Direct milling of 25 nm in diameter gold and graphene nanogears by a focused He+ ion beam

Abstract

The direct focused helium ion beam milling of solid-state nanogears down to 25 nm in diameter is presented. Sapphire is the supporting surface to release the heat created by this milling process. For this free of resist process, the He+ dosing was first calibrated to limit the lateral fusion in the deposited nanomaterial during the sculpturing of the teeth. 25 nm in diameter solid-state nanogears were fabricated in a 20 nm in thickness Au nanomaterial, in a graphene multilayer and in a monolayer having a van der Waals thickness compatible with a single molecule-gears for transmission of rotation. Optimizing again the He+ dosing for a transmission electron microscope grid, free standing graphene monolayer nanogears were also sculptured down to 40 nm in diameter.