A Directly Patternable, Click-Active Polymer Film via Initiated Chemical Vapor Deposition

Abstract

Click-active surfaces patterned at 200 nm resolution are demonstrated using the dual functional polymeric film, poly(propargyl methacrylate) (PPMA). The commercially available monomer of propargyl methacrylate (PMA) is polymerized in a single step by initiated chemical vapor deposition (iCVD). FT-IR and X-ray photoelectron spectroscopy confirm retention of the click-active acetylene functional group in the bulk and surface of the iCVD film, respectively. Treating substrates with silane coupling agents prior to deposition results in grafting of iCVD PPMA polymers onto various inorganic surfaces. This grafting technique provides the chemical and mechanical stability required for the PPMA layer to survive the subsequent wet chemical steps used for click functionalization. Successful attachment of an azido-functionalized coumarin dye is demonstrated. Moreover, the PPMA film displays direct positive-tone sensitivity to e-beam irradiation, which enables e-beam patterning without the use of a resist layer. Direct e-beam exposure of the multifunctional PPMA iCVD layer results in a 200 nm pattern to which quantum dot nanoparticles are selectively conjugated on the substrates by click chemistry.