Large-Scale Fabrication of Optically Active Plasmonic Arrays via Displacement Talbot Lithography

Abstract

Periodic nanoapertures fabricated in thin metal films exhibit a range of interesting properties in the presence of electromagnetic waves including phenomena such as extraordinary optical transmission (EOT). Fundamentally, these effects are mediated by plasmons and have been shown to have a vast range of applications, including, colour filtering, chemical sensing, and as components in solar cells. In the majority of cases, the high spatial resolution required for precise fabrication of these structures is limited to direct writing techniques such as Focused Ion Beam (FIB) and Electron beam lithography (EBL), which only cover relatively small, micron-sized, areas. In this article, we describe and demonstrate the fabrication of plasmonically active devices in the visible range using Displacement Talbot Lithography (DTL). This method allows nanometre-resolution photolithography to be performed over very large areas (whole wafers) without any significant degradation in quality. We present experimental results for a range of different structures including periodic, aperiodic and hexagonal configurations in silver films.