Generation of magnetically driven shunting arc discharge and amorphous carbon film preparation

Abstract

Summary form only given. The shunting arc discharge is an alternating capacitor discharge through a rod of metal or semi-metal. An optimization of the discharge condition has realized the self-ignition of the arc discharge at a low input power to the rod, leading to a much longer lifetime of the rod compared with the conventional shunting arc and the peripheral arc. The shunting-arc-produced plasma mainly consists of metal or semi-metal ions, and it has also been demonstrated that the ions can be extracted from the plasma. Thus, the shunting arc can be used as pulsed ion sources of metal and semi-metal for plasma-based ion implantation and deposition (PBII&D). Amorphous carbon films were deposited at a deposition rate of approximately 1 nm/min using omnidirectional shunting arcs. In order to improve the deposition rate, the arc was driven towards the substrate using a Lorentz force arisen from the interaction between the self magnetic field and the arc current. The deposition rate was improved by a factor of approximately 100 compared with the omnidirectional case. The sinusoidal half-cycle current has a peak of 1500 A and a duration of 20 /spl mu/s at 20 /spl mu/F-capacitor charging voltage of 600 V. The driving speed of the magnetically driven speed is about 1.3 mm//spl mu/s. The arc characteristics are analyzed using the Lorentz force. From the equation of motion, the plasma density of the shunting arc is estimated to be an order of 10/sup 17/ m/sup -3/. In PBII&D experiment, the ions are extracted from the magnetically driven shunting arc discharge. In comparison with the ion current characteristics between magnetically driven and omnidirectional shunting arcs, dominant species for the carbon film deposition by magnetically driven shunting arc discharges, are carbon neutrals emitted from the carbon holders and electrodes during the plasma acceleration.