PHOTOEMISSION-STUDIES OF POLYIMIDE SURFACES

Surface-sensitive analysis using X-ray photoelectron spectroscopy (XPS) has been performed to characterize surfaces of several polyimides and a related imide. Molecular orbital calculations were carried out to estimate the chemical shifts and characterize the surface chemical states. On polyimide and imide surfaces, both the photoelectron intensity decrease of the carbonyl group and the shake-up phenomenon were detected. It is proposed that (1) the photoelectron intensity decrease of the carbonyl group on the polyimide film surfaces is caused by the shake-up phenomenon, and not by carbonyl deficiencies on the surfaces, and that (2) the intensity decrease of the carbonyl group on the imide film surface is caused by the combination of shake-up phenomenon and carbonyl deficiences on the surfaces.