PLASMONIC NANOLITHOGRAPHY: TOWARDS NEXT GENERATION NANOPATTERNING

Abstract

Plasmonic nanolithography (PNL) is a surface plasmons (SPs)-based high resolution nanolithography technology. It has attracted great interests for its capability of forming sub-diffraction-limit patterns. It explores the properties of surface plasmons in tight light confinement, strongly localized optical field and the enhancement of evanescent filed for super-resolution imaging and lithography. SPs can be manipulated by the interaction of light with metallic structures to generate a strongly enhanced spatial distribution of an electric field in the proximity of metal surface. Once its resonance frequency falls into the photoresponse range of a resist, the resulting optical field would be recorded with nanoscale resolution. Using the low cost light sources, PNL has demonstrated high resolution comparable to the industrial achievement of sub-22 nm half-pitch resolution, which is accomplished using the costly state-of-the-art deep UV lithography tools. Upon the distinct interactions between the light and nanostructures, the PNL is categorized into three types, i.e. enhanced near-field lithography (ENL), superlens (planar lens) lithography (SLL) and focused plasmonic lithography (FPL). This paper will give an overview of the development of these technologies and the latest achievements.