Reactive HiPIMS of Oxides: Hysteresis and Discharge behaviour
2014 (English)In: Invited talk, 42th International Conference on Metallurgical Coatings and Thin Films, San Diego, CA, April 28 -May 2, 2014, 2014Conference paper, Abstract (Refereed)
In High Power Impulse Magnetron Sputtering (HiPIMS), high degree of ionization of the sputtered material is achieved thanks to the high instantaneous peak powers and thus high plasma densities. HiPIMS is therefore beneficial for deposition of dense films, uniform coatings on complex-shaped surfaces as well as interface engineering for improved adhesion. In reactive HiPIMS, compound thin films are deposited from metal targets in an atmosphere of argon and a suitable reactive gas, such as oxygen. As a result of the interaction between sputtered metal and the reactive gas, the relation between the deposition rate and reactive gas flow is nonlinear and typically exhibits hysteresis behaviour.
This contribution deals with reactive HiPIMS, mainly with the effect of HiPIMS on the hysteresis. First, results from various hysteresis studies are summarized. We show that the frequency dependence indicates an influence of gas rarefaction. The optimum frequency is related with the gas refill time as demonstrated by experiments with targets of different dimensions. Formation of compound at the target surface is also accompanied by a pronounced change in the shape of discharge current waveforms. In HiPIMS, the discharge behaviour is dominated by ionized oxygen sputtered from the target. This is shown from the ion energy distribution functions of different species characterized by energy and time resolved mass spectroscopy. Finally, we simulate the target surface sputtering by TRIDYN code. The predicted time to completely remove the compound from a target is in reasonable agreement with measurements.
Place, publisher, year, edition, pages
HiPIMS, Thin Films, Reactive Sputtering, Oxides
Manufacturing, Surface and Joining Technology
IdentifiersURN: urn:nbn:se:uu:diva-234699OAI: oai:DiVA.org:uu-234699DiVA: diva2:757621
42th International Conference on Metallurgical Coatings and Thin Films, San Diego, CA, April 28 -May 2, 2014
FunderCarl Tryggers foundation , 12:252