  We report optical characterization of PtSi films for thermoelectric device
applications by nondestructive spectroscopic ellipsometry (SE). Pt monolayer
and Pt-Si multilayer which consists of 3 pairs of Pt and Si layers were
deposited on p-doped-silicon substrates by sputtering method and then rapid
annealing process was done to form PtSi films through intermixing of Pt and Si
atoms at the interface. Pseudodielectric function data <{\epsilon}> =
<{\epsilon}1> + i<{\epsilon}2> of the PtSi/Si samples were obtained from 1.12
to 6.52 eV by using spectroscopic ellipsometry. Employing Tauc-Lorentz and
Drude models, the dielectric function ({\epsilon}) of PtSi films were
determined. We found that the composition ratio of Pt:Si is nearly 1:1 for PtSi
monolayer and we observed transitions between occupied and unoccupied states in
Pt 5d states. We also observed formation of PtSi layers in Pt-Si multilayer
sample. The SE results were confirmed by the transmission electron microscopy
and energy dispersive X-ray spectroscopy.
