Preparation of BaTiO₃–BaZrO₃ Films by Metal-Organic Chemical Vapor Deposition

Barium titanate zirconate (Ba(Ti_1-xZr_x)O₃) films in the range of x=0 to 1.0 were prepared on (100)Pt/(100)MgO substrates at 973 K by metalorganic chemical vapor deposition (MOCVD). The effects of zirconium content (x) on the microstructure and dielectric properties of films were investigated. At x≤0.15, the Ba(Ti_1-xZr_x)O₃ films showed highly crystallized and significant (001) orientation. The (001) orientation of the films decreased with increasing x, and the orientation became random at x>0.36. The dielectric constant of Ba(Ti_1-xZr_x)O₃ films changed with x from 35 to 689 and showed a maximum at x=0.15. The remanent polarization (2P_r) and the coercive field (2E_C) of Ba(Ti_0.85Zr_0.15)O₃ film were 3 µC·cm^-2 and 14 kV·cm^-1, respectively. The onset electric field for nonohmic conduction of Ba(Ti_1-xZr_x)O₃ film increased from 10 k to 1 MV·cm^-1 with increasing x.