RADIATION-ENHANCED NETWORK FORMATION IN COPOLYMER GALVANOFORMS FOR DIFFRACTIVE NICKEL X-RAY OPTICS WITH HIGH ASPECT RATIOS

High-resolution x-ray microscopy makes use of nanostructured diffracti ve optics such as Fresnel zone plates made of nickel. These micro zone plates are manufactured using microscopic galvanoforms and electrodep osition techniques. Copolymer galvanoforms for nickel micro zone plate s were irradiated with high doses of x-ray radiation to increase the d egree of cross-linking of the copolymer network; in this way, exact pa ttern replication in the galvanoform was obtained for zone aspect rati os of up to 8:1. Using these galvanoforms, nickel micro zone plates we re produced for the soft x-ray wavelength lambda = 2.4 nm, with smalle st zone widths of 30 nm and 40 nm, achieving first-order diffraction e fficiencies of up to 13% nd 20%, respectively. (C) 1998 American Insti tute of Physics.