Tailoring the structural and optical properties of TiN thin films by Ag ion implantation

Abstract

Titanium nitride (TiN) thin films thickness of ∼260nm prepared by dc reactive sputtering were irradiated with 200keV silver (Ag) ions to the fluences ranging from 5×1015ions/cm2 to 20×1015ions/cm2. After implantation TiN layers were annealed 2h at 700°C in a vacuum. Ion irradiation-induced microstructural changes were examined by using Rutherford backscattering spectrometry, X-ray diffraction and transmission electron microscopy, while the surface topography was observed using atomic force microscopy. Spectroscopic ellipsometry was employed to get insights on the optical and electronic properties of TiN films with respect to their microstructure. The results showed that the irradiations lead to deformation of the lattice, increasing disorder and formation of new Ag phase. The optical results demonstrate the contribution of surface plasmon resonace (SPR) of Ag particles. SPR position shifted in the range of 354.3–476.9nm when Ag ion fluence varied from 5×1015ions/cm2 to 20×1015ions/cm2. Shift in peak wavelength shows dependence on Ag particles concentration, suggesting that interaction between Ag particles dominate the surface plasmon resonance effect. Presence of Ag as second metal in the layer leads to overall decrease of optical resistivity of TiN.