01855nas a2200145   4500008004100000050001500041245005500056210005500111520137800166100001901544700002201563700001801585700002801603856007801631       2007                        eng d  aLBNL-6214700aPhysics of High Power Impulse Magnetron Sputtering0 aPhysics of High Power Impulse Magnetron Sputtering3 a<p>High power impulse magnetron sputtering is characterized by discharge pulses whose target power density exceeds conventional sputtering power densities by two orders of magnitude or more; the goal is to provide a large flux of ionized sputtered material. The processes of pulse evolution are briefly reviewed, including secondary electron emission, self-sputtering, and rarefaction. Using a pulse power supply capable of providing constant voltage for target peak power densities up to 5 kW/cm<sup>2</sup>, the evolution of the current-voltage characteristics was investigated for copper and titanium. It is shown that the characteristic cannot be reduced to value pairs. Rather, a strong but reproducible development exists. The details depend on the argon pressure and applied voltage. Each target material exhibits a distinct and sharp transition to a high current regime that appears to be dominated by metal plasma. Despite the higher sputter yields for copper, the transition to the high current regime occurs much earlier and stronger for titanium, which may be attributed to a higher secondary electron yield and hence a higher density of electrons confined in the magnetron structure. At high currents, the closed-drift Hall current generates a magnetic field that weakens plasma confinement, thereby enabling large ion currents to reach a biased substrate.</p>1 aAnders, André1 aAndersson, Joakim1 aHorwat, David1 aEhiasarian, Arutiun, P.  uhttps://facades.lbl.gov/publications/physics-high-power-impulse-magnetron