Abstract
We found that the mean grain size of TiSi2 films on Si wafers deponds on deposited Ti amount of every time rather than annealing temperature. From SEM micrographs, it was found that no morphologies are varied before and after oxidation in air at temperature from 100°C to 800°C. But above 1000°C, the TiSi2 film was thermally grooved at its grain boundaries and grain size was increased. From analytic electron microscope photographs, it was found that crystalline grain represent TiSi2, but the grain boundary was found to be Ti free-zone.
Quantitative depth profile of chemical composition of the thermal oxide of the TiSi2 have been studied by XPS in conjunction with argon ion sputtering. From chemical depth profiles of the thermal oxide of TiSi2, we observed that SiO2 is dominant in oxide products of the TiSi2 at various oxidation temperatures. From FWHM and Si/Ti atomic ratio analysis, we can see that except for the TiO2, TiOx was detected, but no the intermediate Ti-silicide (TiSi and Ti5Si3) in oxidized TiSi2. We also observed the growth of a Ti-free layer of SiO2 at 1000°C.
