Consideration on the Optical Model in Measuring Complex Refractive Index for the Purpose of Judging Real Contact

Abstract

In the real contact measurement by ellipsometry, there is a problem that the measured complex refractive index changes gently at the contact/non-contact boundaries. In this report, the multiple reflection in the gap between contact surfaces was considered in the optical model which was used to estimate complex refractive index. The sample measured result for a glass plane pressed by a glass lens in the air was successfully accounted for by the estimation by the optical model which considered the gap of layered structure. Thereby, it could be possible to improve the accuracy of real contact judgement by excluding the influence of multiple reflection in the gap on the estimation of complex refractive index.