Development of a Pb(Zr,Ti)O₃ capacitor employing an IrOx/Ir bottom electrode for highly reliable ferroelectric random access memories

A highly {111}-oriented metal-organic CVD Pb(Zr,Ti)O 3 (PZT) is successfully developed using IrO x /Ir instead of Ir as the bottom electrode. The {111} PZT orientation strongly depends on the IrO x thickness and the O 2 content of the atmosphere (PO 2 ) during IrO x deposition. During PZT deposition, the Ir surface easily oxidizes and becomes rough, resulting in poor {111} PZT orientation. IrO x prevents Ir surface oxidation and transforms the Ir metal via O 2 reduction after the PZT deposition completion. Highly {111}-oriented PZT can be obtained by optimizing the IrO x thickness and PO 2 content.