ABSTRACT
Reliability of ferroelectric memories is depended mainly on quality of ferroelec tric capacitors such as fatigue and imprint. The degradation is caused by some reasons as follows; - Loss of Pb or other elements - Disorder of crystal structure at the electrodes / ferroelectric interfaces - Oxygen vacancy To improve the characteristics of the films, we have used Ir based material as elec trodes of PZT capacitors[3,4L As the result, the high quality of PZT films were obtained and improvement in ferroelectric characteristics were observed. The im provement of fatigue and imprint properties were probably caused by good diffusion barrier effect of Ir02. It confirmed Pb, O and other elements were never diffused into Ir based electrodes. Moreover, by using Ir based electrodes as top electrodes, we could find little degradation in back end process after fabrication of PZT ca pacitors. Figure 5 shows process degradation of PZT capacitors using Pt and Ir based top electrodes.
