Research on Improved Genetic Algorithm of Film Optical Constants

摘要

Ellipsometry can not be directly tested by thin film optical parameters,which need approximate solution method for numerical inversion.Using genetic algorithms,improved three important operator-the selection operator,mutation operator and crossover operator drawing from competition,selection,and fitness niche adjustment idea.The improved algorithm is effective in preventing the "premature" phenomenon,searched the global optimal,reduces the requirements on the operator to set the initial value on the fitted model.In practice,by comparing the results of the three fitting methods,gained reliable optical constants of DLC films prepared under certain conditions.Show that the proposed improved genetic algorithm is effectiveness to fit thin film optical constants through a large number of fitting.