Tuning the electronic properties in TaNx/Ag nanocomposite thin films

Abstract

The temperature coefficient of resistance (TCR) of TaN_x/Ag nanocomposite thin films could be substantially tuned by changing the components, even down to zero. In the work of this paper, it is unexpectedly found that the concentration of silver incorporation in the TaN_x/Ag thin films could be controlled over a broad range from 5.4 at% to 31.14 at% through changing the N₂ partial pressure during magnetron sputtering. In particular, the near-zero TCR of −15 ppm K⁻¹ and the highest resistivity of 6038 μΩ cm were obtained in the TaN_x/Ag thin films with 12.39 at% Ag. The high resistivity can be attributed to the low carrier density as a result of recombination of holes in the TaN_x matrix and electrons in Ag. The composites changes from p-type to n-type at a higher Ag component. The results highlight a new approach to obtain high-performance thin films with zero TCR.