High-resolution X-ray Microdiffraction System for Characterization of Selectively Grown Layers using a Zone Plate Combined with a Narrow Slit

摘要

We have developed a high-resolution x-ray microdiffraction system at the BL24XU of the SPring-8. This system uses a focused beam produced by using a zone plate combined with a narrow slit. The size of the focused beam is 0.32 μm vertically and 1.3 μm horizontally and the angular divergence in the horizontal direction is about 70 μrad at a photon energy of 15 keV. This low-divergence microbeam enables us to perform high-resolution x-ray microdiffraction experiments using a precise θ-2θ goniometer with sub-100-nm-resolved XYZ sample positioning stages. We demonstrate that the spatial non-uniformity of the strain and the period in InGaAsP multi-quantum-well structures, fabricated by selective metalorganic-vapor-phase epitaxy, can be measured with sufficient accuracy using this system.