Optimal calibration for rotating analyzer ellipsometer

Abstract

We have modeled most errors, which affect the measurement accuracy, with Jone's matrix. From the simulation, we can characterize the errors and take good aids for selecting components and designing ellipsometer. The traditional residual method has good performance when there are only azimuth angle errors and extinction errors, but it has not good performance when there are other errors. We have proposed the optimal calibration method for overcoming the residual method. The optimal method selects error values to have the least square difference between the measured thickness and the simulated thickness. We can reduce the design variables to three, incident angle error, and azimuth angle errors of polarizer and analyzer. The optimization results are slightly different from the residual method, and have smaller standard deviation of errors than the residual method. The experiment shows good agreement with the simulations.