Electrical properties of Bi4-xLaxTi3O12 ferroelectric thin films prepared by metalorganic decomposition method

Bi4-xLaxTi3O12 (BLT) ferroelectric thin films were prepared on a Pt/TiOx/SiO2/Si substrate using metalorganic decomposition (MOD) method, and their electrical properties were evaluated with thickness, composition and crystallization annealing temperature. Irrespective of the preparation conditions, BLT films were c-axis oriented. and had a dense surface morphology without pore to produce smooth Pt/BLT/Pt interfaces of capacitor, The film thickness was controlled as 90 nm to obtain a low coercive voltage (2V(c)) without the problem of capacitor short-fail. The proper composition of Bi3.35La0.85Ti3O12 was selected for the largest switching polarization (P* - P-boolean AND), good fatigue endurance and a low leakage current density (J(L)). After crystallization annealing at 700degreesC, the optimized film of 90 nm Bi3.35La0.85Ti3O12 showed the good electrical properties. such as 2V(c) of 2.0 V P* - P-boolean AND of 13 muC/cm(2), J(L) of 1 X 10(-6) A/cm(2) at a applied voltage of 3 V and no polarization loss up to I x 10(11) fatigue cycles, for ferroelectric random access memory (FeRAM) application.