KINETICS OF THE C49-C54 PHASE TRANSITION IN TiSi2: NEW INDICATIONS FROM SHEET RESISTANCE, INFRARED SPECTROSCOPY AND MOLECULAR DYNAMICS SIMULATIONS

The kinetics and mechanism of the C49-C54 polymorphic transformation in titanium disilicides thin films were investigated by sheet resistance and optical spectroscopy. Fine grained C49 films were prepared by depositing Ti films on heated amorphous silicon substrates. The transformation to the C54 phase occurred after rapid thermal processing at temperatures between 700 and 775 degrees C. The time to transform the film at a fixed temperature decreases with the grain size and no strain can be detected during the transformation. The activation energy for the transformation is 3.9 +/- 0.2 eV. Total energy calculations suggests that the activation energy is associated to the breaking of Ti-Si bonds during the massive-reconstructive transformation.