Scanning x-ray diffraction with 200 nm spatial resolution

We report a scanning technique, which combines high resolution x-ray diffraction (in reciprocal space) along with a submicrometer spatial resolution (in real space). SiGe/Si(001) Stranski-Krastanow islands served here as a well investigated model system to check the limits of the developed method. A set of refractive silicon x-ray lenses focused the x-ray beam size down to a diameter of 200 nm (full width at half maximum), which enables scanning of individual micrometer-sized and even smaller islands. By illuminating diverse {111} island side facets, crystal truncation rods of different orientations were independently excited and thus became distinguishable in the scattering patterns. The reassembling of these locally resolved diffraction patterns coincides with both an integral measurement and a corresponding scattering simulation. (C) 2008 American Institute of Physics.