Effects of the High Power Pulsed Magnetron Sputtering Deposition Conditions on Structure of Diamond Like Carbon:Cu Films

In the present study diamond like carbon films containing copper nanoparticles were deposited by reactive magnetron sputtering. High power pulsed magnetron sputtering and direct current magnetron sputtering of copper in the acetylene and argon gas were used. Both unbalanced and balanced magnetron configurations were applied for the film deposition. Structure of the films was investigated by multiwavelength Raman scattering spectroscopy as well as by Transmission Electron Microscopy. Chemical composition of the films was studied by energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Surface morphology was investigated by Atomic Force Microscopy. Dependence of the parameters of Raman scattering spectra such as G peak position, G peak full width half maximum and dispersion of G peak on high power pulse peak current as well as on acetylene and argon gas flow ratio was studied. It seems that copper nanoparticles embedded into the diamond like carbon matrix were coated by oxide interlayer. It was found that sp(3)/sp(2) carbon bond ratio of diamond like carbon films containing copper nanoparticles (that was in 0.52-0.61 range) decreased with copper atomic concentration in diamond like carbon films containing copper nanoparticles. sp(2) bonded carbon cluster size as well as structural disorder decreased with the increase of copper amount in diamond like carbon nanocomposite films. Structure of the both diamond like carbon matrix and copper nanoclusters was independent of the depositionmethod and was defined only by the copper atomic concentration. In the case of reactive high power pulsed magnetron sputtering of diamond like carbon films containing copper nanoparticles, more homogeneous distribution of copper nanoclusters across the film as compared to the reactive direct current magnetron sputtering was found. Formation of the large copper nanoclusters in the surface layer was avoided as well.