Characteristics of PZT films with SRO/PT stack electrodes for high density MBIT feram devices

Reliable PZT capacitors have been developed by using stable PZT sputtering technique and Pt/thinSRO(SrRuO3) stack electrodes. Introduction of SRO electrodes with no leakage current degradation is a key to realize reliable and scalable PZT capacitors. Roles of top electrode (TE) SRO and bottom electrode (BE) SRO were investigated respectively from reliability and process damage points of view. The SRO works as hydrogen resistant electrodes, fatigue free interfaces and nucleation sites for perovskite formation. Relationship between SRO crystallinity and PZT electrical properties was elucidated. Templates made of thin SRO were found to function as barrier layers against diffusion of Pb and Ru from BE resulting in new possible cell structures.