Approach to error analysis and reduction for rotating-polarizer-analyzer ellipsometer

摘要

We proposed an approach to error analysis and reduction for the rotating-polarizer-analyzer ellipsometer. The Au bulk sample was taken as an example to confirm the effect of this approach. The results show that the discrete-Fouriertransform (DFT)-induced systematic error can be monotonically reduced by increasing the sampling rate of the analyzer. For further improvement in the measurement accuracy at the same sampling rate of the analyzer, an analytical error reduction method of linearly fitting the δψ-F (F = ψ, Δ, n, and k) distributions was proposed and tested in both theoretical simulation and experimental measurement. The experimentally obtained optical constants from different incident angles are very close to each other, in good agreement with the simulated results, providing a possible means of compensating for the DFT-induced systematic error due to the existence of the random error induced by the light source and detector noise in the measurement system.