Influence of poling on RF and pulsed DC sputtered PZT thin films

This paper elaborates on the poling behaviour of pulsed DC reactive sputter deposited and RF sputter deposited 1.3μm thick PZT films. Pulsed DC reactive sputtering with metallic target and RF sputtering with oxide target was done on suitable platinum bottom electrode. After rapid thermal annealing, the XRD spectra for pulsed DC sputtered film showed a clear (110) peak, while RF sputtered film had clear (110) and (111) peaks. The dielectric and ferroelectric properties of the film after poling at 15V, 150°C for 10 min, displayed a strong shift in P-E loops in both cases. It is interpreted as the occurrence of asymmetric distribution of oxygen vacancies, which are abundant in case platinum electrodes are used. The transverse piezoelectric coefficient (e₃₁) values showed significant improvement after poling with values of 4.5 and 4.1 C/m², for pulsed DC and RF sputtered film respectively.