Surface sol-gel synthesis of silica films on polyimide substrate

Silica films were grown on polyimide substrate using surface sol-gel reaction, and the film growth process was characterized by ellipsometry, atomic force microscopy, and X-ray photoelectron spectroscopy. On the activated polyimide surface, silica film was grown by sequential immersion in SiCl(4) solution and H(2)O. The thickness of silica films is linear with the depositing cycle, about 5.0 nm per cycle. The silica films present an island-like growth type and are not a strict equilibrium SiO(2) structure. Moreover, the result of the tensile test suggests that the silica films have a good adhesion to the polyimide substrate.