THE THICKNESS EFFECT OF PZT19 IN PZT19/PTZT/PZT19 THIN FILM

ABSTRACT

RF sputtered 10% Pb excess PbZr_0.1Ti_0.9O₃ (PZT19) placed at the top and bottom of RF sputtered 10%Pb excess PbTa_0.005Zr_0.3Ti_0.695O₃ (PTZT) films are grown on a stabilized Pt/TiO_x/SiO₂/Si bottom electrode at a relative low temperature. In order to check the influence of the PZT19 seeding layer thickness, the PZT19 seeding layers were sputtered for 1, 3, 8, 15 minutes with the thickness about 2, 6, 16, 30 nm. The sputtered films were annealed at 650°C for 10 minutes in O₂ atmospheres. The PTZT film and PZT19/PTZT/PZT19 sandwich structure films XRD measurements show that the major perovskite orientations (100), (110) and (111) have been found. The best ferroelectrics values and fatigue properties have been measured for the sample PZT19/PTZT/PZT19 film with the seeding layer thickness about 6 nm. The fatigue characteristic of PTZT and PZT19/PTZT/PZT19 thin films show suggests that the PZT19 seeding layers alleviate the accumulation of oxygen vacancies near the interface which has been proposed as a primary cause of fatigue in lead base perovskite thin films. The comparison of these results with PTZT/Pt/TiO_x basic structures suggests that an appropriate thickness seeding layer can improve the ferroelectric properties greatly.

Keywords:

• PTZT
• sandwich structure
• rf-magnetron sputtering
• fatigue

ACKNOWLEDGMENTS

This work is supported by the Key program of National Nature Science Foundation of China, No. 90407023.