Thermal processing of a copper-poly(phenyl quinoxaline) interface: Diffusion of the metal in the polymer studied by high resolution electron-energy-loss spectroscopy

Thin layers of metallic copper (up to a few hundreds angström) were deposited onto poly(phenyl quinoxaline) (PPQ), a new thermostable polymer. As suggested by x-ray photoelectron spectroscopy (XPS) and ascertained by a new type of application of high resolution electron-energy-loss spectroscopy, further processing of the interface by thermal anneal (300 °C) induces diffusion of Cu species into the bulk of the polymer. By studying the electronic transitions of the Cu-PPQ system, we show that it is possible to get a significant understanding of the copper diffusion into the polymer. The combination of the spectroscopic surface sensitive methods allows us to propose a morphological description of the Cu-PPQ interface before and after anneal.