Fabrication of Ta-Si-N/Ag nanocomposite thin films with near-zero temperature coefficient of resistance

Ta-Si-N/Ag nanocomposite thin films were prepared by reactive magnetron co-sputtering of Ta, Si and Ag targets in the plasma of N-2 and Ar. It was found that Ag nano-grains were uniformly distributed in the amorphous matrix due to the incorporation of Si. The sizes of Ag grains and the separation between them could be well controlled by changing the Si component, which can be adopted to improve the electronic properties of the composite resistive films. A near-zero temperature coefficient of resistance (TCR) of +39.7 ppm/K was obtained in the thin films with a Si component of 5.88 at.% as a result of the balance of quantum tunneling effect and phonon scattering effect. This is consolidated by the changes in the measured carrier density and Hall mobility at different temperatures. Particularly, the near-zero TCR could be maintained at an extremely low temperature from 105 K to 225 K. The results are of great significance for the exploitation of high-performance resistive thin films. (C) 2015 Elsevier B.V. All rights reserved.