20-nm-resolution Soft x-ray microscopy demonstrated by use of multilayer test structures

A spatial resolution of 20 nm is demonstrated at 2.07-nm wavelength by use of a soft x-ray microscope based on Fresnel zone plate lenses and partially coherent illumination. Nanostructural test patterns, formed by sputtered multilayer coatings and transmission electron microscopy thinning techniques, provide clear experimental results.