当前位置：
X-MOL 学术
›
Adv. Funct. Mater.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Smart Design of Fermi Level Pinning in HfO2-Based Ferroelectric Memories
Advanced Functional Materials ( IF 18.5 ) Pub Date : 2023-10-08 , DOI: 10.1002/adfm.202307120
Lutz Baumgarten 1 , Thomas Szyjka 1, 2 , Terence Mittmann 3 , Andrei Gloskovskii 4 , Christoph Schlueter 4 , Thomas Mikolajick 3, 5 , Uwe Schroeder 3 , Martina Müller 2
Advanced Functional Materials ( IF 18.5 ) Pub Date : 2023-10-08 , DOI: 10.1002/adfm.202307120
Lutz Baumgarten 1 , Thomas Szyjka 1, 2 , Terence Mittmann 3 , Andrei Gloskovskii 4 , Christoph Schlueter 4 , Thomas Mikolajick 3, 5 , Uwe Schroeder 3 , Martina Müller 2
Affiliation
|
How and why the reliability of ferroelectric HfO2- and HZO (Hf0.5Zr0.5O2)-based memory devices strongly depends on the choice of electrode materials is currently under intense discussion. Interface conditions such as band alignment, defect formation, and doping are recognized as decisive and interrelated parameters, but a unified picture of the physical mechanisms is still missing. Here, two opposite scenarios of band alignment are found in TiN/HZO/TiN and IrO2/HZO/IrO2 using hard X-ray photoelectron spectroscopy, revealing on the one hand the conditions for a stable device performance, and the origin of their degradation on the other. As a key difference, TiN electrodes scavenge oxygen from the HZO, while IrO2 electrodes supply it. Considering the electronic doping limit of HfO2, a key condition for the stability of ferroelectric devices can be identified: The alignment of the charge neutrality levelwith respect to the metallic Fermi level, which is pinned by the doping limit. Stable device performance can only be achieved for oxygen-deficient HfO2-based interfaces, where the Fermi level of the metal electrode is close to the conduction band of the ferroelectric insulator. This empirical model explains the fatigue behavior of HfO2-based capacitors using either oxygen-scavenging TiN or oxygen-supplying IrO2 electrodes.
中文翻译：
HfO2 基铁电存储器中费米能级钉扎的智能设计
目前正在激烈讨论基于铁电HfO 2 - 和HZO (Hf 0.5 Zr 0.5 O 2 )的存储器件的可靠性如何以及为何强烈依赖于电极材料的选择。能带排列、缺陷形成和掺杂等界面条件被认为是决定性且相互关联的参数，但仍然缺乏物理机制的统一图像。这里，使用硬X射线光电子能谱在TiN/HZO/TiN和IrO 2 /HZO/IrO 2中发现了两种相反的能带排列情况，一方面揭示了稳定器件性能的条件，以及它们的起源。另一方面退化。一个关键的区别是，TiN 电极从 HZO 中清除氧气，而 IrO 2电极则提供氧气。考虑到HfO 2的电子掺杂极限，可以确定铁电器件稳定性的关键条件：电荷中性能级相对于金属费米能级的对准，这是由掺杂极限所固定的。只有缺氧的HfO 2基界面才能实现稳定的器件性能，其中金属电极的费米能级接近铁电绝缘体的导带。该经验模型解释了使用除氧TiN 或供氧IrO 2电极的HfO 2基电容器的疲劳行为。
更新日期：2023-10-08
中文翻译：
HfO2 基铁电存储器中费米能级钉扎的智能设计
目前正在激烈讨论基于铁电HfO 2 - 和HZO (Hf 0.5 Zr 0.5 O 2 )的存储器件的可靠性如何以及为何强烈依赖于电极材料的选择。能带排列、缺陷形成和掺杂等界面条件被认为是决定性且相互关联的参数，但仍然缺乏物理机制的统一图像。这里，使用硬X射线光电子能谱在TiN/HZO/TiN和IrO 2 /HZO/IrO 2中发现了两种相反的能带排列情况，一方面揭示了稳定器件性能的条件，以及它们的起源。另一方面退化。一个关键的区别是，TiN 电极从 HZO 中清除氧气，而 IrO 2电极则提供氧气。考虑到HfO 2的电子掺杂极限，可以确定铁电器件稳定性的关键条件：电荷中性能级相对于金属费米能级的对准，这是由掺杂极限所固定的。只有缺氧的HfO 2基界面才能实现稳定的器件性能，其中金属电极的费米能级接近铁电绝缘体的导带。该经验模型解释了使用除氧TiN 或供氧IrO 2电极的HfO 2基电容器的疲劳行为。
京公网安备 11010802027423号