Paper
22 February 2012 Pyramid nano-voids in GaN and InGaN
A. B. Yankovich, A. V. Kvit, H. Y. Liu, X. Li, F. Zhang, V. Avrutin, N. Izyumskaya, Ü. Özgür, H. Morkoc, P. M. Voyles
Author Affiliations +
Abstract
High resolution transmission electron microscopy and aberration-corrected scanning transmission electron microscopy (STEM) reveal a new void defect in GaN, Si-doped GaN, and InGaN. The voids are pyramid shaped with symmetric hexagonal {0001} base facets and {10-11} side facets. The pyramid void has a closed or open core dislocation at the peak of the pyramid, which continues up along the [0001] growth direction. The closed dislocations have a 1/3 11-20 edge dislocation Burgers vector component, consistent with known threading dislocations. The open core dislocations are hexagonal shaped with pure screw character, {10-10} side facets, varying lateral widths, and varying degrees of hexagonal symmetry. STEM electron energy loss spectroscopy spectrum imaging revealed a larger C concentration inside the void and below the void than above the void. We propose that carbon deposition during metal organic chemical vapor deposition growth acts as a mask, stopping the GaN deposition locally. Subsequent layers of GaN deposited around the C covered region create the overhanging {10-11} facets, and the meeting of the six {10-11} facets at the pyramid's peak is not perfect, resulting in a dislocation.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. B. Yankovich, A. V. Kvit, H. Y. Liu, X. Li, F. Zhang, V. Avrutin, N. Izyumskaya, Ü. Özgür, H. Morkoc, and P. M. Voyles "Pyramid nano-voids in GaN and InGaN", Proc. SPIE 8262, Gallium Nitride Materials and Devices VII, 826205 (22 February 2012); https://doi.org/10.1117/12.912097
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KEYWORDS
Gallium nitride

Scanning transmission electron microscopy

Indium gallium nitride

Gallium

Quantum wells

Transmission electron microscopy

Carbon

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