Application of mass-separated focused ion beams in nano-technology

Abstract

FIB applications like writing ion implantation, ion beam mixing or ion beam synthesis in the μm- or nm range often require ion species other than gallium. Therefore alloy liquid metal ion sources (LMIS) have to be developed and applied in FIB tools. The energy distribution of ions emitted from an alloy LMIS is one of the crucial parameters for the performance of a FIB column. Different source materials like AuGe, AuSi, AuGeSi, CoNd, ErNi, ErFeNiCr, MnGe, GaBi, GaBiLi, SnPb,… were investigated with respect to the energy spread of the different ion species as a function of emission current, ion mass and emitter temperature. Different alloy LMIS’s have been developed and used in the FZD – FIB system especially for writing implantation to fabricate sub-μm pattern without any lithographic steps. Co and various other ion species were applied to generate CoSi2 nano-structures, like dots and wires by ion beam synthesis or to manipulate the properties of magnetic films. Additionally, the possibility of varying the flux in the FIB by changing the pixel dwell-time can be used for the investigation of the radiation damage and dynamic annealing in Si, Ge and SiC at elevated implantation temperatures. Furthermore, a broad spectrum of ions was employed to study in a fast manner the sputtering process depending on temperature, angle of incidence and ion mass on a couple of target materials. These studies are important for the 3D-fabrication of various kinds of micro-tools by FIB milling.