Article
Chemistry, Multidisciplinary
Heng Xiang, Yu-Chieh Chien, Lingqi Li, Haofei Zheng, Sifan Li, Ngoc Thanh Duong, Yufei Shi, Kah-Wee Ang
Summary: This study demonstrates the capabilities of an integrated ferroelectric HfO2 and 2D MoS2 channel FeFET for achieving high-performance 4-bit per cell memory and low variation and power consumption synapses. The device retains the ability to implement diverse learning rules and accurately recognizes MNIST handwritten digits with over 94% accuracy using online training mode. These results highlight the potential of FeFET-based in-memory computing for future neuromorphic computing applications.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Thomas Mikolajick, Min Hyuk Park, Laura Begon-Lours, Stefan Slesazeck
Summary: Due to the low voltage driven switching and nonvolatility, ferroelectric materials have great potential for low power nonvolatile electronic devices. However, the incompatibility of well-known ferroelectrics with existing semiconductor technology has hindered the competitiveness of these devices. The discovery of ferroelectricity in hafnium oxide has changed this situation. This article summarizes the material science of ferroelectricity in hafnium oxide, discusses the status of nonvolatile ferroelectric memories, explores applications like in-memory computing, and showcases the realization of neuromorphic computing systems using basic building blocks of spiking neural networks.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Keerthana Shajil Nair, Marco Holzer, Catherine Dubourdieu, Veeresh Deshpande
Summary: The wake-up behavior and ON/OFF current ratio of TiN-Al2O3-Hf0.5Zr0.5O2-W ferroelectric tunnel junction (FTJ) devices were investigated for different wake-up voltage waveforms. It was found that the wake-up behavior in these FTJ stacks is highly influenced by the field cycling waveform, with square waveform providing wake-up with the lowest number of cycles and achieving higher remnant polarization and ON/OFF ratio compared to a triangular waveform. The wake-up is dependent on the number of cycles rather than the total time of the applied electric field, and different voltage magnitudes are necessary for positive and negative polarities during field cycling for efficient wake-up. Utilizing an optimized waveform with unequal magnitudes for the two polarities, a reduction in wake-up cycles and a large enhancement of the ON/OFF ratio can be achieved in ferroelectric tunnel junctions.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Review
Computer Science, Information Systems
Zhaohao Zhang, Guoliang Tian, Jiali Huo, Fang Zhang, Qingzhu Zhang, Gaobo Xu, Zhenhua Wu, Yan Cheng, Yan Liu, Huaxiang Yin
Summary: This review presents the potential of hafnium oxide-based ferroelectric field-effect-transistors (FeFET) for post-Moore integrated circuit innovations and discusses recent research progress in hafnium oxide-based ferroelectric films, device integration, and applications.
SCIENCE CHINA-INFORMATION SCIENCES
(2023)
Article
Nanoscience & Nanotechnology
David Lehninger, Martin Ellinger, Tarek Ali, Songrui Li, Konstantin Mertens, Maximilian Lederer, Ricardo Olivio, Thomas Kaempfe, Norbert Hanisch, Kati Biedermann, Matthias Rudolph, Varvara Brackmann, Shawn Sanctis, Michael P. M. Jank, Konrad Seidel
Summary: Thin-film transistors (TFTs) based on amorphous indium-gallium-zinc-oxide (a-IGZO) are popular for use in organic light-emitting diode (AMOLED) displays due to their high electron mobility and large current on-off ratio, but variations in threshold voltage (V-th) could lead to uneven brightness distribution. Integrating a programmable ferroelectric (FE) film can simplify pixel cells and reduce the need for compensation circuits.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Ayse Suenbuel, Tarek Ali, Konstantin Mertens, Ricardo Revello, David Lehninger, Franz Mueller, Maximilian Lederer, Kati Kuehnel, Matthias Rudolph, Sebastian Oehler, Raik Hoffmann, Katrin Zimmermann, Kati Biedermann, Philipp Schramm, Malte Czernohorsky, Konrad Seidel, Thomas Kaempfe, Lukas M. Eng
Summary: This article investigates the characteristics and performance of zirconium-doped hafnium oxide-based ferroelectric tunnel junction (FTJ) devices in terms of ferroelectric (FE) switching and reliability. The switching characteristics of FTJ memory, the effects of polarization switching on write conditions, and the impact of pulse width and amplitude on switching are studied. The results show that the maximum FTJ I-ON/I-OFF ratio and reliable performance can be achieved by tuning the stack structure and FE layer thickness.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Multidisciplinary
Fang-Jui Chu, Yu-Chieh Chen, Li-Chung Shih, Shi-Cheng Mao, Jen-Sue Chen
Summary: In this study, a dual-gate ferroelectric polymer P(VDF-TrFE)-coupled IGZO thin-film transistor is proposed, which exhibits both short- and long-term memory functionalities and can be utilized in the reservoir and readout layers of neuromorphic computers. This technology holds significant potential for next-generation hybrid intelligent applications.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Veeresh Deshpande, Keerthana Shajil Nair, Marco Holzer, Sourish Banerjee, Catherine Dubourdieu
Summary: This study introduces ferroelectric tunnel junction devices based on hafnium dioxide solid solutions, offering potential for ultra-low power ferroelectric device integration with CMOS. By employing low temperature annealing, the devices demonstrate performance on par with those subjected to higher temperature conditions.
