High aspect ratio pattern collapse of polymeric UV-nano-imprint molds due to cleaning

Polymeric molds replicated from a master structure can provide intrinsic anti-sticking behavior and UV-transparency. They can be replicated from various substrates and offer cost efficient replication of multiple working stamps from only one master. They also allow the use of various imprint methods including UV- or thermal-assisted ones. Usually, the polymer material exhibits mechanical and surface-chemical properties which differ from hard mold materials like silicon, silicon dioxide or metals. Due to this, the molds might be deformed or even destroyed during imprint or cleaning. This is pronounced for high aspect ratio patterns, as they occur, if imprint is used as direct pattering method. The affinity to pattern damage of polymeric molds during cleaning is investigated in this paper. Different possible polymeric mold materials are considered. Experimental data is compared to simulation results and shows good agreement. Different exemplary patterns are investigated and a best suitable material is found. It is stable for feature aspect ratios up to 10 for half pitch gratings in the considered range of dimensions. (C) 2013 Elsevier B.V. All rights reserved.