Antireflection (AR) films are useful in preventing the reflection of light from the displays of mobile phones and tablet computers. In particular, films with an AR structure known as the moth-eye structure show excellent performance in preventing light reflection. In a previous study, the authors reported the fabrication of an AR structure by oxygen ion-beam irradiation of glassy carbon (GC). The fabricated pattern consisted of a series of self-assembled conical structures and it had a low-reflection surface. In this study, the authors transferred this AR structure onto a polymer film by roll-to-roll ultraviolet nanoimprint lithography using a replica mold produced from a GC master mold with the AR structure. As a result, the authors were able to produce high-performance AR film at a feed rate of 1.8 m/min. The reflectivity of the film was about 0.1% and its transmittance was about 95% at visible wavelengths.

Roll-to-roll ultraviolet nanoimprint lithography (RTR UV-NIL) has attracted much attention as a high-throughput nanofabrication process. In particular, high-density nanoscale line-and-space (L&S) patterns are widely used for optical devices and printed circuits, such as wire-grid polarizers and transparent electrode films. To realize a simplified high-throughput RTR process, the authors developed a replica roll mold fabrication process and examined the feed speed of RTR UV-NIL. The replica mold was fabricated by applying parallel-plate UV-NIL using a silicon master mold with 100-nm L&S patterns and 200-nm groove depth. Replica molds were coated with 10-nm-thick tungsten and a fluorinated silane coupling agent to prevent the adhesion of UV-curable resin during RTR UV-NIL. The release-coated replica molds were wrapped around roll substrate having a diameter of 150 mm. Using the replica mold, RTR UV-NIL was carried out at different UV doses, which were determined as the product of the UV light intensity and feed speed. The results confirmed that a sufficient UV dose enabled successful pattern transfer, while an insufficient UV dose caused the pattern to break down. In this experiment, a rapid feed speed of 18 m/min was possible under conditions of high UV light intensity. In addition, the release agent was still active after 500 revolutions of the replica roll mold (235.5 m).