X-ray zone plates fabricated using electron-beam and x-ray lithography

Abstract
Fresnel zone plate patterns, free of spherical aberration, with diameters of up to 0.63 mm and linewidths as small as 1000 Å were fabricated on polyimide membrane x-ray masks using scanning electron beam lithography. Distortion of the electron beam scan raster was reduced to ?2500 Å over a 2×2 mm field by applying deflection corrections, while viewing the distortion using a Moiré method. CK x-ray lithography was used to replicate the zone plate pattern in thick PMMA over a 100 Å thick plating base on a glass substrate. Zones plates in 1.3 μm thick gold were fabricated by plating, and made free-standing by removal of the plating base and the supporting glass substrate. Zone plates were tested as imaging elements with visible light and soft x-rays.