Initial resolution measurements of miniaturized electrostatic lenses for LVSEM

Theoretical and experimental investigations on miniaturized electrostatic lenses for high-resolution low-voltage scanning electron microscopical applications are presented. The electron optical column consists of a Schottky emitter including the extraction anode and a miniaturized three electrode lens consisting of conventional (electron microscopical) platinum apertures. The lens has been optimized with respect to resolution and a value of about 5 nm at a working distance of 1 mm and a beam energy of 1 keV is predicted by simulation. Details on the resolution measurements are presented. An initial experimental value amounts to 31 nm. Specific problems encountered during building and alignment of the lens and measuring the resolution are discussed as well.