Numerical study on bubble trapping in UV-nanoimprint lithography

Bubble trapping in the template pattern during the resist filling process is one of the most serious issues in UV-nanoimprint lithography. The mechanism of bubble trapping is studied based on a numerical analysis of the resist flow in a simple model. Flow behavior of water-like low viscosity liquid as a resist is investigated for particular structures of the template and the contact angles for the template and the substrate. Time evolutions of the flow of the resist are simulated and the mechanism of bubble trapping is demonstrated. The results show that large contact angle between the resist and the template causes bubble trapping, however the contact angle between the resist and the substrate does not greatly influence the results.