Fabrication and characterization of Pt-oxide electrode for FeRAM application

There has been a lot of works on ferroelectric thin films, since it becomes possible to apply them to memory materials in standard silicon integrated circuits. Pt/PZT/Pt system is a widely studied structure of capacitor for the application to FRAM, because of its remarkable electric properties and stability in device operating range. However, several problems are waiting for the answers, such as damage during etching, ferroelectric-electrode interaction, stability during silicon processing, and serious fatigue behavior. Especially, it has been well known that postmetal annealing (PMA) of Pt/PZT system in a hydrogen-containing ambient (e.g,, forming gas) causes severe degradation of PZT thin film. In this study, to avoid the degradation caused by PMA, we fabricated the capacitor of Pt-oxide/PZT/Pt structure, and reported the resistance of Pt-oxide upper electrode against hydrogen-induced degradation.