Optical emission from tetrafluoromethane plasma and its relationship to surface modification of hexatriacontane

The optical emission from tetrafluoromethane plasma (2% argon included) has been studied by emission spectroscopy. The evolution ofCF ^*,CF ₂ ^* , andF emissions has been followed during the treatment of an organic surface. An-alkane, hexatriacontane, has been used as a model for high density polyethylene surface and treated in different plasma conditions. We found that the evolution of fluorinated species emissions in the plasma gas phase is not only a measurement of the reactive species concentrations, but also an indication of the surface modifications. The surface properties, such as surface energy and surface roughness are correlated to the emission intensity of reactives species in the plasma gas phase. A mild exposure to the plasma can result in a great decrease of surface energy corresponding to the fluorination. The surface roughness only changes under drastic plasma conditions.