GeSe ovonic threshold switch: the impact of functional layer thickness and device size
Abstract Three-dimensional phase change memory (3D PCM), possessing fast-speed, high-density and nonvolatility, has been successfully commercialized as storage class memory. A complete PCM device is composed of a memory cell and an associated ovonic threshold switch (OTS) device, which effectively r...
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Nature Portfolio
2024-03-01
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Online Access: | https://doi.org/10.1038/s41598-024-57029-7 |
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author | Jiayi Zhao Zihao Zhao Zhitang Song Min Zhu |
author_facet | Jiayi Zhao Zihao Zhao Zhitang Song Min Zhu |
author_sort | Jiayi Zhao |
collection | DOAJ |
description | Abstract Three-dimensional phase change memory (3D PCM), possessing fast-speed, high-density and nonvolatility, has been successfully commercialized as storage class memory. A complete PCM device is composed of a memory cell and an associated ovonic threshold switch (OTS) device, which effectively resolves the leakage current issue in the crossbar array. The OTS materials are chalcogenide glasses consisting of chalcogens such as Te, Se and S as central elements, represented by GeTe6, GeSe and GeS. Among them, GeSe-based OTS materials are widely utilized in commercial 3D PCM, their scalability, however, has not been thoroughly investigated. Here, we explore the miniaturization of GeSe OTS selector, including functional layer thickness scalability and device size scalability. The threshold switching voltage of the GeSe OTS device almost lineally decreases with the thinning of the thickness, whereas it hardly changes with the device size. This indicates that the threshold switching behavior is triggered by the electric field, and the threshold switching field of the GeSe OTS selector is approximately 105 V/μm, regardless of the change in film thickness or device size. Systematically analyzing the threshold switching field of Ge–S and Ge–Te OTSs, we find that the threshold switching field of the OTS device is larger than 75 V/μm, significantly higher than PCM devices (8.1–56 V/μm), such as traditional Ge2Sb2Te5, Ag–In–Sb–Te, etc. Moreover, the required electric field is highly correlated with the optical bandgap. Our findings not only serve to optimize GeSe-based OTS device, but also may pave the approach for exploring OTS materials in chalcogenide alloys. |
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language | English |
last_indexed | 2024-04-24T19:56:30Z |
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spelling | doaj.art-e12817f96b644be8a8e9cdf24f432b3c2024-03-24T12:20:11ZengNature PortfolioScientific Reports2045-23222024-03-011411910.1038/s41598-024-57029-7GeSe ovonic threshold switch: the impact of functional layer thickness and device sizeJiayi Zhao0Zihao Zhao1Zhitang Song2Min Zhu3State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of SciencesState Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of SciencesState Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of SciencesState Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of SciencesAbstract Three-dimensional phase change memory (3D PCM), possessing fast-speed, high-density and nonvolatility, has been successfully commercialized as storage class memory. A complete PCM device is composed of a memory cell and an associated ovonic threshold switch (OTS) device, which effectively resolves the leakage current issue in the crossbar array. The OTS materials are chalcogenide glasses consisting of chalcogens such as Te, Se and S as central elements, represented by GeTe6, GeSe and GeS. Among them, GeSe-based OTS materials are widely utilized in commercial 3D PCM, their scalability, however, has not been thoroughly investigated. Here, we explore the miniaturization of GeSe OTS selector, including functional layer thickness scalability and device size scalability. The threshold switching voltage of the GeSe OTS device almost lineally decreases with the thinning of the thickness, whereas it hardly changes with the device size. This indicates that the threshold switching behavior is triggered by the electric field, and the threshold switching field of the GeSe OTS selector is approximately 105 V/μm, regardless of the change in film thickness or device size. Systematically analyzing the threshold switching field of Ge–S and Ge–Te OTSs, we find that the threshold switching field of the OTS device is larger than 75 V/μm, significantly higher than PCM devices (8.1–56 V/μm), such as traditional Ge2Sb2Te5, Ag–In–Sb–Te, etc. Moreover, the required electric field is highly correlated with the optical bandgap. Our findings not only serve to optimize GeSe-based OTS device, but also may pave the approach for exploring OTS materials in chalcogenide alloys.https://doi.org/10.1038/s41598-024-57029-7Ovonic threshold switchGeSeScalabilitySelectorThreshold switching fieldPhase change memory |
spellingShingle | Jiayi Zhao Zihao Zhao Zhitang Song Min Zhu GeSe ovonic threshold switch: the impact of functional layer thickness and device size Scientific Reports Ovonic threshold switch GeSe Scalability Selector Threshold switching field Phase change memory |
title | GeSe ovonic threshold switch: the impact of functional layer thickness and device size |
title_full | GeSe ovonic threshold switch: the impact of functional layer thickness and device size |
title_fullStr | GeSe ovonic threshold switch: the impact of functional layer thickness and device size |
title_full_unstemmed | GeSe ovonic threshold switch: the impact of functional layer thickness and device size |
title_short | GeSe ovonic threshold switch: the impact of functional layer thickness and device size |
title_sort | gese ovonic threshold switch the impact of functional layer thickness and device size |
topic | Ovonic threshold switch GeSe Scalability Selector Threshold switching field Phase change memory |
url | https://doi.org/10.1038/s41598-024-57029-7 |
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