Ion emission in a dc titanium cathodic arc operated with oxygen

The ion emission and its correlation with the deposition rate in a dc titanium cathodic arc run in an oxygen ambient with a current of 115 A has been investigated. The incoming O2 flow was varied between 10-60 sccm, resulting in a working pressure of 0.1-10 Pa. The ion saturation current measurements were carried out with Langmuir probes located on the system axis at two distances, 20 and 30 cm, from the cathode. The deposition rates were determined by weighting the deposited mass on glass substrates located at the same positions as the probes. The ion density and ion energy were estimated for the different operation parameters. The sticking coefficient for titanium was estimated by using the deposition rate and the ion saturation current.