Surface Anisotropy of Different Polyimide Films Induced by Irradiation with Linearly Polarized Ultraviolet Light

Abstract

We have investigated the surface anisotropy of polyimide films induced by irradiation with linearly polarized ultraviolet light (LPUVL). The surface anisotropy was monitored by measuring the polarized infrared absorption spectra of 〜11 nm-thick films as a function of LPUVL exposure. The measurement was performed for) three kinds of polyimides: poly [4,4'-oxydiphenylene-pyromellitimide] (PMDA-ODA), poly [4,4'-oxydiphenylene-1,2,3,4-butanetetracarboximideI (BDA-ODA), and poly [4,4'-oxydiphenylene-1,2,3,4-cyclobutanetetracarboximide] (CBDA-ODA). We found that the LPUVL exposure dependence of the surface anisotropy is strongly influenced by the molecular structure of polyirnides.