1. Memristance and Memcapacitance Modeling of Thin Film Devices Showing Memristive Behavior
Mohamed G. Ahmed, Kyoungrok Cho, and Tae-Won Cho
College of Electrical and Computer Engineering
Chungbuk National University, Republic of Korea

2. Outline Introduction Overview of different fabricated memristors
Periodic Table of Circuit Elements
Circuit Elements with memory
Overview of different fabricated memristors
Different behavior characteristics
Memristor Modeling History
Proposed Memristance Model
Capacitance of different junctions
Proposed behavioral memcapacitance model
Conclusions

3. Introduction
Oxygen deficiencies
D. B. Strukov, G. S. Snider, D. R. Stewart, and R. S. Williams, "The missing memristor found," Nature, vol. 453, pp , 2008

4. Periodic Table of Circuit Elements
Leon Chua, Nonlinear Circuit Foundations for Nanodevices, Part I The Four-Element Torus, Proceedings of IEEE, vol. 91, 11, Nov. 2003

5. Circuit Elements with memory
Massimiliano Di Ventra et al., Circuit Elements With Memory: Memristors, Memcapacitors, and Meminductors, Proceedings of IEEE, vol. 97, 10, 2009

6. Overview of different fabricated memristors
Material
Top Metal
Bottom Metal
Ron
Roff
Year
AlN
(Aluminum nitride) Cu
(Copper) Pt
(Platinum)
~103
~106
2010
AlO
(Aluminum Oxide) Ti
(Titanium)
~5x105
2011
BiFeO3 Ag
102
103~107
ZrO2
108
2008
Cu:SiO2 W
4*104
6x107
2007
Al2O3:RuNCs
TaN
200
5x106
Yb2O3 Ni

7. Memristive Behavior of different fabricated memristors
Leon Chua, Resistance switching memories are memristors, Applied Physics A, 102, 2011

8. Variations in Memristor Behavior
Structure
Spacing
Materials

9. Memristor Modeling History
D. B. Strukov, G. S. Snider, D. R. Stewart, and R. S. Williams, "The missing memristor found," Nature, vol. 453, pp , 2008
D. B. Strukov and R. S. Williams, "Exponential ionic drift: fast switching and low volatility of thin-film memristors," Applied Physics A, vol. 94, pp , 2009

10. Memristor Modeling History (Cont.)
Kamran Eshraghian et al., Memristive Device Fundamentals and Modeling: Applications to Circuits and Systems Simulation, Proceedings of the IEEE, 2012

11. Logarithmic Behavior of memristance modeling
Paper
Logarithmic behavior
Strukov et al., Applied Physics A, 94, 2009
Drift velocity – applied voltage
Hasegawa et al., Advanced Materials, 4, 2012
Channel length – junction current
Hino et al., Sci. Technol. Adv. Mater., 12, 2011
Switching time – applied voltage
Pickett et al., Journal of applied physics, 106, 2009
Yang et al., Nature Nanotechnology, 3, 2008
Junction current – applied voltage
Channel length – applied voltage

12. Memristance Model
[8] Feng Miao et al., Force modulation of tunnel gaps in metal oxide memristive nanoswitches, APPLIED PHYSICS LETTERS 95, , 2009
[16] Kamran Eshraghian et al., Memristive Device Fundamentals and Modeling: Applications to Circuits and Systems Simulation, Proceedings of the IEEE, 2012

13. Proof of memcapacitance in memristors
Xianwen Sun, Guoqiang Li, Li Chen, Zihong Shi and Weifeng Zhang, Bipolar resistance switching characteristics with opposite polarity of Au/SrTiO3/Ti memory cells, Nanoscale Research Letters 2011, 6:599

14. Proof of memcapacitance in memristors
Jie Sun, Erik Lind, Ivan Maximov, and H. Q. Xu, Memristive and Memcapacitive Characteristicsof a Au/Ti–HfO2-InP/InGaAs Diode, IEEE ELECTRON DEVICE LETTERS, VOL. 32, NO. 2, FEBRUARY 2011

15. Proof of memcapacitance in memristors
Jie Sun, Erik Lind, Ivan Maximov, and H. Q. Xu, Memristive and Memcapacitive Characteristicsof a Au/Ti–HfO2-InP/InGaAs Diode, IEEE ELECTRON DEVICE LETTERS, VOL. 32, NO. 2, FEBRUARY 2011

16. Behavioral Model of Memcapacitance
Xmax
X(t)
Xmin
ε permittivity of the sandwiched material
A device cross section area
Af the effective area of the filaments
dmax the gap length without filaments
df the gap thickness between filaments and the next electrode

17. Proposed memristor model

18. Conclusions
Developing new memristance model is not only simple as behavior models, but it also considered to be physical model using some fitting parameters.
Forcing memristance model to work within boundary conditions by choosing new window function which also satisfies logarithmic fashion of drift velocity with junction current.
Including behavioral modeling of junction memcapacitance to model real memristor device.

19. Thank you