Design and Implementation of The Ellipsometer Insensitive to Signal Amplifier Linearity

• Main Authors: Yin-Kun Yen, 顏堙堃
• Other Authors: Sen-far Wen
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/99585964298428295142

碩士 === 中華大學 === 電機工程學系碩士班 === 93 === The extremum ellipsometry is proposed. The system configuration is simple, which comprises two polarizers before the sample and an analyzer after the sample. The azimuth polarization angle of the first polarizer and analyzer are fixed. The second polarizer controls the polarization azimuth angle of incident light that incidents the sample. It is shown that the relative reflectivity of the sample can be solved from the extremum angles of the second polarizer corresponding to the extrema of detected signal. Because there are no optical elements that their transmission characteristics required to be measured, such as compensator, the system calibration is easy. Since only extremum signals are required to be detected, the measurement accuracy does not depend on the linearity of the detector. Numerical analysis and experimental results of measuring dielectric constants and thin film thickness are shown. The results show that extremum ellipsometry is able to accurately measure relative reflectivity and hence the dielectric constant of bulk material and thin film thickness.