Fabrication of x-ray zone plates with a minimum zone width smaller than 100nm by electron beam lithography

Abstract

A partial transmission Fresnel zone plate (PT-FZP), a new kind of modified zone plate, in which part of the normally transparent zones is transparent, is proposed. The resolution of PT-FZP is shown to be nearly the same to that of the normal zone plate. In PT-FZP, the distance between transparent zones can be set large so that a zone plate with very high resolution can be fabricated by electron beam lithography because the proximity effect due to electron scattering in a resist layer can be reduced. Part of the PT-FZP pattern of 100nm thick gold with a zone width of 25nm can be obtained by a 50keV electron beam exposure system.