Hybrid and effective satellites for studying superlattices

Abstract Observation of new synchrotron X-ray scattering processes in semiconductor superlattice structures are reported. They are analogous to the three-beam diffraction in single crystal; however, the basic difference is that in these new processes superlattice-satellite reflections came to play. They give rise to effective-satellite reflections (superlattice–superlattice coupling) and hybrid-satellite reflections (substrate–superlattice coupling). These sort of reflections are features that depend on the rotation of the sample around the surface-normal direction, i.e. an azimuthal or φ rotation. Their positions in φ are very sensitive to the in-plane projection of the reciprocal space, but while the effective-satellite reflections are sensitive to the superlattice parameters, the positions of the hybrid-satellite reflections depend mostly on the substrate ones. The selective sensitivity of these two sort of reflections is the physical fact that can be used as a new tool for studying superlattices.