Fabrication of 3D nanovolcano-shaped nanopores with helium ion microscopy

Abstract

Both helium and gallium ion beams were employed to fabricate nanopores. Herein, three-dimensional nano-volcano-shaped nanopores (3D-NVNs) were directly formed using helium ion beam with no precursors required, while the gallium ion beam produced V-shaped nanopores. Hundreds of 3D-NVNs were fabricated with a mean diameter of 229 ± 7 nm, where the He ion beam milling rate for the 3D-NVNs was 3.6 ± 0.2 μm3/μC. The height of the 3D-NVNs was greater than their depth when the dose range was 0–10 nC/μm2, while the height remained constant for doses above 10 nC/μm2. Trajectory simulations of the ion bombardment into the gold film clarified that ion implantation could primarily account for the volcano-shaped nanopore formation.