Strain analysis of a quantum-wire system produced by cleaved edge overgrowth using grazing incidence x-ray diffraction

A GaAs surface layer of 10 nm thickness was grown on the cleaved edge of an In_0.1Al_0.9As/Al_0.33Ga_0.67As multilayer in order to induce a lateral periodic strain modulation. We apply surface sensitive grazing incidence x-ray diffraction to distinguish between compositional/morphological and purely strain induced modulations. The experimentally determined strain profile is confirmed by finite-element model calculations. The GaAs layer is found to be purely strain modulated with an average lattice parameter change of (0.8±0.1)% with respect to relaxed GaAs. © 2003 American Institute of Physics.