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X‐ray microdiffraction imaging investigations of wing tilt in epitaxially overgrown GaN
Author(s) -
Lübbert D.,
Mikulík Petr,
Pernot Petra,
Helfen Lukas,
Craven Michael D.,
Keller Stacia,
DenBaars Steven,
Baumbach Tilo
Publication year - 2006
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200565251
Subject(s) - tilt (camera) , materials science , diffraction , optics , epitaxy , crystal (programming language) , image resolution , wing , micrometer , resolution (logic) , physics , geometry , nanotechnology , computer science , mathematics , layer (electronics) , artificial intelligence , programming language , thermodynamics
The crystalline quality in epitaxially laterally overgrown (ELO) GaN and the amount of wing tilt is characterized on a local basis, with high spatial and angular resolution. A method of full‐field X‐ray microdiffraction imaging, termed rocking curve imaging, is used to record simultaneously a large set of local X‐ray diffraction profiles originating from sample surface areas of micrometer size. x – ω maps of diffracted intensity allow to quantify the amount of wing tilt in individual lateral ELO periods as well as to monitor the fluctuations of tilt between adjacent periods. Automated shape analysis of the full set of local rocking curves provides a means to quantitatively characterize the local crystalline perfection of GaN. The ELO window and wing regions can be clearly separated; comparison indicates an average improvement of crystal quality by a factor 3–4 due to the lateral overgrowth process. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)