Dynamics of the fast-HiPIMS discharge during FINEMET-type film deposition

Using high power impulse magnetron sputtering (HiPIMS) technique, amorphous FeCuNbSiB thin films have been deposited. Results concerning the influence of certain sputtering conditions (working gas pressure, average power, and pulse duration) on the particle transport and deposition rate of the films are presented. The pulse voltage was set to a constant value of − 1 kV, for relatively short pulses (4-20 μs) with a repetition frequency in the range of 0.05 to 2 kHz, attaining a maximum cathode power density of about 5 kW/cm2. Tunable Diode-Laser Absorption Spectroscopy (TD-LAS), Tunable Diode-Laser Induced Fluorescence (TDLIF), Time Resolve-Optical Emission Spectroscopy (TR-OES), fast imaging and electrical investigations (voltage and current waveforms) have been used to investigate the plasma composition and its change in front of the target and onset of the self-sputtering regime. For an average power of 30 W and pulse duration of 4 μs, the argon pressure around  1.33 Pa assures an optimal transport of the particles between the target and substrate. For the same pulse duration, the deposition rate increases almost proportionally with the average discharge power, while, for the same average power, the deposition rate decreases with pulse duration increase due, in most part, to onset of the self-sputtering regime.