Ferroelectric Characteristics of the Mod-Derived Sr_xBi_2.4(Ta_0.75Nb_0.25)₂O₉ Thin Films and Electrical Properties of the Pt/Sr_xBi_2.4(Ta_0.75Nb_0.25)₂O₉/TiO₂/Si Structure

Abstract

The 400 nm-thick Sr_xBi_2.4(Ta_0.75Nb_0.25)₂O₉ films (0.7 ≤ x ≤ 1.3) were fabricated by metal-organic decomposition and their ferroelectric properties were compared with the Sr_xBi_2.4Ta₂O₉ films. The electrical properties of the Pt/Sr_xBi_2.4(Ta_0.75Nb_0.25)₂O₉/ TiO₂/Si structures were also compared with the characteristics of the Pt/Sr_xBi_2.4Ta₂O₉/TiO₂/Si. While the Sr-deficient Sr_0.85Bi_2.4Ta₂O₉ exhibited a maximum remanent polarization among the Sr_xBi_2.4Ta₂O₉ films, well-saturated hysteresis curves were obtained with the SrBi_2.4(Ta_0.75Nb_0.25)₂O₉ among the Sr_xBi_2.4(Ta_0.75Nb_0.25)₂O₉ films. The Pt/Sr_xBi_2.4(Ta_0.75Nb_0.25)₂O₉/TiO₂/Si and Pt/Sr_xBi_2.4Ta₂O₉/TiO₂/Si exhibited similar variation behavior of the memory window with the Sr content of the ferroelectric film. The Pt/SrBi_2.4(Ta_0.75Nb_0.25)₂O₉/TiO₂/Si and Pt/Sr_0.85Bi_2.4Ta₂O₉/TiO₂/Si exhibited memory windows of 1.35 V and 1.3 V at ±5 V, respectively.

Keywords:

• Ferroelectric properties
• SBT
• SBTN
• thin film
• MFIS
• memory window

ACKNOWLEDGEMENT

This work was supported by 2004 Hongik University Research Fund.