Influences of pulse frequency on structure and mechanical properties of DLC films synthesized by pulsed cathodic arc evaporation

Diamond-like carbon (DLC) films were prepared on the Si (100) substrates by pulsed cathodic arc plasma. The influences of given pulse frequency on the microstructure, morphology, mechanical and optical properties of DLC films were investigated by Raman spectroscopy, atomic force microscopy, Knoop sclerometer, X-ray double-crystal surface profilometer. The results showed that the variation of pulse frequency could significantly change the microstructure of DLC films, including the size and ordering of sp(2) carbon clusters and movement or diffusion of carbon atoms. The increasing of pulse frequency led to the variation of the relative fraction of Csp(3)/Csp(2). The hardness and internal stress of the DLC films were affected accordingly. The results might contribute to the synthesis of DLC films with excellent structure and properties by cathodic arc evaporation.