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Free standing microstructures become necessary when transparent materials are unavailable as supporting layers in transmission components. In this work we use electron beam lithography and reactive ion etching in crystalline silicon membranes to fabricate open stencil patterns for two novel applications: transmission reticles containing resolution test patterns for projection soft x‐ray lithography at λ=36 nm; and a Fresnel zone plate for focusing beams of cold neutral atoms. Various schemes are described for making components with minimum zone plate feature sizes down to 0.23 μm and grating features below 0.1 μm. We also report on several materials and processing issues which limit feature sizes and distortions in these microstructures.

Circular Fresnel zone plates, apodized linear zone plates, and a variety of apertures have been fabricated in smooth germanium films deposited on boron doped silicon membranes. Zone widths as small as 60 nm have been fabricated in absorbing layers from 0.25 to 0.5 μm thick. These results were achieved using electron beam lithography in a trilevel resist followed by reactive ion etching to transfer the patterns. These optical elements are key components in a soft x‐ray ‘‘focalometer’’ currently being tested at the NSLS at Brookhaven National Laboratories. The focalometer is a system which can be used to determine the imaging properties of an optical element. In this work it has been used to evaluate the imaging properties of a convergent mirror both before and after a multilayer reflective coating was applied. Results of knife edge scans of images formed by a spherical mirror using 14 nm radiation are reported. The multilayer coating applied to the mirror is found to have only a small effect on these scans.