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.