Effects of high-temperature metal-organic chemical vapor deposition of Pb(Zr,Ti)O₃ thin films on structural stabilities of hybrid Pt/IrO₂/Ir stack and single-layer Ir bottom electrodes

High-temperature Pb(Zr,Ti)O₃ (PZT) metal-organic chemical vapor deposition (MOCVD) at 620°C was performed on two major bottom electrode candidates, namely, a hybrid Pt/IrO₂/Ir stack electrode and a single-layer Ir electrode. The structural stabilities of both PZT/electrode stacks were investigated. Severe interaction between PZT and the underlayered Pt films was observed, and the interaction resulted in a pyrochlore phase in the PZT film and blister-type deformation in the Pt film. On the other hand, structural stability, which served as the basis for a well-crystallized perovskite PZT film, was preserved in the case of the Ir electrode. Therefore, it could be determined that the Ir electrode as a bottom electrode was better than the Pt electrode from the point of view of the structural stability of a capacitor stack, when high-temperature MOCVD is chosen as a preparation method.