Ion density increase in high power twin-cathode magnetron system

In contrast to conventional plasma deposition methods, High Power Impulse Magnetron Sputtering (HIPIMS) utilizes extremely high power inputs in short pulses, providing for the discharge current densities up to several A/cm(2). High ion densities are observed not only during the plasma on-time, but also within the afterglow period. Once ions are generated, they can contribute to the peak ion density of the next pulse if the off-time between the pulses is sufficiently small. When the HIPIMS cycle contains two pulses, separated by a short plasma off-time and followed by a long afterglow period, the peak ion density for the second pulse can be 5-7 percents higher than for the first pulse. With a dual cathode system and time-shifted pulsing with distinct magnetron heads it was possible to increase ion density gain up to 40% for Ti targets. (C) 2011 Elsevier Ltd. All rights reserved.