Abstract
The nanoimprint process of (CH2)n polymer is studied using molecular dynamics (MD) simulations based on the finitely extensible non-linear elastic (FENE) potential. To consider the effect of the anti-adhesion layer, a self-assembled monolayer (SAM) was coated on a stamp and imprinted onto a specimen. The effects of the imprinting temperature, loading and unloading velocities, and aspect ratio of the stamp are evaluated in terms of molecular trajectories, imprinting force, and elastic recovery ratio. Simulation results show that the weights of the reactive force are 62 % and 38 % for the specimen and the SAM, respectively, for a stamp with a length of 5 nm and a height of 9 nm; the weight of the reactive force for the specimen increases with increasing stamp length. During the imprinting process, the required loading force decreases with increasing imprinting temperature and decreasing imprinting velocity. The formation of the pattern is more stable for imprinting at room temperature than that at high temperature due to lower elastic recovery and adhesion during unloading. High-velocity imprinting leads to non-uniform elastic recovery of an imprinted pattern.
Keywords: Nanoimprint, MD, temperature, aspect ratio, SAM, elastic recovery, molecular trajectories