Metallic film formation using direct micropatterning with photoreactive metal complexes

Palladium, cobalt, and nickel in complex with photoacid-generating ligands, 4-(2-nitrobenzyloxycarbonyl)catechol and 4-(6-nitroveratryloxycarbonyl)catechol, were prepared in solution. Films formed from the metal complex solutions perform as positive-tone, directly photopatternable palladium, cobalt, nickel oxide, or composite film precursors. After exposure, acid-bearing selectively soluble complexes could be removed to give patterned films upon developing in aqueous base, which were transformable to the corresponding pattern-preserving metal/metal oxide film. The photodynamics of photoinduced solubility and direct micropatterning of palladium, cobalt, nickel, and palladium/nickel oxide composite films were investigated. Employing palladium as the initiator for autocatalytic chemical plating, selective direct copper plating on palladium film on polyethylene naphthalate and palladium/nickel oxide composite film on glass was accomplished.