Full-Mueller matrix ellipsometer calibration method

Abstract

The present invention discloses a full-Mueller matrix ellipsometer calibration method, and belongs to the technical field of optical measurements. According to the method, by means of an isotropic and uniform reference sample, the calibrated initial polarization angle Cs1 of a first phase compensator, the calibrated initial polarization angle Cs2 of a second phase compensator, the calibrated polarization angle Ps of a polarizer, the calibrated polarization angle As of an analyzer, the calibrated phase retardation [delta]1 of the first phase compensator, and the calibrated phase retardation [delta]2 of the second phase compensator are adopted as initial values, and through the relational expression between the theoretical Fourier coefficient and the work parameter, a least square method is used to fit by adopting (d, [theta], Ps, As, Cs1, Cs2, [delta]1, [delta]2) as the variable so as to obtain the accurate values of all the full-Mueller matrix ellipsometer work parameters (d, [theta], Ps, As, Cs1, Cs2, [delta]1, [delta]2). According to the present invention, the measured data of the full-Mueller matrix ellipsometer at the same time is completely utilized, the introduced error is relatively small, and the parameter obtained from the calibration is accurate.

Description

technical field [0001] The invention relates to the technical field of optical measuring instruments, in particular to a calibration method for a full Mueller matrix ellipsometer. Background technique [0002] Ellipsometer (referred to as ellipsometer) is an optical measuring instrument that uses the polarization characteristics of light to obtain information about the sample to be measured. Its corresponding working principle is to obtain the information of the sample to be measured by measuring the change of the polarization state (amplitude ratio and phase difference) before and after the incident light and reflected light on the surface of the sample to be measured through the incident light of the polarizer. The ellipsometer with rotating polarizer and rotating single compensator can obtain up to 12 parameters of the sample in one measurement; however, with the advancement of integrated circuit technology and the complexity of device structures, the unknown quantities t...

AI Technical Summary

Problems solved by technology

The system is required to have a straight-through design with an adjustable incident angle, and there is a process of changing the incident angle during the calibration process. These methods increase the complexity of the system, and the calibration process is also more complicated.

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