Zone-doubled fresnel zone plates for scanning transmission X-ray microscopy

Abstract

We demonstrate the highest spatial resolution reported in scanning transmission x-ray microscopy to date. For the first time in x-ray microscopy, features below 10 nm in width were resolved in the soft x-ray regime (1.2 keV) and 20-nm lines and spaces were visible at multi-keV photon energies (6.2 keV). These achievements were accomplished using zone-doubled Fresnel zone plates. These lenses were fabricated by combining electron-beam lithography and atomic layer deposition of iridium. Diffraction efficiencies up to 8% were measured for zone-doubled Fresnel zone plates with an outermost zone width of 25 nm at 6.2-keV photon energy. © 2011 American Institute of Physics.