Real poly(p-phenylene vinylene) features from near-field scanning optical lithography and the implications for further modelling

摘要

Near-field scanning optical lithography (NSOL) has been used to produce ordered structures of the semi-conducting polymer poly(p-phenylene vinylene) at sizes comparable to optical wavelengths. Structures on this scale are of interest for integrated optical devices. Here we study the effect of precursor film thickness upon the size and shape of lithographically produced features. We show that the discrepancies between the predicted and measured structures arise from two key factors: (1) the inherent change in the refractive index of the precursor polymer that occurs during lithography and (2) the considerable length of a precursor polymer relative to the characteristic NSOL feature dimension. Suggestions are made for the improvement of modelling accuracy.