与CMOS工艺兼容的HfO2基FeFET存储窗口非定常性的畴诱导机制

与CMOS工艺兼容的HfO2基FeFET在民用和军用领域都具有广阔的应用前景，但存储窗口非定常性是制约其商业化应用的技术瓶颈。弄清重复擦写操作对电畴演变影响的微观机理，是阐明存储窗口非定常性诱导机制的关键。基于此，本申请项目结合压电力显微镜(PFM)和原位透射电子显微镜(TEM)对HfO2基FeFET在擦写过程中及不同擦写次数下电畴和微观结构的演变进行研究。同时，构建HfO2基FeFET电畴演变的相场模型，并以电畴演变为桥梁，结合场效应晶体管理论，建立HfO2基FeFET微观结构、电畴演变和宏观电学性能之间的关联模型。最后，以PFM和原位TEM的表征结果为基础，结合关联模型系统分析重复擦写操作对电畴演变影响的微观机理及其与存储窗口非定常性之间的关联，揭示HfO2基FeFET存储窗口非定常性的畴诱导机制，为解决HfO2基FeFET可靠性问题提供理论指导和技术支撑。

Complementary-metal-oxide-semiconductor (CMOS) compatible HfO2 based ferroelectric field-effect transistor (FeFET) has a great potential application in information storage devices for both civilian and military uses. However, the non-constant memory window in HfO2 based FeFETs has become the technical bottleneck for the commercialization of this technology. An understanding of the micromechanism for domain evolution during repeated program/erase cycling is critical for revealing the inducement mechanism of non-constant memory window in HfO2 based FeFETs. In this project, with combined use of piezoresponse force microscopy (PFM) and in situ transmission electron microscopy (TEM), the evolutions of domain and microstructure both during program/erase operation and under different program/erase cycling numbers will be investigated. Meanwhile, a phase field model for simulating the evolution of ferroelectric domains will be established. Thus, using domain evolution as a bridge, a correlation model among microstructures, domain evolution, and non-constant memory window in HfO2 based FeFETs could be derived on the basis of the theory of field-effect transistors. Finally, through a combination of the experimental results obtained from PFM and in situ TEM characterizations and the correlation model, the mechanism of repeated program/erase operations affecting domain evolution and its relationship with non-constant memory window can be systematically analyzed. Therefore, domain-induced mechanism for non-constant memory window in CMOS compatible HfO2 based FeFET could be elucidated, which will contribute a lot to improving the reliability of the HfO2 based FeFETs.