The recent discovery of ferroelectricity in HfO2 has revived the interest into non-volatile memories based on ferroelectric transistors (FeFETs). The key advantages of these FeFETs include the low power consumption and the compatibility with the existing CMOS process. On the other hand, issues related mainly to endurance still represent a challenge to the development of the technology. In this Letter, we propose to exploit an analytical expression for the Memory Window (MW) as a simple yet effective characterization tool to evaluate the endurance of FeFETs. The MW is defined as the difference between threshold voltages occurring due to polarization switching. The analytical formulation of the MW allows one to quickly estimate the generated trap concentration as a function of number of writing cycles (or time) without recurring to numerical simulations. With the aid of the analytical model, we find that for typical program/erase pulse amplitudes and duration, endurance has a weak dependence on writing conditions. The characterization technique based on the MW would allow the systematic comparison of the performance and endurance of next-generation FeFETs.

中文翻译：

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用于评估铁电 FET 耐久性的内存窗口表达式

最近在 HfO2 中发现的铁电性重新引起了人们对基于铁电晶体管 (FeFET) 的非易失性存储器的兴趣。这些 FeFET 的主要优势包括低功耗和与现有 CMOS 工艺的兼容性。另一方面，主要与耐力相关的问题仍然是对技术发展的挑战。在这封信中，我们建议利用内存窗口 (MW) 的分析表达式作为一种简单而有效的表征工具来评估 FeFET 的耐用性。MW 定义为由于极化切换而出现的阈值电压之间的差异。MW 的分析公式允许人们快速估计生成的陷阱浓度作为写入周期数（或时间）的函数，而无需重复进行数值模拟。借助分析模型，我们发现对于典型的编程/擦除脉冲幅度和持续时间，耐久性对写入条件的依赖性较弱。基于 MW 的表征技术将允许对下一代 FeFET 的性能和耐久性进行系统比较。