ANGLE-RESOLVED XPS STUDY OF PLASMA-TREATED TEFLON PFA SURFACES

Teflon PFA (polytetrafluoroethylene-co-perfluoroalkoxy vinyl ether) wa s treated by a low-pressure microwave (2.45 GHz) plasma in O-2, N-2, H -2, He and their mixtures. X-ray photoelectron spectroscopy measuremen ts showed ablation of fluorine and incorporation of new O- and N-conta ining groups into the surface, Among the different gases, H-2 is the m ost efficient for defluorination, N-2 + H-2 for surface functionalizat ion, while O-2 showed the least performance for both effects. Plasma t reatments using N-2 + H-2 and O-2 + H-2 resulted in intermediate deflu orination, i.e. between those in the pure gases, and sequential treatm ent by He/(N-2 + H-2) showed an additive effect of He and N-2 + H-2 al one. Angle-resolved XPS measurements revealed a pronounced gradient in the near-surface composition following H-2, N-2 + H-2 and He/(N-2 + H -2) plasma treatments, in contrast to a more uniform depth distributio n upon O-2, N-2 and He exposures. The surface modification of Teflon P FA leads to an enhanced adhesion of metals such as Cu, Ag and Au.