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Title: Electrical properties and transport mechanisms in phase change memory thin films of quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors

Abstract

The temperature dependences of the resistivity and current–voltage (I–V) characteristics of phase change memory thin films based on quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors Ge{sub 2}Sb{sub 2}Te{sub 5}, GeSb{sub 2}Te{sub 5}, and GeSb{sub 4}Te{sub 7} are investigated. The effect of composition variation along the quasibinary line on the electrical properties and transport mechanisms of the thin films is studied. The existence of three ranges with different I–V characteristics is established. The position and concentration of energy levels controlling carrier transport are estimated. The results obtained show that the electrical properties of the thin films can significantly change during a shift along the quasi-binary line GeTe–Sb{sub 2}Te{sub 3}, which is important for targeted optimization of the phase change memory technology.

Authors:
 [1];  [2]; ;  [1];  [3]; ;  [1]
  1. National Research University of Electronic Technology (Russian Federation)
  2. Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation)
  3. Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)
Publication Date:
OSTI Identifier:
22649657
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductors; Journal Volume: 51; Journal Issue: 2; Other Information: Copyright (c) 2017 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANTIMONY TELLURIDES; CHARGE CARRIERS; CONCENTRATION RATIO; ELECTRIC CONDUCTIVITY; ENERGY LEVELS; GERMANIUM TELLURIDES; SEMICONDUCTOR MATERIALS; TEMPERATURE DEPENDENCE; THIN FILMS

