SURFACE MORPHOLOGIES OF BATIO3 THIN-FILMS BY ATOMIC-FORCE MICROSCOPY

Abstract

Surface morphologies of BaTiO3 thin films have been studied by atomic force microscopy (AFM). The films on (111)InSb, indium tin oxide (ITO)-coated glass and (100)Si substrates are deposited by in-situ metalorganic chemical vapor deposition (MOCVD) at different deposition temperatures of 300-degrees-C, 400-degrees-C and 600-degrees-C, respectively. AFM under ambient conditions showed that the BaTiO3 film deposited on the ITO-coated glass had a smooth surface consisting of large hemispherical grains, while the film on (100)Si had a slightly rough surface with [110]textured rectangular grains. As-grown film on the (111)InSb substrate was in the amorphous phase except near the interface, resulting in a rough surface. Our results of dependence on the kind of substrates and growth temperature suggest that the surface morphology of the as-grown films is strongly influenced by the crystallinity and growing characteristic of the film. For low-temperature growth below the deposition temperature of 600-degrees-C, surface roughness of the BaTiO3 film is strongly dependent on growth temperature rather than crystallinity of the films related to substrates.