Abstract
Transmission electron microscopy has been used to observe Al segregation around the threading dislocations in Al 0.1 Ga 0.9 N and Al 0.3 Ga 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.