C. Ferrari et al., Investigation by synchrotron radiation X-ray topography of lattice tilt formation in partially released InGaAs/GaAs compositionally graded layers, J CRYST GR, 205(4), 1999, pp. 474-480
The synchrotron radiation plane wave topography and the Rutherford backscat
tering technique have been used to investigate the lattice tilts between su
bstrates and layers introduced by the preferential orientation of the Burge
rs vectors of the misfit dislocations in compositionally graded InGaAs/GaAs
heterostructures. A monotonic change of the lattice tilt along the sample
surface producing in average a concave curvature of the buffer layer lattic
e has been found with a nearly complete alignment of the Burgers vector of
the misfit dislocations at the sample edges. The topographic observations s
howed that the buffer layers can follow a nearly continuous curvature or ca
n be sub-divided in large domains with different average lattice tilt. The
models recently proposed for the formation of tilt in partially released st
ructures are not able to explain the present observation of a lattice tilt
varying coherently along the sample surface. (C) 1999 Elsevier Science B.V.
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