Preparation and Characterization of Glow Discharge Fluorocarbon-Type Polymers

Abstract

Abstract Thin polymer films have been prepared by electrodeless glow discharge polymerization of tetrafluoroethylene monomer. Process conditions are described for the deposition of adherent, Freon-insoluble polymer films on smooth metal surfaces. The polymer deposition rate is strongly dependent on position in the system. At the operating pressure of 0.05 Torr, the deposition rate was not dependent on rf power over the range of 200 to 500 W. However, the rate did increase with an increase in pressure. The polymer films were characterized by x-ray photoelectron spectroscopy, IR absorption spectrum, and surface wettability. The film deposited in the main chamber had a uniform chemical composition which consists of CF2 functional groups with a small fraction of CF3. The film closer to the plasma zone had a more complex chemistry. The carbon Is binding energies were compared to calculated values based upon group shifts and electrostatic potential models. The critical surface tension of the polymer film in the deposition chamber was lower than Teflon. The presence of CF3 groups and the character of the glow discharge polymer may account for the lower surface energy.