Record‐Low Subthreshold‐Swing Negative‐Capacitance 2D Field‐Effect Transistors

Abstract

Power consumption is one of the most challenging bottlenecks for complementary metal-oxide-semiconductor integration. Negative-capacitance field-effect transistors (NC-FETs) offer a promising platform to break the thermionic limit defined by the Boltzmann tyranny and architect energy-efficient devices. However, it is a great challenge to achieving ultralow-subthreshold-swing (SS) (10 mV dec^-1 ) and small-hysteresis NC-FETs simultaneously at room temperature, which has only been reported using the hafnium zirconium oxide system. Here, based on a ferroelectric LiNbO₃ thin film with great spontaneous polarization, an ultralow-SS NC-FET with small hysteresis is designed. The LiNbO₃ NC-FET platform exhibits a record-low SS of 4.97 mV dec^-1 with great repeatability due to the superior capacitance matching characteristic as evidenced by the negative differential resistance phenomenon. By modulating the structure and operating parameters (such as channel length (L_ch ), drain-sourse bias (V_ds ), and gate bias (V_g )) of devices, an optimized SS from ≈40 to ≈10 mV dec^-1 and hysteresis from ≈900 to ≈60 mV are achieved simultaneously. The results provide a new potential method for future highly integrated electronic and optical integrated energy-efficient devices.