Measurement of indium concentration profiles and segregation efficiencies from high-angle annular dark field-scanning transmission electron microscopy images

T Mehrtens and K Muller and M Schowalter and DZ Hu and DM Schaadt and A Rosenauer, ULTRAMICROSCOPY, 131, 1-9 (2013).

DOI: 10.1016/j.ultramic.2013.03.018

We investigated segregation of indium in an InxGa1-xAs/GaAs heterostructure via high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), where contrast strongly depends on the nuclear charges of the scattering atoms (Z-contrast). Indium concentration maps have been deduced from HAADF-STEM images by comparing normalized measured intensities with multislice simulations in the frozen lattice approach. Segregation coefficients were derived following the segregation model of Muraki et al. 1. This is demonstrated for HAADF-STEM images recorded in 100 and 110 zone-axes. Determined indium concentrations and segregation coefficients are compared with results from composition analysis by lattice fringe analysis (CELFA) measurements and energy-dispersive X-ray analysis (EDX). (C) 2013 Elsevier B.V. All rights reserved.

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