Wafer deformation in ultraviolet-nanoimprint lithography using an element-wise patterned stamp

Nanoimprint lithography is a promising method for high-resolution, low-cost nanopatterning. In particular, ultraviolet-nanoimprint lithography (UV-NIL), which requires low imprint pressure, is effective for multi-layer processes. In this study, we investigated the non-uniformity of the residual layer thickness caused by wafer deformation in an experiment that examined different wafer thicknesses using UV-NIL with an element-wise patterned stamp (EPS). The EPS consisted of a number of elements, each separated by a channel. Experiments using the EPS were performed on an EVG620-NIL. Severe deformation of the wafer served as an obstacle to the spread of resin drops, which caused non-uniformity of the residual layer thickness. We also simulated the imprint process using a simplified model and finite element method to analyze the non-uniformity.