Electrical and mechanical properties of highly conductive nitrogen doped DLC films deposited via high-temperature DC PACVD

Hydrogenated DLC films deposited at high temperatures via pulsed DC PACVD exhibit a distinctly low specific electrical resistance, rendering them viable for a wide range of applications where adequate electrical properties are required in addition to the well-established characteristics of DLC films such as high hardness, wear resistance and low coefficient of friction. In view of the constantly increasing demands on technical components, particularly with regard to energy efficiency, nitrogen doping may be applied for further optimization of the electrical and mechanical properties of DLC. In this work, a-C:H:N films were deposited at 550 °C by a commercially available DC PACVD system on steel and titanium substrates, employing C2H2
and an additional N2 flow. This resulted in an N2 concentration of 0-63 vol. -% in the gas mixture. The films were subsequently analyzed for their thickness, specific electrical resistance, hardness and Young’s modulus as well as incorporated concentration of nitrogen. This was achieved via calotest, the van der Pauw method, nanoindentation and GDOES-analysis, respectively.