Addition Effect of Argon and Water Vapor on Plasma Copolymerization of Trifluoromethanesulfonic Acid with Octafluorocyclobutane

A comparison between argon (Ar) and water vapor that were added to plasma copolymerization of trifluoromethanesulfonic acid (TFMS) with octafluorocyclobutane (OFCB) was studied by means of measurement of a deposition rate of the polymer, X-ray photoelectron spectroscopy, and emission spectrochemical analysis. All data obtained from the three measurements suggested that splitting of F atom from OFCB by Ar formed a bonding site, where C-C bond was formed and sulfonic acid functional group (-SO3H) derived from TFMS was taken up more efficiently. In respect of water vapor, a suppression effect on dissociation of F atom from TFMS and production of HF together with some active species containing O, e.g., O3, were indicated. These species should contribute to suppression of rapid ablation by F radicals and preservation of -SO3H.