Authors: S.N. Moon, J.M. Jung, K.M. Lee, W.I. Lee
Affilation: Seoul National University, Korea
Pages: 520 - 523
Keywords: nano imprint lithography (NIL), demolding, surface treatment, friction, AFM
The NIL process can be divided into two steps: the pressing and demolding stages. In the pressing stage, micro/nano scale patterns on a mold are transferred to a polymer resist. During this stage, there are some issues of polymer flow between the mold and the substrate. In the demolding stage after the pattern transfer stage, the demolding forces, which are derived from the contact area between the mold and the polymer resist, are an important parameter for reliability in the reproducibility of the pattern shapes and the process productivity. The occurrence of these demolding forces can cause serious fractures in the polymer patterns and mold. In this study, the characteristics of the demolding forces derived from the mold-polymer contact areas were investigated for different surface energy states, and the results were compared to friction signals measured with a surface treated AFM tip.The experimental results indicate that the demolding forces were strongly affected by micro/nano scale friction, and micro patterns on the mold also increased the demolding forces due to an increased contact area, and this appeared to be less effective in the FOTS layer.