Recent advances in adapting ionic liquid ion sources to focused ion beams technologies

In this work, we present and discuss our recent advances in Electro-HydroDynamic (EHD) field ion emitters operated using Ionic Liquids (ILs), which we develop towards Focused Ion Beam (FIB) applications. Using a non-conventional approach based on high density nanometer-sized tips (MT) grown on a slab planar emitter, a dedicated ion gun setup and three very dissimilar ILs, we demonstrate that stable unipolar ion emission (positive mode, (2 μA, 8 keV) can be achieved. Each ionic liquid (EMIM + ,BF4 − , EMIM + ,DCA − and DEME,BF4 − ) was successfully operated over 30 min and delivered a total of 3.6 10 −3 C in a unipolar continuous sequence. We compare, detail and discuss, the evolution of these ILs subjected to such intense, stresses, whilst their structure changes are elucidated using spectroscopic analysis using 1 H and 19 F NMR. Our experiments demonstrate that severe ILs degradation, universally encountered so far, can be avoided and thus could pave the way to Task-Oriented ILs (TOILs) capable of moving towards innovative applications such as chemical direct patterning by FIB or complex Integrated Circuits (ICs) devices local delayering.