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The quantitative characterization of SiGe layers by analysing rocking profiles in CBED patterns
Author(s) -
J. Zipprich,
Thomas F. Fuller,
F. Banhart,
Oliver G. Schmidt,
K. Eberl
Publication year - 1999
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1046/j.1365-2818.1999.00454.x
Subject(s) - molecular beam epitaxy , electron diffraction , materials science , diffraction , characterization (materials science) , relaxation (psychology) , layer (electronics) , strain (injury) , monolayer , beam (structure) , optics , bragg's law , molecular physics , epitaxy , chemistry , nanotechnology , physics , medicine , psychology , social psychology
Convergent beam electron diffraction is used for the quantitative determination of layer thickness, composition and strain in pseudomorphic Si/SiGe two‐ and three‐layer systems grown by molecular beam epitaxy. By using plan‐view specimens, we are able to avoid the influence of surface relaxation which generally complicates the determination of strains in cross‐sectional specimens. For quantitative strain determination, rocking curves of Bragg lines in energy‐filtered convergent beam electron diffraction patterns are analysed. The experimentally obtained rocking curves are compared with kinematical calculations by a computerized fit procedure. The resulting layer parameters are then further refined by a dynamical simulation. Results for the strains obtained with this technique are in good agreement with theoretical values. With this method layer thickness is measured down to monolayer precision. The accuracy of the strain analysis depends on the sequence and thickness of the layers.