Voltage shift and deformation in the hysteresis loop of Pb(Zr,Ti)O3 thin film by defects

Voltage shift and deformation in the hysteresis loop of Pb(Zr,Ti)O3 (PZT) capacitors have been studied by varying the annealing temperature after patterning the top sputter-deposited Pt electrode using reactive ion etch (RIE) with Ar gas. It was observed that the hysteresis loop of the film was seriously deformed by both sputtering and RIE induced defects. Voltage shift and polarization suppression can be explained by the charge trapping at electrode interfaces and at defect levels in the film, respectively. Space charges trapped at defect levels in the film suppress polarization parallel to poling direction, however, enhance polarization opposite to the poling direction.