GROWTH OF PYROMELLITIC DIANHYDRIDE ON AN AMINO-TERMINATED SURFACE

A novel strategy with regard to an improvement of polymer/metal adhesion is described and tested for the case of polyimide and copper. Pyromellitic dianhydride (PMDA) has been deposited on an amino-terminated surface, which was prepared by chemical vapor deposition of 4,4'-diaminodiphenyldisulfide (DAPS) on Cu(100). Photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy have been used to show that an oriented monolayer of PMDA grows on the amino-terminated surface by chemical epitaxy. Heating to 450 K induces an imidization reaction. Comparison to data for codeposited DAPS + PMDA multilayers reveals that this imidization reaction produces intact imide units. In case of the multilayer significant amounts of Cu atoms are found to diffuse into the polyimide.