Effect of boron and silicon doping on the surface and electrical properties of diamond like carbon films by magnetron sputtering technique

To improve the surface and electrical properties, silicon (Si) and boron (B) were co-doped in diamond-like carbon (DLC) films prepared on silica substrates by RF magnetron sputtering. In the deposition of a Si, B co-doped DLC film, Si content was controlled by the number of intrinsic Si wafer piece and B content by B target power. The surface roughness and resistivity of film increased by increment in the CC sp3 bond content due to added Si and the surface roughness and resistivity of film decreased by decrement in the CC sp2 bond content due to added B. A CC sp3 bond content in the Si, B co-doped DLC films decreased from 47.4% to 36.5% with increasing B target power compared with from 46.7% to 23.9% in case of the only B doped DLC films. From this result, it can be said that Si can suppress a graphitization of DLC with presence of B. However, the surface roughness and resistivity values of Si, B co-doped DLC films decreased similarly as in only B doped DLC films with an increase in the B target power. These results were caused the SiB sp3 bonds formed smaller than Si sp3 bonds with increase in the B target power as a result of the B-doping effect. In order to minimize the reduction in sp3 bond content over the decrease roughness and resistivity, DLC films were prepared by Si, B co-doping. So, these films can be applied in chemical sensing, electro-synthesis, and electrochemical-based toxic waste detection, remediation, and so on at industrial level.

► B and Si doping diamond like carbon films.
► Mechanical properties can be improved by adding a protective layer of Si-containing DLC.
► The dependence of the residual compressive stress and surface roughness of DLC on Si content in DLC.
► B into DLC decreases residual compressive stress and resistivity in DLC films.
► Surface and electrical properties were enhanced by Si, B co-doping.