Studies on Micropatterning and Photoreaction of Copolymer LB Films Containing Nonionic Photoacid Generator

A series of new chemical amplified copolymer containing nonionic photoacid generator (PAG) p-toluene sulfonyloxymaleimide (TsOMI), film-forming component [N-hexadecylmethacrylamide (HDMA)] and acidolytic deprotection group p(tert-butyloxycarbonyl-oxy) styrene (t-BOCSt) were designed and synthesized. The behavior of copolymer molecular arrangement at air/water interface, patterning properties of copolymer LB films and photochemical reactions in ultrathin film were investigated. The results obtained showed that terpolymer p (HDMA/tBOSt/TsOMI) could form the stable, well-defined molecular orientation Langmuir monolayer on the water surface. UV-visible absorption spectra indicated that a well-ordered layer-by-layer structure could be successfully controlled and transferred onto substrates. Upon deep UV light irradiation, photochemical reaction occurred in the ultrathin LB films and the positive-tone photopattern with the resolution of 0.75 mum was obtained followed by development with alkali aqueous solution. The p (HDMA/t-BOCSt/TsOMI) LB films also show higher resistance ability in the process of etching gold film. The sensitivities of p (HDMA/t-BOCSt/TsOMI) LB films could be improved without decreased resolution. Finally, the photoacidolytic deprotection of the terpolymer was also investigated primarily.