%0 Journal Article %J Applied Physics Letters %D 2013 %T Drifting potential humps in ionization zones: The “propeller blades” of high power impulse magnetron sputtering %A André Anders %A Matjaž Panjan %A Robert Franz %A Joakim Andersson %A Pavel A. Ni %K Electric fields %K ionization %K plasma ionization %K sputter deposition %K sputtering %X

Ion 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.

%B Applied Physics Letters %V 103 %P 144103 %8 10/2013 %N 14 %! Appl. Phys. Lett. %R 10.1063/1.4823827