摘要
铁电隧穿结通常为金属-超薄铁电薄膜-金属三明治结构,利用铁电极化状态调控量子隧穿效应获得不同电阻态,实现数据存储功能.其因读写速度快、功耗低、存储密度高及非易失性存储等特点,成为了新一代信息存储技术重要发展方向.然而,这种超薄铁电薄膜因极化翻转电场大、速度高,往往存在局部温度升高、稳定性降低等问题,因此,进一步降低铁电薄膜驱动电场对铁电隧穿器件设计至关重要.研究表明,铁电薄膜可通过调控衬底应变使其处于多畴共存状态,各畴之间翻转驱动电场随着能量势垒的降低而大幅降低.该文基于WKB近似的电子隧穿理论并结合Landau唯象理论,研究了衬底应变对铁电驱动电场、量子隧穿特性及隧穿电阻开关比的影响.计算结果表明:通过衬底应变调控,经典钙钛矿铁电薄膜PbTiO_(3)和BaTiO_(3)同时存在面外向上、向下极化以及面内极化3种电阻状态,有效驱动电场可降低至25 MV/m,比单畴铁电隧穿结驱动电场减少了76%.研究结果为低能耗、多阻态铁电存储器件设计提供了理论基础.
The ferroelectric tunneling junction,with a metal-ferroelectric ultra-thin film-metal structure,has different tunneling resistance states through polarization manipulation,leading to potential applications in next-generation information storage devices with low-power consumption,fast reading/writing speed,high storage density,and non-volatility.However,the ferroelectric thin films still experience high-temperature rises with reduced stability due to high driving fields,and reducing the driving electric field is crucial for designing ferroelectric tunneling devices.The ferroelectric thin films with coexisting domains have lowered barriers and decreased driving electric fields for domain switching,which are achieved through substrate manipulation.Herein the substrate effects on the driving field,the tunneling resistance switching ratio and the tunneling properties,were studied based on the WKB approximation combined with the Landau phenomenological theory.The results show that,the ferroelectric tunnel junction with coexisting domains exhibits 3 resistive states corresponding to out-of-plane and in-plane polarizations.The effective driving electric field can be reduced to 25 MV/m,which is 76%lower than that with 2 resistive single domains.The proposed theoretical framework provides a fundamental understanding of the formation of multi-state and reduction of the driving field for low-energy,multi-resistance ferroelectric storage devices.
作者
董言哲
路晓艳
DONG Yanzhe;LU Xiaoyan(School of Civil Engineering,Harbin Institute of Technology,Harbin 150090,P.R.China)
出处
《应用数学和力学》
CSCD
北大核心
2024年第10期1320-1331,共12页
Applied Mathematics and Mechanics
基金
国家自然科学基金(面上项目)(12372148)
国家重点研发计划(2021YFF0501001)。
关键词
铁电多态隧穿
低能耗
共存畴
Landau唯象理论
衬底应变
ferroelectric multi-level tunneling
low consumption
coexisting domain
Landau phenomenological theory
substrate misfit strain
