PbTiO 3 buffer layer effects on the structural and electrical properties of Pb(Zr, Ti)O3 thin films grown by sputtering on silicon substrates

Pb(Zr, Ti)O 3 (PZT) thin films have been grown on Si/SiO2 and Si/SiO2/Ti/Pt substrates by rf magnetron sputtering and the effects of PbTiO3 (PT) buffer layers to the structural and electrical properties of PZT films were studied. The PT buffer layers were grown in situ (without postannealing) with thicknesses ranging from 100 to 1200 Å. The PT layer orientation can be adjusted by the deposition temperature. The PZT films with a composition near the morphotropic phase (54/46) were deposited at room temperature followed by a conventional postannealing treatment. The disappearance of cracks in PZT films deposited on Si/SiO2/PT substrates indicates the role of the buffer layer as a stress absorber. By using a PT buffer layer it was possible to control the PZT films’ orientation. Polycrystalline PZT films without a buffer layer changed to highly (100) or (111) oriented films, depending on the preferred orientation of the buffer layer. The influence of the buffer layer thickness and the PZT films’ orientation on the electrical properties was also investigated.