Comparison of Materials for the Ferroelectric Thin Film to be Integrated into High Density FeRAMs

Lead zirconate titanate (PZT) thin films with two different compositions have been used to fabricate integrated ferroelectric capacitors. The capacitors with the higher Ti content exhibited the more square hysteresis loops with peak 2Pr values of 67.3 μ C/ cm2 at room temperature. Static hysteresis loops are used to extract static coercive voltages for both compositions in the temperature range 25°C to 125°C. These static coercive voltages are used to extrapolate the imprint limited lifetime. The Ti rich composition exhibited the faster shift of the hysteresis loop during the imprint experiment resulting in a shorter extrapolated lifetime.