01782nas a2200205 4500008003900000022001400039245008700053210006900140260001200209300001100221490000700232520110700239653003601346653001901382653004001401100002101441700001801462700001901480856007701499 2014 d a0963-025200aAsymmetric particle fluxes from drifting ionization zones in sputtering magnetrons0 aAsymmetric particle fluxes from drifting ionization zones in spu c04/2014 a0250070 v233 a
Electron and ion fluxes from direct current and high-power impulse magnetron sputtering (dcMS and HiPIMS) plasmas were measured in the plane of the target surface. Biased collector probes and a particle energy and mass analyzer showed asymmetric emission of electrons and of singly and doubly charged ions. For both HiPIMS and dcMS discharges, higher fluxes of all types of particles were observed in the direction of the electrons' E x B drift. These results are put in the context with ionization zones that drift over the magnetron's racetrack. The measured currents of time-resolving collector probes suggest that a large fraction of the ion flux originates from drifting ionization zones, while energy-resolving mass spectrometry indicates that a large fraction of the ion energy is due to acceleration by an electric field. This supports the recently proposed hypothesis that each ionization zone is associated with a negative–positive–negative space charge structure, thereby producing an electric field that accelerates ions from the location where they were formed.
10aInstrumentation and measurement10aPlasma physics10aSurfaces, interfaces and thin films1 aPanjan, Matjaž1 aFranz, Robert1 aAnders, André uhttps://facades.lbl.gov/publications/asymmetric-particle-fluxes-drifting01455nas a2200253 4500008003900000022001300039245012000052210006900172260001200241300001100253490000800264520065900272653002000931653001500951653002200966653002300988653001501011100001901026700002101045700001801066700002201084700001801106856007701124 2013 d a0003695100aDrifting potential humps in ionization zones: The “propeller blades” of high power impulse magnetron sputtering0 aDrifting potential humps in ionization zones The propeller blade c10/2013 a1441030 v1033 aIon energy distribution functions measured for high power impulse magnetron sputtering show features, such as a broad peak at several 10 eV with an extended tail, as well as asymmetry with respect to E × B, where E and B are the local electric and magnetic field vectors, respectively. Here it is proposed that those features are due to the formation of a potential hump of several 10 V in each of the traveling ionization zones. Potential hump formation is associated with a negative-positive-negative space charge that naturally forms in ionization zones driven by energetic drifting electrons.
10aElectric fields10aionization10aplasma ionization10asputter deposition10asputtering1 aAnders, André1 aPanjan, Matjaž1 aFranz, Robert1 aAndersson, Joakim1 aNi, Pavel, A. uhttps://facades.lbl.gov/publications/drifting-potential-humps-ionization