Low-Power Forming Free TiO2-x/HfO2-y/TiO2-x-Trilayer RRAM Devices Exhibiting Synaptic Property Characteristics
Low-Power Forming Free TiO2-x/HfO2-y/TiO2-x-Trilayer RRAM Devices Exhibiting Synaptic Property Characteristics
复制标题
DOI：
10.1109/ted.2017.2709338
复制
发表时间：
2017-08-01
影响因子：
3.1
通讯作者：
Tsoukalas, Dimitris
中科院分区：
文献类型：
--
作者：
Bousoulas, Panagiotis;Michelakaki, Irini;Tsoukalas, Dimitris
在TiO 2-x/HfO 2-y/TiO 2-x电阻式随机存取存储器（RRAM）中插入HfO 2-y层产生50 nW（在5 V时10 nA）的低置位功率、3 nW（在-3 V时1 nA）的低复位功率和良好的循环可变性（σ/μ < 0.5）。此外，在脉冲实验下，1 μ s的快速开关时间，良好的107循环耐久性和在150 ℃下的保持性能，被证明。与作为两个串联电阻的调节两层TiO 2-x相比，HfO 2-y膜具有最高的氧含量和更深的氧空位能级，将开关效应限制在HfO 2-y膜中可以解释低的开关能量。电阻的逐渐调制也允许长时程增强突触可塑性的表现，通过应用具有不同重复间隔的脉冲序列诱导。一个定量的模型，以重现模拟SET/SET的三层结构的响应，并突出了氧空位的局部分布的作用。这些效应与所使用的室温制造工艺和薄膜的无成形性质一起被认为是朝向高密度RRAM设计的优化路线。
The insertion of an HfO2-y layer within TiO2-x/HfO2-y/TiO2-x resistive random access memory (RRAM) yields in low set power of 50 nW (10 nA at 5 V), low reset power of 3 nW (1 nA at -3 V), and good cycling variability (sigma/mu < 0.5). In addition, under pulse experiments, fast switching time of 1 mu s, good 107 cycling endurance and retention performance at 150 degrees C, was demonstrated. The confinement of the switching effect into the HfO2-y film, which has the highest oxygen content and deeper oxygen vacancy energy levels compared with the adjusting two layers of TiO2-x which act as two series resistances, can explain the low switching energy. The gradual modulation of the resistance permits also the manifestation of long-term potentiation synaptic plasticity, induced by the application of a train of pulses with different repetition intervals. A quantitative model was applied in order to reproduce the analog SET/RESET responses of the trilayer configuration and highlight the role of the local distribution of oxygen vacancies. These effects in conjunction with the room temperature fabrication process used and the forming-free nature of the thin films are considered as an optimization route toward high-density RRAM design.