The method of thin foil thickness and optical constants' simultaneous determination is proposed. These parameters are found by measurement of the light incidence angle in the attenuated total reflection (ATR) geometry corresponding to zero reflection (ZR) for different dielectric coatings on the ATR-prism base. Recently the excitation of surface plasmons (SP) by ATR has been applied to the investigation of surfaces of solid and thin films. The advantage of this method is the high sensitivity of SP to the surface state. Unlike the ellipsometry, the ATR method requires no phase difference measurement that essentially facilitates the measurement procedure. Two main schemes of the ATR method are that of Otto and of Kretchman. The scheme of Otto allows the investigation of a wider class of objects than that of Kretchman, but its application is dependent on the precise determination and control of the gap between the prism and the sample. For the solution of this problem, an elegant approach was suggested of finding values of the gap and the angle of the light incidence on the prism where the reflection coefficient equals zero. Thus the parameter to be measured is the light incidence angle. In this work, the analysis of measurement accuracy for film thickness and optical constants by the ATR ZR method is carried out and a new method is suggested allowing considerably more accuracy.
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