Ion beam assisted deposition of nitrogen-containing chromium films: A comparison of argon vs nitrogen ions

Chromium films were deposited onto different substrates by two ion beam assisted deposition techniques, one being based on nitrogen ion implantation, the other one being based on nitrogen gas sorption under rare gas ion irradiation. In both cases, a residual gas atmosphere of nitrogen was used. In the first case, nitrogen was both implanted and absorbed from the atmosphere, in the second case, it was only absorbed under the influence of rare gas ion irradiation. In dependence on ion irradiation intensity, the films consist of phase mixtures of nitrogen-containing chromium, di-chromium nitride and chromium nitride. Nitrogen content of the films is a function of both ionic species and ion irradiation intensity. In case of nitrogen irradiation, always more nitrogen is incorporated than for the argon ion case. Under moderate ion irradiation, the surface morphology of the films is almost the same for both, under intense irradiation, argon ion bombardment leads to larger grains.