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Effect of screw threading dislocations and inverse domain boundaries in GaN on the shape of reciprocal‐space maps
Author(s) -
Barchuk Mykhailo,
Motylenko Mykhaylo,
Lukin Gleb,
Pätzold Olf,
Rafaja David
Publication year - 2017
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576717003612
Subject(s) - reciprocal lattice , sapphire , microstructure , transmission electron microscopy , materials science , diffraction , crystallography , electron diffraction , optics , polar , condensed matter physics , physics , chemistry , composite material , nanotechnology , laser , astronomy
The microstructure of polar GaN layers, grown by upgraded high‐temperature vapour phase epitaxy on [001]‐oriented sapphire substrates, was studied by means of high‐resolution X‐ray diffraction and transmission electron microscopy. Systematic differences between reciprocal‐space maps measured by X‐ray diffraction and those which were simulated for different densities of threading dislocations revealed that threading dislocations are not the only microstructure defect in these GaN layers. Conventional dark‐field transmission electron microscopy and convergent‐beam electron diffraction detected vertical inversion domains as an additional microstructure feature. On a series of polar GaN layers with different proportions of threading dislocations and inversion domain boundaries, this contribution illustrates the capability and limitations of coplanar reciprocal‐space mapping by X‐ray diffraction to distinguish between these microstructure features.