A THEORETICAL AND EXPERIMENTAL ANALYSIS OF ELLIPSOMETER

A theoretical analysis of the problem of determining ψ and Δ from instrument readings is made for two commonly used ellipsometer geometries. The significance of the different zones of measurement and the effects due to multiple internal reflections in the retardation plate are emphasized resulting in an unambiguous, exact set of formulae. The optical bandwidth of the light employed as well as several other operational parameters, such as source polarization, collimation, and prism deviation, are considered and the analysis is compared with experimental results in effort to determine the effect of these parameters upon the overall instrumental accuracy. Finally, evidence is presented to show that muscovite mica, such as is normally employed in the fabrication of retardation plates, is a non-homogeneous substance, displaying a fine grained structure in which individual grains have slightly different crystal orientations, thus resulting in differing fast axes" for different grains within a plate. © 1969."