Optical monitoring of a poly(styrene) residual layer on a photocrosslinkable monolayer in thermal nanoimprint lithography

We investigated the residual layer thickness of a poly(styrene) thin film patterned by the reactive-monolayer-assisted thermal nanoimprint lithography using a SiO2 mold with convex patterns on mm-scale. The profile of the residual layer thickness was monitored optically with a reflective thickness monitor. We presented that the residual layer thickness was significantly influenced by maintained temperatures, molecular weights, and additives. Poly(styrene) containing its low molecular-weight component showed suitable concave patterns with the residual layer thickness uniform.