Optical Characterization of Plasma-Deposited SiO2-Like Layers on Anisotropic Polymeric Substrates

In this paper, the characterization of the optical anisotropy of poly(ethylene-2,6-naphthalate) (PEN) by means of Transmission Generalized Ellipsometry coupled with reflection multi-angle Spectroscopic Ellipsometry (SE) measurements is presented. This study is functional to the determination of the refractive index of atmospheric pressure plasma-deposited SiO2-like layers deposited on PEN. The effect of the plasma duty cycle (DC) on the film properties is investigated. From the analysis of the optical properties, complemented with chemical and morphological studies, it is concluded that the increase in DC is responsible for the layer densification process, eventually causing an improvement in the PEN/SiO2 system barrier properties.