叠层结构对HfO2基铁电薄膜极化疲劳性能的影响机理研究

铁电场效应晶体管(FeFET)具有功耗低、擦写速度快、非易失等特点，是下一代存储器的重要发展方向。HfO2基铁电薄膜具有与标准集成电路工艺兼容、可高密度集成等特点，是用于FeFET存储器的绝佳材料。但是，小尺寸HfO2基铁电薄膜之间的性能均一性不佳是阻碍其FeFET存储器产业化的瓶颈，采用叠层结构是改善这一瓶颈问题的有效途径。然而，叠层结构影响了HfO2基铁电薄膜的极化疲劳性能：提高了耐击穿能力、降低了极化稳定性。由于当前研究工作对叠层结构HfO2基铁电薄膜极化疲劳性能的认识停留在宏观层面，因而如何进一步优化疲劳性能也不清楚。基于此，本项目拟通过研究循环电场作用下叠层结构对HfO2基铁电薄膜相稳定性和电畴结构及其翻转动力学的影响，以揭示叠层结构对HfO2基铁电薄膜极化疲劳性能的影响机理，为优化叠层结构HfO2基铁电薄膜的极化疲劳性能提供指导和依据。

Ferroelectric field-effect transistor (FeFET) memory is one of the most promising emerging semiconductor memories, with the merits of fast write/read speed, low power consumption and non-volatile. Due to the excellent compatibility with standard integrated circuit technology and scalability, HfO2 based ferroelectric thin film is extremely suitable for FeFET memory. However, the poor memory performance uniformity between nano-scaled devices significantly limits the industrialization of high-density HfO2 based FeFET memory. Utilizing laminated HfO2 based ferroelectric thin film is an effective way to improve the bottleneck problem. Unfortunately, the laminated structure affects the polarization fatigue properties of HfO2 based ferroelectric film, improving the breakdown resistance and reducing the polarization stability. Because the current researches on the polarization fatigue properties of laminated HfO2 based ferroelectric thin film are only at the macro level, it is unclear to optimize the fatigue properties furtherly. Thus, the project is proposed to reveal the mechanism of the effect of the laminated structure on the polarization fatigue properties of HfO2 based ferroelectric thin film, by studying the ferroelectric phase stability, domain structure and switching dynamics of the laminated HfO2 ferroelectric thin film under cycling electric field. That will be helpful to provide guidance and basis for optimizing the polarization fatigue properties of laminated HfO2 base ferroelectric thin film.