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Title: Understanding the switching mechanism of interfacial phase change memory

Abstract

Phase Change Memory (PCM) is a top candidate for next generation data storage, but it typically suffers from high switching (RESET) current density (20–30 MA/cm2). Interfacial Phase Change Memory (IPCM) is a type of PCM using multilayers of Sb2Te3/GeTe, with up to 100× lower reported RESET current compared to the standard Ge2Sb2Te5-based PCM. Several hypotheses involving fundamentally new switching mechanisms have been proposed to explain the low switching current densities, but consensus is lacking. Here, we investigate IPCM switching by analyzing its thermal, electrical, and fabrication dependencies. First, we measure the effective thermal conductivity (~0.4 W m-1 K-1) and thermal boundary resistance (~3.4 m2 K GW-1) of Sb2Te3/GeTe multilayers. Simulations show that IPCM thermal properties account only for an ~13% reduction of current vs standard PCM and cannot explain previously reported results. Interestingly, electrical measurements reveal that our IPCM RESET indeed occurs by a melt-quench process, similar to PCM. Finally, we find that high deposition temperature causes defects including surface roughness and voids within the multilayer films. Thus, the substantial RESET current reduction of IPCM appears to be caused by voids within the multilayers, which migrate to the bottom electrode interface by thermophoresis, reducing the effective contact area. These resultsmore » shed light on the IPCM switching mechanism, indicating that an improved control of layer deposition is necessary to obtain reliable switching.« less

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1]; ORCiD logo [1];  [3]; ORCiD logo [4];  [5]; ORCiD logo [1]
  1. Stanford Univ., CA (United States). Dept. of Electrical Engineering
  2. Stanford Univ., CA (United States). Dept. of Electrical Engineering; Stanford Univ., CA (United States). Dept. of Mechanical Engineering
  3. Stanford Univ., CA (United States). Dept. of Mechanical Engineering
  4. Stanford Univ., CA (United States). Dept. of Electrical Engineering; Stanford Univ., CA (United States). Dept. of Materials Science and Engineering
  5. Stanford Univ., CA (United States). Dept. of Mechanical Engineering; Stanford Univ., CA (United States). Dept. of Materials Science and Engineering
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE; National Science Foundation (NSF)
OSTI Identifier:
1532494
Grant/Contract Number:  
AC02-76SF00515; ECCS-1542152; ECCS-1709200; EEC-1449548
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 125; Journal Issue: 18; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS

Citation Formats

Okabe, Kye L., Sood, Aditya, Yalon, Eilam, Neumann, Christopher M., Asheghi, Mehdi, Pop, Eric, Goodson, Kenneth E., and Wong, H. -S. Philip. Understanding the switching mechanism of interfacial phase change memory. United States: N. p., 2019. Web. doi:10.1063/1.5093907.
Okabe, Kye L., Sood, Aditya, Yalon, Eilam, Neumann, Christopher M., Asheghi, Mehdi, Pop, Eric, Goodson, Kenneth E., & Wong, H. -S. Philip. Understanding the switching mechanism of interfacial phase change memory. United States. doi:10.1063/1.5093907.
Okabe, Kye L., Sood, Aditya, Yalon, Eilam, Neumann, Christopher M., Asheghi, Mehdi, Pop, Eric, Goodson, Kenneth E., and Wong, H. -S. Philip. Mon . "Understanding the switching mechanism of interfacial phase change memory". United States. doi:10.1063/1.5093907. https://www.osti.gov/servlets/purl/1532494.
@article{osti_1532494,
title = {Understanding the switching mechanism of interfacial phase change memory},
author = {Okabe, Kye L. and Sood, Aditya and Yalon, Eilam and Neumann, Christopher M. and Asheghi, Mehdi and Pop, Eric and Goodson, Kenneth E. and Wong, H. -S. Philip},
abstractNote = {Phase Change Memory (PCM) is a top candidate for next generation data storage, but it typically suffers from high switching (RESET) current density (20–30 MA/cm2). Interfacial Phase Change Memory (IPCM) is a type of PCM using multilayers of Sb2Te3/GeTe, with up to 100× lower reported RESET current compared to the standard Ge2Sb2Te5-based PCM. Several hypotheses involving fundamentally new switching mechanisms have been proposed to explain the low switching current densities, but consensus is lacking. Here, we investigate IPCM switching by analyzing its thermal, electrical, and fabrication dependencies. First, we measure the effective thermal conductivity (~0.4 W m-1 K-1) and thermal boundary resistance (~3.4 m2 K GW-1) of Sb2Te3/GeTe multilayers. Simulations show that IPCM thermal properties account only for an ~13% reduction of current vs standard PCM and cannot explain previously reported results. Interestingly, electrical measurements reveal that our IPCM RESET indeed occurs by a melt-quench process, similar to PCM. Finally, we find that high deposition temperature causes defects including surface roughness and voids within the multilayer films. Thus, the substantial RESET current reduction of IPCM appears to be caused by voids within the multilayers, which migrate to the bottom electrode interface by thermophoresis, reducing the effective contact area. These results shed light on the IPCM switching mechanism, indicating that an improved control of layer deposition is necessary to obtain reliable switching.},
doi = {10.1063/1.5093907},
journal = {Journal of Applied Physics},
number = 18,
volume = 125,
place = {United States},
year = {2019},
month = {5}
}

