Transmission Electron Microscopy Study on the Effect of Thermal and Electrical Stimuli on Ge2Te3 Based Memristor Devices
Transmission Electron Microscopy Study on the Effect of Thermal and Electrical Stimuli on Ge2Te3 Based Memristor Devices
复制标题
DOI：
10.3389/felec.2022.872163
复制
发表时间：
2022-04
影响因子：
8.6
通讯作者：
Austin Shallcross;K. Mahalingam;E. Shin;G. Subramanyam;Md. Shahanur Alam;Tarek Taha;S. Ganguli;Cynthia T. Bowers;Benson Athey;A. Hilton;Anisha Roy;R. Dhall
中科院分区：
文献类型：
--
作者：
Austin Shallcross;K. Mahalingam;E. Shin;G. Subramanyam;Md. Shahanur Alam;Tarek Taha;S. Ganguli;Cynthia T. Bowers;Benson Athey;A. Hilton;Anisha Roy;R. Dhall
在这项研究中，使用硫属化物Ge 2 Te 3相变薄膜的金属-绝缘体-金属结构的忆阻器件的特征在于使用热和电刺激。一旦施加热和电刺激，就进行横截面透射电子显微镜（TEM）和X射线能量色散谱（XEDS）分析以确定装置中的结构和组成变化。对这些器械的电气测量表明，需要在循环之间增加顺应电流，以启动从低电阻状态（LRS）到高电阻状态（HRS）的切换。HRS中测得的电阻也表现出随着顺应电流的增加而稳定下降。高分辨率TEM研究表明，在HRS的设备上存在残留的结晶相在顶部电极/电介质界面，这可以解释所观察到的依从性电流的依赖性。XEDS研究揭示了扩散相关的过程中，在介电电极界面的特点，分离的Ge-和Te-富集的界面层的Ge 2 Te 3。这也伴随着在这些地区的O水平的峰值。此外，原位加热实验上生长的薄膜揭示了有害的影响，Ti的粘附层，其中的Ti的扩散导致的介电层的进一步退化。这项基于实验物理的研究表明，低于1 mA的电流顺应性限制的大HRS/LRS比以及通过改变顺应性电流来控制HRS和LRS的能力对于忆阻器和神经形态计算应用是有吸引力的。
Memristor devices fabricated using the chalcogenide Ge2Te3 phase change thin films in a metal-insulator-metal structure are characterized using thermal and electrical stimuli in this study. Once the thermal and electrical stimuli are applied, cross-sectional transmission electron microscopy (TEM) and X-ray energy-dispersive spectroscopy (XEDS) analyses are performed to determine structural and compositional changes in the devices. Electrical measurements on these devices showed a need for increasing compliance current between cycles to initiate switching from low resistance state (LRS) to high resistance state (HRS). The measured resistance in HRS also exhibited a steady decrease with increase in the compliance current. High resolution TEM studies on devices in HRS showed the presence of residual crystalline phase at the top-electrode/dielectric interface, which may explain the observed dependence on compliance current. XEDS study revealed diffusion related processes at dielectric-electrode interface characterized, by the separation of Ge2Te3 into Ge- and Te- enriched interfacial layers. This was also accompanied by spikes in O level at these regions. Furthermore, in-situ heating experiments on as-grown thin films revealed a deleterious effect of Ti adhesive layer, wherein the in-diffusion of Ti leads to further degradation of the dielectric layer. This experimental physics-based study shows that the large HRS/LRS ratio below the current compliance limit of 1 mA and the ability to control the HRS and LRS by varying the compliance current are attractive for memristor and neuromorphic computing applications.