Microdiffraction imaging of dislocation densities in microstructured samplesD. Lübbert1, T. Baumbach1, V. Holý2, P. Mikulík3, L. Helfen1, P. Pernot1, M. Elyyan1, S. Keller4, T. M. Katona4, S. P. DenBaars4 and J. S. Speck4
1 ANKA/Institute of Synchrotron Radiation, Forschungszentrum Karlsruhe GmbH - Eggenstein-Leopoldshafen, Germany, EU
2 Faculty of Mathematics and Physics, Charles University - Praha, Czech Republic, EU
3 Department of Condensed Matter Physics, Masaryk University - Brno, Czech Republic, EU
4 University of California at Santa Barbara, Electrical and Computer Engineering and Materials Departments Santa Barbara, CA 93106, USA
received 29 October 2007; accepted in final form 7 April 2008; published June 2008
published online 26 May 2008
A full field X-ray microdiffraction technique is developed providing simultaneously both micrometer-resolved information of crystalline perfection as well as statistical information about the macroscopically illuminated sample. The method allows a detailed characterization of patterned substrates grown by epitaxial lateral overgrowth. Local wing tilts and their fluctuation over the sample area as well as the local and average number of grains in the wings are determined, and the reduction of threading dislocation densities in the grains of the ELO wings can be quantitatively estimated.
61.72.Ff - Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, X-ray topography, etc.).
61.05.cc - Theories of X-ray diffraction and scattering.
68.55.-a - Thin film structure and morphology.
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