Compressed-carbon dioxide (CO2) assisted nanoimprint lithography using polymeric mold
We have represented a compressed carbon dioxide (CO2) assisted nanoimprint lithography (CO2-NIL) technique using a fluoropolymer mold. Glass transition temperature (Tg) of polymethylmethacrylate (PMMA) under the compressed-CO2 is apparently depressed by the absorption of CO2, and the plasticized PMMS has enough mobility to rise into the groove of fluoropolymer mold. As a result, the 100nm level of submicron features are uniformly fabricated on the polymer surface over a large area, and the use of fluoropolymer mold having a low interfacial energy assures the clean release from the patterned surface without a release agent. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) observation confirm these results. CO2-NIL process could fabricate micro/nano-patterns without thermal cycle, high pressure and anti-adhesion layer compared to conventional NIL.
nanoimprint lithography compressed carbon dioxide fluoropolymer micro/nano-patterns