Sub-100 nm-scale aluminum nanowires by stencil lithography: Fabrication and characterization

We present the fabrication process and electrical characterization of sub-100 nm scale Al nanowires (NWs) fabricated by stencil lithography (SL). We use a stencil with sub- 100 nm wide nanoslits patterned by focused ion beam (FIB) milling. The stencil is aligned and clamped onto a substrate containing predefined electrical contacts. Then a 60 nm-thick layer of Aluminum (Al) is deposited through the stencil producing NWs with lengths of ~1, 2 and 5 mum and widths down to 65 nm. The NWs show an ohmic behavior with values varying from 30 Omega up to 300 Omega, depending on the dimensions of the structures. We have extracted a resistivity for the Al NWs of ~10 x 10^-8 Omegam. We also show that stencils can be cleaned and reused, proving that SL is a cost-efficient and scalable manufacturing method for the direct fabrication of metallic NWs on a full wafer scale.