氧化铪基铁电电容的唤醒-疲劳效应与相结构演变  

Wake⁃up fatigue effect and phase structure evolution in hafnium oxide based ferroelectric capacitors

作　　者：辛天骄 王怡炜 高兆猛 郑赟喆 郑勇辉 成岩 XIN Tianjiao;WANG Yiwei;GAO Zhaomeng;ZHENG Yunzhe;ZHENG Yonghui;CHENG Yan(Key Laboratory of Polar Materials and Devices(MOE),Department of Electronics,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学,极化材料与器件教育部重点实验室,上海200241

出　　处：《电子显微学报》2024年第3期277-282,共6页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(Nos.62174054,92064003,62104071,12134003);上海市自然科学基金资助项目(No.23ZR1418000);中国科学院战略性先导科技专项(No.XDB44000000).

摘　　要：掺杂氧化铪(HfO_(2))铁电薄膜具有优异的尺寸微缩特性与良好的半导体工艺兼容性,其铁电电容结构兼容主流动态随机存取存储架构,是新型存储器介质材料的有力候选者。HfO_(2)基铁电电容随电学读写操作(循环)次数的增加,其代表“0”和“1”存储状态的剩余极化值会发生先增加后减小的现象,直到存储窗口不足或器件击穿失效,即器件的唤醒和疲劳效应,引发存储的可靠性问题。本文选择基于锆掺杂的HfO_(2)基铁电薄膜(Hf_(0.5)Zr_(0.5)O_(2),HZO)制备电容器结构,对不同电学循环次数的电容器切片进行结构表征,发现器件的剩余极化变化与HZO薄膜的微观相结构演变直接相关:(1)唤醒过程剩余极化增加源自四方到铁电正交相的结构转变;(2)铁电正交到单斜相的结构转变是导致疲劳过程剩余极化衰减的重要原因。Doped hafnium oxide ferroelectric thin films have both excellent size reduction characteristics and good CMOS process compatibility.The ferroelectric capacitor structure is compatible with mainstream DRAM storage architectures,which is a candidate for new memory dielectric materials.As the electrical read and write operations increases,the residual polarization values,representing the"0"and"1"storage states in HfO_(2) based ferroelectric capacitors,firstly increase and then decrease until the storage window is insufficient or the device fails due to breakdown.It is called the wake up and fatigue effect of the device,leading to reliability issues in storage.In this work,HfO_(2) based ferroelectric thin films doped with zirconium were prepared into capacitor structures slices with different electrical cycles.The change of residual polarization was related to the microstructure evolution of Hf_(0.5)Zr_(0.5)O_(2) thin film.The increase of residual polarization during the wake-up process originated from the structural transition from anti ferroelectric tetragonal phase to ferroelectric orthorhombic phase.The structural transformation from ferroelectric orthogonality to paraelectric monoclinic phase was responsible for the residual polarization attenuation during the fatigue process.

关 键 词：掺杂氧化铪 铁电存储 唤醒 疲劳 失效 

分 类 号：O484.1[理学—固体物理] O792[理学—物理] TG115.215.3[金属学及工艺—物理冶金] TN384[金属学及工艺—金属学]