X-ray reflectivity reciprocal space mapping of strained SiGe/Si superlattices

Small-angle diffuse X-ray reflection from a SiGe/Si multilayer has been studied theoretically and experimentally. The scattering process has been described by means of the DWBA method. For the description of the rough interfaces, the results of the Markov chain theory have been used. It has been demonstrated that the distribution of the diffusely scattered intensity in reciprocal plane gives some information on both the in-plane and inter-plane correlation properties of the multilayer roughness. The sample of SiGe/Si multilayer grown on a slightly miscut substrate has been investigated. The most suitable structure model describing the form of the interfaces is a combination of the two-level model with the staircase model.