COPLANAR AND GRAZING-INCIDENCE X-RAY-DIFFRACTION INVESTIGATION OF SELF-ORGANIZED SIGE QUANTUM-DOT MULTILAYERS

We report on a formalism for the calculation of diffusely scattered x- ray intensity from spatially inhomogeneous strain fields in Ge rich is lands and in the surrounding Si matrix of SiGe/Si multilayers. The dat a analysis is based on a theory considering the two-dimensional statis tical distribution of the dot positions, which allows a common formali sm for both coplanar and grazing incidence scattering geometries. The strain fields were simulated based on the approach of the elastic Gree n function, taking the influence of the elastic strain relaxation at t he sample surface into account. From these simulations the degree of r elaxation of the islands was obtained, which compared very well with e xperimental data derived from x-ray reciprocal space maps. [S0163-1829 (98)02736-2].