Control of Orientation of Pb(Zr, Ti)O3 Thin Films Using PbTiO3 Buffer Layer

The orientation of Pb(Zr, Ti)O3 (PZT) thin films grown by metalorganic chemical vapor deposition (MOCVD) using a two-step growth process was controlled by changing the orientation of the PbTiO3 buffer layer. The (111)-oriented and (100)-oriented PZT films were grown on the (111)-oriented and the (001) and (100) mixed-oriented PbTiO3 buffer layers, respectively. From the atomic force microscope (AFM) observations, it was found that in the initial growth stages of the (111)-oriented PbTiO3 layer, the main growth mechanism was two-dimensional growth. In the two-step growth process, the PbTiO3 buffer layer played the important role of providing dense nuclei in the succeeding growth of rhombohedral PZT thin films. The influence of the thickness of a buffer layer on the relative dielectric constants of PZT films was also investigated.