Are the argon metastables important in high power impulse magnetron sputtering discharges?
We use an ionization region model to explore the ionization processes in the high power impulse magnetron sputtering (HiPIMS) discharge in argon with a titanium target. In conventional dc magnetron sputtering (dcMS), stepwise ionization can be an important route for ionization of the argon gas. However, in the HiPIMS discharge stepwise ionization is found to be negligible during the breakdown phase of the HiPIMS pulse and becomes significant (but never dominating) only later in the pulse. For the sputtered species, Penning ionization can be a significant ionization mechanism in the dcMS discharges, while in the HiPIMS discharge Penning ionization is always negligible as compared to electron impact ionization. The main reasons for these differences are a higher plasma density in the HiPIMS discharge, and a higher electron temperature. Furthermore, we explore the ionization fraction and the ionized flux fraction of the sputtered vapor and compare with recent experimental work.
- Department of Space and Plasma Physics, School of Electrical Engineering, KTH Royal Institute of Technology, SE-100 44 Stockholm (Sweden)
- Laboratoire de Physique des Gaz et Plasmas - LPGP, UMR 8578 CNRS, Université Paris-Sud, 91405 Orsay Cedex (France)
- CentraleSupélec, Grande Voie des Vignes, 92295 Chatenay-Malabry Cedex (France)
- Publication Date:
- OSTI Identifier:
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- 74 ATOMIC AND MOLECULAR PHYSICS; ARGON; BREAKDOWN; ELECTRON TEMPERATURE; IONIZATION; MAGNETRONS; PENNING DISCHARGES; PLASMA DENSITY; PULSES; SPUTTERING; TITANIUM