CF2 kinetics and related mechanisms in the presence of polymers in fluorocarbon plasmas

Laser-induced fluorescence was used to characterize the fluorocarbon plasma that was used to modify the wettability of hexatriacontane (HTC), a polymer model. The plasma volume downstream from a microwave plasma source was examined by monitoring the CF2 concentration as well as the CF2 decay rate (in the afterglow of a pulsed discharge) during treatment of the polymer surface (in 20-100 mTorr CF4). In parallel, the behavior of F atoms was monitored by means of actinometric optical emission. Pulsed modulation of the discharge allowed the effects of variations in the loss and production rates for CF2 to be distinguished, in the presence of hexatriacontane. Our observations are consistent with enhanced production of CF2, possibly by an ion-assisted surface mechanism, in the presence of HTC. (C) 1997 American Institute of Physics.