Low-energy ion optical system with a liquid-metal ion source for imaging and processing solid structures

Abstract

A low-energy ion optical system has been developed for scanning ion microscopy (SIM) as well as for processing solid structures under ultra-high-vacuum conditions. The ion optical system is composed of a gallium liquid-metal ion source, two focusing lenses, a stigmator and a deflecting device. The ion optical properties have been determined. This ion optical system has been optimized for the low-energy range between 3 and 15 keV to achieve a high current density (up to 1 A/ cm 2) and a high resolution (of the order of 100 nm). The theoretical results are consistent with beam diameter evaluations from secondary electron images.