Seminar DPE: Mgr. Katarína Bernátová

Mgr. Katarína Bernátová: "Ionisation fraction of sputtered Ti species in HiPIMS discharge"

High power impulse magnetron sputtering (HiPIMS) is a physical vapour deposition method of thin films. Focusing applied power into short pulses with a duty cycle of up to 10% makes it possible to achieve a high-density plasma. Thanks to that, an increased ionisation fraction of sputtered species and consequently a metal ion flux towards the substrate is available. Adding reactive gas such as oxygen or nitrogen into the deposition process makes it possible to increase the number of possible material variations.

Compared to different deposition techniques, thin films deposited by the reactive HiPIMS exhibit improved mechanical, optical, chemical, and other properties. One of the options for understanding the effect of various process parameters (including working pressure, discharge current, duty cycle, and others) on deposition conditions is by studying the sputtered species densities and their ionisation.

The optical emission spectroscopy and effective branching fractions method are utilised to measure sputtered titanium species density. The ionised density fraction in the non-reactive and reactive HiPIMS is studied. The effect of working pressure and discharge current in three regions above the target surface in the deposition chamber is studied in non-reactive HiPIMS. In the case of reactive HiPIMS, the effect of oxygen, nitrogen and acetylene on discharge current and voltage evolution, pressure and the ionisation fraction of sputtered species is studied.