New Polyoxometalates Containing Hybrid Polymers and Their Potential for Nano-Patterning

Two new polyoxometalate (POM)-based hybrid monomers (Bu4N)(5)(H)[P2V3W15O59{(OCH2)(3)CNHCO(CH3)C= CH2}] (2) and (S(CH3)(2)C6H4OCOC(CH3)= CH2)(6)[PV2Mo10O40] (5) were developed by grafting polymerizable organic units covalently or electrostatically onto Wells-Dawson and Keggin-type clusters and were characterized by analytical and spectroscopic techniques including ESI-MS and/or single-crystal Xray diffraction analyses. Radical initiated polymerization of 2 and 5 with organic monomers (methacryloyloxy) phenyldimethylsulfonium triflate (MAPDST) and/or methylmethacrylate (MMA) yielded a new series of POM/polymer hybrids that were characterized by H-1, P-31 NMR and IR spectroscopic techniques, gel-permeation chromatography as well as thermal analyses. Preliminary tests were conducted on these POM/polymer hybrids to evaluate their properties as photo-resists using electron beam (E-beam)/extreme ultraviolet (EUV) lithographic techniques. It was observed that the POM/polymer hybrid of 2 with MAPDST exhibited improved sensitivity under EUV lithographic conditions in comparison to the MAPDST homopolymer resist possibly due to the efficient photon harvesting by the POM clusters from the EUV source.