Modeling of strain fields in semiconductor single-crystals using dynamical diffraction theory.

摘要

The commonly used x-ray kinematical diffraction theory for powder and polycrystalline samples becomes invalid when dealing with x-ray diffraction in single crystals of considerable thickness. In such cases, a more rigorous and complicated theory, the dynamical diffraction theory, must be employed. In this thesis the dynamical diffraction theory was derived from first principles. We observed and studied several dynamical diffraction phenomena, such as back-surface reflection, which would cause a doublet shape of the diffraction spot in a white-beam Laue experiment, as well as anomalous transmission and mirage effects. In order to understand these dynamical phenomena a theoretical analysis was carried out. In addition, we developed a new formulism for the dynamical diffraction on deformed single crystals based on the classical Ewald-von Laue theory, which allowed us to simulate the angular (the plane-wave model) and spatial (the spherical-wave model) diffraction intensity profiles on a single crystal with an arbitrary one-dimensional strain field. Through these studies the quantitative imaging of the strain field in single crystals by x-ray microbeam reflection mapping becomes possible.