HfO2基晶体管型铁电存储单元的空间辐射效应及损伤机理研究

HfO2-based transistor ferroelectric memory is considered to be the most promising next generation ferroelectric memory for aerospace and other field applications, which can break the development bottleneck of ferroelectric memory because it is compatible with silicon-based CMOS technology and easy to be miniaturized. However, its space radiation effect and damage mechanism are lacking. In this project, the space radiation damage of the HfO2-based transistor ferroelectric memory cell will be studied for space application. Firstly, irradiation experiments will be carried out with different high-energy rays and particles, and the influence of the irradiation condition on the key electrical and reliability characteristics of memory cell will be obtained. Then, the phase change transition and domain evolution of HfO2-based ferroelectric thin film in the memory cell under various irradiation conditions will be studied, and the correlation of the change transition, domain evolution and radiation effect will be analyzed. Furthermore, the radiation damage simulation of ferroelectric film and memory cell will be carried out. Finally, based on above-mentioned experiment and simulation studies, the radiation damage mechanism of HfO2-based transistor ferroelectric memory cell will be discovered. These studies will provide theoretical basis and experimental reference for the development of anti-radiation HfO2-based ferroelectric memory.

HfO2基晶体管型铁电存储器由于与硅基CMOS工艺兼容、可微型化能力强等优点，被认为是有望突破铁电存储器发展瓶颈的新型铁电存储器，在航空航天等领域具有很好的应用前景。然而目前比较缺乏HfO2基晶体管型铁电存储器的空间辐射效应及其损伤机制研究。本申请项目基于铁电存储器在空天环境下的重大应用背景，以HfO2基晶体管型铁电存储单元为研究对象，针对其空间辐射损伤的关键科学问题，通过不同高能射线与粒子开展辐照试验，获得存储单元宏观电学及可靠性参数随辐照条件的变化规律，分析辐照导致的HfO2基铁电薄膜相变和畴变及其与存储单元宏观性能退化的相关性，结合薄膜和存储单元的辐射损伤模拟研究，阐述HfO2基晶体管型铁电存储单元的空间辐射损伤机理，为抗辐射HfO2基铁电存储器的研制提供理论依据和实验参考。

本项目紧紧围绕HfO2基晶体管型铁电存储单元的空间辐射效应及损伤机理进行了一系列研究。首先，基于种子层的界面优化作用采用后栅CMOS工艺制备了系列性能优异的HfO2基晶体管型铁电存储单元样品，利用60Co-γ射线、质子等辐照源对其开展了地面模拟辐照试验，研究了累积剂量、辐照源等不同辐照条件对存储单元的存储窗口、保持性能、疲劳性能等电学性能以及铁电相成分、电畴等微观结构的影响，获得了存储单元关键电学和可靠性参数以及微观结构随辐照条件的变化规律。同时，通过粒子输运蒙特卡罗模拟和TCAD仿真研究了HfO2基铁电薄膜栅极结构和晶体管存储单元的辐射损伤，得到了粒子在材料和单元器件中的能量沉积、穿透深度、缺陷等关键参数。综合辐照实验研究结果和材料及器件的辐射损伤模拟研究结果，探讨了HfO2基晶体管型铁电存储单元的辐射损伤机理。此外，对商用铁电存储器开展了单粒子效应地面模拟试验与仿真研究，通过脉冲激光微束和重离子微束对器件开展版图扫描辐照试验得到了铁电存储器单粒子效应敏感区域分布，探讨了N阱电阻的单粒子效应机理以及不同元件参数对单粒子效应的影响，进而基于单粒子效应机理提出了引入低剂量位移损伤的单粒子效应加固方法。这些研究结果可以为HfO2基晶体管型铁电存储器辐射损伤机制的理解和新型抗辐射铁电存储器的开发提供一定的依据和参考。