Identification of a buried single quantum well within surface structured semiconductors using depth resolved x-ray grazing incidence diffraction

A free standing surface wire nanostructure defined on GaAs[001] containing a 5 nm thick GalnAs single quantum well (SQW) was analysed, recording reciprocal space maps by coplanar high-resolution x-ray diffraction (HRXRD) and non-coplanar x-ray grazing incidence diffraction (GID). We were able to evaluate the depth and the thickness of the SQW by depth resolved GID via computer simulations based on a kinematic approach. The identification of the SQW was possible exploiting the large scattering contrast between GaAs and GalnAs at the (200) in-plane Bragg reflection. For HRXRD the nearly rectangular shaped wires directed along [110] give the main contribution to the intensity map in reciprocal space whereas the SQW itself is not visible. This demonstrates that combined HRXRD and GID reciprocal space maps provide an entire 3D analysis of surface nanostructures.