Relationship between structure and electrical resistivity in nano-structured copper-containing carbon films

The microstructure evolution of carbon/copper (C/Cu) films and its relation to the variation of film electrical resistivity has been studied. The films doped with copper in the range of 1.4–22.6 at.% Cu, were deposited by dc magnetron sputtering of composite graphite–copper target. The microstructure of films was studied by Raman spectroscopy and electron diffraction. The electrical resistivity was measured parallel and perpendicular to the substrate surface. The introducing of copper atoms into carbon matrix which consists of disordered graphite-like nano-clusters results in additional distortion of film microstructure at low copper content and some ordering of it at high copper content. At low copper concentrations the additional distortion of graphite-like clusters prevails over the input to electrical conductivity from copper atoms thus increasing the electrical resistivity of C/Cu films. At high copper concentrations the input to electrical conductivity is predominant and the film resistivity decreases.