Polarity determination of single-crystal epitaxial layers by x-ray diffraction

Abstract
The anomalous scattering of x rays has been used to determine the polarity of single‐crystal epitaxial layers, as grown on the substrate material. The method relies on the breakdown of Friedel’s law in noncentrosymmetric structures and is particularly effective when there exists a large difference between the values of the imaginary anomalous dispersion correction, f‘, for the respective atomic species. The method is nondestructive and measurements are taken from only one side of the sample (the side with the epitaxial layer).