Pattern Size Reduction Effect via a “Mix and Match” Sequential Imprinting Technique

Abstract

Nanoimprint lithography is traditionally thought of as a one-to-one pattern replication process, where the negative of the surface relief pattern from a mold is reproduced exactly onto a resist material. As such, each pattern design will require a mold to be fabricated with the pattern required. The mold used is typically fabricated by various lithographic processes, many of which are costly and time-consuming. In this work, we report the use of a "mix and match" sequential imprinting technique where line-space patterns of different gap sizes were achieved through the different combinations of feature size and relative alignments of the molds. More significantly, patterns with gap sizes smaller than the molds were obtained, resulting in a size reduction effect. A gap size reduction as high as 93% had been achieved in imprinted polystyrene and we have exploited the patterns as shadow masks used for the deposition of nanometer sized metal lines. The main advantage of this gap size reduction effect lies in the tunability of the process, which removes the need for the design and purchase of newer and more expensive imprinting molds.