Harutaka Mekaru

Immersion Nanoimprint Lithography Harutaka Mekaru

Thermal nanoimprinting is used to modify a manufacturing process as simple fabrication technology that transfers a fine pattern by pressing a mold with nanoscale patterns against a thermoplastic. The molds can be categorized roughly into two types, namely, a positive mold with a convex pattern, and a negative mold with a concave pattern compared with the base level. Around each concave imprinted pattern, the compressed air that is caused by the imprint pressure, generates capillary bridges; and in case of a convex imprinted pattern the trapped air remaining inside the concave mold pattern gives rise to bubble defects. In order to remove such defective molding, I propose a novel technique that I name as ?immersion nanoimprint? where a fluorine liquid is inserted between the mold pattern and the molding material. In this technique, a fluorine liquid improved accuracy remarkably, and realized a complete filling at a low imprint pressure. Also, it was confirmed that the uniformity was greatly improved by improved heat transfer. Thus the immersion nanoimprint lithography is expected to be one of the epoch-making solution that can dramatically decrease the formation of defective molding.