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

• Published in: Japanese Journal of Applied Physics Vol. 63; no. 8; p. 08SP04
• Main Authors: Sato, Nozomi, Wang, Wensheng, Eshita, Takashi, Oikawa, Mitsuaki, Nakabayashi, Masaaki, Takai, Kazuaki, Nakamura, Ko, Nagai, Kouichi, Mihara, Satoru, Hikosaka, Yukinobu, Saito, Hitoshi
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese Journal of Applied Physics 01-08-2024
• Subjects: Deposition; Electrodes; Ferroelectricity; Lead zirconate titanates; Oxidation; Oxygen content; Random access memory; Thickness; Zirconium
• ISSN: 0021-4922; 1347-4065
• DOI: 10.35848/1347-4065/ad67e9

A highly {111}-oriented metal-organic CVD Pb(Zr,Ti)O3 (PZT) is successfully developed using IrOx/Ir instead of Ir as the bottom electrode. The {111} PZT orientation strongly depends on the IrOx thickness and the O2 content of the atmosphere (PO2) during IrOx deposition. During PZT deposition, the Ir surface easily oxidizes and becomes rough, resulting in poor {111} PZT orientation. IrOx prevents Ir surface oxidation and transforms the Ir metal via O2 reduction after the PZT deposition completion. Highly {111}-oriented PZT can be obtained by optimizing the IrOx thickness and PO2 content.