MZP design and fabrication for efficient hard x-ray nano-focusing and imaging

Abstract

Efficient focusing optics are a key ingredient for high-resolution (few nanometer) hard x-ray imaging. In recent years, a combined optical scheme using prefocusing to match the coherent fraction of the synchrotron’s x-ray beam to a high-resolution multilayer zone plate (MZP) has been presented. This scheme allows sub-5 nm focusing of hard x-rays in two dimensions. Nevertheless, the first lenses prepared by pulsed laser deposition of alternating WW and Si layers were limited by a low deposition rate of W and the formation of lots of Si-droplets during film growth. Thus, the material combination has been changed to Ta 2 O 5 and ZrO 2 , allowing a much faster and more accurate layer growth. Here we present latest developments achieved in both design and fabrication of high-resolution MMZPs: A MZP with a lens diameters of about 15 micrometers, sharp layer interfaces, 5 nm outermost zone widths and a focal length of 0.5 mm. Too increase the focusing efficiency even more, a tilted geometry using a pulled glass fibre was successfully implemented.