Deposition of TiN films using a thermal plasma reactive forming technology

Abstract

TiN films have been deposited on graphite substrates by a novel reactive plasma technique. In this process, NH 3 and TiCl 4 are reacted in the jet of a plasma torch and are deposited onto a substrate forming TiN films at a high growth rate (above 2 μm min −1). It was found that the process parameters strongly affect the microstructure, thickness, density, and growth rate of the TiN films. These parameters include N : Ti ratio, temperature of substrate, spray distance and radial position away from the impingement point. In general, it was found that thick and dense coatings were deposited when the N : Ti ratio was kept low and the substrate temperature was high. Very dense and thin TiN coatings were deposited 3–4 cm away from the impingement point. These coatings are believed to be the result of a gas phase (chemical vapour deposition type) reaction. The limitations and advantages of this technique are also discussed in this paper.