Preparation, Structure and Performance of High Quality Metal-Oxide Composite Electrode Film for Ferroelectric Film Devices (pp. 285-310)
Authors: (Liang Qiao, Xiaofang Bi, Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing, People’s Republic of China, and others)
Abstract: High quality Pt-LaNiO3 (PLNO) metal-oxide composite electrode films were prepared on Si(001) substrates using radio frequency co-sputtering method. Pt content dependent microstructure, electronic structure, transport properties and the influence on the ferroelectricity of upper BaTiO3 films have been systemically investigated. It is found that the PLNO films consist of two individual phases of separated oxide LaNiO3 and metal Pt and the composite films maintain the preferred (001)-orientation until Pt content reaches 36.1 at.%. Then, increasing the Pt content will decrease the oriented texture, increase the film surface roughness and results in the Pt hillocks with (100) basal plane formation on the surface. A net-like nanostructure featured with 5 nm Pt grains embedded in the LaNiO3 matrix for 36.1 at.% PLNO film was revealed by high-resolution transmission electron microscopy (HRTEM). The PLNO films demonstrate a reduced resistivity as compared with LaNiO3, which is consistent with x-ray photoelectron spectroscopy analysis. The resistivity of 36.1 at.% Pt film is as low as 5.84 × 10-5 Ω•cm, which is much smaller than the value of common used oxide electrodes, such as ~ 225 μΩ•cm for LaNiO3 and 340 μΩ•cm for SrRuO3, respectively. Using as a bottom electrode for ferroelectric film growth, it is demonstrated that the microstructure, grain size and interfacial characterization for BaTiO3/PLNO are also strongly dependent on the Pt contents in the PLNO underlayer.