Lift-off process using bilayer ultraviolet nanoimprint lithography and methacryloxypropyl-terminated-polydimethylsiloxane-based imprint resin

Abstract

A high-fidelity lift-off process using bilayer ultraviolet nanoimprint lithography (UV-NIL) to fabricate nanosized metal pattern was demonstrated. High O(2) reactive ion etching (RIE) selectivity of the imprinted resist pattern to the underlayer is necessary to create the undercut pattern profile that is essential for the stable lift-off process. A methacryloxypropyl-terminated polydimethylsiloxane (M-PDMS)-based UV-curable liquid-phase imprint resin and a polyvinyl alcohol (PVA) underlayer were applied to bilayer UV-NIL for the high-fidelity lift-off process. The M-PDMS-based imprinted resist pattern showed high etch resistance to O(2) plasma and the undercut pattern profile of the PVA underlayer for the lift-off process was formed by the O(2) RIE process. The size and shape of the imprinted resist patterns were hardly changed during PVA underlayer etching by O(2) RIE. As a result, high-fidelity and high-aspect-ratio metal patterns without rabbit-ear-shaped defects were fabricated by the lift-off process using bilayer UV-NIL with the M-PDMS-based imprint resin, which has high etch resistance to O(2) RIE, and the PVA underlayer.