Experimental investigations of plasma dynamics in the hysteresis regime of reactive RF sputter processes

  • Reactive radio frequency (RF) sputter processes are highly relevant for thin film deposition, but there is no complete understanding of the fundamentals of their operation. While the Berg model describes the hysteresis regime considering the oxygen coverage of the boundary surfaces, a complete fundamental understanding of the plasma–surface interactions and their effects on the discharge is still missing. In this work, we provide such fundamental insights based on an extensive experimental analysis of the physics in the hysteresis regime of magnetized reactive sputter processes, where the same reactive gas admixture can lead to different discharge characteristics depending on the previous state of the plasma. A variety of plasma and surface diagnostics is used to reveal these insights. A low pressure capacitively coupled RF discharge (CCP, 13.56 MHz) with a magnetron-like magnetic field topology adjacent to the target is operated in argon gas with a variable admixture of O\(_2\). The applied RF power, the gas flows/pumping speed, as well as the neutral gas pressure are changed systematically to understand the effects of these external control parameters on the hysteresis regime. The magnetic asymmetry effect is found to play an important role, since an axially non-uniform magnetic field is used to realize a local electron confinement at the target. Similar to process control in applications, the DC self-bias is measured to stabilize the surface composition using a feedback controller with the oxygen gas flow as the manipulated variable.

Download full text files

Export metadata

Additional Services

Share in Twitter Search Google Scholar
Author:Julian RoggendorfORCiDGND, Birk-Sören BergerORCiDGND, Denis EreminGND, Moritz OberbergORCiDGND, Dennis EngelGND, Christian WölfelGND, Quan-Zhi ZhangORCiDGND, Peter AwakowiczORCiDGND, Jan LunzeGND, Julian SchulzeORCiDGND
Parent Title (English):Plasma sources science and technology
Publisher:IOP Publishing
Place of publication:Bristol, Vereinigtes Königreich
Document Type:Article
Date of Publication (online):2024/02/02
Date of first Publication:2022/09/13
Publishing Institution:Ruhr-Universität Bochum, Universitätsbibliothek
Tag:capacitively coupled RF discharge
DC self-bias voltage; hysteresis; magnetic asymmetry effect; magnetized plasmas; sputtering
Issue:6, Artikel 065007
First Page:065007-1
Last Page:065007-12
Institutes/Facilities:Lehrstuhl für Allgemeine Elektrotechnik und Plasmatechnik
Dewey Decimal Classification:Technik, Medizin, angewandte Wissenschaften / Elektrotechnik, Elektronik
open_access (DINI-Set):open_access
faculties:Fakultät für Elektrotechnik und Informationstechnik
Licence (English):License LogoCreative Commons - CC BY 4.0 - Attribution 4.0 International