Angle‐resolved XPS study of plasma‐treated teflon PFA surfaces

Abstract

Abstract Teflon PFA (polytetrafluoroethylene‐co‐perfluoroalkoxy vinyl ether) was 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 measurements showed ablation of fluorine and incorporation of new O‐ and N‐containing groups into the surface. Among the different gases, H 2 is the most efficient for defluorination, N 2 + H 2 for surface functionalization, while O 2 showed the least performance for both effects. Plasma treatments using N 2 + H 2 and O 2 + H 2 resulted in intermediate defluorination, i.e. between those in the pure gases, and sequential treatment by He/(N 2 + H 2 ) showed an additive effect of He and N 2 + H 2 alone. 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 distribution upon O 2 , N 2 and He exposures. The surface modification of Teflon PFA leads to an enhanced adhesion of metals such as Cu, Ag and Au.