A positive-type photoresist utilizing photoinitiated introduction of pendent amino groups

Novel Photoimaging System Based on Photoinduced Electron Transfer in Polymers Containing Pendant Benzophenone−Borate Salts

“…Attachment of the o -nitrobenzyl protected carbamate groups to the polymer chains in the form of photolabile pendants led to the photogeneration of polymeric amines successfully utilized in the UV-induced cross-linking of epoxy-containing resins , …”

“…19 High-resolution, high-sensitivity positive-tone photoresists have been developed based on the irradiation of copolymers of O-acryloylacetophenone oxime and methyl methacrylate followed by development with aqueous HCl. 20,21 In recent studies we have found that the benzophenone-like triplet state of N,N,N-trialkyl-N-(p-benzoyl)benzylammonium triphenylbutylborate 22 is rapidly quenched (τ ≈ 300 ps in benzene/acetonitrile (1%)) presumably by single-electron transfer (SET) from the borate anion to carbonyl portion of the molecule followed by methylene carbon-nitrogen bond cleavage and reduction of the formed radical cation of the amine by the enolate of benzophenone that leads to the formation of the free amine. We postulated that application of the same process to suitably constituted polymeric quarternary ammonium borates would lead to photochemical generation of polymeric amine which results in development of a new class of positive-tone photoimageable polymers which, after irradiation, could be developed by dissolution in aqueous acid.…”

Enhanced dissolution of copolymers bearing photobase‐ or photoacid‐generating groups in polar solvents by photochemical formation of ionic pairs

“…o ‐Nitorobenzyl carboxylates are representative precursors for carboxylic acids 15. Oxime esters16–20 and o ‐nitrobenzyl carbamates21, 22 are PBGs that generate amino groups.…”