In-operando hard X-ray photoelectron spectroscopy study on the impact of current compliance and switching cycles on oxygen and carbon defects in resistive switching Ti/HfO2/TiN cells
In-operando hard X-ray photoelectron spectroscopy study on the impact of current compliance and switching cycles on oxygen and carbon defects in resistive switching Ti/HfO2/TiN cells
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DOI：
10.1063/1.4879678
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发表时间：
2014-05-28
影响因子：
3.2
通讯作者：
Schroeder, Thomas
中科院分区：
文献类型：
--
作者：
Sowinska, Malgorzata;Bertaud, Thomas;Schroeder, Thomas
在这项研究中，直接的实验材料科学证据的重要理论预测的电阻随机存取存储器（RRAM）技术，需要一个临界量的氧空位，以建立稳定的电阻切换金属氧化物金属样品。详细地说，一种新的在operando硬X射线光电子能谱技术应用于非破坏性研究的影响，电流遵守和直流电压扫描周期的Ti/HfO 2界面化学和物理的电阻开关Ti/HfO 2/TiN电池。这些研究确实证实，电流顺应性是在RRAM单元操作期间控制氧化物层中的导电细丝中的氧空位的量以实现稳定切换的关键参数。此外，在电应力下朝向Ti/HfO 2界面的清楚的碳偏析是可见的。由于碳杂质在电阻切换下影响氧空位缺陷群，因此怀疑Ti/HfO 2界面的这种动态碳偏析对RRAM器件耐久性产生负面影响。因此，这些结果表明，RRAM材料工程需要在介电层中包括所有杂质，以便实现可靠的器件性能。(C)2014 AIP Publishing LLC.
In this study, direct experimental materials science evidence of the important theoretical prediction for resistive random access memory (RRAM) technologies that a critical amount of oxygen vacancies is needed to establish stable resistive switching in metal-oxide-metal samples is presented. In detail, a novel in-operando hard X-ray photoelectron spectroscopy technique is applied to non-destructively investigates the influence of the current compliance and direct current voltage sweep cycles on the Ti/HfO2 interface chemistry and physics of resistive switching Ti/HfO2/TiN cells. These studies indeed confirm that current compliance is a critical parameter to control the amount of oxygen vacancies in the conducting filaments in the oxide layer during the RRAM cell operation to achieve stable switching. Furthermore, clear carbon segregation towards the Ti/HfO2 interface under electrical stress is visible. Since carbon impurities impact the oxygen vacancy defect population under resistive switching, this dynamic carbon segregation to the Ti/HfO2 interface is suspected to negatively influence RRAM device endurance. Therefore, these results indicate that the RRAM materials engineering needs to include all impurities in the dielectric layer in order to achieve reliable device performance. (C) 2014 AIP Publishing LLC.