The fabrication scheme of a high resolution and high aspect ratio UV-nanoimprint mold

We propose a new scheme of fabricating molds for UV-nanoimprint lithography (UV-NIL) that is both high resolution and has a high aspect ratio. The scheme involves the utilization of a hydrogen silsesquioxane (HSQ) electron beam resist for high resolution patterning and the sputter-deposited alpha-Si layer that defines the high-aspect-ratio mold pattern obtained from the high etch selectivity between the HSQ and the alpha-Si. We obtained high resolution line patterns and dot patterns with feature sizes of 40 nm and 25 nm, respectively. The aspect ratio of the patterns was about 3.5 for line patterns and about 5 for dot patterns. These molds also demonstrate successful UV-nanoimprint patterning.