Meniscus-mask lithography for narrow graphene nanoribbons

Described here is a planar top-down method for the fabrication of precisely positioned very narrow (sub-10 nm), high aspect ratio (>2000) graphene nanoribbons (GNRs) from graphene sheets, which we call meniscus-mask lithography (MML). The method does not require demanding high-resolution lithography tools. The mechanism involves masking by atmospheric water adsorbed at the edge of the lithography pattern written on top of the target material. The GNR electronic properties depend on the graphene etching method, with argon reactive ion etching yielding remarkably consistent results. The influence of the most common substrates (Si/SiO2 and boron nitride) on the electronic properties of GNRs is demonstrated. The technique is also shown to be applicable for fabrication of narrow metallic wires, underscoring the generality of MML for narrow features on diverse materials.