Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access Speed

A novel Asymmetrical FET (AsyFET) is proposed to enhance the retention of gain cell memory and is experimentally demonstrated based on standard 300mm logic foundry platform. In AsyFET, the asymmetrical S/D doping and S/D gate spacer are designed to suppress leakage current. The modulated Schottky di...

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Main Authors: Kaifeng Wang, Pengfei Hao, Fangxing Zhang, Lining Zhang, Qianqian Huang, Ru Huang
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Journal of the Electron Devices Society
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Online Access:https://ieeexplore.ieee.org/document/10879406/
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author Kaifeng Wang
Pengfei Hao
Fangxing Zhang
Lining Zhang
Qianqian Huang
Ru Huang
author_facet Kaifeng Wang
Pengfei Hao
Fangxing Zhang
Lining Zhang
Qianqian Huang
Ru Huang
author_sort Kaifeng Wang
collection DOAJ
description A novel Asymmetrical FET (AsyFET) is proposed to enhance the retention of gain cell memory and is experimentally demonstrated based on standard 300mm logic foundry platform. In AsyFET, the asymmetrical S/D doping and S/D gate spacer are designed to suppress leakage current. The modulated Schottky direct tunneling current and band-to-band tunneling current are designed to write &#x201C;1&#x201D; and &#x201C;0&#x201D; respectively without write disturb. The AsyFET-based 2T0C DRAM with significantly enhanced retention and fast access speed is also proposed and experimentally demonstrated on the same wafer. Without area penalty or new materials, the fabricated Si AsyFET can obtain ultralow off-state current of <inline-formula> <tex-math notation="LaTeX">$\sim 10{^{-}17 }$ </tex-math></inline-formula>A/<inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m, leading to the long retention above second-level in 55nm technology node across the 300mm wafer. The on-state currents of AsyFET at forward and reverse bias are <inline-formula> <tex-math notation="LaTeX">$\sim 10{^{-}6 }$ </tex-math></inline-formula>A/<inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m, enabling write speed of below 5ns with negligible temperature dependence. The experimental results show the great potential of proposed AsyFET 2T0C DRAM design for low-power, high-density, and high-speed on-chip memory.
format Article
id doaj-art-3dea44850e124d029637c20760a4331f
institution Kabale University
issn 2168-6734
language English
publishDate 2025-01-01
publisher IEEE
record_format Article
series IEEE Journal of the Electron Devices Society
spelling doaj-art-3dea44850e124d029637c20760a4331f2025-08-20T03:40:26ZengIEEEIEEE Journal of the Electron Devices Society2168-67342025-01-011323724410.1109/JEDS.2025.354058110879406Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access SpeedKaifeng Wang0https://orcid.org/0009-0007-3331-7716Pengfei Hao1Fangxing Zhang2Lining Zhang3https://orcid.org/0000-0003-1472-7852Qianqian Huang4https://orcid.org/0000-0002-3714-8581Ru Huang5School of Integrated Circuits, Peking University, Beijing, ChinaSchool of Integrated Circuits, Peking University, Beijing, ChinaSchool of Electronic and Computer Engineering, Peking University, Shenzhen, ChinaSchool of Electronic and Computer Engineering, Peking University, Shenzhen, ChinaSchool of Integrated Circuits, Peking University, Beijing, ChinaSchool of Integrated Circuits, Peking University, Beijing, ChinaA novel Asymmetrical FET (AsyFET) is proposed to enhance the retention of gain cell memory and is experimentally demonstrated based on standard 300mm logic foundry platform. In AsyFET, the asymmetrical S/D doping and S/D gate spacer are designed to suppress leakage current. The modulated Schottky direct tunneling current and band-to-band tunneling current are designed to write &#x201C;1&#x201D; and &#x201C;0&#x201D; respectively without write disturb. The AsyFET-based 2T0C DRAM with significantly enhanced retention and fast access speed is also proposed and experimentally demonstrated on the same wafer. Without area penalty or new materials, the fabricated Si AsyFET can obtain ultralow off-state current of <inline-formula> <tex-math notation="LaTeX">$\sim 10{^{-}17 }$ </tex-math></inline-formula>A/<inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m, leading to the long retention above second-level in 55nm technology node across the 300mm wafer. The on-state currents of AsyFET at forward and reverse bias are <inline-formula> <tex-math notation="LaTeX">$\sim 10{^{-}6 }$ </tex-math></inline-formula>A/<inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m, enabling write speed of below 5ns with negligible temperature dependence. The experimental results show the great potential of proposed AsyFET 2T0C DRAM design for low-power, high-density, and high-speed on-chip memory.https://ieeexplore.ieee.org/document/10879406/AsyFETeDRAMgain cell2T0CTFET
spellingShingle Kaifeng Wang
Pengfei Hao
Fangxing Zhang
Lining Zhang
Qianqian Huang
Ru Huang
Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access Speed
IEEE Journal of the Electron Devices Society
AsyFET
eDRAM
gain cell
2T0C
TFET
title Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access Speed
title_full Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access Speed
title_fullStr Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access Speed
title_full_unstemmed Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access Speed
title_short Logic-Compatible Asymmetrical FET for Gain Cell eDRAM With Long Retention and Fast Access Speed
title_sort logic compatible asymmetrical fet for gain cell edram with long retention and fast access speed
topic AsyFET
eDRAM
gain cell
2T0C
TFET
url https://ieeexplore.ieee.org/document/10879406/
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AT fangxingzhang logiccompatibleasymmetricalfetforgaincelledramwithlongretentionandfastaccessspeed
AT liningzhang logiccompatibleasymmetricalfetforgaincelledramwithlongretentionandfastaccessspeed
AT qianqianhuang logiccompatibleasymmetricalfetforgaincelledramwithlongretentionandfastaccessspeed
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