Chemical patterning of sub-50-nm half pitches via nanoimprint lithography

Abstract

We report on a fabrication method of achieving local chemical modification of a surface at the sub-50-nm scale by a process sequence of nanoimprint lithography, gas phase surface modification and lift-off. This was combined with a new stamp fabrication via extreme ultraviolet interference lithography to produce extremely small patterns of high density and large area. In this method, we have demonstrated chemical patterns of a fluorinated silane on an unprecedented feature size of as small as 25-nm half pitch. However, chemical contrast of high quality needed for biological and sensing applications was still difficult to achieve due to the contamination on the background surface areas, which is associated with the lift-off process. This will be discussed with results obtained by subsequently immobilizing a fluorescence labeled protein on the chemical patterns using different lift-off conditions and process sequences.