Fabrication of three-dimensional imprint lithography templates by colloidal dispersions

Self-aligned imprint lithography (SAIL) enables patterning and alignment of submicron-sized features on flexible substrates in the roll-to roll (R2R) environment. Soft molds made of elastomers have been used as stamps to pattern three-dimensional masks. Durability of these stamps is one factor that limits their efficiency in a R2R process. Fluorothermoplastics are low cost imprint stamp materials with great mechanical strength and chemical compatibility but with low gas permeability that trap air bubbles in the photopolymer during the imprint process. This paper describes the strategy for increasing gas permeability of fluorothermoplastics by introducing voids in the stamp by using aqueous colloidal dispersions of fluorothermoplastic nanoparticles. The hard fluorinated particles, whose modulus is too high to deform during drying, remain as hard spheres and lead to a porous packing when drying is complete. The selection of additives to eliminate cracks created during water evaporation is also described in this paper. Copyright © 2011 Hewlett-Packard Development Company.