Molecular Level Study of Negative Thick-Film Resist in MEMS by Employing a Coarse-Grained Molecular Dynamics Simulation

Abstract

This paper reports on a newly developed coarse-grained molecular dynamics simulation for epoxy-based chemically-amplified photoresist dedicated to MEMS. To analyze photoresists material properties, Kremer-Grest model (bead-spring model) with an extended angle bending potential was newly employed. A uniaxial elongation simulation and the molecular diffusion simulation were performed to analyze the dependence of an elastic modulus and a molecular permeability on the cross-linked ratio of a photoresists, since these characteristics are important for a permeable membrane made of photoresist to control biological molecules diffusion in biomedical applications. The simulated dependencies of the elastic modulus and the molecular permeability on the cross-linked ratio of photoresists showed good correspondences with the experimental results. This suggests a photoresists membrane can be used as a molecular permeable membrane with controllable permeability by varying photolithography process parameters.