High-throughput nanofabrication of plasmonic structures and metamaterials with high resolution nanostencil lithography

We demonstrate a novel fabrication approach for high-throughput fabrication of engineered plasmonic antenna arrays and metamaterials with Nanostencil Lithography (NSL). NSL technique, relying on deposition of materials through a shadow mask, offers the flexibility and the resolution to fabricate radiatively engineer nanoantenna arrays for excitation of collective plasmonic resonances. We confirmed that the antenna arrays fabricated by NSL shows high optical quality similar to EBL fabricated ones. Furthermore, we show nanostencils can be reused multiple times to fabricate selfsame structures with identical optical responses repeatedly and reliably. This capability is particularly useful when high-throughput replication of the optimized nanoparticle arrays is desired. In addition to its high-throughput capability, NSL permits single step nanofabrication of plasmonic devices on surfaces that are difficult to work with electron/ion beam techniques. Nanostencil lithography is a resist free process thus allows the transfer of the nanopatterns to any planar substrate whether it is conductive, insulating or magnetic. As proof of the versatility of the NSL technique, we show fabrication of plasmonic structures and metamaterials in variety of geometries. In metamaterial and plasmonic devices, unique geometries with small gaps and asymmetries can induce novel electromagnetic responses such as plasmon induced transparency and also giant near-field intensities that are important for enhanced vibrational spectroscopy and non-linear optics applications. This nanofabrication scheme, enabling the reusability of stencil and offering flexibility on the substrate choice and nano-pattern design could significantly enhance wide-use of plasmonics in sensing technologies.