Ion density evolution in a high-power sputtering discharge with bipolar pulsing

Abstract

Time evolution of sputtered metal ions in high power impulse magnetron sputtering (HiPIMS) discharge with a positive voltage pulse applied after a negative one (regime called “bipolar pulse HiPIMS”—BPH) is studied using 2-D density mapping. It is demonstrated that the ion propagation dynamics is mainly affected by the amplitude and duration of the positive pulse. Such effects as ion repulsion from the cathode and the ionization zone shrinkage due to electron drift towards the cathode are clearly observed during the positive pulse. The BPH mode also alters the film crystallographic structure, as observed from X-ray diffraction analysis.

Insights on the Formation of Nanoparticles Prepared by Magnetron Sputtering Onto Liquids: Gold Sputtered Onto Castor Oil as a Case Study

“…The magnetron was cooled by water line, hence allowing stable deposition conditions. Depositions in DC-MS regime were done with commercial power supply (Advanced Energy MDX 500), while for HiPIMS experiments a prototype constructed in MATERIA NOVA R&D center (Britun et al, 2018)) was used. In this case magnetron sputtering was carried out at an argon pressure of 0.7 Pa, at a time-averaged sputter power of 80 W (current 92 mA; voltage 867 V), and with the following pulse parameters (pulse repetition frequency 800 Hz, pulse duration 20 µs; peak target current density 0.3 A/cm 2 ).…”

Pulse length selection for optimizing the accelerated ion flux fraction of a bipolar HiPIMS discharge

“…Bipolar high-power impulse magnetron sputtering (HiPIMS) refers to the application of positive voltage pulses following the conventional negative HiPIMS pulses and has recently attracted significant attention due to its capability of accelerating plasma ions towards the surface of the growing film [1][2][3][4][5], potentially overcoming the deposition rate problem in HiPIMS [6] and as a possible solution for ion bombardment during sputter deposition of insulating materials [7]. It is only recently that a HiPIMS discharge operated in bipolar mode has been realized [1,2,6,8] but the idea of introducing a positive voltage in a HiPIMS discharge can be traced back to the suggestion by Konstantinidis et al [9] for increasing the deposition rate in HiPIMS discharges.…”

Engineered ion-bombardment as a tool in thin film deposition

“…Bipolar HiPIMS is a recent development where a positive pulse voltage Urev is applied after the negative HiPIMS pulse [23][24][25][26][27]. The idea of introducing a positive pulse voltage in a conventional HiPIMS discharge can be traced back to the suggestion by Konstantinidis et al [113] for increasing the deposition rate in a HiPIMS discharge.…”

“…A more recent development within HiPIMS is the application of a positive pulse after the main negative pulse called bipolar HiPIMS [23][24][25][26]. This technique allows for the tuning of the energy distribution of ions without the use of a substrate bias [25][26][27].…”