Control of grain structure of sputtering lead-zirconate-titanate thin film using amorphous lead-titanate buffer layer

Crystalline lead-zirconate-titanate (PZT) films of perovskite structure with fine grains were successfully obtained on Ir substrates using an amorphous lead-titanate (a-PTO) buffer layer. The grain size of PZT ranged from 100 to 150 nm. The results of the temperature dependence of the X-cay diffraction patterns of PZT films prepared on a-PTO buffer layer revealed that PZT films with a single perovskite phase were obtained at 500 degrees C. In addition, 250-nm thick PZT films fabricated with a-PTO buffer layer and crystallized at 600 degrees C showed excellent ferroelectric properties. The 2P(r) values of Ir/PZT/Ir capacitors with a-PTO buffer layer satisfactorily saturated at the applied voltage of 3.5 V. No degradation in the polarization density was observed for switching cycles up to 1 x 10(9).