Measurements of flow distribution in a thin resin layer during ultraviolet nanoimprint lithography by means of digital holographic particle-tracking velocimetry

There is an urgent need for micro- and nano-scale patterning methods with a high throughput and cost-effective process for the manufacture of devices of the next generation. Ultraviolet nanoimprint lithography (UV-NIL) represents a major breakthrough for next-generation lithography because of its higher resolution and greater simplicity compared with conventional technologies. However, transfer defects such as bubble defects or filling failures in the UV-NIL process have been problematic, because UV-NIL is a contact-type method. Therefore, it is important to elucidate the behavior of UV-curable resin flowing to permit control over defects in the duplicated pattern. In this study, we succeeded in measuring the flow distribution of a thin layer of UV-curable resin in situ during the press process of UV-NIL by means of microscale digital holographic particle-tracking velocimetry, and we clearly showed that a release agent coated onto the nanoimprint mold affects the resin flow. We believe that this study will help to provide a better understanding of the behavior of UV-NIL. (C) 2014 Elsevier B.V. All rights reserved.