Characterization of NbC coatings deposited by magnetron sputtering method

The paper presents the results obtained on the deposition and characterization of niobium carbide thin films obtained by reactive magnetron sputtering method in a reactive atmosphere composed by Ar and CH4. The coatings were deposited on Si substrates, at 100 °C, 400 °C and 750 °C, at two different substrate bias values and five different CH4/(Ar + CH4) flow ratios. The films were analyzed for phase (XRD) and elemental (AES) compositions, surface morphology (AFM) and optical reflectivity in UV–VIS domain.X-ray analysis revealed that the coatings crystallized in either cubic or hexagonal structure, depending on the CH4 relative abundance in the deposition atmosphere, independent of the substrate bias or deposition temperature.The films deposited at a lower substrate temperature were less crystallized and had significantly smaller mean grain sizes. The reflectivity values were found to depend on the films crystallographic structure, carbon content and amount of non-reacted metal. The films presented a low roughness, specific to films deposited by magnetron sputtering method.