Laser assisted focused He+ ion beam induced etching with and without XeF2 gas assist.

Focused helium ion (He+) milling has been demonstrated as a high-resolution nanopatterning technique, however it can be limited by its low sputter yield as well as the introduction of undesired sub-surface damage. Here, we introduce pulsed laser and gas assisted processes to enhance the material removal rate and patterning fidelity. A pulsed laser-assisted He+ milling process is shown to enable high resolution milling of titanium while reducing sub-surface damage in situ. Gas-assisted focused ion beam induced etching (FIBIE) of Ti is also demonstrated in which the XeF2 precursor provides a chemical assist for enhanced material removal rate. Finally, a pulsed laser-assisted and gas-assisted FIBIE process is shown to increase the etch yield by ~ 9x relative to the pure He+ sputtering process. These He+-induced nanopatterning techniques improve material removal rate, in comparison to standard He+ sputtering, whilst simultaneously decreasing sub-surface damage, thus extending the applicability of the He+ probe as a nanopattering tool.