BEAM INTERACTIONS IN A FOCUSED ION-BEAM SYSTEM WITH A LIQUID-METAL ION-SOURCE

The quality of focused ion beam systems strongly depends on the aberra tions of the optical elements and the Coulomb interactions between the beam particles. For a one lens system, with an image distance of 500 mm, it is shown, both experimentally and by simulation that a minimum spotsize of about 100 mu m is observed, although the geometrical diame ter is only 7.2 mu m, including aberration effects. The influence of C oulomb interactions on the current density is also demonstrated: the c urrent density on the target even decreases with increasing beam curre nt.