Effects of bottom electrodes (Pt and IrO2) on physical and electrical properties of Bi4-xLaxTi3O12 thin film

Bi3.35La0.85Ti3O12 (BLT) thin (90 nm) films were prepared on Pt (200 nm) and IrO2 (200 nm) electrodes by metalorganic decomposition (MOD) method, and crystallized by rapid thermal annealing (RTA) and the subsequent furnace annealing. BLT films were c-axis oriented on both electrodes irrespective of RTA temperature (600 and 700 degreesC). However. the degree of c-axis orientation was much higher on IrO2 than on Pt, and significantly reduced only on Pt with decreasing RTA temperature. This result was related to the different stress of BLT film which is negligible on Pt, but 500 MPa (tensile) on lrO(2) in the RTA temperature range of 600-700 degreesC. The crystalline orientation of BLT film directly affected switching polarization (P* - P) which had much smaller value of 5 muC/cm(2) on IrO2 than 12 muC/cm(2) on Pt, and was increased to 16 muC/cm(2) only on Pt with the decrease of RTA temperature. On the other hand, leakage characteristics were not changed with bottom electrode materials.