Chemical evaluation of Cu–polyimide interfaces

The interactions of copper overlayers with four different polyimides [pyromellitic dianhydride–oxydianiline (PMDA–ODA), benzophenonetetracarboxylic dianhydride–diaminobenzophenone (BTDA–DABP); oxydiphthalic anhydride–oxydianiline (ODPA–ODA); and pyromellitic dianhydride–phenylene diamine (PMDA–PDA)] have been studied by x‐ray photoelectron spectroscopy. Emergent etherlike functionalities on polyimides without innate ether groups suggest a copper‐induced partial reduction of carbonyl groups. A surface behavior diagram of the carbon chemistry confirms this reaction by indicating a partial conversion of carbonyl moieties to etherlike moieties.