Method of the Ratio of Envelopes of the Reflection Spectrum for Measuring Optical Constants and Thickness of Thin Films

摘要

A spectrophotometric method is proposed that uses the ratio of envelopes of minima and maxima of the interference reflection spectrum for measuring optical constants of a film on a substrate. Because this ratio does not contain the instrumental function of a spectrophotometer, there is no need in careful calibration of the spectrophotometer. In the case of a transparent isotropic film on an absorbing substrate, the inverse problem has an analytic solution. A simple method is proposed for numerical calculations of the optical constants and thickness of an absorbing film.