Low-pressure detachment nanolithography

Abstract

A simple, one-step method is developed to fabricate various nanostructures such as nanoholes and nanolines based on the detachment of an organic polymer film in contact with a patterned polyurethane acrylate mould under a low physical pressure (1-2 bar) at ambient conditions. Calculation of the work of adhesion based on contact angle measurements indicates that the adhesion strength at the organic/mould interface is greater than that at the organic/substrate interface, resulting in a successful detachment without any surface modifications. 4,4'-bis[N-1-napthyl-N-phenyl-amino]biphenyl (NPB) is used as the organic film owing to its low cohesion energy and stability in air. Nanoholes as small as 150 nm and nanolines as small as 50 nm have been fabricated using this approach. These nanostructures are used as a template for selective deposition of silver nanoparticles and a wet/dry etch resist for further pattern transfer.