Structural and electrical properties of Cr doped a-C:H films synthesized by a cathodic-arc activated deposition process

Chromium doped a-C:H (Cr-C:H) films were synthesized by using a cathodic-arc activated deposition (CAAD) process with different bias voltage. Chromium plasma with intensive ion energies catalyzes the decomposition of hydrocarbon gas (C2H2), and induces the formation of hydrogenated DLC films with a mixture of sp2 and sp3 carbon bonds. The deposited carbon films consist of nanocomposite Cr-C:H films on top of a graded chromium nitride interlayer. It has been found that the structural and electrical properties of the films were correlated as a function of bias voltage. The formation of larger cluster of sp2 coordinated carbon atoms under high bias voltage results in a more enhancement of the electrical conductivity. The nature of the heterojunction is confirmed by the spreading resistance characteristics of the Cr-C:H film/CrN/Si junction showing a behavior dependant on the structure changes.