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Identifying threading dislocations in GaN films and substrates by electron channelling
Author(s) -
KAMALADASA RANGA J.,
LIU FANG,
PORTER LISA M.,
DAVIS ROBERT F.,
KOLESKE DANIEL D.,
MULHOLLAND GREG,
JONES KENNETH A.,
PICARD YOOSUF N.
Publication year - 2011
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.2011.03538.x
Subject(s) - channelling , materials science , transmission electron microscopy , threading (protein sequence) , epitaxy , dislocation , electron backscatter diffraction , electron tomography , crystallography , optoelectronics , optics , scanning transmission electron microscopy , nanotechnology , chemistry , physics , microstructure , nuclear magnetic resonance , composite material , ion , organic chemistry , layer (electronics) , protein structure
Summary Electron channelling contrast imaging of threading dislocations in GaN (0002) substrates and epitaxial films has been demonstrated using a conventional polepiece‐mounted backscatter detector in a commercial scanning electron microscope. The influence of accelerating voltage and diffraction vector on contrast features denoting specific threading dislocation types has been studied. As confirmed by coordinated transmission electron microscopy analysis, electron channelling contrast imaging contrast features for edge‐type threading dislocations are spatially smaller than mixed‐type threading dislocations in GaN. This ability to delineate GaN edge threading dislocations from mixed type was also confirmed by defect‐selective etch processing using molten MgO/KOH. This study validates electron channelling contrast imaging as a nondestructive and widely accessible method for spatially mapping and identifying dislocations in GaN with wider applicability for other single‐crystal materials.