Effects of substrate bias and temperature on the structure and dielectric properties of Ti_xZr_1−xN_y ternary nitride thin films

Transition metal nitrides have become a kind of promising alternative plasmonic materials. Ti_xZr_1−xN_y ternary nitride films were prepared by magnetron co-sputtering method, and the effects of bias voltage and temperature on the structure and dielectric properties of the films were investigated. The experimental results show that all the films are fcc-structured, and high substrate bias and temperature can significantly improve the N and Ti content. Increasing substrate bias voltage or temperature can reduce the crossover frequency ω_c at which the films transit from dielectric to metallic phase. Also, a high bias can greatly influence the energy loss of the films. Furthermore, the plasmonic quality factor can be effectively tailored by bias and temperature. Increasing bias can decrease the quality factor while high temperature (600 °C) can enhance the quality factor significantly. The study demonstrates that the Ti_xZr_1−xN_y films, as one kind of alternative plamonic materials, have considerable performances, and their dielectric and plasmonic properties can be modulated by varying the bias voltage and temperature in a wide range.