Ion beam modification of plasmonic titanium nitride thin films

Titanium nitride is regarded as an alternative plasmonic material for its tunability and other high performances. In this work, we prepared $$\hbox {TiN}_x$$ thin films by ion beam assisted deposition and studied the effects of assisting ion energy $$E_\mathrm{a}$$ on the structural, electrical, optical, and plasmonic properties of the films. The results show that the bombardment of assisting ions causes higher crystallinity and higher resistivity. Both the experimental and fitting results show that assisting ions can improve the plasmonic performance of $$\hbox {TiN}_x$$ thin films. Higher $$E_\mathrm{a}$$ leads to lower carrier concentration, lower plasma frequency, and lower optical losses. With $$E_\mathrm{a}$$ increasing, the energy loss function shifts toward low photon energy. Importantly, IBAD– $$\hbox {TiN}_x$$ can serve as a promising plasmonic material in visible and near-IR region, and its plasmonic properties can be effectively tuned by assisting ions energy.