High Power Impulse Magnetron Sputtering for Industrial Applications: Deposition of Chromium Films on Inclined Surfaces

High Power Pulsed Magnetron Sputtering (HIPIMS or HPPMS) is a magnetron sputtering technique that draws increasing interest due to the ability to form droplet-free films out of highly ionized vapor of the target material. Invented by Kouznetsov in 1999 (US patent US6296742), HIPIMS has gone the long way and is nowadays entering the stage of commercial applications. In this work chromium films were deposited by HIPIMS, as well as, by conventional DC magnetron sputtering on a set of substrates with an inclination angle of 0°, 90° and 180° degrees with respect to the target surface normal. The background gas pressure and the average power to the cathode were varied during depositions. Cross-sectional scanning electron microscopy was used for microstructure characterization of produced films and for the determination of deposition rates. The chromium ion content in the plasma, monitored with optical emission spectroscopy, increases with increasing target peak power. Results reveal also quite dramatic quality difference between films grown on tilted substrates by HIPIMS and by conventional DC sputtering.