We develop a new approximation for the amplitude reflection coefficients of a slightly inhomogeneous thin film. This approximation incorporates exactly the interference effects at the substrate and the ambient interfaces. Interference effects inside the inhomogeneous film are incorporated in the Born approximation. We also develop a new approach to the reconstruction of the refractive-index profile from ellipsometric spectra. It is based on a physically sound parameterization of the refractive-index profile. The new approach is tested on the model reconstruction problem.
© 1998 Optical Society of America
(120.2130) Instrumentation, measurement, and metrology : Ellipsometry and polarimetry
(120.5710) Instrumentation, measurement, and metrology : Refraction
(300.0300) Spectroscopy : Spectroscopy
(310.0310) Thin films : Thin films
Alexander V. Tikhonravov, Michael K. Trubetskov, and Anna V. Krasilnikova, "Spectroscopic Ellipsometry of Slightly Inhomogeneous Nonabsorbing Thin Films with Arbitrary Refractive-Index Profiles: Theoretical Study," Appl. Opt. 37, 5902-5911 (1998)