Numerical ellipsometry: Analysis of thin metal layers using n–k plane methods with multiple incidence angles

A major challenge for those utilizing ellipsometry has been data processing of raw measured data. The least-squares numerical methods in common use are plagued by local minima and the multivalued functions in ellipsometry. Previously we have applied complex analysis in the n–k plane to improve ellipsometry modeling for growing films on substrates. The work presented here extends this new methodology to multiple angle measurements over a wavelength range spanning visible for thin absorbing metal films deposited on various substrates. Results show that the new method allows reflection ellipsometry determination of thin absorbing film thickness and properties without the need for additional measurements.