Characterization of carbon nitride produced by high-current vacuum arc deposition

Abstract

Carbon nitride thin films were deposited using the high-current arc (HCA) evaporation technique varying the pressure in the chamber and the position of the samples with respect to the evaporation source. At direct deposition the nitrogen content in the films measured by elastic recoil detection analysis saturates at an atomic ratio of 0.18 due to chemical sputtering. At positions where the substrates are shaded from the carbon plasma by the sample holder the nitrogen content increases up to 48 at. %. This observation can be explained by a decreased energy of the carbon ions, a higher arrival ratio of nitrogen to carbon ions and the high degree of ionization using the HCA technique. Varying the sample position the binding character of nitrogen to carbon atoms in the films changes from sp3 to sp2. When the energy of the deposited particles is reduced graphitic clusters are formed in an amorphous matrix.