Effects of Thin Films and Confinement on Thermal Nanoimprint Lithography Patterning

摘要

Nanoimprint lithography (NIL) is a next generation lithography (NGL) with the potential to realize many emerging technologies with smaller scales compared with conventional lithography. One of the primary differences from conventional lithography is that NIL utilizes a mechanical squeeze-flow mechanism to force the resist material to fill the mold. This requires inducing polymer flow in thin films and into nanoscale spaces. It is well known from the polymer thin film literature that many of the fundamental properties of polymeric materials begin to deviate from their bulk values when the film thickness drops below approximately 50 nm. These are precisely the same length scales that are relevant for NIL. In fact, there are many reports of how viscoelasticity, diffusion, and other transport properties slow down in thin polymer films. These results suggest that NIL mold filling process become more difficult in thin polymer films and nanoscale mold cavities. In this presentation we present evidence in support of this notion.