Document Type
Article
Original Publication Date
2012
Journal/Book/Conference Title
Journal of Applied Physics
Volume
111
Issue
2
DOI of Original Publication
10.1063/1.3679540
Date of Submission
October 2015
Abstract
We report a void defect in gallium nitride (GaN) and InGaN, revealed by aberration-corrected scanning transmission electron microscopy (STEM). The voids are pyramids with symmetric hexagonal {0001} base facets and {101¯1} side facets. Each pyramid void has a dislocation at the peak of the pyramid, which continues up along the [0001] growth direction to the surface. Some of the dislocations are hexagonal open core screw dislocations with {101¯0} side facets, varying lateral widths, and varying degrees of hexagonal symmetry. STEM electron energy loss spectroscopy spectrum imaging showed a large C concentration inside the void and on the void surfaces. There is also a larger C concentration in the GaN (or InGaN) below the void than above the void. We propose that inadvertent carbon deposition during metal organic chemical vapor deposition growth acts as a mask, stopping the GaN deposition locally, which in combination with lateral overgrowth, creates a void. Subsequent layers of GaN deposited around the C covered region create the overhanging {101¯1} facets, and the meeting of the six {101¯1} facets at the pyramid’s peak is not perfect, resulting in a dislocation.
Rights
Yankovich, A. B., Kvit, A. V., & Li, X., et al. Hexagonal-based pyramid void defects in GaN and InGaN. Journal of Applied Physics, 111, 023517 (2012). Copyright © 2012 American Institute of Physics.
Is Part Of
VCU Electrical and Computer Engineering Publications
Comments
Originally published at http://dx.doi.org/10.1063/1.3679540