Study on Optical Constants of DLC Thin Films Based on Modified Genetic Algorithm

Abstract

This document modified the basic genetic algorithm three important operator—selection operator, mutation operator, crossover operator drawing from competition, selection, and fitness niche adjustment idea. Take the unbalanced magnetron sputtering deposition of DLC films on Si substrate as a research sample. When fitting wavelength range is 300 ~ 1500nm, select a point every 1nm, the fitting lasting time is no more than 6s. Fitting results contrast to ellipsometer’s fitting results; the error is less than 2%. Experiments show that: the adaptive modified 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 and is effectiveness to fit thin film optical constants.