Minimizing filling time for ultraviolet nanoimprint lithography with templates with multiple structures

Abstract

Optimizing the locations and sizes of droplets is the key to reducing defects and increasing throughput of ultraviolet nanoimprint lithography. In practice the templates are composed of regions with different structures. The interface between structures will generate complicated fluid flow behavior that will slow the filling time. Here, we explore several strategies through simulations to distribute resist material according to a nonuniform pattern to reduce filling time and ultimately increase throughput. In order to mimic the complexity of a template, the interface between different pairs of template structures is considered and the spreading and merging of droplets are simulated. From these simulations, it is found that the volume and arrangement of droplets underneath strongly affect the imprint time. By distributing the correct amount of resist underneath the template, one can remove the unnecessary fluid transferring step in droplet spreading and reduce the total filling time. Furthermore, by optimally placing the resist droplets, one can delay merging events and accelerate the spreading speed. Finally, the advantage of hexagonal arrangements is explored.