Citation Formats

Sherchenkov, A. A., Kozyukhin, S. A., E-mail: sergkoz@igic.ras.ru, Lazarenko, P. I., Babich, A. V., Bogoslovskiy, N. A., Sagunova, I. V., and Redichev, E. N. Electrical properties and transport mechanisms in phase change memory thin films of quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors. United States: N. p., 2017. Web. doi:10.1134/S1063782617020191.
Sherchenkov, A. A., Kozyukhin, S. A., E-mail: sergkoz@igic.ras.ru, Lazarenko, P. I., Babich, A. V., Bogoslovskiy, N. A., Sagunova, I. V., & Redichev, E. N. Electrical properties and transport mechanisms in phase change memory thin films of quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors. United States. doi:10.1134/S1063782617020191.
Sherchenkov, A. A., Kozyukhin, S. A., E-mail: sergkoz@igic.ras.ru, Lazarenko, P. I., Babich, A. V., Bogoslovskiy, N. A., Sagunova, I. V., and Redichev, E. N. Wed . "Electrical properties and transport mechanisms in phase change memory thin films of quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors". United States. doi:10.1134/S1063782617020191.
@article{osti_22649657,
title = {Electrical properties and transport mechanisms in phase change memory thin films of quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors},
author = {Sherchenkov, A. A. and Kozyukhin, S. A., E-mail: sergkoz@igic.ras.ru and Lazarenko, P. I. and Babich, A. V. and Bogoslovskiy, N. A. and Sagunova, I. V. and Redichev, E. N.},
abstractNote = {The temperature dependences of the resistivity and current–voltage (I–V) characteristics of phase change memory thin films based on quasi-binary-line GeTe–Sb{sub 2}Te{sub 3} chalcogenide semiconductors Ge{sub 2}Sb{sub 2}Te{sub 5}, GeSb{sub 2}Te{sub 5}, and GeSb{sub 4}Te{sub 7} are investigated. The effect of composition variation along the quasibinary line on the electrical properties and transport mechanisms of the thin films is studied. The existence of three ranges with different I–V characteristics is established. The position and concentration of energy levels controlling carrier transport are estimated. The results obtained show that the electrical properties of the thin films can significantly change during a shift along the quasi-binary line GeTe–Sb{sub 2}Te{sub 3}, which is important for targeted optimization of the phase change memory technology.},
doi = {10.1134/S1063782617020191},
journal = {Semiconductors},
number = 2,
volume = 51,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2017},
month = {Wed Feb 15 00:00:00 EST 2017}
}
  • The time-resolved reflectivity measurements were carried out on the interfacial phase change memory (iPCM) materials ([(GeTe){sub 2}(Sb{sub 2}Te{sub 3}){sub 4}]{sub 8} and [(GeTe){sub 2}(Sb{sub 2}Te{sub 3}){sub 1}]{sub 20}) as well as conventional Ge{sub 2}Sb{sub 2}Te{sub 5} alloy at room temperature and above the RESET-SET phase transition temperature. In the high-temperature phase, coherent phonons were clearly observed in the iPCM samples while drastic attenuation of coherent phonons was induced in the alloy. This difference strongly suggests the atomic rearrangement during the phase transition in iPCMs is much smaller than that in the alloy. These results are consistent with the unique phasemore » transition model in which a quasi-one-dimensional displacement of Ge atoms occurs for iPCMs and a conventional amorphous-crystalline phase transition takes place for the alloy.« less
  • The phase-change behavior and microstructure changes of N-doped Ge{sub 3}Sb{sub 2}Te{sub 5}[N-GST(3/2/5)] and Ge{sub 2}Sb{sub 2}Te{sub 5}[GST(2/2/5)] films during the phase transition from an amorphous to a crystalline phase were studied using in situ temperature-dependent sheet resistance measurements, X-ray diffraction, and transmission electron microscopy. The optical band gaps of N-GST(3/2/5) films are higher than that of GST(2/2/5) film in both the amorphous and face-centered-cubic (fcc) phases. Ge nitride formation by X-ray photoelectron spectroscopy analysis increased the optical band gap and suppressed crystalline grain growth, resulting in an increase in the crystallization temperature and resistance in the fcc phase. As amore » result, the Ge- and N-doped GST(2/2/5) composite films can be considered as a promising material for phase-change memory application because of improved thermal stability and reduced power consumption.« less
  • Here, we report on the electrical characterization of phase change memory cells containing a Ge{sub 3}Sb{sub 2}Te{sub 6} (GST) alloy grown in its crystalline form by Molecular Beam Epitaxy (MBE). It is found that the high temperature growth on the amorphous substrate results in a polycrystalline film exhibiting a rough surface with a grain size of approximately 80–150 nm. A detailed electrical characterization has been performed, including I-V characteristic curves, programming curves, set operation performance, crystallization activation at low temperature, and resistance drift, in order to determine the material related parameters. The results indicate very good alignment of the electrical parametersmore » with the current state-of-the-art GST, deposited by physical vapor deposition. Such alignment enables a possible employment of the MBE deposition technique for chalcogenide materials in the phase change memory technology, thus leading to future studies of as-deposited crystalline chalcogenides as integrated in electrical vehicles.« less
  • The energy band alignment between stoichiometric phase change alloys residing along the pseudobinary line of GeTe-Sb{sub 2}Te{sub 3}[(GeTe){sub x}(Sb{sub 2}Te{sub 3}){sub 1-x}] and SiO{sub 2} was obtained employing high-resolution x-ray photoelectron spectroscopy. The valence band offsets were determined using both the core-level spectra and valence band spectra in the analysis. The results obtained show that the band offsets vary with the composition of the (GeTe){sub x}(Sb{sub 2}Te{sub 3}){sub 1-x} alloy, exhibiting a parabolic dependence on the amount of GeTe in the alloy. Increasing the proportion of GeTe in the (GeTe){sub x}(Sb{sub 2}Te{sub 3}){sub 1-x} alloy was generally found to increasemore » (decrease) the valence band (conduction band) offsets, while the binary alloys (GeTe, Sb{sub 2}Te{sub 3}) have similar band offset values. This information could be useful for phase change memory device design and optimization.« less
  • Data on the Raman spectra of thin Ge{sub 2}Sb{sub 2}Te{sub 5} chalcogenide semiconductor films are reported. The study is performed with the purpose of determining the temperatures of phase transitions initiated by laser radiation.