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 i n titanium disilicides thin films were investigated by sheet resistanc e and optical spectroscopy. Fine grained C49 films were prepared by de positing Ti films on heated amorphous silicon substrates. The transfor mation to the C54 phase occurred after rapid thermal processing at tem peratures between 700 and 775 degrees C. The time to transform the fil m at a fixed temperature decreases with the grain size and no strain c an be detected during the transformation. The activation energy for th e transformation is 3.9 +/- 0.2 eV. Total energy calculations suggests that the activation energy is associated to the breaking of Ti-Si bon ds during the massive-reconstructive transformation.