Comparison of CSD and sputtered PZT with iridium electrodes

Several recent reports have combined Ir electrodes with PbZrxTi1-xO3 (PZT) made by chemical solution deposition (CSD) to produce capacitors with low f atigue rates, but the same behavior has not been reported for sputtered PZT with Ir electrodes. This paper presents a comparison of the performance of sputtered and CSD PZT capacitors with Ir electrodes. It was found that rep lacing the Pt top electrode with Ir was sufficient for obtaining improved f atigue performance for both sputtered and CSD deposited PZT. A comparison o f Ir and Pt top electrodes shows that Ir can extend the number of useful sw itching cycles by 3 to 4 orders of magnitude for both sputtered and CSD dep osited PZT. As has been previously observed for Pt electrodes, the fatigue with Ir top electrodes is dependent on the switching voltage. Excellent fat igue performance has been observed to 10(11) cycles for both 3 and 5 V swit ching potentials. In addition to fatigue performance, a detailed analysis o f switching, retention and leakage current behavior will also be presented.