Synthesis and properties of CS _x F _y thin films deposited by reactive magnetron sputtering in an Ar/SF₆ discharge

A theoretical and experimental study on the growth and properties of a ternary carbon-based material, CS _x F _y , synthesized from SF₆ and C as primary precursors is reported. The synthetic growth concept was applied to model the possible species resulting from the fragmentation of SF₆ molecules and the recombination of S-F fragments with atomic C. The possible species were further evaluated for their contribution to the film growth. Corresponding solid CS _x F _y thin films were deposited by reactive direct current magnetron sputtering from a C target in a mixed Ar/SF₆ discharge with different SF₆ partial pressures ([Formula: see text]). Properties of the films were determined by x-ray photoelectron spectroscopy, x-ray reflectivity, and nanoindentation. A reduced mass density in the CS _x F _y films is predicted due to incorporation of precursor species with a more pronounced steric effect, which also agrees with the low density values observed for the films. Increased [Formula: see text] leads to decreasing deposition rate and increasing density, as explained by enhanced fluorination and etching on the deposited surface by a larger concentration of F/F₂ species during the growth, as supported by an increment of the F relative content in the films. Mechanical properties indicating superelasticity were obtained from the film with lowest F content, implying a fullerene-like structure in CS _x F _y compounds.