Filling behavior and mold release force in UV nanoimprinting using PDMS mold in different atmosphere

Abstract

Ultraviolet nanoimprint lithography (UV-NIL) is a recently developed technology that allows low-cost nanofabrication. Bubble-free filling needs to be achieved to realize high-throughput mass production in UV-NIL. Although bubble-free filling can be accomplished by performing UV-NIL under vacuum, nonvacuum processes can lower equipment and operation costs. Polydimethylsiloxane (PDMS) is known as a gas transmittable materials due to its molecular feature and used for flexible molds in UV-NIL. In this work, we investigated the effects of UV-NIL using PDMS mold for filling behaviors and mold release force in different atmosphere. Bubble-free filling of UV-NIL was successfully demonstrated in air, and 1, 1, 1, 3, 3-pentafluoropropane (PFP) gas atmosphere. The average release force following UV-NIL in PFP was 8.14 N, which is 52 % smaller than that following UV-NIL in air. Fine nanopatterns with 250 nm width were successfully fabricated by UV-NIL in PFP atmosphere without any defects.