Using binary resistors to achieve multilevel resistive switching in multilayer NiO/Pt nanowire arrays

Reliable multilevel resistive switching in nanoscale cells is desirable for the wide adoption of resistive random access memory as the next-generation nonvolatile memory. We designed NiO-based cells in arrays of multilayered NiO/Pt nanowires to explore multilevel memory effects. Nonpolar resistive switching reproducibly occurs with significantly reduced switching voltages, narrow switching voltage distributions and a robust multilevel memory effect. A high resistance ratio (∼105) between the high- and low-resistance states in nanoscale cells enables stable multilevels that can be induced easily by a series of pulsed voltage. The existence of intermediate resistance states in NiO/Pt nanowire arrays can be well explained by the binary-resistor model combined with energy perturbations induced by the pulse voltage. We also verified that the conduction mechanism in multilayered NiO/Pt nanowires is dominated by the hopping of holes. Our bottom-up approach and proposed mechanism explain the controllable multilevel memory effect and facilitate sound device design to encourage their universal adoption. Metal-insulator-metal structures that can switch between low and high resistance states under electrical stimulus hold promise as components for future non-volatile memory devices. A Taiwan-based research team, led by Chih-Huang Lai at the National Tsing Hua University, has now devised a nanowire array that exhibits multilevel resistive switching behavior — that is, between low, high and also intermediate states — under voltage pulses, giving rise to robust memory effects. Each nanowire consists of multilayered, alternating nickel oxide and platinum parts, and the multilevel resistive switching phenomenon is attributed to averaging over all possible binary configurations for each nickel oxide segment in the multilayered nanowire array. The researchers explain these observations using a binary resistor model of conduction generated by the hopping of holes through defects, which may be applicable to other multilevel resistive switching systems. Nonpolar resistive switching reproducibly occurs in arrays of nanoscale cells composed of multilayered NiO/Pt nanowires with significantly reduced switching voltages, narrow switching voltage distributions and a robust multilevel memory effect. A high resistance ratio (∼105) between the high- and low-resistance states in nanoscale cells enables stable multilevels to be induced easily by a series of pulsed voltages. The existence of intermediate resistance states in NiO/Pt nanowire arrays can be well explained by the binary-resistor model combined with energy perturbations induced by the pulse voltage. Our bottom-up approach and proposed mechanism explain the controllable multilevel memory effect.

[1]  Kenji Fukuda,et al.  Ordered Metal Nanohole Arrays Made by a Two-Step Replication of Honeycomb Structures of Anodic Alumina , 1995, Science.

[2]  X. A. Tran,et al.  Oxide-based RRAM: Unified microscopic principle for both unipolar and bipolar switching , 2011, 2011 International Electron Devices Meeting.

[3]  Tseung-Yuen Tseng,et al.  Multilevel resistive switching in Ti/CuxO/Pt memory devices , 2010 .

[4]  Qi Liu,et al.  Multilevel resistive switching with ionic and metallic filaments , 2009 .

[5]  T. Chin,et al.  Improvement of resistive switching in NiO-based nanowires by inserting Pt layers , 2012 .

[6]  Young-soo Park,et al.  Two Series Oxide Resistors Applicable to High Speed and High Density Nonvolatile Memory , 2007 .

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

[8]  Byoungil Lee,et al.  Fabrication and Characterization of Nanoscale NiO Resistance Change Memory (RRAM) Cells With Confined Conduction Paths , 2011, IEEE Transactions on Electron Devices.

[9]  Hanchul Kim,et al.  Interaction and ordering of vacancy defects in NiO , 2008 .

[10]  B. Park,et al.  Dual defects of cation and anion in memristive nonvolatile memory of metal oxides. , 2012, Journal of the American Chemical Society.

[11]  Tomoji Kawai,et al.  Resistive-switching memory effects of NiO nanowire/metal junctions. , 2010, Journal of the American Chemical Society.

[12]  K. Ohmi,et al.  Opposite bias polarity dependence of resistive switching in n-type Ga-doped-ZnO and p-type NiO thin films , 2010 .

[13]  A. Atkinson.  Transport processes during the growth of oxide films at elevated temperature , 1985 .

[14]  V. Garcia,et al.  Giant tunnel electroresistance for non-destructive readout of ferroelectric states , 2009, Nature.

[15]  Masateru Taniguchi,et al.  Resistive switching multistate nonvolatile memory effects in a single cobalt oxide nanowire. , 2010, Nano letters.

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

[17]  B. Kahng,et al.  Random Circuit Breaker Network Model for Unipolar Resistance Switching , 2008 .

[18]  Daniele Ielmini,et al.  Resistive-switching crossbar memory based on Ni-NiO core-shell nanowires. , 2011, Small.

[19]  Tomoji Kawai,et al.  Intrinsic mechanisms of memristive switching. , 2011, Nano letters.

[20]  A. Sawa.  Resistive switching in transition metal oxides , 2008 .

[21]  Sung In Kim,et al.  Reversible resistive switching behaviors in NiO nanowires , 2008, 2010 3rd International Nanoelectronics Conference (INEC).

[22]  Qi Liu,et al.  Nonpolar Nonvolatile Resistive Switching in Cu Doped $\hbox{ZrO}_{2}$ , 2008, IEEE Electron Device Letters.

[23]  I. Yoo,et al.  A simple device unit consisting of all NiO storage and switch elements for multilevel terabit nonvolatile random access memory. , 2011, ACS applied materials & interfaces.

[24]  N. Mott,et al.  Polarons in crystalline and non-crystalline materials , 2001 .

[25]  Wen-Chieh Shih,et al.  Nonpolar resistive switching in the Pt/MgO/Pt nonvolatile memory device , 2010 .

[26]  S. O. Park,et al.  Electrical observations of filamentary conductions for the resistive memory switching in NiO films , 2006 .

[27]  M. Volpe,et al.  Cation Self‐Diffusion and Semiconductivity in NiO , 1970 .

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

[29]  Tomoji Kawai,et al.  Nonvolatile bipolar resistive memory switching in single crystalline NiO heterostructured nanowires. , 2009, Journal of the American Chemical Society.

[30]  D. Ielmini,et al.  Nanowire-based RRAM crossbar memory with metallic core-oxide shell nanostructure , 2011, 2011 Proceedings of the European Solid-State Device Research Conference (ESSDERC).

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

[32]  Jung-Hyun Lee,et al.  Electrical manipulation of nanofilaments in transition-metal oxides for resistance-based memory. , 2009, Nano letters.

[33]  Kentaro Kinoshita,et al.  Direct observation of oxygen movement during resistance switching in NiO/Pt film , 2008 .

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

[35]  Xin Peng Wang,et al.  Optimized Ni Oxidation in 80-nm Contact Holes for Integration of Forming-Free and Low-Power Ni/NiO/Ni Memory Cells , 2009, IEEE Transactions on Electron Devices.

[36]  Jianlin Liu,et al.  Resistive switching in single epitaxial ZnO nanoislands. , 2012, ACS nano.

[37]  David Adler,et al.  Electrical and Optical Properties of Narrow-Band Materials , 1970 .

[38]  Marisol Martín-González,et al.  High-aspect-ratio and highly ordered 15-nm porous alumina templates. , 2013, ACS applied materials & interfaces.

[39]  U-In Chung,et al.  Improvement of resistive memory switching in NiO using IrO2 , 2006 .

[40]  I. Baek,et al.  Write Current Reduction in Transition Metal Oxide Based Resistance Change Memory , 2008 .

[41]  Z. Fan,et al.  ZnO nanowire field-effect transistor and oxygen sensing property , 2004 .