A Bismuth Liquid Metal Ion Source for mass separated FIB Applications

A bismuth liquid metal ion sources (LMIS) is investigated with respect to the emission behaviour as a function of current and temperature, the mass spectra and the energy distribution of the individual ion species [1]. For this Bi-LMIS the sputtering yields for monomer Bi ions as well as Bi-clusters (Bi2+, Bi3+, Bi4+, Bi3++) on Si, SiO2 and Ge substrates were compared with that of Ga projectile ions applied in a mass separating focused ion beam system (CANION 31Mplus). Additionally, a self-organisation of very regular, high-amplitude dot and ripple patterns depending on the angle of incidence on (001)Ge has been found under bombardment with heavy ions of bismuth dimers and trimers. Some applications in surface modification will be presented and discussed.

[1] L. Bischoff, W. Pilz, P. Mazarov, A.D.Wieck, Comparison of bismuth emitting liquid metal ion sources, Appl. Phys. A 99 (2010)145.