Article
Computer Science, Information Systems
Akira Goda
Summary: The introduction of 3D NAND technology has significantly increased the density, with up to 176 layers and a density exceeding 10 Gb/mm(2). TLC is currently the mainstream, while QLC is on the rise.
Article
Nanoscience & Nanotechnology
Chen Sun, Chao Li, Subhranu Samanta, Kaizhen Han, Zijie Zheng, Jishen Zhang, Qiwen Kong, Haiwen Xu, Zuopu Zhou, Yue Chen, Cheng Zhuo, Kai Ni, Xunzhao Yin, Xiao Gong
Summary: 3D NAND has been scaled beyond conventional 2D NAND by introducing an a-IGZO channel, which overcomes the low mobility, instability caused by grain boundaries, and device-to-device variations in electrical characteristics. Ultrascled FG transistors with a 60 nm channel length achieved the highest ON current among reported a-IGZO-based flash devices, making them suitable for high-density, low-power, and high-performance 3D NAND applications. Additionally, a nonvolatile and area-efficient TCAM using only two parallel-connected a-IGZO FG transistors addressed the scalability issue and achieved significant energy reduction compared to other TCAM technologies.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Munhyeon Kim, Sihyun Kim, Kitae Lee, Jong-Ho Lee, Byung-Gook Park, Daewoong Kwon
Summary: A novel floating fin-structured nanosheet (FNS) is proposed to improve the work function (WF) variation by the fluctuation of the space between channels (T-sp) in vertically stacked nanosheet devices. Through computer aided design (TCAD) simulations, it is found that FNS is more robust against T-sp fluctuation than laterally long nanosheet (LNS) and has significantly improved slow corner margin without sacrificing device performances, which is advantageous for near-threshold-voltage (NTV) designs.
IEEE ELECTRON DEVICE LETTERS
(2021)
Proceedings Paper
Computer Science, Hardware & Architecture
S. Rachidi, A. Arreghini, D. Verreck, G. L. Donadio, K. Banerjee, K. Katcko, Y. Oniki, G. Van den Bosch, M. Rosmeulen
Summary: This study demonstrates the first 25 nm pitch 3D-NAND gate-all-around macaroni device with a gate length of 10 nm. The key fabrication processes and appropriate biasing scheme are discussed to achieve optimal transistor characteristics and memory operation. The research provides a foundation for future ultra-high bit density 3D-NAND memories.
2022 14TH IEEE INTERNATIONAL MEMORY WORKSHOP (IMW 2022)
(2022)
Article
Chemistry, Multidisciplinary
Mohammad Karbalaei, Daryoosh Dideban, Zeinab Ramezani, Iraj Sadegh Amiri
Summary: The study introduces an auxiliary gate to recover subthreshold characteristics and short channel endurance of GAA-FETs through scaling. It enhances the splitting of electron energy sub-bands, reducing electron concentration in the channel and decreasing leakage current and subthreshold slope. The proposed AuxG-GAAFET shows improved I-ON/I-OFF current ratio, lower threshold voltage roll-off, better subthreshold slope, and better DIBL factor caused by scaling.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Engineering, Electrical & Electronic
Anshul Gupta, Charu Gupta, Anabela Veloso, Bertrand Parvais, Abhisek Dixit
Summary: The experimental investigation on the influence of hot-carrier degradation (HCD) on lateral trap distribution within gate-all-around nanowire (NW) nFETs reveals that different degrading mechanisms alter the trap distribution with changes in nanowire width. The study also explores the relative contribution of degradation caused by single and multi carriers degradation process, showing significant effects on the HC damage profile along the device channel.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Ming-Yen Kao, Sayeef Salahuddin, Chenming Hu
Summary: In this study, a TCAD simulation of the negative capacitance gate-all-around (NCGAA) field-effect transistor was conducted using the 3-D Ginzburg-Landau-Khalatnikov Model. The performance of the NC-GAA transistor was optimized to meet the requirements of different nodes, showing significant improvements in off current and on current performance. These benefits were demonstrated across various ferroelectric parameter sets, indicating the potential for NC-GAA to achieve high performance in advanced technology nodes beyond the 1.5 nm baseline.
