%0 Journal Article
%A André Anders
%B Applied Physics Letters
%D 2012
%N 22
%R 10.1063/1.4724205
%T Self-organization and self-limitation in high power impulse magnetron sputtering
%V 100
%2 LBNL-5685E
%8 05/2012
%X <p>The plasma over the racetrack in high power impulse magnetron sputtering develops in traveling ionization zones. Power densities can locally reach 10<sup>9&thinsp;</sup>W/m<sup>2</sup>, which is much higher than usually reported. Ionization zones move because ions are “evacuated” by the electric field, exposing neutrals to magnetically confined, drifting electrons. Drifting secondary electrons amplify ionization of the <em>same</em>ionization zone where the primary ions came from, while sputtered and outgassing atoms are supplied to the <em>following</em> zone(s). Strong density gradients parallel to the target disrupt electron confinement: a negative feedback mechanism that stabilizes ionization runaway.</p>