Ion energy distributions in reactive arc evaporation discharges used for deposition of TiN films

In this paper we report on measured ion energy distributions in are discharges operated with a titanium cathode in nitrogen gas pressures between 0 and 45 mTorr. An electrostatic retarding field analyser (RFA) was used to decelerate and filter ions, depending on their energy-to-charge ratio E/z. The RFA was placed at two distances from the Ti-cathode, L=20 and 40 cm. The differentiated ion spectra were used to determine the ion energy distribution function (IEDF) and the average ion energy [E]. Gaussian fitting functions were used to reveal the possible contributions from single- and multiple-charged Ti ions to the net ion current. The measurements showed that the average energy [E] and current density j of Ti ions decreases as a result of their interaction with N-2-molecules. Both [E] and j decreases with a factor of similar to 10, from 60 to 6 eV and 6 to 0.5 mA cm(-2), respectively, as the nitrogen pressure is increased from 0 to 45 mTorr.