Gradient-Field-Plasma Modification of Imprinted Nanopatterns

We report on a one-step progressive modification of imprinted nanopatterns for the induction of a structural and physicochemical gradient in a single chip with the use of gradually attenuated oxygen plasma. Imprinted line patterns could be easily tapered off to up to 60% of their original line width, which was found to be dependent upon the rate of plasma attenuation. Gradually modified nanopatterns are believed to have a continuous variation of physicochemical properties along the pattern gradient, which in this study was exemplified in contact angle variation, which was observed to be more than a factor of about 5 in 2 cm separation on a sample surface. It was also demonstrated for modified patterns used as replica molds for pattern reversal in consecutive processes. Furthermore, it was also proven that this gradual modification method is applicable to various imprint patterns of different structures and resist materials.