Examination of the temperature dependent electronic behavior of GeTe for switching applications

Journal Article · Tue Jun 28 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4954313· OSTI ID:22596829

Champlain, James G.; Ruppalt, Laura B.; Guyette, Andrew C. ^[1]; El-Hinnawy, Nabil; Borodulin, Pavel; Jones, Evan; Young, Robert M.; Nichols, Doyle ^[2]

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1. Naval Research Laboratory, Washington, DC 20375 (United States)
2. Northrop Grumman Electronics Systems, Linthicum, Maryland 21090 (United States)

The DC and RF electronic behaviors of GeTe-based phase change material switches as a function of temperature, from 25 K to 375 K, have been examined. In its polycrystalline (ON) state, GeTe behaved as a degenerate p-type semiconductor, exhibiting metal-like temperature dependence in the DC regime. This was consistent with the polycrystalline (ON) state RF performance of the switch, which exhibited low resistance S-parameter characteristics. In its amorphous (OFF) state, the GeTe presented significantly greater DC resistance that varied considerably with bias and temperature. At low biases (<1 V) and temperatures (<200 K), the amorphous GeTe low-field resistance dramatically increased, resulting in exceptionally high amorphous-polycrystalline (OFF-ON) resistance ratios, exceeding 10{sup 9} at cryogenic temperatures. At higher biases and temperatures, the amorphous GeTe exhibited nonlinear current-voltage characteristics that were best fit by a space-charge limited conduction model that incorporates the effect of a defect band. The observed conduction behavior suggests the presence of two regions of localized traps within the bandgap of the amorphous GeTe, located at approximately 0.26–0.27 eV and 0.56–0.57 eV from the valence band. Unlike the polycrystalline state, the high resistance DC behavior of amorphous GeTe does not translate to the RF switch performance; instead, a parasitic capacitance associated with the RF switch geometry dominates OFF state RF transmission.

• OSTI ID: 22596829
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 24; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CAPACITANCE
CRYOGENICS
DEFECTS
GEOMETRY
GERMANIUM TELLURIDES
METALS
NONLINEAR PROBLEMS
PERFORMANCE
PHASE CHANGE MATERIALS
POLYCRYSTALS
P-TYPE CONDUCTORS
SPACE CHARGE
SWITCHES
TEMPERATURE DEPENDENCE
VALENCE