Mechanism of Nonlinear Switching in HfO2-Based Crossbar RRAM With Inserting Large Bandgap Tunneling Barrier Layer

In this paper, the nonlinear switching mechanism of the Ti/HfO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub>/TiN crossbar structure resistive random access memory device with good reliability is investigated. The nonlinearity of the device can be revealed by inserting a large bandgap of an Al<sub>2</sub>O<sub>3</sub> thin layer between the TiN bottom electrode and the HfO<sub>2</sub> switching film. The nonlinear switching mechanism caused by Flower-Nordheim tunneling involves the tunneling barrier of the Al<sub>2</sub>O<sub>3</sub> layer. Besides, the nonlinear behavior is also sensitive to the thickness of the inserting Al<sub>2</sub>O<sub>3</sub> layer. A high nonlinear factor of 37, large endurance more than 10<sup>4</sup>, and good retention properties are achieved in the Ti/HfO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> (1-nm)/TiN structure.

[1]  T. Tseng,et al.  Compact Ga-Doped ZnO Nanorod Thin Film for Making High-Performance Transparent Resistive Switching Memory , 2014, IEEE Transactions on Electron Devices.

[2]  Shimeng Yu,et al.  Metal–Oxide RRAM , 2012, Proceedings of the IEEE.

[3]  I. Yoo,et al.  2-stack 1D-1R Cross-point Structure with Oxide Diodes as Switch Elements for High Density Resistance RAM Applications , 2007, 2007 IEEE International Electron Devices Meeting.

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

[5]  Alessandro Calderoni,et al.  Statistical Fluctuations in HfOx Resistive-Switching Memory: Part I - Set/Reset Variability , 2014, IEEE Transactions on Electron Devices.

[6]  Byung Joon Choi,et al.  Engineering nonlinearity into memristors for passive crossbar applications , 2012 .

[7]  O. Richard,et al.  10×10nm2 Hf/HfOx crossbar resistive RAM with excellent performance, reliability and low-energy operation , 2011, 2011 International Electron Devices Meeting.

[8]  L. Goux,et al.  Endurance/Retention Trade-off on $\hbox{HfO}_{2}/\hbox{Metal}$ Cap 1T1R Bipolar RRAM , 2013, IEEE Transactions on Electron Devices.

[9]  R. Waser,et al.  Current Compliance-Dependent Nonlinearity in ${\rm TiO}_{2}$ ReRAM , 2013, IEEE Electron Device Letters.

[10]  C. Chung,et al.  A non-linear ReRAM cell with sub-1μA ultralow operating current for high density vertical resistive memory (VRRAM) , 2012, 2012 International Electron Devices Meeting.

[11]  T. Tseng,et al.  Effects of Ti top electrode thickness on the resistive switching behaviors of rf-sputtered ZrO2 memory films , 2009 .

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

[13]  S. M. Sze,et al.  Physics of semiconductor devices , 1969 .

[14]  H.-S. Philip Wong.  Beyond the conventional transistor , 2002, IBM J. Res. Dev..

[15]  Hyunsang Hwang,et al.  Nonlinear current-voltage behavior of the isolated resistive switching filamentary channels in CuC nanolayer , 2011 .

[16]  K. Sankaran,et al.  First-principles simulation of oxygen diffusion in HfOx: Role in the resistive switching mechanism , 2012 .

[17]  Umesh Chand,et al.  Suppression of endurance degradation by utilizing oxygen plasma treatment in HfO2 resistive switching memory , 2015 .

[18]  C. Hu,et al.  Effect of Top Electrode Material on Resistive Switching Properties of $\hbox{ZrO}_{2}$ Film Memory Devices , 2007, IEEE Electron Device Letters.

[19]  T. Tseng,et al.  Switching mechanism of double forming process phenomenon in ZrOx/HfOy bilayer resistive switching memory structure with large endurance , 2014 .

[20]  Shimeng Yu,et al.  3-D Cross-Point Array Operation on ${\rm AlO}_{y}/{\rm HfO}_{x}$ -Based Vertical Resistive Switching Memory , 2014, IEEE Transactions on Electron Devices.

[21]  W. Jang,et al.  Improved Resistive Switching Characteristics by Al2O3 Layers Inclusion in HfO2-Based RRAM Devices , 2013 .

[22]  Yan Wang,et al.  Self-rectifying effect in gold nanocrystal-embedded zirconium oxide resistive memory , 2009 .

[23]  Jea-Gun Park,et al.  Oxygen Ion Drift‐Induced Complementary Resistive Switching in Homo TiOx/TiOy/TiOx and Hetero TiOx/TiON/TiOx Triple Multilayer Frameworks , 2012 .

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

[25]  L. Goux,et al.  Asymmetry and Switching Phenomenology in TiN\(Al2O3)\HfO2\Hf Systems , 2012 .

[26]  Umesh Chand,et al.  Mechanism of High Temperature Retention Property (up to 200 °C) in ZrO2-Based Memory Device With Inserting a ZnO Thin Layer , 2014, IEEE Electron Device Letters.

[27]  Tuo-Hung Hou,et al.  Bipolar Nonlinear $\hbox{Ni/TiO}_{2}\hbox{/}\hbox{Ni}$ Selector for 1S1R Crossbar Array Applications , 2011, IEEE Electron Device Letters.

[28]  Frederick T. Chen,et al.  Electrical evidence of unstable anodic interface in Ru∕HfOx∕TiN unipolar resistive memory , 2008 .

[29]  G. Pourtois,et al.  HfOx as RRAM material – First principles insights on the working principles , 2014 .