Double-plasmon broadband response of engineered titanium silicon oxynitride

Titanium nitride is a CMOS-compatible alternative material to conventional metals for plasmonics and metamaterials applications. We demonstrate complete tunability at visible and near-infrared frequencies of the optical dispersion of titanium nitride nanolayers deposited on Si (100) substrates from metallic to dielectric behavior by alteration of reactive magnetron sputtering growth conditions and, via co-deposition, the addition of Si and/or O-2 elemental components. The dielectric function and region of metallic character is found to be further modified by post-deposition vacuum annealing. We categorize this dispersion behavior as anomalous due to a distinctive line shape that allows for double-plasmon resonances, which we investigate analytically using Mie scattering theory. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement