Electrochemical metallization memories—fundamentals, applications, prospects

This review focuses on electrochemical metallization memory cells (ECM), highlighting their advantages as the next generation memories. In a brief introduction, the basic switching mechanism of ECM cells is described and the historical development is sketched. In a second part, the full spectra of materials and material combinations used for memory device prototypes and for dedicated studies are presented. In a third part, the specific thermodynamics and kinetics of nanosized electrochemical cells are described. The overlapping of the space charge layers is found to be most relevant for the cell properties at rest. The major factors determining the functionality of the ECM cells are the electrode reaction and the transport kinetics. Depending on electrode and/or electrolyte material electron transfer, electro-crystallization or slow diffusion under strong electric fields can be rate determining. In the fourth part, the major device characteristics of ECM cells are explained. Emphasis is placed on switching speed, forming and SET/RESET voltage, R(ON) to R(OFF) ratio, endurance and retention, and scaling potentials. In the last part, circuit design aspects of ECM arrays are discussed, including the pros and cons of active and passive arrays. In the case of passive arrays, the fundamental sneak path problem is described and as well as a possible solution by two anti-serial (complementary) interconnected resistive switches per cell. Furthermore, the prospects of ECM with regard to further scalability and the ability for multi-bit data storage are addressed.

[1]  D. Wolf,et al.  Bistable Current Fluctuations in Reverse‐Biased p‐n Junctions of Germanium , 1967 .

[2]  D. Morgan,et al.  Electrical phenomena in amorphous oxide films , 1970 .

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

[4]  S Manhart,et al.  Memory switching in SiO films with Ag and Co electrodes , 1973 .

[5]  Y. Hirose,et al.  Polarity‐dependent memory switching and behavior of Ag dendrite in Ag‐photodoped amorphous As2S3 films , 1976 .

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

[7]  D. P. Oxley,et al.  ELECTROFORMING, SWITCHING AND MEMORY EFFECTS IN OXIDE THIN FILMS , 1977 .

[8]  J. Merz,et al.  Raman scattering and zone‐folding effects for alternating monolayers of GaAs‐AlAs , 1977 .

[9]  S. Morrison Electrochemistry at Semiconductor and Oxidized Metal Electrodes , 1980 .

[10]  J. Werner Electronic Properties of Grain Boundaries , 1985 .

[11]  Taher Daud,et al.  Solid-state reprogrammable analog resistive devices for electronic neural networks , 1990 .

[12]  K. H. Gundlach,et al.  Electric forming and telegraph noise in tunnel junctions , 1993 .

[13]  Joachim Maier,et al.  Ionic conduction in space charge regions , 1995 .

[14]  R. Waser Electronic properties of grain boundaries in SrTiO3 and BaTiO3 ceramics , 1995 .

[15]  D. Blom,et al.  Defect thermodynamics and electrical properties of nanocrystalline oxides: pure and doped CeO2 , 1997 .

[16]  L. A. Akers,et al.  Programmable current mode Hebbian learning neural network using programmable metallization cell , 1998, ISCAS '98. Proceedings of the 1998 IEEE International Symposium on Circuits and Systems (Cat. No.98CH36187).

[17]  Michael N. Kozicki,et al.  Equivalent circuit modeling of the Ag|As0.24S0.36Ag0.40|Ag system prepared by photodissolution of Ag , 1998 .

[18]  D. Wilmer,et al.  Concept of mismatch and relaxation derived from conductivity spectra of solid electrolytes , 2000 .

[19]  Sangtae Kim,et al.  On the conductivity mechanism of nanocrystalline ceria , 2002 .

[20]  J. Kawamura,et al.  Medium range structure and activation energy of ion transport in glasses , 2002 .

[21]  M. Kozicki,et al.  Silver incorporation in Ge-Se glasses used in programmable metallization cell devices , 2002 .

[22]  Sangtae Kim,et al.  Space charge conduction: Simple analytical solutions for ionic and mixed conductors and application to nanocrystalline ceria , 2003 .

[23]  Maria Mitkova,et al.  Information storage using nanoscale electrodeposition of metal in solid electrolytes , 2003 .

[24]  Thomas H. Lee,et al.  512-Mb PROM with a three-dimensional array of diode/antifuse memory cells , 2003 .

[25]  P. van der Sluis,et al.  Non-volatile memory cells based on ZnxCd1−xS ferroelectric Schottky diodes , 2003 .

