Using of light and heavy ion beams in modern FIBs

The incident ion defines the interaction mechanism with the sample surface caused by the energy deposition and thus has significant consequences on resulting nanostructures [1]. Therefore, we have extended the FIB technology towards the stable delivery of multiple ion species by liquid metal alloy ion sources (LMAIS) [2]. These LMAIS provides single and multiple charged ion species of different masses. As an example we introduce the GaBiLi LMAIS [3]. Such “universal” source enables high resolution imaging with light Li ions and sample modification with Ga or heavy polyatomic Bi clusters, all coming from the same ion source. Light ions are of increasing interest due to the available high resolution in the nanometer range and their special chemical and physical behavior in the substrate. We compare helium and neon ion beams from a helium ion microscope with beams such as lithium, boron, and silicon, obtained from a mass-separated FIB using a LMAIS with respect to the imaging and milling resolution, as well as the current stability [4]. The bombardment of solids by poly-atomic (cluster) ions leads to nonlinear collision cascades in near-surface regions. In comparison with linear cascades by monoatomic ions, much higher energy deposition occurs up to local surface melting [5]. Here, we also report the study on the sputter yield of Si under the bombardment by atomic Bi+ and cluster Bin+ (n = 2-4) ions with the same specific energy related to one incidence single atom [6]. [1] P. Mazarov, V. Dudnikov, A. Tolstoguzov, Electrohydrodynamic emitters of ion beams, Phys. Usp. 63 (2020) 1219. [2] L. Bischoff, P. Mazarov, L. Bruchhaus, and J. Gierak, Liquid Metal Alloy Ion Sources – An Alternative for Focused Ion Beam Technology, Appl. Phys. Rev. 3 (2016) 021101. [3] W. Pilz, N. Klingner, L. Bischoff, P. Mazarov, and S. Bauerdick, Lithium ion beams from liquid metal alloy ion sources, JVSTB 37(2), Mar/Apr (2019) 021802. [4] N. Klingner, G. Hlawacek, P. Mazarov, W. Pilz, F. Meyer