Endurance Characteristics of Negative Capacitance FinFETs With Negligible Hysteresis

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 1010 switching pulse cycles. The average values of the threshold voltages ( ${V}_{t}\text{s}$ ) 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.