Article
Engineering, Electrical & Electronic
Wen-Chung Chen, Yung-Fang Tan, Shih-Kai Lin, Yong-Ci Zhang, Kai-Chun Chang, Yun-Hsuan Lin, Chien-Hung Yeh, Chung-Wei Wu, Yu-Hsuan Yeh, Kao-Yuan Wang, Hui-Chun Huang, Tsung-Ming Tsai, Jen-Wei Huang, Ting-Chang Chang
Summary: Electrical measurements and transmission electron microscope imaging were used to investigate the impact of grain size on the performance and reliability of HfZrOx ferroelectric material. A model was proposed to explain the phenomenon and provide a method to achieve better ferroelectric memory.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Puyang Cai, Hao Li, Zhiwei Liu, Tianxiang Zhu, Min Zeng, Zhigang Ji, Yanqing Wu, Andrea Padovani, Luca Larcher, Milan Pesic, Runsheng Wang, Ru Huang
Summary: Through characterization and simulation, it is found that defects are localized during the bipolar stress cycling and play a significant role in the shift of E-c. The mismatch of work function and defect distribution affect the symmetry of E-c and the breakdown property. The shift of E-c is mainly attributed to the redistribution of defects from the ferroelectric phase to the non-ferroelectric phase and grain boundaries.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Ting-Chieh Lai, Tien-Hong Kao, Yung-Hsien Wu
Summary: HfZrOx-based p- and n-FeFETs with high-k AlON interfacial layer were used to evaluate the effects of gamma-rays radiation on memory performance and reliability. The results showed that the memory window and retention were hardly changed even with a radiation dose of 1 Mrad, thanks to the improved interfacial quality. In addition, p-FeFETs demonstrated higher endurance against radiation and improved read latency compared to n-FeFETs.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Tien-Hong Kao, Yu-Cheng Kao, Pin-Jiun Wu, Yung-Hsien Wu
Summary: Research on Si-based n- and p-FeFETs with 5-nm ferroelectric HfZrOx and high-k AlON interfacial layer showed that optimizing materials and interface quality can significantly reduce memory window asymmetry, improve cycling endurance, and achieve retention performance comparable to n-FeFETs.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Chemistry, Physical
Kyung Kyu Min, Junsu Yu, Yeonwoo Kim, Chae Soo Kim, Taejin Jang, Sungmin Hwang, Hyungjin Kim, Jong-Ho Lee, Daewoong Kwon, Byung-Gook Park
Summary: This study demonstrated the ferroelectricity of pure HfOx without additional ion doping and confirmed its feasibility in memory devices. By controlling oxygen vacancies and the thermal quenching process, variation-resistant and thermally stable ferroelectric pure HfOx with remarkable polarization can be achieved. The modulation of tunneling resistance in MFIS ferroelectric tunnel junction devices showed adjustable tunneling current over a 2-order current range, indicating the potential for multilevel memory operations.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Halid Mulaosmanovic, Dominik Kleimaier, Stefan Duenkel, Sven Beyer, Thomas Mikolajick, Stefan Slesazeck
Summary: A novel asymmetric double-gate FeFET structure has been proposed, with a read operation at the non-ferroelectric gate, resulting in an amplified MW exceeding 12 V and enabling the implementation of multi-level cell storage featuring 4 bits per cell. The fully disturb-free read operation is achieved by exploiting the separated write and read paths in the structure.
Article
Chemistry, Multidisciplinary
Mohit Kumar, Seung-Ik Han, Yeonghwan Ahn, Yerin Jeon, Jiyeong Park, Hyungtak Seo
Summary: Nontrivial topological polar textures in ferroelectric materials have the potential to revolutionize memory storage and processing units. However, integrating these polar textures into silicon using a large area fabrication technique at room temperature has not been demonstrated yet. In this study, the electric field switchable polar nanotexture is observed at room temperature in HfO2-ZrO2 nanolaminates grown directly onto silicon. A ferroelectric tunnel junction is also designed, showing ultrafast nonvolatile multilevel current switching, long-term durability, and giant tunnel electroresistance. The results indicate a potential approach to high-performance multilevel in-memory processing technology.
