CHARACTERIZATION OF PT-SI INTERFACE BY SPECTROSCOPIC ELLIPSOMETRY

Spectroscopic ellipsometric measurements for Pt/n-Si samples with different thickness of Pt films have been performed. The thickness of the Pt films determined with the three-phase model (air/Pt/Si) changes with the wavelength λ while that with the four-phase model (air/Pt/interface layer/Si) remains unchanged, showing the existence of an interface layer. At the same time, the apparent optical dielectric constants of the interface layer as a function of λ are also obtained. A calculation based on the effective medium theory is carried out to simulate the optical dielectric data of the interface layer. Some structural information of the interface layer is obtained from the calculation. © 1994 American Institute of Physics.