Observation of conducting filament growth in nanoscale resistive memories

Nanoscale resistive switching devices, sometimes termed memristors, have recently generated significant interest for memory, logic and neuromorphic applications. Resistive switching effects in dielectric-based devices are normally assumed to be caused by conducting filament formation across the electrodes, but the nature of the filaments and their growth dynamics remain controversial. Here we report direct transmission electron microscopy imaging, and structural and compositional analysis of the nanoscale conducting filaments. Through systematic ex-situ and in-situ transmission electron microscopy studies on devices under different programming conditions, we found that the filament growth can be dominated by cation transport in the dielectric film. Unexpectedly, two different growth modes were observed for the first time in materials with different microstructures. Regardless of the growth direction, the narrowest region of the filament was found to be near the dielectric/inert-electrode interface in these devices, suggesting that this region deserves particular attention for continued device optimization.

[1]  L. Chua.  Memristor-The missing circuit element , 1971 .

[2]  L.O. Chua,et al.  Memristive devices and systems , 1976, Proceedings of the IEEE.

[3]  C. Gerber,et al.  Current-driven insulator–conductor transition and nonvolatile memory in chromium-doped SrTiO3 single crystals , 2001 .

[4]  S. O. Park,et al.  Highly scalable nonvolatile resistive memory using simple binary oxide driven by asymmetric unipolar voltage pulses , 2004, IEDM Technical Digest. IEEE International Electron Devices Meeting, 2004..

[5]  M. Kozicki,et al.  Nanoscale memory elements based on solid-state electrolytes , 2005, IEEE Transactions on Nanotechnology.

[6]  K. Terabe,et al.  Quantized conductance atomic switch , 2005, Nature.

[7]  T. Sakamoto,et al.  A nonvolatile programmable solid-electrolyte nanometer switch , 2004, IEEE Journal of Solid-State Circuits.

[8]  D. Strukov,et al.  CMOL FPGA: a reconfigurable architecture for hybrid digital circuits with two-terminal nanodevices , 2005 .

[9]  R. Waser,et al.  Nanoionics-based resistive switching memories. , 2007, Nature materials.

[10]  Sunae Seo,et al.  Observation of electric-field induced Ni filament channels in polycrystalline NiOx film , 2007 .

[11]  S. Menzel,et al.  Understanding the switching-off mechanism in Ag+ migration based resistively switching model systems , 2007 .

[12]  T. Hasegawa,et al.  Electronic transport in Ta2O5 resistive switch , 2007 .

[13]  A. Alavi,et al.  Opportunities and Challenges , 1998, In Vitro Diagnostic Industry in China.

[14]  Konstantin K. Likharev,et al.  Hybrid CMOS/Nanoelectronic Circuits: Opportunities and Challenges , 2008 .

[15]  D. Stewart,et al.  The missing memristor found , 2008, Nature.

[16]  W. Lu,et al.  CMOS compatible nanoscale nonvolatile resistance switching memory. , 2008, Nano letters.

[17]  J. Yang,et al.  Memristive switching mechanism for metal/oxide/metal nanodevices. , 2008, Nature nanotechnology.

[18]  D. Ielmini,et al.  Study of Multilevel Programming in Programmable Metallization Cell (PMC) Memory , 2009, IEEE Transactions on Electron Devices.

[19]  Warren Robinett,et al.  Memristor-CMOS hybrid integrated circuits for reconfigurable logic. , 2009, Nano letters.

[20]  F. Zeng,et al.  Fully room-temperature-fabricated nonvolatile resistive memory for ultrafast and high-density memory application. , 2009, Nano letters.

[21]  R. Waser,et al.  Electrode kinetics of Cu–SiO2-based resistive switching cells: Overcoming the voltage-time dilemma of electrochemical metallization memories , 2009 .

[22]  R. Dittmann,et al.  Redox‐Based Resistive Switching Memories – Nanoionic Mechanisms, Prospects, and Challenges , 2009, Advanced materials.

[23]  Rainer Waser,et al.  Faradaic currents during electroforming of resistively switching Ag-Ge-Se type electrochemical metallization memory cells. , 2009, Physical chemistry chemical physics : PCCP.

[24]  W. Lu,et al.  Programmable Resistance Switching in Nanoscale Two-terminal Devices , 2008 .

[25]  Massimiliano Di Ventra,et al.  Experimental demonstration of associative memory with memristive neural networks , 2009, Neural Networks.

[26]  Wei Yang Lu,et al.  Nanoscale memristor device as synapse in neuromorphic systems. , 2010, Nano letters.

[27]  Rainer Waser,et al.  Complementary resistive switches for passive nanocrossbar memories. , 2010, Nature materials.

[28]  X. Bai,et al.  Real-time in situ HRTEM-resolved resistance switching of Ag2S nanoscale ionic conductor. , 2010, ACS nano.

[29]  Massimiliano Di Ventra,et al.  Practical Approach to Programmable Analog Circuits With Memristors , 2009, IEEE Transactions on Circuits and Systems I: Regular Papers.

[30]  Jae Hyuck Jang,et al.  Atomic structure of conducting nanofilaments in TiO2 resistive switching memory. , 2010, Nature nanotechnology.

[31]  Gregory S. Snider,et al.  ‘Memristive’ switches enable ‘stateful’ logic operations via material implication , 2010, Nature.

[32]  M. Kozicki,et al.  Electrochemical metallization memories—fundamentals, applications, prospects , 2011, Nanotechnology.

[33]  Yasuo Takahashi,et al.  In situ transmission electron microscopy analysis of conductive filament during solid electrolyte resistance switching , 2011 .