Comparison of pulsed dc and rf hollow cathode depositions of Cr and CrN films

A cylindrical chromium hollow cathode powered by a pulsed dc generator working in a constant power mode was used for PVD of chromium and chromium nitride films on silicon substrates in argon and nitrogen plasmas, respectively. A comparison of the pulsed dc process with the radio frequency hollow cathode depositions of Cr and CrN films at identical power levels shows considerable differences particularly in the deposition rate of Cr films. At the pulsed power above 250 W the hot cathode/diffuse arc regimes were reached with the cathode outlet temperature as high as 1300 °C and the maximum deposition rates of both Cr and CrN films exceeded 1 μm/min. The resulting film properties, e.g. the microstructure and morphology were studied and compared with the films obtained by the rf hollow cathode PVD.