Fabrication of refractive X-ray focusing lenses by deep X-ray lithography

This report describes the fabrication process by deep X-ray lithography of a new type of hard X-ray lens made of stacks of identical prisms with dimensions in the 10-20 μm range. The size deviations of the structural dimensions are evaluated for lenses fabricated in PMMA and SU-8 polymer materials. Radiographs taken on a synchrotron allows the measurement of the prism etched depth showing that the focusing quality is directly correlated with the quality of the etching. Finally the technological process parameters are optimized to achieve aspect ratio of 25:1.