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Works referenced in this record:

Low-Energy Robust Neuromorphic Computation Using Synaptic Devices
journal, December 2012

  • Kuzum, Duygu; Jeyasingh, Rakesh Gnana David; Yu, Shimeng
  • IEEE Transactions on Electron Devices, Vol. 59, Issue 12
  • DOI: 10.1109/TED.2012.2217146

Low-Power Switching of Phase-Change Materials with Carbon Nanotube Electrodes
journal, March 2011


Self-Aligned Nanotube–Nanowire Phase Change Memory
journal, January 2013

  • Xiong, Feng; Bae, Myung-Ho; Dai, Yuan
  • Nano Letters, Vol. 13, Issue 2, p. 464-469
  • DOI: 10.1021/nl3038097

An Ultra-Low Reset Current Cross-Point Phase Change Memory With Carbon Nanotube Electrodes
journal, April 2012

  • Liang, Jiale; Jeyasingh, Rakesh Gnana David; Chen, Hong-Yu
  • IEEE Transactions on Electron Devices, Vol. 59, Issue 4
  • DOI: 10.1109/TED.2012.2184542

Nanosecond switching in GeTe phase change memory cells
journal, July 2009

  • Bruns, G.; Merkelbach, P.; Schlockermann, C.
  • Applied Physics Letters, Vol. 95, Issue 4
  • DOI: 10.1063/1.3191670

Ultrafast Characterization of Phase-Change Material Crystallization Properties in the Melt-Quenched Amorphous Phase
journal, May 2014

  • Jeyasingh, Rakesh; Fong, Scott W.; Lee, Jaeho
  • Nano Letters, Vol. 14, Issue 6
  • DOI: 10.1021/nl500940z

Phase-Change Memory—Towards a Storage-Class Memory
journal, November 2017

  • Fong, Scott W.; Neumann, Christopher M.; Wong, H. -S. Philip
  • IEEE Transactions on Electron Devices, Vol. 64, Issue 11
  • DOI: 10.1109/TED.2017.2746342

Equivalent-accuracy accelerated neural-network training using analogue memory
journal, June 2018


Training a Probabilistic Graphical Model With Resistive Switching Electronic Synapses
journal, December 2016

  • Eryilmaz, Sukru Burc; Neftci, Emre; Joshi, Siddharth
  • IEEE Transactions on Electron Devices, Vol. 63, Issue 12
  • DOI: 10.1109/TED.2016.2616483

Ultra-low switching energy and scaling in electric-field-controlled nanoscale magnetic tunnel junctions with high resistance-area product
journal, January 2016

  • Grezes, C.; Ebrahimi, F.; Alzate, J. G.
  • Applied Physics Letters, Vol. 108, Issue 1
  • DOI: 10.1063/1.4939446

Crossbar RRAM Arrays: Selector Device Requirements During Write Operation
journal, August 2014


Investigation of multi-level-cell and SET operations on super-lattice phase change memories
journal, January 2014

  • Egami, Toru; Johguchi, Koh; Yamazaki, Senju
  • Japanese Journal of Applied Physics, Vol. 53, Issue 4S
  • DOI: 10.7567/jjap.53.04ED02

Interfacial phase-change memory
journal, July 2011

  • Simpson, R. E.; Fons, P.; Kolobov, A. V.
  • Nature Nanotechnology, Vol. 6, Issue 8
  • DOI: 10.1038/nnano.2011.96

Electrical-field induced giant magnetoresistivity in (non-magnetic) phase change films
journal, October 2011

  • Tominaga, Junji; Simpson, Robert E.; Fons, Paul
  • Applied Physics Letters, Vol. 99, Issue 15
  • DOI: 10.1063/1.3651275

Investigation of switching region in superlattice phase change memories
journal, October 2016


Phase change random access memory cell with superlattice-like structure
journal, March 2006

  • Chong, T. C.; Shi, L. P.; Zhao, R.
  • Applied Physics Letters, Vol. 88, Issue 12
  • DOI: 10.1063/1.2181191

GeTe sequences in superlattice phase change memories and their electrical characteristics
journal, June 2014

  • Ohyanagi, T.; Kitamura, M.; Araidai, M.
  • Applied Physics Letters, Vol. 104, Issue 25
  • DOI: 10.1063/1.4886119

The Design and Application on Interfacial Phase‐Change Memory
journal, December 2018

  • Tominaga, Junji
  • physica status solidi (RRL) – Rapid Research Letters, Vol. 13, Issue 4
  • DOI: 10.1002/pssr.201800539

