Numerical Analysis of Nano-imprinting Process Based on Continuum Hypothesis

摘要

Nano-imprint lithography (NIL) is a processing technique capable of transferring nano-scale patterns onto a thin film of thermoplastics such as polymethyl methacrylate (PMMA). Feature sizes down to 10 nm have been demonstrated to be made possible using this process. In NIL, it is imperative to thoroughly understand the flow of resin to ensure complete transfer of the pattern. Due to the size of the pattern, experimental observation may be very difficult, if not totally impossible. In this study, a numerical simulation tool to calculate the two dimensional resin flows and heat transfer during NIL has been developed. The code is based on the continuum hypothesis with some modify-cation to accommodate the size effect, such as slip along the boundary. In order to fully account for the surface tension effect, which may play a dominant role, a moving grid system is adopted. Numerical simulations have been performed for different sets of process parameters. Parametric study shows that the surface tension effect indeed is a dominant factor. With change in the values of the surface tension as well as the contact angle, filling patterns and the resulting free surface become different.