Application of quantitative X-ray phase retrieval from Fraunhofer diffraction data to nano-resolution profiling of materials

X-ray Fraunhofer diffraction data have been collected from a series of weakly thickness-modulated samples using a synchrotron source. Three different areas of a linear Fresnel zone structure etched in a silicon wafer each 10 μm wide were studied. Each area studied included different numbers of zones, ranging from 6 to 20. An X-ray phase retrieval technique was used to profile the complex refractive index within the areas examined. The zone structure thickness profiles were mapped with a spatial resolution of 100 nm.