Ionic liquid ion sources as a unique and versatile option in FIB applications

This work discusses the potential applicability of point sources to focused ion beam (FIB) technology based on molten salts at room temperature, known as ionic liquid ion sources (ILIS). The beam shape and divergence angles for ILIS using the ionic liquid EMI-BF(4) (1-ethyl-3-methylimidazolium tetrafluoroborate) are reported, as well as the stability of the source in an alternating polarity regime. Stable emission from ILIS using the liquid BMI-lm (1-butyl 3-methylimidazolium imide) was obtained, and the energy characteristics of the full beam are presented. A magnetic filter is proposed to separate the ion beam by degrees of solvation to determine the energy characteristics of individual species. (C) 2010 Elsevier B.V. All rights reserved.