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.