Electrical characteristics of arc-free high-power pulsed sputtering glow plasma

Abstract

A high power pulsed sputtering (HPPS) plasma is generated using a Penning discharge, and is featured to be highly ionized in a glow discharge mode. An electric field and a magnetic field are parallel to each other. Argon ions are initially produced in the plasma and are accelerated towards the cathode as a sputtering target. An arc-free plasma can be realized by adjusting a pulse width of the rectangular-shaped voltage of the power supply, using the switching of insulated gate bipolar transistor (IGBT) devices.The plasma source has features as follows: (1) the plasma generation unit is small with a volume of 60×60×60 mm3, (2) a power density is on the order of a few kW/cm2 for a gap length of 10 mm. For a power-supply voltage of − 1.6 kV and an argon pressure of 2.0 Pa, a plasma current is approximately 57 A at a current limiting resistance of 20 Ω. The current density is approximately 2.4 A/cm2. The instantaneous peak power is approximately 25 kW, which corresponds to a power density of approximately 1 kW/cm2. The energy consumed in the plasma per shot is approximately 0.65 J, which results in an average power of approximately 410 W at a repetition rate of 625 Hz. The plasma density is estimated to be on the order of 1013 cm− 3.