Application of the simulated annealing — Simplex hybrid algorithm to the ellipsometric data inversion of double films

With an effective combination of advantages of the simulated annealing algorithm and the simplex algorithm, a new simulated annealing-simplex hybrid algorithm is presented to deal with the ellipsometric data inversion of double films. In experiments of single wavelength measurement, any two optical parameters of double layer films can be extracted with a measurement of only one group of ellipsometric parameters. Likewise, two or more groups of known ellipsometric parameters can determine four optical parameters simultaneously. Results of actual measurements show that using the hybrid algorithm to obtain the optical parameters of double layer film is feasible and reliable, and has the effective applicability to various samples. The algorithm is suitable to inversion and actual measurement of double layer films and multi-layer films by single wavelength ellipsometer.