Near-diffraction limited coherent X-ray focusing using planar refractive lenses made of epoxy SU-8 resist

摘要

We present results on comprehensive studies of high resolution SU-8 planar refractive lenses. Lens optical properties were investigated using coherent high energy X-ray radiation. Resolution of about 270 nm was measured for the lens consisting of 31 individual lenses at energy 14 keV. Coherent properties of the set-up permit to resolve near-focus fine structure, which is determined by tiny aberrations caused by lens imperfections close to the parabola apex. This study allows understanding as far SR deep lithography as possible can maintaine to close tolerances for lens parameters. Two-dimensional focusing crossed lenses were tested and imaging experiments in projection and imaging mode were conducted. Radiation stability test was performed and conclusions on the applicability of SU-8 lenses were done.