Highly uniform and reliable resistance switching properties in bilayer WOx/NbOx RRAM devices

Memory performances, especially uniformity and reliability of resistance random access memory (RRAM) devices with W/NbOx/Pt structures were investigated. Scaling down the active device area (ø = 250 nm) can significantly minimize extrinsic defects related to nonuniform switching and also demonstrate low‐voltage SET/RESET operations due to increased Joule heating. Electromigration of oxygen ions under the bipolar electric field, bilayer formation, and lightning‐rod effect localized at WOx/NbOx interface can explain the improved switching behavior in this novel stack. Excellent device characteristics such as lower switching voltage, fast switching speed (100 ns), high‐temperature retention (>104 s, 85 °C), stable cycling endurance (107 cycles), almost 100% device yield and excellent switching uniformity are obtained.

[1]  H. Hwang,et al.  Resistive switching characteristics and mechanism of thermally grown WOx thin films , 2011 .

[2]  B. Park,et al.  Unipolar resistive switching in insulating niobium oxide film and probing electroforming induced metallic components , 2011 .

[3]  N. Singh,et al.  $\hbox{HfO}_{x}/\hbox{TiO}_{x}/\hbox{HfO}_{x}/ \hbox{TiO}_{x}$ Multilayer-Based Forming-Free RRAM Devices With Excellent Uniformity , 2011, IEEE Electron Device Letters.

[4]  Hyunsang Hwang,et al.  Effect of ZrOx/HfOx bilayer structure on switching uniformity and reliability in nonvolatile memory applications , 2010 .

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

[6]  H. Hwang,et al.  Excellent Switching Uniformity of Cu-Doped $\hbox{MoO}_{x}/\hbox{GdO}_{x}$ Bilayer for Nonvolatile Memory Applications , 2009, IEEE Electron Device Letters.

[7]  C. Hwang,et al.  The conical shape filament growth model in unipolar resistance switching of TiO2 thin film , 2009 .

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

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

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

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

[12]  Byung Joon Choi,et al.  Resistive Switching in Pt ∕ Al2O3 ∕ TiO2 ∕ Ru Stacked Structures , 2006 .

[13]  Byung Joon Choi,et al.  Identification of a determining parameter for resistive switching of TiO2 thin films , 2005 .

[14]  Dr.-Ing.B. Rumpf.  Thermochemical Data of Pure Substances , 1997 .