[26]  T. Hasegawa,et al.  Nanometer-scale switches using copper sulfide , 2003 .

[27]  M. Mitkova,et al.  Nonvolatile memory based on solid electrolytes , 2004, Proceedings. 2004 IEEE Computational Systems Bioinformatics Conference.

[28]  Joachim Maier,et al.  Ionic transport in nano-sized systems , 2004 .

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

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

[31]  H. Kawaura,et al.  Three terminal solid-electrolyte nanometer switch , 2005, IEEE InternationalElectron Devices Meeting, 2005. IEDM Technical Digest..

[32]  R. Symanczyk,et al.  Conductive bridging RAM (CBRAM): an emerging non-volatile memory technology scalable to sub 20nm , 2005, IEEE InternationalElectron Devices Meeting, 2005. IEDM Technical Digest..

[33]  M. Kozicki,et al.  Germanium sulfide-based solid electrolytes for non-volatile memory , 2005, 63rd Device Research Conference Digest, 2005. DRC '05..

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

[35]  M. Kozicki,et al.  Programmable metallization cell memory based on Ag-Ge-S and Cu-Ge-S solid electrolytes , 2005, Symposium Non-Volatile Memory Technology 2005..

[36]  Zheng Wang,et al.  Nonvolatile SRAM Cell , 2006, 2006 International Electron Devices Meeting.

[37]  Sung-Min Yoon,et al.  Characterization of silver-saturated Ge–Te chalcogenide thin films for nonvolatile random access memory , 2006 .

[38]  Maria Mitkova,et al.  Crystallization effects in annealed thin Ge–Se films photodiffused with Ag , 2006 .

[39]  M. Kozicki,et al.  A Low-Power Nonvolatile Switching Element Based on Copper-Tungsten Oxide Solid Electrolyte , 2006, IEEE Transactions on Nanotechnology.

[40]  T. Hasegawa,et al.  Effect of Ion Diffusion on Switching Voltage of Solid-Electrolyte Nanometer Switch , 2005 .

[41]  I. Eisele,et al.  A programmable metallization cell based on Ag-As2S3 , 2006 .

[42]  M. Kozicki,et al.  Mass transport in chalcogenide electrolyte films - materials and applications , 2006 .

[43]  M. Kozicki,et al.  A Low Power Non-Volatile Memory Element Based on Copper in Deposited Silicon Oxide , 2006, 2006 7th Annual Non-Volatile Memory Technology Symposium.

[44]  Bart J. Kooi,et al.  Polarity-dependent reversible resistance switching in Ge-Sb-Te phase-change thin films , 2007 .

[45]  R. Waser,et al.  Resistive switching in Ag-Ge-Se with extremely low write currents , 2007, 2007 Non-Volatile Memory Technology Symposium.

[46]  Y. Nishi,et al.  Copper sulfide-based resistance change memory , 2007, 2007 Non-Volatile Memory Technology Symposium.

[47]  T.G. Noll,et al.  Fundamental analysis of resistive nano-crossbars for the use in hybrid Nano/CMOS-memory , 2007, ESSCIRC 2007 - 33rd European Solid-State Circuits Conference.

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

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

[50]  N.E. Gilbert,et al.  An Embeddable Multilevel-Cell Solid Electrolyte Memory Array , 2007, IEEE Journal of Solid-State Circuits.

[51]  M. Kozicki,et al.  Bipolar and Unipolar Resistive Switching in Cu-Doped $ \hbox{SiO}_{2}$ , 2007, IEEE Transactions on Electron Devices.

[52]  Gerhard Müller,et al.  A Nonvolatile 2-Mbit CBRAM Memory Core Featuring Advanced Read and Program Control , 2007, IEEE Journal of Solid-State Circuits.

[53]  K. Aratani,et al.  A Novel Resistance Memory with High Scalability and Nanosecond Switching , 2007, 2007 IEEE International Electron Devices Meeting.

[54]  K. Terabe,et al.  A Ta2O5 solid-electrolyte switch with improved reliability , 2007, 2007 IEEE Symposium on VLSI Technology.

[55]  M. Kozicki,et al.  Solid electrolyte memory for flexible electronics , 2007, Non-Volatile Memory Technology Symposium.

[56]  J. Jameson,et al.  Bipolar resistive switching in polycrystalline TiO2 films , 2007 .

