Characterization of plasma deposited halocarbon polymer films containing small gold particles

Composite thin films were prepared by simultaneous plasma polymerization of chlorotrifluoroethylene and sputtering of gold in an rf glow discharge (20 MHz) excited by a planar magnetron. The concentration depth profile analyses including AES and ESCA have disclosed that the amount of fluorine and chlorine decreases with increasing gold concentration and that the film surface is not representative for the bulk of the layer. Structural examination using TEM observations evidenced that gold is incorporated in an amorphous polymer matrix in the form of polycrystalline grains 10–20 nm in diameter in the case of low film filling factors ( f ≲0.1). Two particle size systems have been found at higher filling factors when the grain diameters reached about 130 nm ( f ∼0.5). Spectral dependence of the absorption coefficient is described in terms of optical resonance. A hypothesis of energetic particle bombardment of the growing layer was suggested to explain the film structure and composition.