CHARACTERIZATION OF MULTILAYER THIN-FILM STRUCTURES BY DIFFERENTIAL REFLECTION SPECTROSCOPY

Calculated and experimental differential reflectograms for silicon oxi de/silicon nitride/silicon oxide (ONO) structures as utilized by the e lectronics industry for dielectric layers are shown. The pertinent equ ations for the simulations of multilayer structures are presented. Exp eriments and calculations are in good qualitative agreements. Moreover , the differential reflectance values for both experiment and simulati on display a strong dependence on the film thickness. The quantitative agreement could be improved if the optical properties of the thin die lectric layers were better known.