PLASMA POLYMERIZATION OF TETRAFLUOROETHYLENE .1. INDUCTIVE RADIO-FREQUENCY DISCHARGE

The plasma polymerization of tetrafluoroethylene in an inductively coupled radio frequency glow discharge, using a flow system, was studied. A simple long tube reactor, with the coupling coil placed at the middle of the tube and gas entrance and exit at the respective ends, was used. Deposition rates and the chemical nature of the polymer (as revealed by ESCA spectra and surface energy studies) are obtained as a function of location in the reactor tube with respect to the coupling coil and of applied energy per unit mass of tetrafluoroethylene (W/FM). It was found that a fluorinepoor polymer, containing considerable carbon–oxygen bonds (after contact with air), is obtained at all locations at high W/FM. When a low W/FM is utilized, such a fluorine‐poor polymer is also obtained at locations downstream from the coupling coil (the location of the highest energy density) in the reactor. In the latter case a fluorine‐rich polymer containing very little oxygen is formed upstream from the coil. The polymer deposition rate distribution is also considerably broader in a high W/FM plasma than when low W/FM is used. These results are in agreement with earlier studies indicating that fluorine abstraction and decomposition due to fluorine etching occur when the energy density, as expressed by W/FM, is high. Copyright © 1979 John Wiley & Sons, Inc.