The effect of different oxygen exchange layers on TaO_xbased RRAM devices

Abstract

In this work, we investigated the effect of the oxygen exchange layer (OEL) on the resistive switching properties of TaO x based memory cells. It was found that the forming voltage, SET-RESET voltage, R off , R on and retention properties are strongly correlated with the oxygen scavenging ability of the OEL, and the resulting oxygen vacancy formation ability of this layer. Higher forming voltage was observed for OELs having lower electronegativity/lower Gibbs free energy for oxide formation, and devices fabricated with these OELs exhibited an increased memory window, when using similar SET-RESET voltage range.

Influence of Nitrogen Adsorption of Doped Ta on Characteristics of SiNx‐Based Resistive Random Access Memory

“…It means that Ta 2 O 5 is more stable and less easily induced by external conditions. Also, specific ionic movement will be analyzed later …”

Oxygen Affinity of Metal Electrodes as Control Parameter in Tuning the Performance of CuxO‐Based Resistive Random Access Memory Devices

“…The correlation between chemical potential and switching parameters has also been demonstrated. The metal electrode (Al, Ni, or Cr in the present case) or the presence of a metal scavenging layer shifts the chemical potential of the film toward an oxygen deficient limit . A point made is that the Frenkel (vacancy + interstitial) defect formation energy is large in all oxides and lower the free energy of formation of the host oxide (Cu x O in the present case) better is the stability of switching .…”

“…The phenomena that occur at the metal/metal–oxide interface and their role in resistive switching have been discussed by several authors. These include the thermodynamics of the switching process, determined by Gibbs free energy, mobility of oxygen vacancies, and formation of conductive filaments . The filament‐based conduction mechanism was first suggested by Dearnaley et al who also mentioned that the forming voltage is directly proportional to the free energy of oxide formation .…”

“…The filament‐based conduction mechanism was first suggested by Dearnaley et al who also mentioned that the forming voltage is directly proportional to the free energy of oxide formation . There is evidence in the literature to show that these oxygen vacancies are the mobile species that are crucial for switching from HRS to LRS, i.e., the SET process . During the transition from LRS to HRS, i.e., the RESET process, one or more of the following phenomena can occur: the vacancies can move toward electrodes leaving a narrower filament or move from the filament into the resistive bulk oxide or recombine with O interstitials.…”

“…Each of these has an important role to play in determining the switching characteristics . Although much of the work focuses on the switching layer, the role of the metal–dielectric interface in determining the switching characteristics has also been discussed in reports earlier …”