Chemical Species in a Low Pressure Arc Plasma and Topographies of the Plasma Deposited Surface

Abstract

The present paper aims to establish a better understanding of species and their concentrations in an arc plasma and of the topographies of the deposited surface.
A zirconium dioxide plasma was produced by arcing betwee n a hollow cylinder of a sintered zirconium dioxide anode and a tantalum ribbon filament in the center of the anode at vacuum, and the ions inside the plasma were introduced into a mass spectrometer directly. The data from the mass spectrometric analyses were compared with those from calculations of statisticalthermodynamics. The deposition from plasma on a tantalum filament was examined by scanning electron microscopy.
The results sugg est that the collision of energetic particles (in this case, electron) with neutral ones plays an important role to estimate the concentration of ionic species in a plasma and that the values of particle collision processes should be combined with those of thermodynamical calculation to understand the chemical species in a low pressure arc plasma.
Topographies of plasma deposited surface were discussed in comparison with those of glow plasma and vapor depositions.
Characteristic pa ttern of the arc plasma deposition had a waterlily-like shape and the number of the pedals decreased with substrate temperature and duration of arcing, and increased with the plasma current density. It should be noted that the topographies were very similar to those of the sputtered surface published by others.