High-performing submicron organic thin-film transistors fabricated by residue-free embossing

In this study, we report on an innovative residue-free nanoimprint lithography process for the patterning of submicron-spaced contacts, used as source and drain electrodes in downscaled organic thin-film transistors. The method is based on thermally initiated radical polymerization of a novel imprint resist whose outstanding chemical and physical properties are responsible for the excellent results in processability and structure transfer. In combination with a pretreated stamp the thermally curable resist enables residue-free imprinting, thus making etching obsolete. In addition, this process implies only moderate temperature budgets and it is eco-friendly due to a water-based lift-off. To validate the process, source and drain patterned submicron organic thin-film transistors with pentacene as the semiconductor were fabricated, which show excellent transistor behavior parameterized by a low switch-on voltage of Vso = −3 V, an on–off ratio of more than 105 and a charge carrier mobility of μ = 0.25 cm2/V s.