Evaluation of filling behavior on UV nanoimprint lithography using release coating

Ultra violet nanoimprint lithography (UV-NIL), which is able to obtain the nano-scale pattern effectively and quickly, is strongly desired for the next-generation lithography technology. However, it is well known that the higher viscosity UV-curable resin with UV-NIL tends to be the shorter obtained pattern without the sufficient transfer pressure. This phenomenon is caused by the filling behavior of UV-curable resin into the UV-NIL mold, thus, the investigation of the filling behavior is very important. In this study, the filling behavior in UV-NIL was observed by using a “midair structure mold”, which is able to eliminate the bubble defect. As a result, it is clear that the filling behavior with low transfer pressure was depended on the capillary force in the mold pattern, which is described by the mold aperture size, the mold surface condition and the resin property.