/1.2056582},
journal = {Proposed for publication in Applied Physics Letters.},
number = 12,
volume = 87,
place = {United States},
year = {Wed Jun 01 00:00:00 EDT 2005},
month = {Wed Jun 01 00:00:00 EDT 2005}
}