Ferroelectric Nanogap‐Based Steep‐Slope Ambipolar Transistor

Abstract The subthreshold swing (SS) of metal–oxide‐semiconductor field‐effect transistors is limited to 60 mV dec⁻¹ at room temperature by the Boltzmann tyranny, which restricts the scaling of the supply voltage. A nanogap‐based transistor employs a switchable nanoscale air gap as the channel, offering a steep‐slope switching process. Meanwhile, nanogaps featuring even sub‐3 nm can efficiently block the current flow, exhibiting the potential for tackling the short‐channel effect. Here, an electrically switchable ferroelectric nanogap to construct steep‐slope transistors, is exploited. An average SS of 15.9 mV dec⁻¹ across 5 orders and a minimum SS of 13.23 mV dec⁻¹ are obtained in the high current density range. The transistor exhibits excellent performance with near‐zero off‐state leakage current and a maximum on‐state current of 202 µA µm⁻¹ at V_DS = 0.5 V. In addition, the transistor can turn off with either a positive or negative increase in the gate voltage, exhibiting ambipolar characteristics.