Article
Physics, Applied
Jihoon Jeon, Song-Hyeon Kuk, Ah-Jin Cho, Seung-Hyub Baek, Sang-Hyeon Kim, Seong Keun Kim
Summary: We have fabricated n-type ferroelectric field-effect transistors (FeFETs) using atomic-layer-deposited HfZrOx (HZO) films with a large memory window (MW) immediately after the write operation. Charge trapping at the HZO/Si interface in FeFETs is identified as the main cause of memory window reduction. By controlling the properties of the interfacial layer through varying the O-3 injection time during atomic layer deposition, the FeFETs based on HZO (long O-3 of 7 s) exhibit a larger MW (2.1 V) compared to the FeFETs based on HZO (short O-3 of 0.3 s) (0.9 V). Pulsed I-V measurements confirm that the FeFETs based on HZO (long O-3 of 7 s) show a large MW of 1.0 V with an extremely short delay time of 100 ns between pulses. The improvement in the performance of HZO-based FeFETs suggests a reduction in trap density in the interfacial layer by using a long O-3 injection time.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Weijun Wang, You Meng, Yuxuan Zhang, Zhuomin Zhang, Wei Wang, Zhengxun Lai, Pengshan Xie, Dengji Li, Dong Chen, Quan Quan, Di Yin, Chuntai Liu, Zhengbao Yang, SenPo Yip, Johnny C. Ho
Summary: Atomically 2D layered ferroelectric semiconductor bismuth oxychalcogenides (Bi2O2Se) with a thickness of 7.3 nm and a piezoelectric coefficient (d(33)) of 4.4 +/- 0.1 pm V-1 is investigated. The random orientations and electrically dependent polarization of the dipoles are uncovered, and the interplay between ferroelectricity and semiconducting characteristics in Bi2O2Se is explored on device-level operation, showing hysteresis behavior and memory window formation. Leveraging the ferroelectric polarization, the fabricated device exhibits smart photoresponse tunability and excellent electronic characteristics.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Zhuo Li, Jixuan Wu, Xiaoran Mei, Xingyu Huang, Takuya Saraya, Toshiro Hiramoto, Takanori Takahashi, Mutsunori Uenuma, Yukiharu Uraoka, Masaharu Kobayashi
Summary: A vertical channel FeFET with HfO2-based ferroelectric and ALD InOx channel has been developed for high-density memory applications. Reliable memory operation with a memory window greater than 1V has been confirmed. The polar-axis transition of the ferroelectric material has been verified, and a vertical channel anti-ferroelectric FET has also been demonstrated as a solution for the erase problem in oxide semiconductor channel FeFETs.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Xiwen Liu, John Ting, Yunfei He, Merrilyn Mercy Adzo Fiagbenu, Jeffrey Zheng, Dixiong Wang, Jonathan Frost, Pariasadat Musavigharavi, Giovanni Esteves, Kim Kisslinger, Surendra B. Anantharaman, Eric A. Stach, Roy H. Olsson III, Deep Jariwala
Summary: The deluge of sensors and data generating devices has driven a paradigm shift in modern computing, resulting in a data-centric processing approach. In this study, we present a transistor-free CIM architecture that allows storage, search, and neural network operations on sub-50 nm thick Aluminum Scandium Nitride ferroelectric diodes (FeDs). By leveraging the programmability, nonvolatility, and nonlinearity of FeDs, we demonstrate efficient search operations and neural network operations, highlighting FeDs as promising candidates for multifunctional CIM platforms.
Article
Multidisciplinary Sciences
Seongae Park, Benjamin Spetzler, Tzvetan Ivanov, Martin Ziegler
Summary: Redox-based memristive devices have great potential for application in neuromorphic computing systems. In this study, we demonstrate that by tailoring the stoichiometry of HfOx and the operating conditions, memristive devices with a functional trilayer of HfOx/Al2O3/TiO2 can achieve resistive switching from area type to filament type in the same device. The stability of the area-type switching mechanism is attributed to the Al2O3 layer, which controls the formation of oxygen vacancies at the Al2O3/HfOx interface. These stabilized area-type devices exhibit multi-level analog switching, linear resistance change, and long retention times, making them potentially interesting for future integration into memristive circuits for neuromorphic applications.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
Junghyeon Hwang, Sehee Lim, Giuk Kim, Seong-Ook Jung, Sanghun Jeon
Summary: This study demonstrates a non-volatile majority function logic unit formed by using a hafnia ferroelectric capacitor for computing in memory and nonvolatile logic-in-memory, showing low voltage, high speed, and improved endurance characteristics. Additionally, a circuit-level analysis of an NV 1bit full adder reveals significant performance improvements.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yi-Fan Chen, Chia-Wei Hu, Yu-Cheng Kao, Chun-Yi Kuo, Pin-Jiun Wu, Yung-Hsien Wu
Summary: Ferroelectric HfZrOx integrated with ZrO2 interlayer and bottom layer is explored as a new stack for capacitors. The capacitors exhibit high remnant polarization and wake-up free behavior up to 10^8 long-pulse cycles. The high o-phase ratio and the role of ZrO2 layers are identified as the key factors for the wake-up free behavior and small device-to-device variation, making the stack suitable for high-performance embedded memory applications.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Kaifei Kang, Wenjin Zhao, Yihang Zeng, Kenji Watanabe, Takashi Taniguchi, Jie Shan, Kin Fai Mak
Summary: We have achieved the pulsed control of the superlattice effect in two-dimensional materials through the ferroelectric effect, switching between the correlated and superlattice insulating states, and observing the nonlinear anomalous Hall effect. This study demonstrates the potential for creating new functional superlattice materials by incorporating intrinsic symmetry-breaking orders.
