Residue-free room temperature UV-nanoimprinting of submicron organic thin film transistors

In this study we report on an innovative nanoimprint process for the fabrication of entirely patterned submicron OTFTs in a bottom-gate configuration. The method is based on UV-Nanoimprint Lithography (UV-NIL) combined with a novel imprint resist whose outstanding chemical and physical properties are responsible for the excellent results in structure transfer. In combination with a pretreated stamp the UV-curable resist enables residue-free imprinting thus making etching obsolete. A subsequent lift-off can be done with water. The UV-NIL process implies no extra temperature budget, is time saving due to short curing times, eco-friendly due to a water-based lift-off, simple because it is etch-free and completely r2r compatible. It works perfectly even if ultra-thin organic and hybrid films are used as gate dielectrics. On this basis entirely patterned functional submicron OTFTs with pentacene as the semiconductor are fabricated showing clear saturation, low switch-on voltage (similar to 3 V) and a sufficiently high on-off ratio (10(3)). (C) 2009 Published by Elsevier B.V.