Photogenerated Amines in the Design of Imaging Materials: The Radiation-induced Imidization of Functionalized Polystyrenes Bearing Amide-ester Side Chains.

Abstract : The use of photogenerated base in polymer modification processes has been investigated with the study of the amine catalyzed intramolecular imidization of reactive functional groups attached to a polystyrene matrix. The monomers are prepared by reaction of 4-hydroxystyrene with suitable anhydrides such as phthalic anhydride or the corresponding diacid chlorides, followed by amidation with hexamethyldisilazane. Following their free-radical polymerization, the functionalized polystyrenes have been tested in imaging experiments involving in situ photogeneration of amine from a photoactive carbamate precursor followed by low temperature imidization. The amine catalyzed imidization occurs as a much lower temperature than the uncatalyzed process thereby allowing photopatterning. Because the imidization process results in the formation of aqueous base soluble by-products, image development may be accomplished used standard water-based developers. While the new materials themselves can be used as resists, the concepts demonstrated in this study can be used to design novel photopatternable imaging and packaging materials for microelectronics. (jg)