Investigations on mechanical and electrical properties of N⁺ ions implanted TiN thin films

In the present work, we have grown titanium (Ti) thin films using DC sputtering system in argon atmosphere. Ti films are implanted using low energy ion beam(having 70 keV energy) at a fluence of 2  ×  10¹⁶ ions cm⁻² by varying the implantation angles from 15° to 45°. TiN films were then characterized for their structural, mechanical, optical and electrical properties. XRD measurements show an enhancement in the (1 1 1) peak with increase in implantation angle indicating the improvement in the crystallinity due to deeper implantation of N ions in host lattice. Also, a small shift in this peak towards higher angle side is noticed with the implantation angle which confirms that strain is modified depending upon the implantation angle. The change in the strain value in turn is responsible for the variation in various physical properties. UV–Vis measurements show decrease in optical band gap (from 2.41 eV to 2.39 eV) while improvement in electrical conductivity with implantation angle. Furthermore, increase in implantation angle leads to enhancement in mechanical hardness of the TiN thin films from pristine 3.0 GPa–19.6 GPa for 30° angle. (paper)