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High-resolution reciprocal space mapping of distributed Bragg reflectors and virtual substrates

✍ Scribed by Zhylik, A. ;Rinaldi, F. ;Myronov, M. ;Saito, K. ;Menzel, S. ;Dobbie, A. ;Leadley, D. R. ;Ulyanenkova, T. ;Feranchuk, I. D. ;Ulyanenkov, A.


Book ID
105366653
Publisher
John Wiley and Sons
Year
2011
Tongue
English
Weight
866 KB
Volume
208
Category
Article
ISSN
0031-8965

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✦ Synopsis


Abstract

Epitaxially grown silicon germanium alloy layers, prepared as virtual substrates for modulation‐doped field effect transistors, and In~x~Ga~1−x~As and GaP~x~As~1−x~ graded layers on GaAs substrates prepared as distributed Bragg reflectors (DBRs), have been investigated by the reciprocal space mapping (RSM) technique. These structures possess a strong concentration gradient and crystallographic lattice relaxation across the layer, which makes the data analysis challenging. Using kinematic diffraction theory for RSM analysis gives a rather simple way to evaluate the concentration, tilt and relaxation gradients, and the layer thicknesses, as well as the dependence of these values on the azimuthal direction of the diffraction plane. The density of 60° misfit dislocations for partially relaxed layers is also estimated. Characteristics of wide aperture Bragg reflectors based on these structures are calculated.