Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistors

Abstract AlScN emerges as a promising material for ferroelectric field-effect transistors due to its high coercive field (>6 MV/cm). However, its high remanent polarization (>100 μC/cm2) can degrade memory window and retention, limiting its use in memory applications. This study introduces an...

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Main Authors: Kyung Do Kim, Seung Kyu Ryoo, Min Kyu Yeom, Suk Hyun Lee, Wonho Choi, Yunjae Kim, Jung-Hae Choi, Tianjiao Xin, Yan Cheng, Cheol Seong Hwang
Format: Article
Language:English
Published: Nature Portfolio 2025-08-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-62904-6
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author Kyung Do Kim
Seung Kyu Ryoo
Min Kyu Yeom
Suk Hyun Lee
Wonho Choi
Yunjae Kim
Jung-Hae Choi
Tianjiao Xin
Yan Cheng
Cheol Seong Hwang
author_facet Kyung Do Kim
Seung Kyu Ryoo
Min Kyu Yeom
Suk Hyun Lee
Wonho Choi
Yunjae Kim
Jung-Hae Choi
Tianjiao Xin
Yan Cheng
Cheol Seong Hwang
author_sort Kyung Do Kim
collection DOAJ
description Abstract AlScN emerges as a promising material for ferroelectric field-effect transistors due to its high coercive field (>6 MV/cm). However, its high remanent polarization (>100 μC/cm2) can degrade memory window and retention, limiting its use in memory applications. This study introduces an AlScN/AlN/AlScN multi-layer designed to decouple the polarization and coercive field, thereby increasing the coercive field while maintaining polarization value. The AlN layer switches ferroelectrically in response to the AlScN layer’s switching, even though a single AlN layer is piezoelectric. The lower dielectric constant of AlN compared to AlScN increases the coercive field of the stack, while the AlScN layer primarily determines the polarization. This study shows that increasing the AlN ratio in the multi-layer significantly enhances the memory window and retention performance of ferroelectric thin-film transistors with amorphous indium-gallium-zinc-oxide channels. A maximum memory window of 15 V is achieved, enabling the development of a penta-level cell for next-generation storage.
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institution Kabale University
issn 2041-1723
language English
publishDate 2025-08-01
publisher Nature Portfolio
record_format Article
series Nature Communications
spelling doaj-art-3e33f3dda7c8486882da9e37768ce1742025-08-20T04:02:55ZengNature PortfolioNature Communications2041-17232025-08-0116111010.1038/s41467-025-62904-6Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistorsKyung Do Kim0Seung Kyu Ryoo1Min Kyu Yeom2Suk Hyun Lee3Wonho Choi4Yunjae Kim5Jung-Hae Choi6Tianjiao Xin7Yan Cheng8Cheol Seong Hwang9Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National UniversityDepartment of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National UniversityDepartment of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National UniversityDepartment of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National UniversityDepartment of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National UniversityDepartment of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National UniversityElectronic Materials Research Center, Korea Institute of Science and TechnologyKey Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal UniversityKey Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal UniversityDepartment of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National UniversityAbstract AlScN emerges as a promising material for ferroelectric field-effect transistors due to its high coercive field (>6 MV/cm). However, its high remanent polarization (>100 μC/cm2) can degrade memory window and retention, limiting its use in memory applications. This study introduces an AlScN/AlN/AlScN multi-layer designed to decouple the polarization and coercive field, thereby increasing the coercive field while maintaining polarization value. The AlN layer switches ferroelectrically in response to the AlScN layer’s switching, even though a single AlN layer is piezoelectric. The lower dielectric constant of AlN compared to AlScN increases the coercive field of the stack, while the AlScN layer primarily determines the polarization. This study shows that increasing the AlN ratio in the multi-layer significantly enhances the memory window and retention performance of ferroelectric thin-film transistors with amorphous indium-gallium-zinc-oxide channels. A maximum memory window of 15 V is achieved, enabling the development of a penta-level cell for next-generation storage.https://doi.org/10.1038/s41467-025-62904-6
spellingShingle Kyung Do Kim
Seung Kyu Ryoo
Min Kyu Yeom
Suk Hyun Lee
Wonho Choi
Yunjae Kim
Jung-Hae Choi
Tianjiao Xin
Yan Cheng
Cheol Seong Hwang
Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistors
Nature Communications
title Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistors
title_full Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistors
title_fullStr Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistors
title_full_unstemmed Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistors
title_short Decoupling polarization and coercive field in AlScN/AlN/AlScN stack for enhanced performance in ferroelectric thin-film transistors
title_sort decoupling polarization and coercive field in alscn aln alscn stack for enhanced performance in ferroelectric thin film transistors
url https://doi.org/10.1038/s41467-025-62904-6
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