HIGHLY C-AXIS ORIENTED PB(ZR, TI)O3 THIN FILMS GROWN ON IR ELECTRODE BARRIER AND THEIR ELECTRICAL PROPERTIES

We have investigated the structural and electrical properties of sol-gel derived Pb(Zr, Ti)O3 (PZT) thin films deposited on Ir electrode barrier (Ir/poly-Si/SiO2/Si). Owing to the interface-controlled growth, highly c-axis oriented perovskite PZT thin films were obtained for the postdeposition annealing temperature of 580 °C. Additionally, we found that the ferroelectric properties of IrO2/PZT/Ir/poly-Si capacitors were remarkably changed by the partial pressure of oxygen during the deposition of IrO2 top electrodes, which could be due to the enhanced reaction of IrO2 with PZT by the oxygen ion bombardments. Remanent polarization and coercive field of IrO2/PZT/Ir/poly-Si capacitor with the top electrodes deposited at PO2=1 mTorr was 20 μC/cm2 and 30 kV/cm, respectively, and showed negligible polarization fatigue up to 1011 switching repetitions. The leakage current density at a field of 80 kV was 5×10−8 A/cm2.