Theory of diffuse X-ray scattering from an epitaxial layer with quantum rings

A theory of diffuse X-ray scattering from a crystalline layer containing quantum rings (QRs) randomly distributed in lateral directions has been developed. The QR is modeled by a truncated cone with a crater that has the shape of an embedded inverted truncated cone. Reciprocal-space maps of the scattering intensity distribution are obtained by numerical calculations for epitaxial layers containing QRs of various shapes. It is established that the angular distribution of the diffuse scattering significantly depends on the slope of the external cone generatrix, as well as on the crater shape and dimensions.