TY - JOUR
T1 - A low-power nonvolatile switching element based on copper-tungsten oxide solid electrolyte
AU - Kozicki, Michael
AU - Gopalan, Chakravarthy
AU - Balakrishnan, Muralikrishnan
AU - Mitkova, Maria
N1 - Funding Information:
Manuscript received March 30, 2006; revised May 1, 2006. This work was supported by Axon Technologies Corporation. The review of this paper was arranged by Associate Editor B. G. Park. M. N. Kozicki, M. Balakrishnan, and M. Mitkova are with the Center for Solid State Electronics Research, Arizona State University, Tempe, AZ 85287-6206 USA (michael.kozicki@asu.edu). C. Gopalan is with Spansion Inc., Sunnyvale, CA 94085 USA Color versions of Figs. 2–12 are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TNANO.2006.880407
PY - 2006/9
Y1 - 2006/9
N2 - We describe the materials aspects and electrical characteristics of W - (Cu/WO 3) - Cu switching elements. These materials are compatible with back-end-of-line processing in CMOS integrated circuits where both tungsten and copper already play a significant role. Devices based on Cu/WO 3 solid electrolytes formed by photodiffusion of copper into tungsten oxide switch via the electrochemical formation of a conducting filament within the high resistance electrolyte film. They are able to switch reversibly between widely spaced nonvolatile resistance states at low voltage (<1 V) and current (< 10 μA). Electrical characterization revealed that devices consisting of plasma-grown oxides have a variable initial threshold voltage and poor retention, whereas devices based on deposited oxide exhibit a stable switching threshold and good retention, even at elevated operating temperature (> 125°C). This difference in behavior was attributed to the observation that the copper tends to oxidize in the plasma-grown oxide whereas the copper in the deposited oxide exists in an unbound state and is, therefore, more able to participate in the switching process.
AB - We describe the materials aspects and electrical characteristics of W - (Cu/WO 3) - Cu switching elements. These materials are compatible with back-end-of-line processing in CMOS integrated circuits where both tungsten and copper already play a significant role. Devices based on Cu/WO 3 solid electrolytes formed by photodiffusion of copper into tungsten oxide switch via the electrochemical formation of a conducting filament within the high resistance electrolyte film. They are able to switch reversibly between widely spaced nonvolatile resistance states at low voltage (<1 V) and current (< 10 μA). Electrical characterization revealed that devices consisting of plasma-grown oxides have a variable initial threshold voltage and poor retention, whereas devices based on deposited oxide exhibit a stable switching threshold and good retention, even at elevated operating temperature (> 125°C). This difference in behavior was attributed to the observation that the copper tends to oxidize in the plasma-grown oxide whereas the copper in the deposited oxide exists in an unbound state and is, therefore, more able to participate in the switching process.
KW - Copper electrodeposition
KW - Nonvolatile memory devices
KW - Raman spectroscopy
KW - Resistance change
KW - Solid electrolyte
KW - Tungsten oxide
KW - X-ray photoelectron spectroscopy
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U2 - 10.1109/TNANO.2006.880407
DO - 10.1109/TNANO.2006.880407
M3 - Article
AN - SCOPUS:33748997398
SN - 1536-125X
VL - 5
SP - 535
EP - 544
JO - IEEE Transactions on Nanotechnology
JF - IEEE Transactions on Nanotechnology
IS - 5
M1 - 1695953
ER -