Application of X-ray diffraction in Laue geometry to imperfect near-surface layers

The paper presents the X-ray diffractometry analysis of thin-layer structures made by exploiting the combination of two diffraction geometries-the Bragg one and the Laue one. For this purpose a three-crystal setting was applied. Since the structural parameters of thin layers vary primarily along the surface normal, directing the diffraction vector along this normal, one can succeed in the assessment of the quality in whole, but not in the extraction of different components of lattice damage. The paper shows that, in order to evaluate the contributions, the application of the Laue geometry is promising; it substantially facilitates the study of relaxation, the determination of compositionally dependent properties and the evaluation of macro- as well as micro-strain components. The objects under study were GaAs/Si and SiGe/Si heterostructures as well as (CaF2 + CdF2)/Si superlattices.