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.

Research highlights
► Considerable difference between pulsed dc and rf hollow cathode PVD of Cr and CrN.
► CrN and Cr deposition rates exceed 1000 nm/min in the diffuse arc regime.
► Pulsed dc generated hollow cathode enhances the PVD rate of Cr films.
► Rf generated hollow cathode enhances PVD of highly oriented CrN films.