Nanoscale tensile stress approach for the direct writing of plasmonic nanostructures

Abstract

One- and two-dimensional plasmonic nanostructures can be fabricated using nanoscale tensile stress. A polymer layer, coated with a thin metal film, is exposed to an interference pattern produced by ultraviolet laser beams. Crosslinking is induced between the polymeric molecules located within the bright fringes. This process not only increases the refractive index but also reduces the polymer layer thickness. Corrugations occur on the continuous thin metal film due to the nanoscale stress in the polymer layer. Thus, a periodic nanostructure of area 3 × 3 mm and depth 50 nm is created both in the polymer and metal films with excellent homogeneity and reproducibility. This method enables direct writing of a large-area plasmonic nanostructure at low cost which can be used in the design of optoelectronic devices and sensors.