A Dummy-Pattern-Assisted Lift-Off Method for Small and Dense Nanostructures

Abstract

Nanostructures have attracted much attention because of wide application. Moreover, most of the nanostructures play the function through small and dense patterns in irregular shape, which indicates that the fabrication process is utmost important. In general, a lift-off process is used to transfer the pattern from resist to substrate. However, for small and dense patterns, the lift-off does not work well. In this paper, a dummy-pattern-assisted lift-off method is present. With added dummy patterns, a deep and thin valley forms on the resist but does not contact the substrate. The following deposited metal film may not fully cover the valley or form a weak connection in the valley. Therefore, the metal film is easily lifted off in the valley when the sample is dipped in the acetone, which could result in a successful lift-off. This novelty method is able to improve the quality of nanofabrication by lift-off process.