Phase composition of Cr-C thin films deposited by a double magnetron sputtering system

Non-reactive d.c. magnetron sputtering by two magnetron sources with inclined geometry was used for deposition of Cr-C thin films with C:Cr ratio in the range 0.08-2.40. The phase composition of the films was investigated by x-ray diffraction, XPS, SEM and resistivity measurements. Four phase compositional regions were distinguished in the investigated large compositional range: films containing mainly microcrystalline Cr or Cr-C solid solution; films containing both the microcrystalline Cr phase and the stoichiometric Cr23C6 carbide phase (β-phase); amorphous-like films composed of the ultradisperse Cr crystalline phase and different metastable carbides; and amorphous films consisting of a carbon matrix with a limited amount of a high-carbon carbide phase dispersed in it. The films from the first two regions exhibit very high microhardness and good wear resistivity, and at the same time a relatively low electrical resistivity, which make them promising coating materials for electronic applications.