Dopant and Defect Physics for Device Optimization for Hafnium Oxide based Devices

用铁电氧化铪实现的器件是硅兼容的、功率高效的，并且可以成本有效地集成到用于传感器、非易失性存储器、逻辑和神经形态应用的先进技术节点中。目前，铌锆混合氧化物（HfxZr 1-xO 2）提供了最宽的化学计量窗口，用于制备具有大反射极化的铁电薄膜。尽管如此，该膜需要氧空位（VO）来稳定铁电相，并且具有可靠性问题。VO浓度难以控制，并且会影响诸如极化稳定性的电性能，危及基于氧化物的存储器和低功耗逻辑的前景。一种替代方案可以是从化学计量的、准无空位的氧化物开始，并使用合适的掺杂剂来优化铁电性能。这将具有比HfxZr 1-xO 2中VO的相当不受控制的生成更可再现的显著优点。 我们将探索这种可能性，通过研究的原子和电子结构的选择性和可控掺杂的氧化物使用从头计算和相场模拟来描述掺杂剂调制的原子和电子结构的铁电性能的影响。一系列的掺杂剂，浓度和工艺条件将被认为是提供一个初步评估的掺杂剂化学和铁电性能之间的相关性。所选材料将在大面积电容器上进行表征，并通过连续的模拟、加工和表征迭代进行优化。然后将它们集成到缩放的电容器阵列中，以提供统计上显著的铁电电容器性能结果。在基础水平上，D3 PO将更好地了解掺杂剂对局部化学，电子结构，相组成的影响，以及它们对材料和铁电参数的影响，包括再结晶温度和reversible极化。然后，我们将阐述基于真实的设备的物理模型，使用从头计算模拟和结构和电气特性获得的参数来预测，通过统计分析，关键指标，如唤醒，耐久性，保留，泄漏，和击穿使用无空位掺杂氧化物。

Devices realized with ferroelectric hafnium oxide are silicon compatible, power-efficient, and can be cost-effectively integrated into advanced technology nodes for sensor, nonvolatile memory, logic, and neuromorphic applications. Currently, hafnium-zirconium mixed oxide (HfxZr1-xO2) offers the widest stoichiometry window for fabricating ultrathin ferroelectric films with large remanent polarization. Still, the film requires oxygen vacancies (VO) to stabilize the ferroelectric phase and has reliability issues. VO concentration is difficult to control and can affect electrical properties such as polarization stability, jeopardizing the prospect of hafnia-based memory and low-power logic. An alternative could be to start from stoichiometric, quasi-vacancy-free hafnia and use suitable dopants to optimize the ferroelectric properties. This would have the significant advantage of being more reproducible than the rather uncontrolled generation of VO in HfxZr1-xO2. We will explore this possibility by studying the atomic and electronic structure of selectively and controllably doped hafnia using ab initio calculations and phase-field simulations to describe the influence of the dopant modulated atomic and electronic structure on the ferroelectric properties. A range of dopants, concentrations, and process conditions will be considered to provide an initial assessment of the correlations between dopant chemistry and the ferroelectric properties. The chosen materials will be characterized on large area capacitors and optimized by successive simulation, processing, and characterization iterations. Then they will be integrated into scaled capacitor arrays to provide statistically significant results on ferroelectric capacitor performance. At a fundamental level, D3PO will give a better understanding of the influence of dopants on local chemistry, electronic structure, phase composition, and their effects on material and ferroelectric parameters, including recrystallization temperature and remanent polarization. We will then elaborate physical models based on real devices, using parameters obtained from ab initio simulations and structural and electrical characterization to predict, through statistical analysis, key metrics such as wake-up, endurance, retention, leakage, and breakdown using vacancy-free doped hafnia.