AVS 45th International Symposium
    Thin Films Division Monday Sessions
       Session TF-MoP

Paper TF-MoP28
The Dislocation Network Developed Deep in Titanium Nitride by Ion Implantation

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Thin Films Poster Session
Presenter: A.J. Perry, A.I.M.S. Marketing, Japan
Authors: A.J. Perry, A.I.M.S. Marketing, Japan
D.E. Geist, Analytical Reference Materials International
Y.P. Sharkeev, Russian Academy of Sciences
S.V. Fortuna, Tomsk State University of Architecture & Building, Russia
Correspondent: Click to Email
After treatment by ion implantation, the implanted ions in metallic materials reside in an implanted zone, IZ, extending to a depth of some hundreds of nanometers. Earlier work has shown that the momentum carried by the ions affects the material to far greater depths with a dislocation network extending many microns deep. Dense, thick coatings of titanium nitride can be deposited with low residual stress and low dislocation densities at high temperatures, some 950 C, without the application of substrate bias. Normally used for wear resistance, these coatings are an ideal model system for studying the nature of the IZ and the development of the dislocation network well below it. Studies have been carried out by TEM and glancing incidence XRD. The TEM study shows that implantation leads to the formation of sub-grains within the original grain structure without any grain comminution occurring. A mechanism is then proposed to explain the development of the dense dislocation network below the IZ which is studied by XRD as a function of ion species, acceleration voltage and dose in an extended series of samples. It is found that while any ion bombardment produces a dislocation network, there is a momentum threshold level before a compressive residual stress is developed. This stress is proportional to the ion momentum, reaching values as high as 3-4 GPa, i.e. as high as that found in materials made by PVD methods. Finally we find that there is a significant change in the stress in the substrate below the titanium nitride coating which, surprisingly, can be tensile or compressive and is sensitive to the ion species implanted.