Effects of Ag addition on phase transformation and resistivity of TiSi2 thin films

In this study, the effects of adding Ag to TiSi2 thin films are examined. It is demonstrated that both the C49 → C54 transformation temperature and the electric resistivity are appreciably lowered with Ag addition. Due to the presence of Ag nanocrystals precipitated at the C49 grain boundaries, the overall grain boundary density would increase to result in the higher nucleation rate of C54 and the lower transformation temperature. The precipitation of pure Ag network can provide another electric current conductive path except for the TiSi2 grains. Due to the lower vacuum condition and the higher oxygen content in the current sputtered and annealed films, the C49 → C54 transformation temperature and the resistivity of the TiSi2-20 at%Ag films can only be reduced by ∼100 °C and 10 μΩ cm, as compared with the non-Ag additive films. With better fabrication vacuum, the transformation temperature and resistivity might be lowered to a level below 700 °C and 15 μΩ cm, which are highly applausive for engineering applications.