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Highly scalable non-volatile and ultra-low-power phase-change nanowire memory

Nature Nanotechnology volume 2, pages 626–630 (2007)Cite this article

Abstract

The search for a universal memory storage device that combines rapid read and write speeds, high storage density and non-volatility is driving the exploration of new materials in nanostructured form1,2,3,4,5,6,7. Phase-change materials, which can be reversibly switched between amorphous and crystalline states, are promising in this respect, but top-down processing of these materials into nanostructures often damages their useful properties4,5. Self-assembled nanowire-based phase-change material memory devices offer an attractive solution owing to their sub-lithographic sizes and unique geometry, coupled with the facile etch-free processes with which they can be fabricated. Here, we explore the effects of nanoscaling on the memory-storage capability of self-assembled Ge2Sb2Te5 nanowires, an important phase-change material. Our measurements of write-current amplitude, switching speed, endurance and data retention time in these devices show that such nanowires are promising building blocks for non-volatile scalable memory and may represent the ultimate size limit in exploring current-induced phase transition in nanoscale systems.

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Figure 1: Structural characterization and electrical switching behaviour of Ge2Sb2Te5 nanowires.
Figure 2: Ge2Sb2Te5 nanowire size-dependent memory switching properties.
Figure 3: Recrystallization (data-retention) properties of a 60-nm Ge2Sb2Te5 nanowire.
Figure 4: Size-dependent recrystallization dynamics of Ge2Sb2Te5 nanowires with thickness ranging from 30 nm to 200 nm.

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Acknowledgements

The authors would like to thank Hee-Suk Chung for helpful discussions. This work was supported by startup funds from the University of Pennsylvania, Materials Research Science & Engineering Center (MRSEC) seed award (DMR05-20020) and in part by NSF, DMR-0706381 and the University of Pennsylvania Research Foundation (URF) award.

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  1. Se-Ho Lee and Yeonwoong Jung: These authors contributed equally to this work.

Authors and Affiliations

  1. Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, 19104, Pennsylvania, USA

    Se-Ho Lee, Yeonwoong Jung & Ritesh Agarwal

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  1. Se-Ho Lee
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  2. Yeonwoong Jung
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  3. Ritesh Agarwal
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Contributions

R.A., S.L. and Y.J. conceived and designed the experiments. Y.J. and S.L. performed the experiments. R.A., S.L. and Y.J. analysed the data. R.A., S.L. and Y.J. co-wrote the paper.

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Correspondence to Ritesh Agarwal.

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The authors declare no competing financial interests.

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Supplementary Information

Supplementary information and figures S1-S3 (PDF 219 kb)

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Lee, SH., Jung, Y. & Agarwal, R. Highly scalable non-volatile and ultra-low-power phase-change nanowire memory. Nature Nanotech 2, 626–630 (2007). https://doi.org/10.1038/nnano.2007.291

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