Structural and dielectric properties of ion beam deposited titanium oxynitride thin films

Titanium oxynitride (\({\hbox {TiO}}_{x}{\hbox {N}}_{y}\)) thin films were fabricated by ion beam-assisted sputtering deposition. Effects of oxygen contribution, assisting ion energy (\(E_{\mathrm{a}}\)), assisting ion beam current (\(I_{\mathrm{a}}\)) on the microstructure and dielectric behavior of the films were analyzed. The results show that increasing O content made the films to turn from fcc-TiN (111)-oriented to fcc \({\hbox {TiO}}_{x}{{\hbox {N}}}_{y}\) (220)-oriented. Proper \(E_{\mathrm{a}}\) and low \(I_{\mathrm{a}}\) can enhance the (220) orientation in \({\hbox {TiO}}_{x}{{\hbox {N}}}_{y}\) thin films. The increase in oxygen content leads to the red-shift of plasmonic resonant frequency and makes the films more dielectric. Higher \(E_{\mathrm{a}}\) and \(I_{\mathrm{a}}\) make the \({\hbox {TiO}}_{x}{{\hbox {N}}}_{y}\) films more metallic. Atomic composition is an important factor underlying the results. The study provides a method to control the plasmonic properties of oxynitride films in a wide range by atomic composition and assisting ions.