Investigation of the use of rotating linearly polarized light for characterizing SiO<inf>2</inf> thin-film on Si substrate

Abstract

This research is based on the Fresnel's equations and the ellipsometric technique that investigate the sample of SiO2 thinfilm on Si substrate. The investigation is made by a probing beam which is in the form of a rotating linearly polarized light generated by the polarizing Mach-Zehnder interferometer (pMZi). The detection of the changed polarization states of the incident light due to reflection on the sample surfaces led to a set of unique characteristics describing a thin-film substrate system in terms of ellipsometric parameters ψ and Δ. SiO 2 thin-films were chosen to study because of their well known characteristics. The accuracy of measurements was confirmed by comparisons to calculated values derived from Fresnel's equations and a standard instrument. The results clearly reveal a feasibility of using the rotating linearly polarized light produced by pMZi for a non-destructive characterization of the thin-film system. © 2011 SPIE-OSA-IEEE.