Elliptic Polarization Of The Optical Thin Film Model Analysis And Data Processing

Ellipsometry is an optical analytical technique used to determine the optical constants and the film thickness from measurements of the change in polarization state of reflecting light. It has the advantages of remarkable sensitivity, nondestructive character, and etc. However, we can not get the film parameters directly because the ellipsometer equation is a transcendental equation. We can hardly get the analytical solution for film parameters from the measured ellipsometric parameters ψ and △. Therefore, to find an algorithm to inverse the measured data ψ and △ becomes a primary but important problem.In this dissertation we take a research of the process of spectroscopic ellipsometry data. The main task includes three parts. First, constructing a model (including structural model and optical function) of optical thin film system is discussed. According to the model calculation, we analyze the sensitivity region of ellipsometric parameters with respect to film parameters (refractive index n, extinction coefficient k and thickness d) and incident angle. Second, we introduce the Simulated Annealing algorithm to the data processing. And designing and writing the data processing program. Third, we measure the standard thin film provided by the ellipsometer manufacture and samples made by ourselves. And good results are obtained by using the Simulated Annealing algorithm.