Ferroelectric Order Control of the Dirac-Semimetal Phase in GeTe-Sb 2 Te 3 Superlattices
journal, December 2013

  • Tominaga, J.; Kolobov, A. V.; Fons, P.
  • Advanced Materials Interfaces, Vol. 1, Issue 1
  • DOI: 10.1002/admi.201300027

Mirror-symmetric Magneto-optical Kerr Rotation using Visible Light in [(GeTe)2(Sb2Te3)1]n Topological Superlattices
journal, July 2014

  • Bang, Do; Awano, Hiroyuki; Tominaga, Junji
  • Scientific Reports, Vol. 4, Issue 1
  • DOI: 10.1038/srep05727

Giant multiferroic effects in topological GeTe-Sb 2 Te 3 superlattices
journal, February 2015

  • Tominaga, Junji; Kolobov, Alexander V.; Fons, Paul J.
  • Science and Technology of Advanced Materials, Vol. 16, Issue 1
  • DOI: 10.1088/1468-6996/16/1/014402

Coherent phonon study of (GeTe) l (Sb 2 Te 3 ) m interfacial phase change memory materials
journal, October 2014

  • Makino, Kotaro; Saito, Yuta; Fons, Paul
  • Applied Physics Letters, Vol. 105, Issue 15
  • DOI: 10.1063/1.4897997

Dual-Layer Dielectric Stack for Thermally Isolated Low-Energy Phase-Change Memory
journal, November 2017

  • Fong, Scott W.; Neumann, Christopher M.; Yalon, Eilam
  • IEEE Transactions on Electron Devices, Vol. 64, Issue 11
  • DOI: 10.1109/TED.2017.2756071

Energy-Efficient Phase-Change Memory with Graphene as a Thermal Barrier
journal, September 2015


Engineering thermal and electrical interface properties of phase change memory with monolayer MoS 2
journal, February 2019

  • Neumann, Christopher M.; Okabe, Kye L.; Yalon, Eilam
  • Applied Physics Letters, Vol. 114, Issue 8
  • DOI: 10.1063/1.5080959

Thermal conduction in lattice–matched superlattices of InGaAs/InAlAs
journal, August 2014

  • Sood, Aditya; Rowlette, Jeremy A.; Caneau, Catherine G.
  • Applied Physics Letters, Vol. 105, Issue 5
  • DOI: 10.1063/1.4892575

Anisotropic and inhomogeneous thermal conduction in suspended thin-film polycrystalline diamond
journal, May 2016

  • Sood, Aditya; Cho, Jungwan; Hobart, Karl D.
  • Journal of Applied Physics, Vol. 119, Issue 17
  • DOI: 10.1063/1.4948335

Thermal Boundary Resistance Measurements for Phase-Change Memory Devices
journal, January 2010


Spatially Resolved Thermometry of Resistive Memory Devices
journal, November 2017


Thermal conductivity of phase-change material Ge2Sb2Te5
journal, October 2006

  • Lyeo, Ho-Ki; Cahill, David G.; Lee, Bong-Sub
  • Applied Physics Letters, Vol. 89, Issue 15
  • DOI: 10.1063/1.2359354

Viscosity and Thermal Conductivity of Dry Air in the Gaseous Phase
journal, October 1985

  • Kadoya, K.; Matsunaga, N.; Nagashima, A.
  • Journal of Physical and Chemical Reference Data, Vol. 14, Issue 4
  • DOI: 10.1063/1.555744

Electrical and optical properties of epitaxial binary and ternary GeTe-Sb2Te3 alloys
journal, April 2018


Electrical Resistivity of Liquid $\hbox{Ge}_{2} \hbox{Sb}_{2}\hbox{Te}_{5}$ Based on Thin-Film and Nanoscale Device Measurements
journal, January 2013

  • Cil, Kadir; Dirisaglik, Faruk; Adnane, Lhacene
  • IEEE Transactions on Electron Devices, Vol. 60, Issue 1
  • DOI: 10.1109/TED.2012.2228273

The Soret Effect
journal, October 1926

  • Chipman, John
  • Journal of the American Chemical Society, Vol. 48, Issue 10
  • DOI: 10.1021/ja01421a012

Interface formation of two- and three-dimensionally bonded materials in the case of GeTe–Sb 2 Te 3 superlattices
journal, January 2015

  • Momand, Jamo; Wang, Ruining; Boschker, Jos E.
  • Nanoscale, Vol. 7, Issue 45
  • DOI: 10.1039/C5NR04530D

    Works referencing / citing this record:

    Disordering process of GeSb 2 Te 4 induced by ion irradiation
    journal, January 2020

    • Mio, A. M.; Privitera, S. M. S.; Zimbone, M.
    • Journal of Physics D: Applied Physics, Vol. 53, Issue 13
    • DOI: 10.1088/1361-6463/ab642d