METHOD OF GENERATING X-RAY DIFFRACTION DATA FOR INTEGRAL DETECTION OF TWIN DEFECTS IN SUPER-HETERO-EPITAXIAL MATERIALS

摘要

A method provides X-ray diffraction data suitable for integral detection of a twin defect in a strained or lattice-matched epitaxial material made from components having crystal structures having symmetry belonging to different space groups. The material is mounted in an X-ray diffraction (XRD) system. In one embodiment, the XRD system's goniometer angle O is set equal to {TB - ß) where TB is a Bragg angle for a designated crystal plane of the alloy that is disposed at a non-perpendicular orientation with respect to the (111) crystal plane, and ß is the angle between the designated crystal plane and a (111) crystal plane of one of the epitaxial components. The XRD system's detector angle is set equal to (TB ~ ß). The material can be rotated through an angle of azimuthal rotation f about the axis aligned with the material. Using the detector, the intensity of the X-ray diffraction is recorded at least at the angle at which the twin defect occurs.