Room Temperature Detachment Nanolithography Using a Rigiflex Polymeric Mold

Abstract

We report on detachment nanolithography of an organic thin film at room temperature mediated by ultraviolet (UV) exposure. A nanopatterned, UV curable polyurethane acrylate (PUA) mold was placed on a spin-coated organic film made of 4,4'-bis[N-1-napthyl-N-phenyl-amino]biphenyl (NPB) under a low pressure (1-2 bar). A higher work of adhesion at the organic/mold interface induced detachment of the contacting layer on silicon or gold substrate, resulting in well-defined nanopatterns without a residual layer. The detachment was highly improved by a short-term UV exposure, rendering the film surface free from contaminant hydrocarbons with a lower cohesive force, as confirmed by Fourier transform infrared (FTIR) spectroscopy and measurements of contact angle of water.