For more than four decades, the magnetron sputter discharge has been successfully used for the deposition of thin films and coatings. It is used in a range of different applications ranging from microelectronics and photovoltaics to the production of optical elements. Essential in this process is the magnetic field of the magnetron, which is determined by a central and an external magnet pack and strongly influences the discharge characteristics. This is particularly evident in high-power pulsed magnetron sputtering discharge (HiPIMS), where small changes in the magnetic field can lead to large variations in the discharge characteristics, especially the peak discharge current and/or discharge voltage during a pulse. Scientists at IOM and universities in Linköping, Stockholm, Reykjavík, Enschede and Paris have now analyzed the influence of the magnetic field on the electron density and temperature, the partitioning of the discharge voltage over the sheath and the ionization region, and the mechanism of electron heating in a HiPIMS discharge. The study shows, that the electron density and ionization probability of the sputtered species strongly depend on the discharge current. It can be used to tune the electron density and temperature and influence the ionization probability, which allows the ionization rate of the metal atoms to be tuned.    

The results have now been published in the Journal of Physics D: Applied Physics. For more information, see the article

Influence of the magnetic field on the discharge physics of a high power impulse magnetron sputtering discharge
M. Rudolph, N. Brenning, H. Hajihoseini, M. A. Raadu, T. M. Minea, A. Anders, J. T. Gudmundsson, D. Lundin
https://doi.org/10.1088/1361-6463/ac2968