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 subsurface 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 subsurface 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 ∼9× relative to the pure He⁺ sputtering process. These He⁺ induced nanopatterning techniques improve material removal rate, in comparison to standard He⁺ sputtering, while simultaneously decreasing subsurface damage, thus extending the applicability of the He⁺ probe as a nanopattering tool.