Experimental analysis of Hyper Power Impulse Magnetron discharge with long pulse operation

Glow discharges are known to be limited for running at high currents (< 0.1 . −2). Magnetically enhanced plasmas could overcome this limitation by increasing the current density for two decades. However, the discharge current density hardly exceeds 10 . −2. Here, we report on long (~1 ms) hyper-currentpulsed operation of magnetron while preserving the glow mode for current densities at least 3 times larger than the ones reported for high power pulsed magnetrons (HiPIMS). These huge currents were obtained for two cathode materials, molybdenum (Mo) and tungsten (W). Different experimental diagnostics bring insights into the physical phenomena governing the Hyper Power Impulse Magnetron (HyPIM). A discussion on the role played by the metal atoms on the current unveils the origin of such exceptional levels of current reached all along the pulse and the key role of the helium metastable atoms. A schematic of the kinetic steps of the HyPIM discharge is proposed.