Development of sputtered SrBi2Ta2O9 thin films for nonvolatile random access memory application

Utilization of ferroelectric thin films for nonvolatile random access memory (NvRAM) applications has been under intensive investigation. Films for transistor-type memory require possessing these properties: a large remnant polarization, a low coercive field (2Ec), sufficient fatigue endurance again...

全面介紹

Saved in:
書目詳細資料
主要作者: Li, Yibin
其他作者: Zhang Shanyong, Sam
格式: Theses and Dissertations
出版: 2008
主題:
在線閱讀:https://hdl.handle.net/10356/5277
標簽: 添加標簽
沒有標簽, 成為第一個標記此記錄!
機構: Nanyang Technological University
實物特徵
總結:Utilization of ferroelectric thin films for nonvolatile random access memory (NvRAM) applications has been under intensive investigation. Films for transistor-type memory require possessing these properties: a large remnant polarization, a low coercive field (2Ec), sufficient fatigue endurance against repetitive polarization switching. Layered perovskite structure SrBi2Ta2O9 (SBT) thin film has attracted ever increasing attention because it exhibits fatigue-free property up to 1012 cycles (even on Pt bottom electrode), excellent retention characteristics, and low leakage current density. However, two shortcomings are involved in SBT thin films: the low remnant polarization (2Pr<10?C/cm2) and high annealing temperature (>800?). Substitution at A or B site can effectively modify polarization properties. Trivalent elemental substitution such as Bi3+, La3+ and Nd3+ with the Sr2+ site induces A-site cation vacancies to satisfy charge neutrality, which significantly improves the low-field polarization.