Numerical analysis of impact of imprinting pressure on profile shape and mold deformation in UV-NIL

In this paper, in order to reveal the interrelationship among the imprinting pressure, the evolution profile and the mold deformation, a novel numerical model accounted for surface tension and contact angle was established to simulate the resist filling process and mold deformation by using computational fluid dynamics (CFD). As a basic study to understand the resist filling characteristics in UV-NIL, we had chosen a simple rectangular cavity as a computational domain. In order to fully account for the effect of imprinting pressure, numerical simulations have been performed for different imprinting pressure. The evolution profile of the resist and mold deformation was found to be significantly influenced by the imprinting pressure. Numerical results show that a higher imprinting pressure will make the profile shape of resist more flat, which can improve the filling rate of the resist and reduce the filling time. However, too high imprinting pressure is easy to cause larger mold deformation that is unfavorable to the demoulding process and finial quality of imprinted pattern. Through a synthetic consideration of the influence of the imprinting pressure on the evolution profile and the mold deformation, we considered that the optimum imprinting pressure should be about 0.1MPa.