The surface fluorination of graphite in some glow discharge plasmas was studied. The plasmas contained excited fluorine atoms, and were, generated by various discharges, Direct-Current, Radio-Frequency (13.56MHz) and Micro-Wave (2450MHz), with CF4 as source gas. The contact angles formed by water, dropped on the treated surfaces, were over 160°, and changes of mass indicated addition of the fluorine.
But the effect of etching appeared as a decrease of mass under some conditions, and such effects were observed also by a scanning electron microscope. The ESCA results on the surfaces treated by plasma were similar to those which were measured on the surfaces treated by F2 gas at high temperature.
