Ferroelectric Hafnium Oxide Material Enhanced Reliability

该项目的主要目标是了解电容器结构中电介质和HfO 2或ZrO 2基铁电层之间的相互作用。在该双层结构堆叠内，铁电偶极子与电荷（例如，电子、空穴、带电氧空位）之间发生强相互作用。由于介电层和铁电层的不同厚度比存在于从铁电电容器经由铁电场效应晶体管和铁电隧道结到负电容FET和红外传感器的宽范围的半导体器件中，因此效果可能从一个器件到另一个器件改变，但基本特性保持相似。到目前为止，对缺陷和电荷的影响的详细了解是有限的，迫切需要进一步的研究，使HfO 2基铁电材料在广泛的应用中的引入成为可能。HfO 2-和ZrO 2-基铁电层掺杂原子具有不同的价态，以了解掺杂剂价态对铁电电容器可靠性（存储窗口，泄漏，唤醒行为，保持，疲劳和耐久性）的影响。此外，将研究铁电/介电层的厚度比以及电极材料对电容器膜堆叠的影响，以减少陷阱行为并获得更好的性能。为了实现这些结果，活性介质的电子和原子结构将通过不同的表征技术进行研究，这些技术将通过从头计算模拟的实验发光和电荷传输实验进行补充和加强。所获得的结果可以得到一个详细的微观模型的铁电性能的退化行为，以制定实用的建议，铁电器件。该项目的总体目标是优化这种新型无铅铁电材料的可靠性、性能、环境兼容性、CMOS兼容性和基础材料的可用性。

The main objective of the project is to understand the interplay between a dielectric and a HfO2- or ZrO2-based ferroelectric layer within a capacitor structure. Within this bi-layer structure stack a strong interaction between the ferroelectric dipoles and charges (e.g. electrons, holes, charged oxygen vacancies) occur. Since different thickness ratio of dielectric and ferroelectric layer are present in a wide range of semiconductor devices from ferroelectric capacitor via ferroelectric field effect transistors and ferroelectric tunnel junctions to negative capacitance FETs and infrared sensors, effects might change from one device to another, but basic characteristics remain similar. So far, a detailed understanding of the effects of defects and charges is limited, and further studies are urgently needed to make the introduction of HfO2 based ferroelectric materials in a wide range of applications possible. HfO2- and ZrO2-based ferroelectric layers are doped by atoms with different valence to understand the impact of dopant valence on the ferroelectric capacitor reliability (memory window, leakage, wake-up behavior, retention, fatigue, and endurance). Furthermore, the impact of the thickness ratio of ferroelectric/dielectric layers as well as electrode materials will be studied on the capacitor film stacks to reduce trapping behavior and get better performance. To achieve these results, the electronic and atomic structure of active mediums will be studied by different characterization techniques which will be supplemented and strengthened by experimental luminescence and charge transport experiments with ab initio simulations. Obtained results allow to obtain a detailed microscopic model for the degradation behavior of ferroelectric properties in order to develop practical recommendations for ferroelectric devices. The overall goal of the project is an optimization of this new lead-free ferroelectric material with respect to reliability, performance, environmental compatibility, CMOS compatibility, availability of the basic material.