Microstructure, Stress and Texture in Sputter Deposited TiN Thin Films: Effect of Substrate Bias

Jay Chakraborty,S Mukherjee,Kishor Kumar,Tias Maity

doi:10.4028/www.scientific.net/amr.996.855

Abstract

Titanium nitride thin films deposited by reactive dc magnetron sputtering under various substrate bias voltages have been investigated by X-ray diffraction. TiN thin films exhibits lattice parameter anisotropy for all bias voltages. Preferential entrapment of argon atoms in TiN lattice has been identified as the major cause of lattice parameter anisotropy. Bombardment of argon ions during film growth has produced stacking faults on {111} planes of TiN crystal. Stacking fault probability increases with increasing substrate bias voltages. X-ray diffraction line profile analysis indicates strain anisotropy in TiN thin films. Diffraction stress analysis byd-sin2ψmethod reveals pronounced curvature in the plot of inter-planar spacing (d) (or corresponding lattice parameter (a)) versussin2ψ. Direction dependent elastic grain interaction has been considered as possible source of the observed anisotropic line broadening.

Highlights

Titanium nitride (TiN) thin films deposited by reactive magnetron sputtering is widely used for improving the hardness and wear resistance of materials surfaces [1]
Stacking faults and lattice parameter anisotropy in TiN films: x-ray diffraction (XRD) analysis Fig. 1(a) shows the XRD patterns corresponding to polycrystalline titanium nitride thin films deposited under various substrate bias voltages
The net stacking fault probabilities (α) in TiN thin films have been determined from the change of the diffraction angular separation of 111 and 200 reflections of TiN films with respect to bulk TiN containing no stacking faults

Summary

Introduction

Titanium nitride (TiN) thin films deposited by reactive magnetron sputtering is widely used for improving the hardness and wear resistance of materials surfaces [1]. Such functional properties critically depend on the microstructure of TiN thin films. Negative bias voltage of the substrate can be varied in order to change the energy of the bombarding ions which is the key to change the film microstructure. Microstructure of TiN thin films deposited at various substrate bias voltages has been studied by X-ray diffraction. Intrinsic/growth stresses and crystallographic textures in TiN films have been studied as a function of substrate bias voltages (i.e. energies of the bombarding ions)

Results

Discussion

Conclusion