Amorphized Length and Variability in Phase Change Memory Line Cells

  1. Nafisa NoorORCID Logo,
  2. Sadid Muneer,
  3. Raihan Sayeed Khan,
  4. Anna GorbenkoORCID Logo and
  5. Helena SilvaORCID Logo

Submitting author affiliation: North South University, Dhaka, Bangladesh

Beilstein Arch. 2020, 202058. doi:10.3762/bxiv.2020.58.v1

Published 07 May 2020

  • Preprint

Abstract

The dimensions of amorphized regions in phase-change memory cells are critical parameters to design devices for different applications but are difficult to determine by direct imaging. In this work, the length of amorphized regions in multiple, identical Ge2Sb2Te5 (GST) line cells was extracted from electrical measurements. After each cell was programmed to an amorphous state, a sequence of increasing amplitude post-reset voltage pulses separated by low-amplitude read DC-sweeps was applied. When a sufficient amplitude post-reset voltage pulse was applied to a given cell, the measured current and the post-pulse resistance increased drastically, indicating the cell re-amorphized after threshold switching, melting, and quenching. The amorphized length was calculated using the measured voltage at which threshold switching took place and the expected drifted threshold field at that time. The measured threshold voltages, hence, the extracted amorphized lengths, generally increase linearly with the programmed resistance levels, but significant variability arises from the intrinsic uniqueness in the crystallization and amorphization processes in these devices. For example, cells programmed to ~50 MΩ amorphous resistance show threshold voltages of ~5-7 V, corresponding to amorphized lengths of ~240-360 nm. This unpredictable programming feature in phase-change memory devices can be utilized in hardware security applications.

Keywords: Amorphous materials, drift, electrical breakdown, electrical resistivity, phase change memory, pulse measurement, stochastic processes, threshold switching.

How to Cite

When a peer-reviewed version of this preprint is available in the Beilstein Journals, this information will be updated in the information box above. If no peer-reviewed version is available, please cite this preprint using the following information:

Noor, N.; Muneer, S.; Khan, R. S.; Gorbenko, A.; Silva, H. Beilstein Arch. 2020, 202058. doi:10.3762/bxiv.2020.58.v1

Download Citation
Download RIS (Reference Manager) Download BIB (BIBTEX)

© 2020 Noor et al.; licensee Beilstein-Institut.
This is an Open Access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0). Please note that the reuse, redistribution and reproduction in particular requires that the authors and source are credited.
The license is subject to the Beilstein Archives terms and conditions: (https://www.beilstein-archives.org/xiv/terms)

Other Beilstein-Institut Open Science Activities

Logo
Logo
Logo
Symposia