SOLID-STATE ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Anil Kumar Gundu, Volkan Kursun
Summary: This article presents a comprehensive computational study on gate-all-around (GAA) devices with 3-D stacked silicon nanosheets and provides technology development guidelines for low-power applications. The 3-D stacked nanosheet devices show advantages in reducing power consumption, increasing voltage gain, and decreasing energy consumption compared to the SOI FinFET technology.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Jung-Woo Lee, Joon-Kyu Han, Myung-Su Kim, Ji-Man Yu, Jin-Woo Jung, Seong-Yun Yun, Yang-Kyu Choi
Summary: The endurance to cyclic program/erase (P/E) of a gate-all-around (GAA)-based junctionless (JL) silicon flash memory was improved by the Joule heat generated from the inherent nanowire current. The increased temperature resulting from the Joule heat was utilized to cure the damage caused by repetitive P/E operations.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Yohan Kim, SoYoung Kim
Summary: This article presents an accurate compact modeling methodology to optimize the gate-induced drain leakage (GIDL)-assisted erase operation for 3-D vertically integrated NAND (V-NAND) flash memory. Artificial neural network (ANN) and physics-based RC network models are used to describe various GIDL characteristics. The SPICE-compatible compact model enables highly accurate simulations for GIDL-assisted erase operations.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Geon-Beom Lee, Jeong-Yeon Kim, Yang-Kyu Choi
Summary: A charge pumping (CP) technique using gate-induced drain leakage (GIDL) current is proposed for extracting interface trap density (${N}_{\text {it}}$) in GAA MOSFETs. This GIDL CP allows analysis of even advanced MOSFETs with a floating body, small size, and thin gate dielectric which are difficult to analyze with conventional CP techniques. LabVIEW control is used to automate synchronized voltage pulses, effectively recombining the generated holes with the traps for ${N}_{\text {it}}$ extraction. Furthermore, the proposed CP is confirmed to be a reliable analysis tool for extracting ${N}_{\text {it}}$ while minimizing device stress during measurement.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Jung-Woo Lee, Joon-Kyu Han, Ji-Man Yu, Geon-Beom Lee, Il-Woong Tcho, Yang-Kyu Choi
Summary: This study reveals that the endurance to cyclic program/erase (P/E) in a gate-all-around (GAA)-based SONOS flash memory device can be improved by Joule heat generated by the gate-induced drain leakage (GIDL) current (I-GIDL). Through COMSOL simulation and experimental analysis, it is found that the induced temperature (T) by I-GIDL is higher in the GAA device with ONO gate dielectrics compared to the one with a thermal gate oxide, enabling effective damage curing and enhancing device performance.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Ning Zhang, Wanpeng Zhao, Xinyu Zhang, Yang Liu, Shurong Dong, Jikui Luo, Zhi Ye
Summary: The study presents a transparent floating gate memory based on zinc oxide thin film transistors, which utilizes alumina tunneling and zinc oxide charge-trap layers deposited through one-step atomic layer deposition. The mechanism of free electron trapping in this memory device is proposed after investigating gate voltage scanning and thickness of the trapping layer. Furthermore, the relationship between the geometrical size of the charge-trapping layer and the memory window is explored.
IEEE JOURNAL OF THE ELECTRON DEVICES SOCIETY
(2022)
Article
Engineering, Electrical & Electronic
Yanna Luo, Qingzhu Zhang, Lei Cao, Weizhuo Gan, Haoqing Xu, Yu Cao, Jie Gu, Renren Xu, Gangping Yan, Jiali Huo, Zhenhua Wu, Huaxiang Yin
Summary: This article introduces a novel hybrid channel CFET (HC-CFET) device, which aims to achieve higher performance through vertical structure and optimized channel surface orientation. At the device level, HC-CFET achieves over 20% current gain and exhibits higher frequency gain and comparable energy consumption in a ring oscillator.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
D. Verreck, A. Arreghini, F. Schanovsky, G. Rzepa, Z. Stanojevic, F. Mitterbauer, C. Kernstock, O. Baumgartner, M. Karner, G. Van den Bosch, M. Rosmeulen
Summary: A physical modeling approach is presented to explain the non-ideal ISPP slope in charge trap layer (CTL) flash memory and its impact on 3-D NAND vertical pitch scaling. An expression for the V-T change rate is derived to reproduce experimental vertical NAND ISPP slopes, and a 2.5-D TCAD model is implemented to show significant program voltage increase in realistic 3-D NAND flash devices with scaling vertical pitch. Mitigation measures such as high-k CTL and airgaps are evaluated for scaled pitch.
2021 IEEE INTERNATIONAL ELECTRON DEVICES MEETING (IEDM)
(2021)