Engineering Negative Differential Resistance in NCFETs for Analog Applications

In negative capacitancefield- effect transistors (NCFETs), drain current may decrease with increasing V-ds in the saturation region, leading to negative differential resistance (NDR). While NDR is useful for oscillator design, it is undesirable for most analog circuits. On the other hand, the tendency toward NDR may be used to reduce the normally positive output conductance (g (ds)) of a short-channel transistor to a nearly zero positive value to achieve higher voltage gain. In this paper, we analyze the NDR effect for NCFET in the static limit and demonstrate that it can be engineered to reduce g(ds) degradation in short-channel devices. Small and positive gds is achieved without compromising the subthreshold gain, which is crucial for analog applications. The 7-nm ITRS 2.0 FinFET with 0.7 V V-dd is used as the baseline device in this paper.