High-resolution photoemission study of the interfacial reaction of Cr with polyimide and model polymers.

Abstract

The chemical nature of the adhesive interface between Cr and three polymers has been investigated using synchrotron-radiation-excited photoemission from the polymer carbon and oxygen 1s core levels. Pyromellitic dianhydride--oxydianiline (PMDA-ODA) polyimide, an important polymer in the electronics industry, was studied along with two simple polymers. Poly(methylphenylene oxide) and poly(vinylmethyl ketone) contain structural fragments of the complicated PMDA-ODA polyimide protomer. The core-level spectra were decomposed into distinct peaks which were assigned to specific chemical species and monitored as a function of Cr coverage. Our results confirm that the carbonyl groups on these polymer surfaces are targets for reactive metals during the initial stages of metal deposition. This initial reaction stage was followed by gradual formation of an electron-rich, carbidelike, carbon species.