SOLID-STATE ELECTRONICS
(2021)
Article
Materials Science, Multidisciplinary
Laura Begon-Lours, Mattia Halter, Youri Popoff, Bert Jan Offrein
Summary: A resistive memory device was fabricated using hafnium-based ferroelectric properties for neuromorphic hardware. The device demonstrated controlled resistive switching through thickness adjustment in the hafnium-based layer and the use of a TiOx interlayer. The redistribution of oxygen vacancies in the ferroelectric layer post-ferroelectric wake-up led to the realization of memristive functionality.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Nanoscience & Nanotechnology
Zhouchangwan Yu, Balreen Saini, Yunzhi Liu, Fei Huang, Apurva Mehta, John D. Baniecki, H. -S. Philip Wong, Wilman Tsai, Paul C. McIntyre
Summary: This study systematically investigates the effects of deposition and annealing processes on Hafnia-based ferroelectric thin films. Crystallites consistent with the polar orthorhombic phase were observed in films deposited at elevated ALD temperature, and high-polarization ferroelectric switching was achieved after low-temperature rapid annealing.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Ryun-Han Koo, Wonjun Shin, Seungwhan Kim, Jiseong Im, Sung-Ho Park, Jong Hyun Ko, Dongseok Kwon, Jae-Joon Kim, Daewoong Kwon, Jong-Ho Lee
Summary: This study analyzes the origin and impact of non-ideal characteristics in hardware neuromorphic systems, focusing on the variations in synaptic weights caused by ferroelectric tunnel junctions. The analysis identifies dynamic variation as the main bottleneck for achieving high-performance systems. To overcome this limitation, an adaptive read-biasing scheme is proposed, which significantly reduces power consumption and improves scalability by exploiting different noise sensitivities in each layer.
Article
Physics, Applied
Min-Kyu Kim, Ik-Jyae Kim, Jang-Sik Lee
Summary: A ferroelectric thin-film transistor (FeTFT) utilizing zirconium-doped hafnia and indium zinc tin oxide has been proposed for neuromorphic computing applications, showing reliable conductance modulation characteristics suitable for both deep neural networks and spiking neural networks. The FeTFT demonstrated high recognition accuracy for hand-written images and ability to emulate spike-time-dependent plasticity, indicating its promise as a candidate for neuromorphic computing hardware.
APPLIED PHYSICS LETTERS
(2021)
Review
Chemistry, Multidisciplinary
Dong Hyun Lee, Younghwan Lee, Yong Hyeon Cho, Hyojun Choi, Se Hyun Kim, Min Hyuk Park
Summary: Ferroelectric materials are regarded as ideal for emerging memory devices due to their unique remanent polarization. However, the slow progress of ferroelectric memories is attributed to issues like the lack of CMOS-compatible and scalable materials. In recent years, the discovery of ferroelectricity in CMOS-compatible materials like (Hf,Zr)O-2 and (Al,Sc)N has sparked increasing interest. With advancements in material fabrication, a metastable polar phase and switchable polarization can be induced in these materials. However, challenges still exist for their use in emerging memory devices, which are comprehensively reviewed in this article.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Mirine Leem, Deokjoon Eom, Heesoo Lee, Kwangwuk Park, Kwangsik Jeong, Hyoungsub Kim
Summary: In this study, HZO films were grown directly on single-crystalline MoS2 flakes using ALD with H2O or O3 oxidants. The O3-based ALD process oxidizes the MoS2 surface at the atomic layer level and facilitates the conformal deposition of an HZO film without surface treatment of MoS2. Annealing the O3-based HZO film significantly improves the ferroelectric properties, but also leads to diffusion of S, Hf, Zr, and O towards the Mo layer, reducing the weak HZO bonds.
