Observations of Al segregation around dislocations in AlGaN

Chang, L.; Lai, S. K.; Chen, F. R.; Kai, J. J.
August 2001
Applied Physics Letters;8/13/2001, Vol. 79 Issue 7
Academic Journal
Transmission electron microscopy has been used to observe Al segregation around the threading dislocations in Al[sub 0.1]Ga[sub 0.9]N and Al[sub 0.3]Ga[sub 0.7]N grown by metalorganic chemical vapor deposition on 6H–SiC. Dislocation lines were found to have up to 70% more Al concentration than those regions free of dislocations in the matrix. The Al-depleted regions around the dislocations are shown to be within a few nanometers from the dislocation lines. The results also show that more Al segregate to edge dislocations than to screw ones. © 2001 American Institute of Physics.


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