Multilayer thin-film inspection through measurements of reflection coefficients

作者:Wu Kai; Lee Cheng Chung*; Brock Neal J; Kimbrough Brad
来源:Optics Letters, 2011, 36(16): 3269-3271.
DOI:10.1364/OL.36.003269

摘要

A vibration-insensitive interferometer is described to measure the thickness, refraction index and surface profile of thin-film stack at normal incidence. By satisfying the continuous boundary conditions of electric and magnetic fields at interfaces in a multilayer film stack, the reflection coefficient phase of the thin-film stack can be distinguished from the phase of spatial path difference, thus thickness and refraction index can be extracted. The experiment results showed that the measurement precision is significantly increased after the phase analysis was added into the reflectance analysis.