Filamentary switching of ReRAM investigated by in-situ TEM

Abstract

The filament operation of resistive random-access memory (ReRAM) was studied via in-situ transmission electron microscopy (in-situ TEM), and the contribution of the conductive filament to the resistance switching was experimentally confirmed. In addition to the operation principles, the device degradation mechanism was studied through repeated write/erase operations. The importance of controlling Cu movement in the switching layer was confirmed for stable CBRAM (conductive bridge random access memory) operations. A device structure with double switching layers and device miniaturization was effective in restricting over accumulation of Cu in the switching layer and localizing the filament. This may improve the robustness of the device against performance degradation.

Top electrode modulated W/Ag/MgO/Au resistive random access memory for improved electronic synapse performance

“…[34][35][36] This high degree of crystallinity shows high mobility of Ag + species within the switching layer, forming percolation paths for the formation and rupture of the filament during the repeated ON/OFF cycle. [35][36][37][38][39][40] EDX scan and mapping are conducted on the cross-sectioned samples to confirm the chemical information of the conducting filament. Figure S6 in the supplementary material shows the crosssectioned TEM EDX scan mapping of the filament region of sample C. It is important to note that the W signal remains stable and uniform throughout the sample.…”

Low‐Frequency‐Noise Spectroscopy of TaOx‐based Resistive Switching Memory

“…The fundamental mechanism for the transition between the high‐resistive state (HRS) and low‐resistive state (LRS) in ReRAM cells is the nanoscale redox reaction involving oxygen ion migration. [ 7–15 ] Redox reactions are observed in various oxides that can be handled in a process compatible with existing semiconductor technologies, which support the practical application and commercialization of ReRAM. [ 16 ] One of the advantages of resistance changes in ReRAM is the high resistance change ratio, and it is possible to control the resistance change in an analog manner.…”

“…The fundamental mechanism for the transition between the high-resistive state (HRS) and low-resistive state (LRS) in ReRAM cells is the nanoscale redox reaction involving oxygen ion migration. [7][8][9][10][11][12][13][14][15] Redox low temperature to room temperature. The temperature dependence of the noise spectra at given frequencies revealed that multiple trap levels exist and that they are related to the electrical resistance of the device.…”

Forming-Free, Low-Voltage, and High-Speed Resistive Switching in Ag/Oxygen-Deficient Vanadium Oxide(VOx)/Pt Device through Two-Step Resistance Change by Ag Filament Formation

“…The device for RRAM operates via the resistive switching of the MIM structure between a high-resistance state (HRS) and a low-resistance state (LRS) using the formation and rupture of conducting filaments or the modulation of the oxide−metal interface. 1 To date, the performance of oxide-based RRAM has been substantially improved using various materials such as HfO 2 , 2 Al 2 O 3 , 3 TiO x , 4,5 ZnO, 6 CeO 2 , 7 and Fe 2 O 3 . 8 In particular, filament-based switching devices are classified as valence change memory (VCM) or conductive-bridge random access memory (CBRAM) devices depending on whether the filament is composed of oxygen vacancies (V o ) or metal cations generated from active electrodes, respectively.…”

“…The device for RRAM operates via the resistive switching of the MIM structure between a high-resistance state (HRS) and a low-resistance state (LRS) using the formation and rupture of conducting filaments or the modulation of the oxide–metal interface . To date, the performance of oxide-based RRAM has been substantially improved using various materials such as HfO 2 , Al 2 O 3 , TiO x , , ZnO, CeO 2 , and Fe 2 O 3 .…”