Influence of Substrate Temperature and Plasma Power Density on the Properties of Plasma-Assisted Chemical Vapor Deposited Titanium Nitride

Abstract

Titanium nitride films deposited onto high speed steel substrates by plasma-assisted chemical vapor deposition (PACVD) from TiCl₄, H₂, N₂, and Ar gas mixtures have been investigated. The substrate temperature was varied between 250 and 550^° C via the plasma power density or via an additional electrical heater. The influence of temperature and plasma power density on the morphology, chemical composition, hardness and adhesion of the coatings was studied. At a temperature of 500^° C different plasma power densities caused changes of the morphology of the coatings. At low plasma power densities fine grained polycrystalline layers were observed. A significant change from coarse to fine grained structures was also observed with decreasing deposition temperature. Scratch test results indicate that coatings deposited at a given substrate temperature with lower plasma power density showed increased values of the critical load.

Notes

This paper was presented at the Eighth International Conference on Surface Modification Technologies, Nice, France, 1994 and is reprinted by permission from Proceedings of Surface Modification Technologies VIII, Institute of Materials, London, U.K., 1995.