PECVD of Fluorocarbon Coatings from Hexafluoropropylene Oxide: Glow vs. Afterglow

Smooth and micro/nano-structured fluorocarbon coatings are obtained by radio frequency (RF), 13.56 MHz, glow discharges fed with hexafluoropropylene oxide (C3F6O, HFPO) both in glow and in afterglow. It is shown that the extent of micro/nanostructuring, as well as the F/C ratio of the coatings, can be precisely tuned with both substrate position and deposition time. Nodular and ''stone roses'' morphological features are easily obtained, with good reproducibility, by controlling the plasma parameters. Both chemical and morphological features are shown to deeply affect film properties and, in turn, wetability, allowing a move from a hydrophobic behavior to a superhydrophobic one.