Diffuse X-ray scattering from misfit and threading dislocations in relaxed epitaxial layers

A statistical theory of X-ray scattering from dislocations oriented parallel or perpendicular to the surface in semiconductor thin film is presented. We apply this theory to two particular cases. At first, we derive formulae for diffusively scattered X-ray intensity from screw threading dislocations in GaN thin film in high-density approximation. Correlation in dislocation positions is involved in calculations. Diffuse X-ray scattering is calculated in case of PbTe thin films with various thicknesses in the second case. From the fit, the dislocation density was determined.