Damage-free Fabrication of Perfluoropolymer Microaperture Array Device for Single-molecule Imaging

Abstract

Optical microdevices have attracted much attention as promising tools for advanced bioimaging and/or biosensing at the single-molecule level. Various technologies developed by the semiconductor industry are applied effectively to fabricate their microstructures. We studied fabrication process of a new single-molecule imaging device consisting of a microaperture array in a transparent perfluoropolymer film coated on a glass plate, with special attention to process-induced optical damage. Highly anisotropic etching using argon/oxygen mixed plasmas was firstly examined for engraving the aperture array, but it was found that the UV emission from the excited argon in the plasma causes optical damage to the polymer and that the degree of damage was not negligible for the purpose of using the device in single-molecule imaging. Then, an alternative process that involves thermal nanoimprinting and oxygen-plasma removal of thin residual layers was adopted to enable damage-free fabrication process of the polymeric microaperture array device for single-molecule imaging.