Sub-10 nm thick gadolinium-doped hafnia (Gd:HfO2) layers were grown in metal–insulator–metal (TiN/Gd:HfO2/TiN) stacks using a plasma-enhanced atomic layer deposition process. Thermally annealed Gd:HfO2 layers with a thickness of 8.8, 6.6, and 4.4 nm exhibited orthorhombic crystalline structure and showed ferroelectric properties. Indeed, polarization vs electric field hysteresis loops were recorded with 2P r polarization ranging from 2 to 20 μC/cm2. The studied layers showed the same coercive electric field (∼2 MV/cm). Consequently, polarization switching voltage between +P r and −P r decreased down to 0.9 V for the thinnest layer. Remanent polarization cycling showed a strong wake-up effect, with no fatigue, up to 109, followed by a stabilization up to 1010 cycles, where 2P r reached 33 μC/cm2 for 8.8 nm Gd:HfO2. This endurance result and the absence of noticeable remanent polarization fatigue can be attributed to the optimal chemical composition of the TiN/Gd:HfO2 interface, which is supposed to be at the origin of defect generation, mostly oxygen vacancies, that leads to ferroelectric polarization fatigue.

中文翻译：

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亚 10 纳米铁电 Gd 掺杂 HfO2 层

亚 10 nm 厚的钆掺杂氧化铪 (Gd:HfO2个) 层生长在金属-绝缘体-金属 (TiN/Gd:HfO2个/TiN）堆叠使用等离子增强原子层沉积工艺。热退火 Gd:HfO2个厚度为 8.8、6.6 和 4.4 nm 的层表现出正交晶体结构并显示出铁电性能。实际上，用 2P 记录了极化与电场磁滞回线r极化范围为 2 至 20 μC/cm2个. 所研究的层显示出相同的矫顽电场（~2 MV / cm）。因此，+P 之间的极化转换电压r和-Pr最薄层下降到 0.9 V。剩余极化循环显示出强烈的唤醒效果，无疲劳，高达 109, 然后稳定到 1010周期，其中 2Pr达到 33 μC/cm2个对于 8.8 nm Gd:HfO2个. 这种耐久性结果和没有明显的剩余极化疲劳可归因于 TiN/Gd:HfO 的最佳化学成分2个界面，这应该是缺陷产生的起源，主要是氧空位，导致铁电极化疲劳。