Influence of Hafnium Defects on the Optical and Structural Properties of Zirconium Nitride

Recently, the application of transition metal mononitrides (TMNs) to plasmonics and nonlinear optics has grown at an astounding rate. TiN and ZrN have emerged as the dominating materials in this direction. However, even though ZrN is reported to have lower dielectric losses and enhanced tunability in plasmonic applications when compared with TiN, the body of work regarding TiN is much more mature than that of ZrN. This imbalance of work regarding ZrN may be in part an effect of pollution in precursor materials for the fabrication of ZrN, leading to an increased imaginary part of permittivity and frustration in reproduction of ZrN with literature-like properties. Herein, the effects of Hf defects (a common pollutant in Zr) on the optical properties of nitride films grown with radio frequency (RF) magnetron sputtering are reported. Hf defects are introduced into nitride films with a sputtering target made of the Hf-polluted grade 702 Zr alloy. Hf defects are found in all analyzed films with concentrations at around approximate to 0.5-1 at %. Chemical, structural, and optical properties of RF magnetron-sputtered Hf- x :Zr y N z films (x MUCH LESS-THAN y,z) are characterized and discussed.

Automated summary

The application of transition metal mononitrides (TMNs) in plasmonics and nonlinear optics has seen rapid growth, with TiN and ZrN emerging as dominant materials. While ZrN is reported to have advantages over TiN, such as lower dielectric losses and enhanced tunability, research on TiN is more mature. The presence of Hf defects in ZrN films grown with RF magnetron sputtering is found to have implications on the optical properties of the films.