Mechanisms of deposition and etching of thin films of plasma-polymerized fluorinated monomers in radio frequency discharges fed with C2F6-H2 and C2F6-O2 mixtures

Abstract

Deposition and etching of thin plasma-polymerized fluorinated monomers have been studied in discharges fed with C2F6-H2 and C2F6-O2 mixtures, respectively. A parallel plate reactor with thermostated electrodes has been utilized for the present study. The experiments have allowed us to ascertain the role of positive ions and of radicals, as well as the effect of pressure and substrate temperature, on the mechanism of deposition. The mechanism of etching has also been investigated, and it has been found that both O and F atoms contribute to the process through overall first-order kinetics. Conditions for a selective etching of noncross-linked films with respect to cross-linked ones have also been found.