The effect of substrate temperature and biasing on the mechanical properties and structure of sputtered titanium nitride thin films

The mechanical properties of titanium nitride (TiNx) thin films have been i nvestigated using depth sensing nanoindentation tests. The effects of subst rate temperature (T-s) and of substrate biasing (V-b) on the mechanical pro perties and the microstructure of the TiNx films were studied. T-s and V-b have strong effect on the film's microstructural characteristics such as de nsity, grain size and orientation. It was found that deposition at high T-s and V-b promotes the growth of (002) oriented films with density close to the bulk density of stoichiometric TIN, indicating the absence of voids and the growth of stoichiometric TiN. The film hardness and elastic modulus we re measured using the continuous stiffness measurements technique. It was f ound that there exists a direct correlation between the film's mechanical p roperties and microstructure. The films that exhibit the best mechanical pe rformance are those grown along the (002) orientation and being denser and stoichiometric. (C) 2000 Elsevier Science S.A. All rights reserved.