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Mosaicity of GaN Epitaxial Layers: Simulation and Experiment
Author(s) -
Chierchia R.,
Böttcher T.,
Figge S.,
Diesselberg M.,
Heinke H.,
Hommel D.
Publication year - 2001
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200111)228:2<403::aid-pssb403>3.0.co;2-5
Subject(s) - mosaicity , materials science , sapphire , coalescence (physics) , diffraction , coherence length , reciprocal lattice , epitaxy , metalorganic vapour phase epitaxy , optics , crystallography , condensed matter physics , x ray crystallography , physics , chemistry , nanotechnology , laser , superconductivity , layer (electronics) , astrobiology
High‐resolution X‐ray diffraction has been used to analyze GaN epilayers with varying coalescence thickness which were grown by MOVPE on (0001) oriented sapphire. The decrease of the density of edge type threading dislocations with increasing coalescence thickness causes a marked difference in the mosaicity of the samples. As the defects form along the grain boundaries, this corresponds to an increase in lateral coherence length with increasing coalescence thickness. The lateral coherence length has been obtained from simulations of reciprocal lattice points of off‐axis Bragg reflections, measured in asymmetric diffraction geometry.