Ion flux characteristics in high-power pulsed magnetron sputtering discharges

High-power pulsed dc magnetron discharges for ionized high-rate sputtering of copper films were investigated. The repetition frequency was 1 kHz at a fixed 20% duty cycle and argon pressures of 0.5 Pa and 5 Pa. Time evolutions of the discharge characteristics were measured at a target power density in a pulse up to 950 W/cm². Time-averaged mass spectroscopy was performed at substrate positions. It was shown that copper ions are strongly dominant (up to 92%) in total ion fluxes onto the substrate. Their energy distributions with a broadened low-energy part at a lower pressure are extended to higher energies (up to 45 eV relative to ground potential for the target-to-substrate distance of 100 mm).