APPLIED SURFACE SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Shelby S. Fields, Truong Cai, Samantha T. Jaszewski, Alejandro Salanova, Takanori Mimura, Helge H. Heinrich, Michael David Henry, Kyle P. Kelley, Brian W. Sheldon, Jon F. Ihlefeld
Summary: The presence of the top electrode during thermal processing is shown to increase ferroelectric phase fraction and polarization response through larger tensile biaxial stress. Film chemistry, microstructure, and crystallization temperature are not affected. The top electrode inhibits out-of-plane expansion in HZO during crystallization, preventing equilibrium monoclinic phase formation and stabilizing the orthorhombic phase.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Yu-Hung Liao, Daewoong Kwon, Suraj Cheema, Nirmaan Shanker, Ava J. Tan, Ming-Yen Kao, Li-Chen Wang, Chenming Hu, Sayeef Salahuddin
Summary: Measurements on ultrathin body negative-capacitance (NC) field-effect transistors exhibit subthreshold behaviors that deviate from classical MOSFET, with subthreshold swing (SS) decreasing at low drain bias as gate bias increases. Utilizing a Landau-Khalatnikov ferroelectric (FE) model calibrated with measured Capacitance-Voltage and TCAD simulations, the anomalous behaviors can be quantitatively explained, showing field-induced permittivity enhancement and substantial scaling improvement predicted at the end of the roadmap.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Yu-Hung Liao, Khandker Akif Aabrar, Wriddhi Chakraborty, Wenshen Li, Suman Datta, Sayeef Salahuddin
Summary: In this study, state-of-the-art fully-depleted silicon-on-insulator transistors with different gate lengths were tested. A quasi-ballistic virtual source model showed good agreement with the observed data for both NFET and PFET. The injection velocity increased with decreasing channel length, potentially due to quantum confinement and strain effects. Further research may make it possible to approach the non-degenerate thermal velocity.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Chien-Ting Tung, Sayeef Salahuddin, Chenming Hu
Summary: This paper develops a compact model of antiferroelectric capacitors, which can describe the behavior of antiferroelectric materials in circuit simulation. By considering the antiferroelectric material as a collection of multiple crystal groups and modeling the switching rate with a statistical distribution of local field, this model is capable of reproducing experimental data and demonstrating the dependency of antiferroelectric capacitor switching.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Chien-Ting Tung, Girish Pahwa, Sayeef Salahuddin, Chenming Hu
Summary: The article introduces a compact model of metal-ferroelectric-insulator-semiconductor tunnel junction suitable for commercial SPICE IC simulation. It is capable of capturing polarization switching, calculating the potential profile of the MFIS stack, and analyzing tunneling current.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Nanoscience & Nanotechnology
Suraj S. Cheema, Nirmaan Shanker, Cheng-Hsiang Hsu, Adhiraj Datar, Jongho Bae, Daewoong Kwon, Sayeef Salahuddin
Summary: The study integrated FTJs with Zr-doped HfO2 ferroelectric barriers, grown by atomic layer deposition on silicon, to demonstrate the potential for large polarization-driven electroresistance and tunneling current. This combination overcomes the major drawbacks of prototypical FTJs, providing a Si-compatible ultrathin ferroelectric barrier with large electroresistance and read current for high-speed operation.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Michael Hoffmann, Ava Jiang Tan, Nirmaan Shanker, Yu-Hung Liao, Li-Chen Wang, Jong-Ho Bae, Chenming Hu, Sayeef Salahuddin
Summary: In this study, n-type FeFETs with SiNx interfacial layer and high write endurance show immediate read-after-write behavior, overcoming one of the major challenges faced by FeFET technologies today.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Chien-Ting Tung, Girish Pahwa, Sayeef Salahuddin, Chenming Hu
