Lifetime evaluation of release agent for ultraviolet nanoimprint lithography

Abstract

Ultraviolet-nanoimprint lithography (UV-NIL) is a powerful tool for mass production of nano-scale patterns. In UV-NIL, it is very important to coat the mold surface with a release agent to prevent the adhesion of UV curable resin. However, the release agent has a lifetime and by repeated UV-NIL transfer, the release layer is degraded and finally, UV curable resin adheres to the mold surface. To clarify the lifetime of the release agent, this study measured the contact angles of a silicon (Si) mold surface coated with various release agents during repetition of the UV-NIL process. Three types of fluorinated silane coupling agent were used for the release layer and the durability was measured on a patternless Si surface. The results showed that the C8H4Cl3F13Si release agent has high durability. A patterned Si mold was then coated with this release agent and evaluated during repetition of the UV-NIL process. After 1000 repetitions, the contact angle was still high, but a defect occurred at the 900th repetition. Therefore, the lifetime of this release agent when using a Si mold and UV curable resin is approximately 800times.