Hard X-ray microbeam lithography using a Fresnel zone plate with a long focal length.

The article investigates the focused hard X-ray microbeams for use in X-ray nanolithography. It confirms that the focused X-ray beam retains a high degree of collimation owing to the long focal length of the Fresnel zone plate (FZP), which facilitates hard X-ray nanoscale lithography. It also discusses the estimation of the focusing efficiency from the integrated intensity ratio between the focused beam and the unfocused direct beam.