Investigation of Optical Anisotropy at Polymer Surfaces and in Thin Polymer-Films by Variable-Angle Ellipsometry

Abstract

Variable angle ellipsometry has been used to study laterally homogeneous, interfacial structures whose index of refraction varies only in the normal direction. A polyimide film (almost-equal-to 1.4 mum thick) was studied on glass and the thickness and the indices of anisotropy n(perpendicular-to) and n(parallel-to) perpendicular and parallel to the lateral plane determined with high precision. Better fits to experimental data were obtained by assuming an additional thin layer, with different film parameters, at the polymer/substrate interface.