High aspect ratio pattern transfer in imprint lithography using a hybrid mold

Abstract

A new method has been developed to obtain high aspect ratio patterns transfer by using a combination of imprint lithography and photolithography through a hybrid mold on a flexible transparent plastic substrate. The hybrid mold was fabricated by optical lithography and wet etching of a commercial blank template containing photoresist, chromium and transparent glass. Etching barrier used in this method was a negative photoresist with a low softening point to achieve the pattern transfer on a flexible plastic substrate. After imprinting and the following development by an aqueous Na2CO3 solution, high aspect ratio patterns contributed by imprint and mask were successfully transferred. Using this method, we were able to obtain the desired high aspect ratio patterns on the plastic substrate without using expensive or specific photoresists. It was also easy to remove the residual layer that usually has to be treated by reactive ion etching (RIE) in conventional imprinting process.