The out of beam sight effects in focused ion beam processing

Abstract

We report that during focused ion beam chemical vapor deposition (FIB-CVD) the effect ofdeposition is not limited to the area where the ion beam scanning takes placebut occurs on regions which are out of sight of the incident beam and extendsup to several micrometers away from the specified site. This phenomenon hasdeleterious effects, especially when the nanocontacts are fabricated for the electricalcharacterization of the nanodevices. The deposition occurs into the gap between thecontact pads and acts as a resistance in parallel with the resistance of the nanostructureto be measured. The extended deposition has been explained on the basis ofmolecular cracking of the precursor gas molecules induced by forward scatteredGa ions, and appropriate measures to remove the effect have been suggested.