Influence of grain size on the transformation temperature of C49 TiSi2 to C54 TiSi2

Titanium disilicide exists in two possible crystallographic structures: the C49 (ZrSi2) structure and the C54 structure. At low annealing temperatures (400–650 °C), the C49 TiSi2 phase is formed. It transforms to the C54 phase at annealing temperatures between 650–800 °C. The transformation temperature (Ttr), however, appears to be influenced by the microstructure of the C49 phase. This is concluded from the observed difference in Ttr for TiSi2 thin films with varying average grain sizes.