Simulated annealing-simplex hybrid algorithm for ellipsometric data inversion of multilayer films.

A simulated annealing–simplex hybrid algorithm that accurately measures the optical parameters of multilayer films is proposed for ellipsometric data inversion of multilayer films. In single-wavelength ellipsometry experiments, multiple groups of ellipsometric parameters measured by multiple incident angles can determine multiple optical parameters. Analysis of the measurement accuracy of multilayer films indicates that probabilities of uncertainty increase as films become thinner. Accurate measurements show that using the hybrid algorithm to obtain the optical parameters of multilayer films is feasible and reliable. The algorithm can be used for the inversion and the actual measurement of double-layer and multilayer films by single-wavelength ellipsometry.