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

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

Introduction Oxygen deficiencies D. B. Strukov, G. S. Snider, D. R. Stewart, and R. S. Williams, "The missing memristor found," Nature, vol. 453, pp. 80-83, 2008

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

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

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

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

Variations in Memristor Behavior Structure Spacing Materials

Memristor Modeling History D. B. Strukov, G. S. Snider, D. R. Stewart, and R. S. Williams, "The missing memristor found," Nature, vol. 453, pp. 80-83, 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. 515-519, 2009

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

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

Memristance Model [8] Feng Miao et al., Force modulation of tunnel gaps in metal oxide memristive nanoswitches, APPLIED PHYSICS LETTERS 95, 113503, 2009 [16] Kamran Eshraghian et al., Memristive Device Fundamentals and Modeling: Applications to Circuits and Systems Simulation, Proceedings of the IEEE, 2012

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

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

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

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

Proposed memristor model

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.

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