Calibration of a simple heterodyne interferometric ellipsometer

摘要

In this study, we develop a simple heterodyne interferometric ellipsometer, which is a heterodyne interferometer based on a dual-frequency, linearly polarized laser that is integrated with a common-path interferometric configuration. This device can measure ellipsometric parameters with high accuracy because it incorporates a method to calibrate the polarization effect of the beam splitter and the nonidentical characteristics of the photodetectors. The measured deviation in the ellipsometric parameters of a quarter-wave plate was less than 0.9%. The measurement results for a thin gold film deposited on silicon substrate were compared with those obtained by a commercial ellipsometer.