Amplification of specular x-rays caused by grazing-angle incidence backscattering diffraction in epitaxial bi-layer grown on relaxed crystalline substrate

Abstract

This paper concerns the application of the extremely sensitive, high-resolution and non-destructive grazing-angle incidence x-ray backscattering diffraction (GIXB) technique for the investigation of a bi-crystal-like Si/Si1−α−βGeαCβ bi-layer, which is epitaxially grown on a bulk relaxed Si substrate. The diffracting lattice planes of a relaxed Si cap layer and a strain-compensated Si1−α−βGeαCβ layer have the same value of spacing parameter dhkl along the growth surface. Amplification of a mirror x-ray vacuum wave is revealed and illustrated graphically. Such a phenomenon is caused by a shift between diffracting lattice planes of the epilayers. Hence, this phenomenon can be applied, for example, to the characterization of the interface quality of crystalline epilayers.