Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-14T06:15:53.412Z Has data issue: false hasContentIssue false

Analysis of strain in sub-grains with variable misorientation in GaN epilayers by digital processing of HRTEM images

Published online by Cambridge University Press:  17 March 2011

S. Kret
Affiliation:
Permanent address: Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa, Poland.
P. Ruterana
Affiliation:
ESCTM-CRISMAT UMR 6508 CNRS-ISMRA, 6 Boulevard du Marãchal Juin, 14050 CAEN Cedex, France.CAEN Cedex, France.
J. Chen
Affiliation:
ESCTM-CRISMAT UMR 6508 CNRS-ISMRA, 6 Boulevard du Marãchal Juin, 14050 CAEN Cedex, France.CAEN Cedex, France.
G. Nouet
Affiliation:
ESCTM-CRISMAT UMR 6508 CNRS-ISMRA, 6 Boulevard du Marãchal Juin, 14050 CAEN Cedex, France.CAEN Cedex, France.
Get access

Abstract

In epitaxial GaN layers on (0001) sapphire, the distance between edge dislocations in sub-grain boundaries is variable. The strain state in such sub-grains is quantitatively measured by processing of HRTEM images. The dislocation core distribution maps and in plane Burgers vectors components are derived from experimental strain tensor by applying the continuum dislocation theorem. For image simulationsthe atomic models of edge dislocations are calculated using a modified Stillinger-Weber potential. It is shown that the strain field extracted from simulated images matches that from experimental ones. The corresponding dislocation density peaks are larger and more splitted than those from simulated images.

Type
Research Article
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Hÿtch, M.J., Snoeck, E. and Killaas, R., Ultramicroscopy 74, 131, 1998.Google Scholar
[2] Kret, S., Dluzewski, P., Dluzewski, P., Sobczak, E., J. Phys.: Condens. Matter 12, 10313, 2000 Google Scholar
[3] Optimas 6.5 User Guide and Technical Reference 1999, Media Cybernettics.Google Scholar
[4] Potin, V., Ruterana, P., Nouet, G., Pond, R.C., Morkoç, H., Phys. Rev.B 61, 5587, 2000 Google Scholar
[5] Aichoune, N., Ruterana, P., Hairie, A., Nouet, G., Paumier, E., Comp. Mater. Sci. 17, 380 2000 Google Scholar
[6] Stadelmann, P., Ultamicroscopy 21 131, (1987)Google Scholar