Advanced nanoimprint lithography using a graded functional imprinting material tailored for liquid crystal alignment

摘要

Nanoimprint lithography technology, which is able to easily create nanometer-resolution two-dimensional surface grooves on substrates over a large area by a step and stamp process, opens up an intriguing opportunity for functional liquid crystal (LC) alignment. We describe here a hybrid polymer consisting of two distinct moieties with largely different thermomechanical properties and surface activity. We present the results of nanoimprint lithography experiment using the hybrid polymer to demonstrate the practical applicability as an LC alignment layer. This material shows excellent capability both as a nanoimprinting material, requiring softness at moderate temperatures, and as a LC alignment layer, requiring sufficient rigidity. LC devices using the alignment layer show fairly stable electro-optic characteristics even after thermal aging, due to its high thermal stability. The soft component of the hybrid polymer helps it provide the multiple imprinting capabilities at higher temperatures virtually without any mold damages.