Endurance Characteristics of Negative Capacitance FinFETs With Negligible Hysteresis
Yuwei Cai, Qingzhu Zhang, Zhaohao Zhang, Gaobo Xu, Yanna Luo, Jie Gu, Weizhuo Gan, Xiang Lin, Renren Xu, Zhenhua Wu, Huaxiang Yin, Wenwu Wang, Qiuxia Xu, Tianchun Ye
Abstract
In this letter, the endurance characteristics of negative capacitance (NC) FinFETs with an ultra-steep subthreshold swing (SS) and negligible hysteresis were investigated by an examination approach to emulate long-term logic operation. Detailed variation characteristics for different electrical parameters are summarized for devices subjected to up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> switching pulse cycles. The average values of the threshold voltages (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> s) and hysteresis of the NC-FinFETs exhibited a clear initial increase followed by a decrease as the number of switching cycles was increased; however, the variation of the SS had a different behavior. This result could be attributed to capacitance mismatching in the NC devices induced by a capacitance change of the ferroelectric film. These findings provide an effective method for confirming the capacitance matching model and also offer a guide for design of NC-FET devices and their implementation in future real circuit applications.