Electrical characteristics of the MOD-derived SrBi2xTa2O9 and SrBi2.4(Ta,Nb)(2)O-9 thin films

Abstract

Ferroelectric and leakage current characteristics of the MOD-derived SrBi2xTa2O9 (0.8 less than or equal to x less than or equal to 1.6) and SrBi2.4(Ta1-yNby) O-2(9) (0 less than or equal to y less than or equal to 1) thin films were investigated. The SBT and SBTN films were fully crystallized to Bi-layered perovskite structure by annealing at 800 degrees C for 1 hour in oxygen atmosphere. The ferroelectric characteristics of the SBT films were optimized at the Bi/Ta mole ratio x of 1.2. The leakage current density of the Bi-excess SBT films decreased remarkably by the post-metallization annealing at 800 degrees C for 10 minutes in oxygen ambient. The ferroelectric characteristics of the SBTN films were optimized with the SBN content y of 0.25. The SrBi2.4(Ta0.75Nb0.25) O-2(9) film exhibited 2P(r) and E-c of 19.04 mu C/cm(2) and 24.94 kV/cm at +/- 5 V, which were superior to 2P(r) of 11.3 mu C/cm(2) and E-c of 39.6 kV/cm obtained for the SrBi2.4Ta2O9 film after the post-metallization annealing. The MOD-derived SrBi2.4(Ta0.75Nb0.25)(2)O-9 film did not exhibit the polarization fatigue after 10(11) switching cycles at +/- 5 V. (C) 2000 Kluwer Academic Publishers.