Summary: This study presents a compact model of nanoscale ferroelectric capacitors, investigating the polarization switching process with phase-field simulations. Different switching mechanisms of grains under high and low applied voltages are identified and incorporated into the model, along with a voltage-dependent dielectric model to represent the nonlinear capacitance. The compact model is verified by fitting with phase-field modeling results, showing excellent agreement.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Chien-Ting Tung, Girish Pahwa, Sayeef Salahuddin, Chenming Hu
Summary: In this letter, a compact model of ferroelectric field-effect-transistor (FEFET) is presented, which combines the characteristics of ferroelectric and MOSFET and accurately simulates the observed switching and current variations in experiments, as well as the storage window behavior caused by charge trapping.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Girish Pahwa, Sayeef Salahuddin, Chenming Hu
Summary: This article provides physical insights into the operation of FinFET-based FEFETs using a phase-field framework built on time-dependent Landau-Ginzburg thermodynamic theory. Experimental analysis of FEFinFETs reveals that power consumption can be reduced and memory window can be increased by controlling parameters such as source-drain fringing field and spacer permittivity.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Michael Hoffmann, Ava Jiang Tan, Nirmaan Shanker, Yu-Hung Liao, Li-Chen Wang, Jong-Ho Bae, Chenming Hu, Sayeef Salahuddin
Summary: This study reveals that FeFETs with a thin HfO2 based ferroelectric and SiNx interfacial layer are immune to pulsed write disturbs but not to continuous write disturbs. This finding provides a new perspective on the characteristics of FeFETs.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Jung-Han Hsia, Yu-Hung Liao, Neelesh Ramachandran, Sayeef Salahuddin
Summary: Through TCAD simulations, we found that large negative gate biases during memory programming of an n-type silicon-on-insulator ferroelectric field-effect transistor can lead to excess hole concentrations, causing a boost in polarization and retention time. These excess holes also have dynamic effects on the electrostatics and FE polarizations, influencing the readout operation and memory window.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Editorial Material
Engineering, Electrical & Electronic
Sayeef Salahuddin
Summary: It is a pleasure to welcome Dr. Ahmad Ehteshamul Islam to the Editorial Board of IEEE Electron Device Letters. Dr. Islam specializes in compound semiconductor devices, as well as solid-state power and high-voltage devices.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Sayeef Salahuddin
Summary: We are pleased to welcome Prof. Masaharu Kobayashi to the Editorial Board of IEEE Electron Device Letters. Prof. Kobayashi's expertise lies in memory devices and technology, thin-film transistors, and silicon and column IV semiconductor devices.
IEEE ELECTRON DEVICE LETTERS
(2023)
Review
Physics, Multidisciplinary
Javier Junquera, Yousra Nahas, Sergei Prokhorenko, Laurent Bellaiche, Jorge iniguez, Darrell G. Schlom, Long-Qing Chen, Sayeef Salahuddin, David A. Muller, Lane W. Martin, R. Ramesh
Summary: The past decade has witnessed significant progress in understanding emergent topological polar textures in oxide nanostructures, including vortices, skyrmions, merons, hopfions, dipolar waves, and labyrinthine domains. The discovery of low-dimensional ferroelectric oxide nanostructures has altered the perceived energy cost associated with the formation of these structures, allowing for manipulation of order parameters. This review provides a historical context, scientific description, and discussion of the potential applications and future challenges in this field.
REVIEWS OF MODERN PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Chien-Ting Tung, Avirup Dasgupta, Harshit Agarwal, Sayeef Salahuddin, Chenming Hu
Summary: In this study, a new compact model of a perpendicular spin-transfer-torque magnetic tunnel junction (MTJ) is proposed. The model accurately represents the time-dependent magnet moment and resistance, and is validated through comparison with experimental data and an LLG-based STT-MTJ model. The model demonstrates geometry dependence and temperature dependence, and a continuous switching probability model is developed to track the probabilities of states under arbitrary waveforms.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
