Characteristics of W doped nanocrystalline carbon films prepared by UBM sputtering method

초록

We prepared nanocrystalline tungsten doped carbon (WC) films by unbalanced magnetron sputtering method. Tungsten was used as the doping material in carbon thin films for the application of contact strip in electric railway. The structural, physical, and electrical properties of the fabricated WC films with various DC bias voltages were investigated. The WC films exhibited uniform and smooth surface. The hardness and frication characteristics of WC films were improved, and the resistivity and sheet resistance were decreased with increasing negative DC bias voltage. These results are associated with the nanocrystalline WC phase and sp2 clusters in carbon networks increased by ion bombardment enhanced with increasing DC bias voltage. Consequently, the increase of sp2 clusters containing WC nanocrystalline in the carbon films is attributed to the improvement in the physical and electrical properties.