Comparative Study of Reliability of Ferroelectric and Anti-Ferroelectric Memories
Comparative Study of Reliability of Ferroelectric and Anti-Ferroelectric Memories
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DOI：
10.1109/tdmr.2018.2829112
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发表时间：
2018-06-01
影响因子：
2
通讯作者：
Mikolajick, Thomas
中科院分区：
文献类型：
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作者：
Pesic, Milan;Schroeder, Uwe;Mikolajick, Thomas
随着HfO2铁电(FE)特性的发现，尖端技术节点和基于FE材料的非易失性存储器之间的比例差距可以弥合。除了非易失性，新的记忆概念应该保证足够的耐用性和操作稳定性。然而，与优化的基于钙钛矿的FES相比，基于二进制氧化物的FE存储器仍然在存储器窗口(MW)中显示变化，随后是硬击穿或关闭MW。最近，我们发现抗FE(AFE)材料比FE材料表现出非常稳定和显著更高的耐久性。受AFE材料的坚固性和卓越的循环性能的启发，我们分析了这些器件剩余的可靠性方面。通过表征电容堆叠的纯膜特性和集成到器件中时的开关性能，我们比较和研究了FE和AFE存储器的温度稳定性、印迹、保持和可变性。我们研究了要克服的较低的能垒以及部分开关和较低的开关感应应力是否导致AFE相对于基于FE的存储器具有更高的耐久性。通过利用电荷俘获和电荷泵浦实验，结合泄漏电流谱，结合综合模型，我们验证了这一假设。此外，我们认为界面缓冲层是这些器件中最薄弱的一环。
With the discovery of the ferroelectric (FE) properties within HfO2, the scaling gap between state-of-the-art technology nodes and non-volatile memories based on FE materials can be bridged. In addition to non-volatility, new memory concepts should guarantee sufficient endurance and operation stability. However, in contrast to optimized perovskite based FEs, binary oxide based FE memories still show changes in the memory window (MW) followed by either hard breakdown or closure of the MW. Recently, we have shown that anti-FE (AFE) materials exhibit very stable and significantly higher endurance with respect to the FE counterparts. Inspired by the robustness and remarkable cycling performance of the AFE materials, we analyze the remaining reliability aspects of these devices. By characterizing the pure film properties of capacitor stacks and switching performance when integrated into devices, we compare and investigate temperature stability, imprint, retention, and variability of both FE and AFE memories. We investigate if the lower energetic barrier to be overcome together with partial switching and lower switching induced stress are responsible for the higher endurance of the AFE with respect to the FE based memories. By utilizing charge trapping and charge pumping tests together with leakage current spectroscopy in combination with comprehensive modeling we check that assumption. Moreover, we identify the interfacial buffer layer as the weakest link of these devices.