High-Performance Negative Capacitance Field-Effect Transistors with Synthetic Monolayer MoS.

Although negative capacitance field-effect transistors (NCFETs) have been extensively studied to overcome the fundamental Boltzmann limit, many prior reports on sub-60 mV/dec subthreshold swings (SS) suffer from inadequate data ranges, measurements near the noise floor, and a lack of robust device simulations, raising questions about the true efficacy of NCFETs. Moreover, recent efforts with MoS channels have frequently relied on mechanically exfoliated flakes, limiting device uniformity and scalability. Here, we present an NCFET that employs a synthetic monolayer MoS channel and a ferroelectric hafnium zirconium oxide layer in the gate stack integrated with indium metal contacts.

Ion-Induced Phase Changes in 2D MoTe Films for Neuromorphic Synaptic Device Applications.

Two-dimensional molybdenum ditelluride (2D MoTe) is an interesting material for artificial synapses due to its unique electronic properties and phase tunability in different polymorphs 2H/1T'. However, the growth of stable and large-scale 2D MoTe on a CMOS-compatible Si/SiO substrate remains challenging because of the high growth temperature and impurity-involved transfer process. We developed a large-scale MoTe film on a Si/SiO wafer by simple sputtering followed by lithium-ion intercalation and applied it to artificial synaptic devices.

Ultrafast Negative Capacitance Transition for 2D Ferroelectric MoS/Graphene Transistor.

Negative capacitance gives rise to subthreshold swing (SS) below the fundamental limit by efficient modulation of surface potential in transistors. While negative-capacitance transition is reported in polycrystalline Pb(ZrTi)O (PZT) and HfZrO (HZO) thin-films in few microseconds timescale, low SS is not persistent over a wide range of drain current when used instead of conventional dielectrics. In this work, the clear nano-second negative transition states in 2D single-crystal CuInPS (CIPS) flakes have been demonstrated by an alternative fast-transient measurement technique.

Superior and stable ferroelectric properties of hafnium-zirconium-oxide thin films deposited atomic layer deposition using cyclopentadienyl-based precursors without annealing.

HfO2-based ferroelectric thin films deposited via atomic layer deposition have been extensively studied as promising candidates for next-generation ferroelectric devices. The conversion of an amorphous Hf1-xZrxO2 film to the ferroelectric phase (non-centrosymmetric orthorhombic phase) has been achieved through annealing using a post-thermal process. However, in this study, we present the first report of ferroelectricity of hafnium-zirconium-oxide (HZO) thin films deposited via atomic layer deposition using cyclopentadienyl-based precursors without additional post-thermal processing.