A multilayer nanostructure for linear zone-plate applications

A multilayer nanostructure of 728 alternating WSi2 and Si layers with thicknesses gradually increasing from 10 to ∼58 nm according to the Fresnel zone-plate formula has been fabricated using dc magnetron sputtering. This structure was analyzed with a scanning electron microscope (SEM) and tested with 19.5-keV synchrotron X-rays after sectioning and polishing. Line focus sizes as small as 30.6 nm have been achieved using a sectioned multilayer in transmission diffraction geometry.