Degradation and surfactant-aided regeneration of fluorinated anti-sticking mold treatments in UV nanoimprint lithography
In nanoimprint lithography, the most common approach to prevent resist to adhere to the mold is to graft a fluorinated anti-sticking layer on the molds surface. But it is known that these layers suffer from degradation after a certain number of imprints. In this work, we study the influence of the presence, type and quantity of fluorinated surfactant additives in the resist formulation on the degradation of the molds treatment. It is found that the presence of a fluorinated surfactant drastically increases the possible maximal number of imprints before retreatment. Also, we observed that fluorinated surfactants with a silane end-group are able to be adsorbed at the surface of the mold after repeated imprints to progressively replace the initial molds treatment. Nevertheless, a balance has still to be found between quantity, reactivity and type of surfactant to maintain a smooth and extremely thin fluorinated layer at the surface of the mold.
surfactant anti-sticking uv-nil fluorinated molecules fused silica molds