[57]  P. Schrogmeier,et al.  Time Discrete Voltage Sensing and Iterative Programming Control for a 4F2 Multilevel CBRAM , 2007, 2007 IEEE Symposium on VLSI Circuits.

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

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

[60]  R. Waser,et al.  Fast resistance switching of TiO2 and MSQ thin films for non-volatile memory applications (RRAM) , 2008, 2008 9th Annual Non-Volatile Memory Technology Symposium (NVMTS).

[61]  K. Abe,et al.  Ultra-high bandwidth memory with 3D-stacked emerging memory cells , 2008, 2008 IEEE International Conference on Integrated Circuit Design and Technology and Tutorial.

[62]  M. Kozicki,et al.  Low current resistive switching in Cu–SiO2 cells , 2008 .

[63]  An Chen Ionic memories: Status and challenges , 2008, 2008 9th Annual Non-Volatile Memory Technology Symposium (NVMTS).

[64]  N. Banno,et al.  On-state reliability of solid-electrolyte switch , 2008, 2008 IEEE International Reliability Physics Symposium.

[65]  Y. Nishi,et al.  Research on switching property of an oxide/copper sulfide hybrid memory , 2008, 2008 9th Annual Non-Volatile Memory Technology Symposium (NVMTS).

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

[67]  R. Bruchhaus,et al.  Investigation of the Reliability Behavior of Conductive-Bridging Memory Cells , 2009, IEEE Electron Device Letters.

[68]  Jung-hyun Lee,et al.  Improvement of CBRAM Resistance Window by Scaling Down Electrode Size in Pure-GeTe Film , 2009 .

[69]  Low Power Operation of Resistive Switching Memory Device Using Novel W/Ge0.4Se0.6/Cu/Al Structure , 2009, 2009 IEEE International Memory Workshop.

[70]  Michael Kund,et al.  Selection of Optimized Materials for CBRAM Based on HT-XRD and Electrical Test Results , 2009 .

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

[72]  R. Waser,et al.  A Nonvolatile Memory With Resistively Switching Methyl-Silsesquioxane , 2009, IEEE Electron Device Letters.

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

[74]  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.

[75]  D. Ielmini,et al.  Voltage-Driven On–Off Transition and Tradeoff With Program and Erase Current in Programmable Metallization Cell (PMC) Memory , 2009, IEEE Electron Device Letters.

[76]  M. Kozicki,et al.  Influence of Cu diffusion conditions on the switching of Cu-SiO2-based resistive memory devices , 2010 .

[77]  S. Z. Rahaman,et al.  Improved resistive switching memory characteristics using novel bi-layered Ge0.2Se0.8/Ta2O5 solid-electrolytes , 2010, 2010 IEEE International Memory Workshop.

[78]  Qi Liu,et al.  Resistive Switching Properties of $\hbox{Au}/ \hbox{ZrO}_{2}/\hbox{Ag}$ Structure for Low-Voltage Nonvolatile Memory Applications , 2010, IEEE Electron Device Letters.

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

[80]  Michael N. Kozicki,et al.  Power and Energy Perspectives of Nonvolatile Memory Technologies , 2010, Proceedings of the IEEE.

[81]  Stephan Menzel,et al.  Memory Devices: Energy–Space–Time Tradeoffs , 2010, Proceedings of the IEEE.

[82]  Qi Liu,et al.  Controllable growth of nanoscale conductive filaments in solid-electrolyte-based ReRAM by using a metal nanocrystal covered bottom electrode. , 2010, ACS nano.

[83]  Rainer Waser,et al.  Voltage-time dilemma of pure electronic mechanisms in resistive switching memory cells , 2010 .

[84]  M. Aono,et al.  Nonvolatile triode switch using electrochemical reaction in copper sulfide , 2010 .

[85]  Rainer Waser,et al.  Probing Cu doped Ge0.3Se0.7 based resistance switching memory devices with random telegraph noise , 2010 .

[86]  Masakazu Aono,et al.  Off-state and turn-on characteristics of solid electrolyte switch , 2010 .

[87]  Yi Ma,et al.  Demonstration of Conductive Bridging Random Access Memory (CBRAM) in logic CMOS process , 2011 .

[88]  Michael N. Kozicki,et al.  Inherent diode isolation in programmable metallization cell resistive memory elements , 2011 .