High flowability monomer resists for thermal nanoimprint lithography

In this paper, we have been using polymer and thermally curable monomer resists in a full 8 in. wafer thermal nanoimprint lithography process. Using exactly the same imprinting conditions, we observed that a monomer solution provides a much larger resist redistribution than a polymer resist. Imprinting Fresnel zone plates, composed of micro- and nano-meter features, was possible only with the monomer resist. In order to reduce the shrinkage ratio of the monomer resists, acrylate-silsesquioxane materials were synthesised. With a simple diffusion-like model, we could extract a mean free path of 1.1 mm for the monomer resist, while a polymer flows only on distances below 10 μm in the same conditions.