Polymer Bulletin 43, 409–416 (1999) * Corresponding author Polymer Bulletin Springer-Verlag 1999 Deposition of high fluorine content macromolecular thin layers under continuous-flow-system corona discharge conditions S.-D. Lee, S. Manolache, M. Sarmadi * , F. Denes Center for Plasma-Aided Manufacturing, and SHUEC, University of Wisconsin - Madison, Madison, WI 53706, USA Received: 1 June 1999/Revised version: 1 September 1999/Accepted: 1 September 1999 Summary High fluorine content macromolecular layers were deposited on polyethylene (PE) film surfaces under an originally designed, continuos-flow-system plasma reactor conditions. Survey and angle resolution, ESCA data and ATR-FTIR results indicate that the plasma- created films are thin and have a fairly uniform structure. The fluorinated layers have a 60% relative fluorine atomic concentration, and are mainly composed of CF 2 -CF, and C-CF 3 groups. AFM images collected from virgin and plasma-exposed PE surfaces show a significantly rougher surface of the plasma-treated substrates. Applications can be envisaged for creating Teflon-like coatings on various polymeric film surfaces using a continuous plasma process. Introduction The fluorination of natural and synthetic polymeric substrates is a process of great importance, since it can provide special surface properties at an economical price, such as: chemical inertness, low dielectric constant, hydrophobicity, thermal stability, low friction, low electrical conductivity, low gas permeability, etc. Literature data indicate that plasma enhanced surface fluorination reactions can be carried out on even the most inert polymeric surfaces, both from saturated and unsaturated fluorocarbon compounds and their mixtures with oxygen, and from inorganic fluorides, by depositing macromolecular layers or by generating fluorine- and carbon-atom based functionalities (1-12). It was shown that the efficiencies of the deposition of fluorinated macromolecular layers depend strongly on the overall active fluorine-to-carbon ratio of the reaction mixture (13-20). Low fluorine-to-carbon ratios result in fluorinated plasma-"polymer" deposition processes, while high fluorine-to- carbon ratios lead to ablation (etching) reactions. CF 4 -plasmas, for instance, do not deposit under common low density cold-plasma conditions macromolecular layers regardless of the nature of the substrates, in comparison to the volatile (CF 2 ) x (x = 1-4), and C x F y X z (X = H, Cl, Br, etc.) compounds where plasma films are instantaneously formed. However, it has been demonstrated that high density plasma conditions can lead to the deposition of fluorinated macromolecular layers even involving carbon tetrafluoride (21).