Coarse-Grain Simulations of the Polymer Filling Process in Nanolithography

Abstract

A coarse-grained molecular dynamics model was established to investigate the deformation characteristics of the polymer in nanoimprint lithography (NIL). The proposed simulation model consists of a Si mold with a line pattern, an amorphous PMMA thin film, and a Si substrate with the periodic boundary condition in the horizontal direction. The effect of the degree of polymerization and the imprinting temperature on the polymer deformation behavior were investigated from the aspects of the density change of the polymer and the pressing force required to fill the mold cavity. Simulation results show that the closer the polymer molecules are getting to the mold surface, the more obvious the effect of extension due to the interfacial friction and adhesion between the polymer molecules and the mold surface is. The pressing force increases with increasing degree of polymerization and/or decreasing imprinting temperature.