High-resolution X-ray diffraction is nowadays a powerful tool for the non-destructive structural analysis of epitaxial layers, heterostructures and superlattice systems. It is a standard tool used in industrial production as well as in the development phase of epitaxial grown structures.
A lot of important information can be obtained from the diffraction patterns: alloy composition and uniformity of epitaxial layers, their thicknesses, the strain and strain relaxation, and the crystalline perfection related to their dislocation density. Even the formation of interdiffusion and intermixings of interfaces can be investigated under certain circumstances.
For a quick inspection, the peak positions of the substrate and layers can be used for the analysis. However, in general full pattern simulations based on dynamical scattering theory are applied for the quantitative determination of relevant parameters.