Ionic Liquid Ion Source Development
Ionic Liquid Ion Sources (ILIS) consist of an electrochemically-sharpened tungsten needle, which is covered in an organic ionic liquid. By applying an electric potential between the needle and a downstream metallic extractor, a structure known as a Taylor cone is formed at the tip of the needle. Once we exceed a threshold voltage, ions and droplets are extracted from the cone, and pass through a hole in the extractor. One possible application of ILIS is the field of lithography, specifically for Focused Ion Beam (FIB) applications. The ILIS beam can be focused using special optics and then directed to a substrate for patterning. Traditionally, Liquid Metal Ion Sources (LMIS) have been used in FIB, but the ILIS, which has the same working mechanisms, could bring many advantages to these processes. For instance, the stable operation at low currents helps improve the resolution of the beam. Also, the variety of ionic liquids is immense, which increases the number of possible applications of an ILIS based FIB.  Ions present in some of the ionic liquids are reactive, which could eliminate the need of reactive assistance in some FIB etching processes .
This work evaluates porous carbon based resorcionol-formaldehyde xerogels as emitter substrates, and the feasibility of laser micro-machining of high aspect ratio emitter features.
Interaction with materials
The SPL developed carbon based ILIS has been implemented in an ion gun geometry traditionally used in FIB which was provided by LPN-CNRS. In the irradiation experiments performed, the ion gun with the carbon xerogel ILIS is fired towards a target covered with a copper mask.
After irradiation at constant emitter current for several minutes, the shadow mask is removed and the resulting pattern is profiled to determine if the beam exposure resulted in deposition or etching of the substrate.