Spectroscopic Indications of Tunnel Barrier Charging as the Switching Mechanism in Memristive Devices
Spectroscopic Indications of Tunnel Barrier Charging as the Switching Mechanism in Memristive Devices
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DOI：
10.1002/adfm.201702282
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发表时间：
2017-12-01
影响因子：
19
通讯作者：
Dittmann, Regina
中科院分区：
文献类型：
--
作者：
Arndt, Benedikt;Borgatti, Francesco;Dittmann, Regina
电阻式随机存取存储器是一种有前景、节能、低功耗的存储级存储器技术，有潜力取代闪存和片上动态存储器。虽然最广泛使用的系统表现出丝状电阻开关，但基于可调谐隧道势垒的界面型开关系统越来越受到人们的关注。它们较少受到随机细丝形成过程引起的变化的影响，并且隧道势垒厚度的选择提供了使存储器件电流适应给定电路要求的可能性。采用由氧化钇稳定氧化锆（YSZ）隧道势垒和镨钙亚锰酸钙（PCMO）层组成的异质结构。电阻切换过程发生在整个电极下方，而不是空间局部的细丝。通过在原位硬X射线光电子能谱和电子能量损失能谱中采用电学测量的组合，揭示了PCMO和YSZ之间氧离子的交换导致YSZ隧道势垒的有效高度的静电调制，从而成为这些器件中电阻切换的基本机制。
Resistive random access memory is a promising, energy-efficient, low-power storage class memory technology that has the potential to replace both flash storage and on-chip dynamic memory. While the most widely employed systems exhibit filamentary resistive switching, interface-type switching systems based on a tunable tunnel barrier are of increasing interest. They suffer less from the variability induced by the stochastic filament formation process and the choice of the tunnel barrier thickness offers the possibility to adapt the memory device current to the given circuit requirements. Heterostructures consisting of a yttria-stabilized zirconia (YSZ) tunnel barrier and a praseodymium calcium manganite (PCMO) layer are employed. Instead of spatially localized filaments, the resistive switching process occurs underneath the whole electrode. By employing a combination of electrical measurements, in operando hard X-ray photoelectron spectroscopy and electron energy loss spectroscopy, it is revealed that an exchange of oxygen ions between PCMO and YSZ causes an electrostatic modulation of the effective height of the YSZ tunnel barrier and is thereby the underlying mechanism for resistive switching in these devices.