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Ultrafast non-volatile flash memory based on van der Waals heterostructures

Abstract

Flash memory has become a ubiquitous solid-state memory device widely used in portable digital devices, computers and enterprise applications. The development of the information age has demanded improvements in memory speed and retention performance. Here we demonstrate an ultrafast non-volatile flash memory based on MoS2/hBN/multilayer graphene van der Waals heterostructures, which achieves an ultrafast writing/erasing speed of 20 ns through two-triangle-barrier modified Fowler–Nordheim tunnelling. Using detailed theoretical analysis and experimental verification, we postulate that a suitable barrier height, gate coupling ratio and clean interface are the main reasons for the breakthrough writing/erasing speed of our flash memory devices. Because of its non-volatility this ultrafast flash memory could provide the foundation for the next generation of high-speed non-volatile memory.

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Fig. 1: Van der Waals heterostructure flash memory with an atomic-level flat interface.
Fig. 2: Transfer and output characteristic curves of the flash memory device.
Fig. 3: Performance characterization of the ultrafast flash memory device.
Fig. 4: Band diagram and electric field of Cr/MoS2/hBN/MLG heterostructure from the technology computer-aided design device simulation.
Fig. 5: Theoretical calculations based on the two-triangle-barrier modified FN tunnelling model.

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The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request. Source data are provided with this paper.

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Acknowledgements

This work was supported by the National Natural Science Foundation of China (61925402, 61851402 and 62090032), the Science and Technology Commission of Shanghai Municipality (19JC1416600), the Shanghai Education Development Foundation and the Shanghai Municipal Education Commission Shuguang Program (18SG01), and the Strategic Priority Research Program of the Chinese Academy of Sciences under grant XDB44000000.

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Authors and Affiliations

Authors

Contributions

P.Z. conceived the project and designed the experiments. L.L. and C.L. carried out most of the experiments and analysed the data. L.J., S.C., S.W. and Y.-B.S. contributed to theoretical calculations. J.L., Y.D., Y.-G.J., D.W.Z. and J.W. analysed the data, L.L., C.L. and P.Z. co-wrote the manuscript. All authors discussed the results.

Corresponding authors

Correspondence to Shiyou Chen or Peng Zhou.

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The authors declare no competing interests.

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Peer review information Nature Nanotechnology thanks the anonymous reviewers for their contribution to the peer review of this work.

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Extended data

Extended Data Fig. 1 Summary of device parameters and performance of representative flash memory.

* The parameter is not given in the literature. × This parameter does not need to be involved in this kind of device. ! Characterization by transmission electron microscopy with clean and flat interfaces. # No specific information is given about the interfaces.

Supplementary information

Supplementary Information

Supplementary sections 1–13 containing Figs. 1, 2-1, 2-2, 3-1, 3-2, 4, 5, 6, 7-1, 7-2, 8, 9-1, 9-2, 9-3, 10, 11, 12, Table 1.

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Liu, L., Liu, C., Jiang, L. et al. Ultrafast non-volatile flash memory based on van der Waals heterostructures. Nat. Nanotechnol. 16, 874–881 (2021). https://doi.org/10.1038/s41565-021-00921-4

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