Optical and Plasmonic Properties of High-Electron-Density Epitaxial and Oxidative Controlled Titanium Nitride Thin Films.

The present paper reports on the fabrication, detailed structural characterizations, and theoretical modeling of titanium nitride (TiN) and its isostructural oxide derivative, titanium oxynitride (TiNO) thin films that have excellent plasmonic properties and that also have the potential to overcome the limitation of noble metal and refractory metals. The TiNO films deposited at 700 °C in high vacuum conditions have the highest reflectance ( = ∼ 95%), largest negative dielectric constant (ε = -161), and maximal plasmonic figure of merit (FoM = -ε/ε) of 1.2, followed by the 600 °C samples deposited in a vacuum ( = ∼ 85%, ε = -145, FoM = 0.