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 (Lch), drain–sourse bias (Vds), and gate bias (Vg)) 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.

Reconfigurable Quasi‐Nonvolatile Memory/Subthermionic FET Functions in Ferroelectric–2D Semiconductor vdW Architectures

“…An NCFET is reported to exhibit hysteresis‐free transfer characteristics with a subthermionic subthreshold swing ( SS ), which drastically differentiates it from an FeFET and is favorable for low‐power consumption logic applications. [ 12,13 ]…”

“…An NCFET is reported to exhibit hysteresis-free transfer characteristics with a subthermionic subthreshold swing (SS), which drastically differentiates it from an FeFET and is favorable for low-power consumption logic applications. [12,13] Recently, based on the so-called ferroelectric proximity effect, that is, nonvolatile electrostatic doping by ferroelectric polarization, programmable doping profiles in semiconductor channels have been reported by controlling local ferroelectric polarizations using a scanning probe technique or multiple-gate operation. [14,15] Consequently, a single 2D FeFET is capable of simultaneously performing logic, memory, and synaptic operations, and its functionality can be customized on demand.…”

Strain tuning of negative capacitance in ferroelectric KNbO3 thin films

“…Subsequently, many efforts have been devoted to developing the mechanism of NC from monodomain to multidomain and the dynamics of polarization switching by theoretical calculation [8][9][10][11] . A wealth of investigations on ferroelectric devices and transistors have reported the capacitance enhancement and sub-60mV/decade subthreshold swings without hysteresis in crystalline ferroelectric-dielectric bilayer [12][13][14][15][16] . In 2014, Khan et al achieved direct measurement of the NC effect in single-crystal ferroelectric Pb(Zr,Ti)O 3 thin lms by constructing a simple resistor-capacitor (R-C) network and monitoring the time-dependence voltage and charge 17 .…”

Low‐Energy Oxygen Plasma Injection of 2D Bi2Se3 Realizes Highly Controllable Resistive Random Access Memory

“…In the age of data explosion, resistive random access memory (RRAM) with high density, low power consumption, and fast speed are highly required for the massive data storage, inmemory computing, and artificial neural network. [1][2][3][4][5] Due to their unique properties including high mechanical flexibility, ultimately thin bodies, and easy electrostatic control, 2D materials such as graphene, MoS 2 , h-BN, etc., have demonstrated great potential for advanced RRAM in the past decade. [6][7][8][9] To make improvements in 2D RRAM, several methods containing natural oxidation, solution processing, and gate-tunability have been proposed to effectively produce or regulate the resistive switching (RS) dielectric layer in the devices.…”