Recent Progress and Applications of HfO_(2)-Based Ferroelectric Memory

The discovery of ferroelectricity in hafnium oxide (HfO_(2)) based thin films in 2011 renewed the interest inferroelectrics. These new ferroelectrics possess completely different crystal morphology with conventional perovskiteferroelectrics, and present more robust ferroelectric properties upon aggressive scaling and compatibility withstandard integrated circuit fabrication processes. In this article, we give a brief introduction to the conventionalferroelectric memories, then review the basic properties, recent progress, and memory applications of theseHfO_(2)-based ferroelectrics.

Low-Programmable-Voltage Nonvolatile Memory Devices Based on Omega-shaped Gate Organic Ferroelectric P(VDF-TrFE) Field Effect Transistors Using p-type Silicon Nanowire Channels

A facile approach was demonstrated for fabricating high-performance nonvolatile memory devices based on ferroelectric-gate field effect transistors using a p-type Si nanowire coated with omega-shaped gate organic ferroelectric poly(vinylidene fluoride-trifluoroethylene)(P(VDF-Tr FE)). We overcame the interfacial layer problem by incorporating P(VDF-Tr FE) as a ferroelectric gate using a low-temperature fabrication process. Our memory devices exhibited excellent memory characteristics with a low programming voltage of ±5 V, a large modulation in channel conductance between ON and OFF states exceeding 105, a long retention time greater than 3 9 104 s, and a high endurance of over 105 programming cycles while maintaining an ION/IOFFratio higher than 102.

Ionizing radiation effect on single event upset sensitivity of ferroelectric random access memory

The impact of ionizing radiation effect on single event upset（SEU） sensitivity of ferroelectric random access memory（FRAM） is studied in this work. The test specimens were firstly subjected to ^60Co γ-ray and then the SEU evaluation was conducted using ^209Bi ions. As a result of TID-induced fatigue-like and imprint-like phenomena of the ferroelectric material, the SEU cross sections of the post-irradiated devices shift substantially. Different trends of SEU cross section with elevated dose were also found, depending on whether the same or complementary test pattern was employed during the TID exposure and the SEU measurement.

Challenges and recent advances in HfO_(2)-based ferroelectric films for non-volatile memory applications

The emergence of data-centric applications such as artificial intelligence(AI),machine learning,and the Internet of Things(IoT),has promoted surges in demand for storage memories with high operating speed and nonvolatile characteristics.HfO_(2)-based ferroelectric memory technologies,which emerge as a promising alternative,have attracted considerable attention due to their high performance,energy efficiency,and full compatibility with the standard complementary metal-oxide-semiconductors(CMOS)process.These nonvolatile storage elements,such as ferroelectric random access memory(FeRAM),ferroelectric field-effect transistors(FeFETs),and ferroelectric tunnel junctions(FTJs),possess different data access mechanisms,individual merits,and specific application boundaries in next-generation memories or even beyond von Neumann architecture.This paper provides an overview of ferroelectric HfO2 memory technologies,addresses the current challenges,and offers insights into future research directions and prospects.

Single event effect in a ferroelectric-gate field-effect transistor under heavy-ion irradiation

The single event effect in ferroelectric-gate field-effect transistor （FeFET） under heavy ion irradiation is investigated in this paper. The simulation results show that the transient responses are much lower in a FeFET than in a conventional metal-oxide-semiconductor field-effect transistor （MOSFET） when the ion strikes the channel. The main reason is that the polarization-induced charges （the polarization direction here is away from the silicon surface） bring a negative surface po- tential which will affect the distribution of carders and charge collection in different electrodes significantly. The simulation results are expected to explain that the FeFET has a relatively good immunity to single event effect.

Sensing with extended gate negative capacitance ferroelectric field-effect transistors

With major signal analytical elements situated away from the measurement environment,extended gate(EG)ion-sensitive fieldeffect transistors(ISFETs)offer prospects for whole chip circuit design and system integration of chemical sensors.In this work,a highly sensitive and power-efficient ISFET was proposed based on a metal-ferroelectric-insulator gate stack with negative capacitance–induced super-steep subthreshold swing and ferroelectric memory function.Along with a remotely connected EG electrode,the architecture facilitates diverse sensing functions for future establishment of smart biochemical sensor platforms.

Ferro-floating memory:Dual-mode ferroelectric floating memory and its application to in-memory computing

Various core memory devices have been proposed for utilization in future inmemory computing technology featuring high energy efficiency.Flash memory is considered as a viable choice owing to its high integration density,stability,and reliability,which has been verified by commercialized products.However,its high operating voltage and slow operation speed issues caused by the tunneling mechanism make its adoption in in-memory computing applications difficult.In this paper,we introduce a dual-mode memory device named“ferro-floating memory”,fabricated using van der Waals(vdW)materials(h-BN,MoS2,andα-In2Se3).The vdW material,α-In2Se3,acts as a polarization control layer for the ferroelectric memory operation and charge storage layer for the conventional flash memory operation.Compared to the tunnelingbased memory operation,the ferro-floating memory operates 1.9 and 3.3 times faster at 6.7 and 5.8 times lower operating voltages for programming and erasing operations,respectively.The dual-mode operation improves the linearity of conductance change by 5 times and the dynamic range by 48%through achieving conductance variation regions.Furthermore,we assess the effects of the variation in device operating voltage on neural networks and suggest a memory array operating scheme for maximizing the networks'performance through various training/inference simulations.

Field-effect transistor memories based on ferroelectric polymers

Field-effect transistors based on ferroelectrics have attracted intensive interests, because of their non-volatile data retention, rewritability, and non-destructive read-out. In particular, polymeric materials that possess ferroelectric properties are promising for the fabrications of memory devices with high performance, low cost, and large-area manufacturing, by virtue of their good solubility, low-temperature processability, and good chemical stability. In this review, we discuss the material characteristics of ferroelectric polymers, providing an update on the current development of ferroelectric field-effect transistors（Fe-FETs） in non-volatile memory applications.