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Title: X-ray determination of threading dislocation densities in GaN/Al{sub 2}O{sub 3}(0001) films grown by metalorganic vapor phase epitaxy

Densities of a- and a+c-type threading dislocations for a series of GaN films grown in different modes by metalorganic vapor phase epitaxy are determined from the x-ray diffraction profiles in skew geometry. The reciprocal space maps are also studied. Theory of x-ray scattering from crystals with dislocations is extended in order to take into account contribution from both threading and misfit dislocations. The broadening of the reciprocal space maps along the surface normal and the rotation of the intensity distribution ellipse is attributed to misfit dislocations at the interface. We find that the presence of a sharp AlN/GaN interface leads to an ordering of misfit dislocations and reduces strain inhomogeneity in GaN films.
Authors:
;  [1] ; ; ; ; ;  [2] ;  [3]
  1. Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5–7, 10117 Berlin (Germany)
  2. Ioffe Physical-Technical Institute of the Russian Academy of Sciences, Politekhnicheskaya 26, 194021 St.-Petersburg (Russian Federation)
  3. CEMES-CNRS and Université de Toulouse, 29 rue J. Marvig, 31055 Toulouse (France)
Publication Date:
OSTI Identifier:
22278042
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; ALUMINIUM OXIDES; CRYSTALS; DISLOCATIONS; GALLIUM NITRIDES; INTERFACES; STRAINS; SURFACES; THIN FILMS; VAPOR PHASE EPITAXY; X-RAY DIFFRACTION