Focused ion beam nanolithography on AlF3 at a 10 nm scale

We have investigated the potential use of AlF3 thin films (50 nm thick) as negative inorganic resist layers for focused ion beam nanolithography. We demonstrate that 10 nm-wide lines can be fabricated using a Ga+ beam of 30 keV incident energy. The resist sensitivity of 1010 Ga+/cm is two orders of magnitude lower than for polymethylmethacrylate organic resist. We emphasize that this low sensitivity associated with the exposure mechanism of the resist minimize the influence of the tails of the current distribution within the ion spot.