NATURE NANOTECHNOLOGY
(2023)
Article
Physics, Applied
Hao-Kai Peng, Chi-Yu Chan, Kuen-Yi Chen, Yung-Hsien Wu
Summary: By utilizing AlON as the interfacial layer for HfZrOx-based FeFET memory devices, significant improvements in memory window, stability, and process simplification can be achieved, unravelling the potential for high reliability in FeFET memory devices.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Siao-Cheng Yan, Guan-Min Lan, Chong-Jhe Sun, Ya-Han Chen, Chen-Han Wu, Hao-Kai Peng, Yu-Hsien Lin, Yung-Hsien Wu, Yung-Chun Wu
Summary: In this study, HfZrO2 ferroelectric fin field-effect transistors were fabricated and demonstrated excellent performance in terms of memory window, retention time, compatibility with current FinFET process, and reliability. These Fe-FinFETs are considered promising candidates for high-density ferroelectric field-effect transistor memory applications.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Tien-Hong Kao, Yu-Cheng Kao, Pin-Jiun Wu, Yung-Hsien Wu
Summary: Research on Si-based n- and p-FeFETs with 5-nm ferroelectric HfZrOx and high-k AlON interfacial layer showed that optimizing materials and interface quality can significantly reduce memory window asymmetry, improve cycling endurance, and achieve retention performance comparable to n-FeFETs.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Yi-Fan Chen, Lee-Wen Hsu, Chia-Wei Hu, Guan-Ting Lai, Yung-Hsien Wu
Summary: The introduction of TiAl into the electrode structure lowers the effective work function, leading to improved characteristics of FTJ devices such as higher tunnel electroresistance ratio and faster switching speed. The TiAl-based electrode also shows long-term plasticity and robust endurance, making it a compelling choice for high-performance FTJ devices.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Ting-Chieh Lai, Tien-Hong Kao, Yung-Hsien Wu
Summary: HfZrOx-based p- and n-FeFETs with high-k AlON interfacial layer were used to evaluate the effects of gamma-rays radiation on memory performance and reliability. The results showed that the memory window and retention were hardly changed even with a radiation dose of 1 Mrad, thanks to the improved interfacial quality. In addition, p-FeFETs demonstrated higher endurance against radiation and improved read latency compared to n-FeFETs.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Cheng-Yuan Chiu, Yu-Cheng Kao, Pin-Jiun Wu, Yung-Hsien Wu
Summary: This study proposes a new method of crystallization, post deposition annealing (PDA), to form the ferroelectric phase of HfZrOx on an epitaxial Ge film with higher reliability. The PDA process effectively controls the amount of oxygen vacancies, resulting in higher switching speed and reliability of the devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Chia-Ming Liu, Yu-Cheng Kao, Pin-Jiun Wu, Yung-Hsien Wu
Summary: By reducing the oxygen vacancy (Vo) in the HZO film through a high-quality SiNx interfacial layer, the FeFET memory achieves improved reliability and performance for MLC operation. It also successfully demonstrates stable threshold voltage (V-TH) for each state in TLC operation and desirable retention for QLC operation.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Ting-Chieh Lai, Yu-Cheng Kao, Chia-Ming Liu, Pin-Jiun Wu, Yung-Hsien Wu
Summary: This study proposes an AlON/HfZrOx (HZO)/HfO2 stack with postdeposition annealing (PDA) process at 400 degrees C to implement BEOL compatible ferroelectric (FE) capacitors. The interface engineering and PDA process enhance the performance of the capacitors, allowing for higher bit storage and better stability. The FE capacitors demonstrate wake-up free behavior and the ability to operate with 3 bits per cell and 8 stable states, outperforming other FE capacitors and showing potential for high-density embedded FeRAM.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Hao-Kai Peng, Jian-Zhi Chen, Yung-Hsien Wu
Summary: Microwave annealing with subsequent rapid thermal annealing is proposed to improve the performance of HfZrOx-based germanium p-channel ferroelectric FET memory. The proposed annealing scheme achieves the required polarization and a memory window of 2.5 V, with good read latency and robust endurance.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Siao-Cheng Yan, Chen-Han Wu, Chong-Jhe Sun, Xin-Chan Zhong, Chih-Siang Chang, Hao-Kai Peng, Yung-Hsien Wu, Yung-Chun Wu
Summary: In this study, scaled ferroelectric fin field-effect transistors (Fe-FinFETs) based on HfZrO2 were fabricated and characterized for multi-level cell (MLC) operations. The Fe-FinFET exhibited a large memory window of 2.8 V, a high switching speed of 100 ns, and clearly separated intermediate states, making it suitable for MLC operations. It also demonstrated robust endurance and data retention, indicating its potential for high-density nonvolatile memory applications.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Guan-Ting Lai, Hao-Kai Peng, Yi-Fan Chen, Shih-Chieh Teng, Chuan-Pu Chou, Yu-Cheng Kao, Pin-Jiun Wu, Yung-Hsien Wu
Summary: Ultra-violet laser thermal annealing (LTA) process shows significant advantages in forming contact TiSix for sub-10 nm FinFETs, including reduced total series resistance, enhanced transconductance, improved contact resistivity, without concerns of hot carrier stress.
IEEE TRANSACTIONS ON NANOTECHNOLOGY
(2021)
