Behaviour of spokes in reactive HiPIMS
| Authors | |
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| Year of publication | 2020 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Plasma in high-power impulse magnetron sputtering (HiPIMS) discharge, similarly to other discharges utilizing ExB field (Hall thrusters, homopolar devices), undergoes self-organization into the ionization zones rotating in the ExB direction, called spokes [1]. Many studies were conducted focusing on the characterization of their appearance, number, rotational velocity, merging and splitting events in different experimental conditions. Nevertheless, only very little research was conducted in the case of reactive sputtering, where only general spoke characteristics were evaluated [2]. A dual-image fast camera screening was utilized to capture plasma emission on 3” Nb target in a reactive mixture of nitrogen and argon. Spoke characteristics were evaluated while overall pressure and supplied power was kept constant and the ratio of N2/Ar was varied. The shape, velocity and spoke number were significantly affected by higher ratio of N2 in the mixture. To distinguish between the effects of the poisoned target and reactive gas present in the plasma on spokes, plasma emission was screened as the Nb target was cleaned in pure Ar atmosphere. Additionally, obtained spoke characteristics were compared to those made on a fully compound NbN target |
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