High Spatial Resolution STXM at 6.2 keV Photon Energy

Abstract

We report on a zone‐doubling technique that bypasses the electron‐beam lithography limitations for the production of X‐ray diffractive optics and enables the fabrication of Fresnel zone plates with smaller outermost zone widths than other well‐established approaches. We have applied this method to manufacture hard X‐ray Fresnel zone plates with outermost zone widths of 25 and 20 nm. These lenses have been tested in scanning transmission X‐ray microscopy (STXM) at energies up to 6.2 keV, producing images of test structures that demonstrate a spatial resolution of 25 nm. High spatial resolution STXM images of several biological specimens have been acquired in transmission, dark‐field and differential phase contrast modes.