Operating the HIPIMS discharge with ultra-short pulses: a solution to overcome the deposition rate limitation

摘要

This study presents results on the influence of pulse duration in HiPIMS discharge on the sputtering mechanisms, target-to-substrate particles transport, and deposition rate. A copper disk-shaped target was sputtered in argon atmosphere, increasing the pulse duration from 3 μs to 50 μs and adjusting the pulsing frequency in order to keep a constant average power of 100 W. Voltage and current waveforms, time-resolved fast imaging, time resolved-optical emission spectroscopy, time evolution of the ion flux towards the substrate, and energy-resolved mass spectrometry were used in order to investigate the plasma composition and its change in front of the target. Increasing the pulse duration, the sputtering mechanism is gradually transformed from dominant gas sputtering to self-sputtering driven mode and the deposition rate decreases.