Planar Magnetron Discharge With Confinement Of Injected Electrons

We have explored the operation and characteristics of a planar magnetron discharge system with central on-axis electron injection and a reflector electrode. The diameter of the magnetron copper target was 125 mm; the operating gas was argon and the pressure range 2 x 10(-4) - 2 x 10(-3) Torr. To increase the efficiency of electron injection, a negatively-biased reflecting electrode was located on the system axis. We have investigated the effect of the reflector electrode on the characteristics of the magnetron discharge, as a function of reflector shape, cross-sectional area, electrical bias, and distance from the target. It is shown that the simultaneous use of central injection of electrons with their acceleration across the cathode layer of the magnetron discharge, and a cone-shaped reflector electrode allows the current to be increased and the operating pressure to be decreased by a factor of several for a fixed magnetron discharge voltage.