%0 Journal Article
%K Sputtering
%K Sputter deposition
%K Ionization
%K Plasma ionization
%K Electric fields
%A André Anders
%A Matjaž Panjan
%A Robert Franz
%A Joakim Andersson
%A Pavel A Ni
%B Applied Physics Letters
%D 2013
%N 14
%P 144103
%R 10.1063/1.4823827
%T Drifting potential humps in ionization zones: The “propeller blades” of high power impulse magnetron sputtering
%V 103
%8 10/2013
%! Appl. Phys. Lett.
%X <p>Ion energy distribution functions measured for high power impulse magnetron sputtering show features, such as a broad peak at several 10&thinsp;eV with an extended tail, as well as asymmetry with respect to <em>E</em> × <em>B</em>, where <em>E</em> and <em>B</em> 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&thinsp;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.</p>