Fabrication of 3 nm wires using 100 keV electron beam lithography and poly(methyl methacrylate) resist
We report the fabrication of 3 nm NiCr wires on a solid silicon substrate. The process uses conventional 100 keV electron beam lithography and poly(methyl methacrylate) resist. The wires consist of short, continuous, lengths of metal that are attached at either end to 20 nm wide wires. Instead of exposing continuous lines in the resist, we blank the beam for several pixels to leave a gap. The resist in the gap is therefore exposed only by the secondary electrons from the neighboring regions that are directly exposed by the beam. The technique is repeatable and we demonstrate that it is possible to make 3 nm features on demand.