Uncovering the Indium Filament Revolution in Transparent Bipolar ITO/SiO_x/ITO Resistive Switching Memories

Abstract

Transparent resistive switching random access memory (ReRAM) is of interest for the future integrated invisible circuitry. However, poor understanding of its working mechanism in transparent ReRAMs with the indium tin oxide (ITO) electrode is still a critical problem and will hinder its widespread applications. To reveal the actual working mechanism in transparent ReRAMs with the ITO electrode, we investigate the transparent ITO/SiO x /ITO memory devices (∼82% transmittance in the visible region) and compare it with ITO/SiO x /Au memory devices, which both can exhibit reproducible bipolar switching. The indium (In) filament evolution, which accounts for the bipolar switching behaviors in the ITO/SiO x /ITO (or Au) memories, is directly observed using transmission electron microscopy on samples with different memory states (electroformed, ON, and OFF). These studies uncover the microscopic mechanism behind the bipolar switching in SiO x -based ReRAM devices with the ITO electrode, providing a general guidance for the design of high-performance ReRAMs with large scalability and high endurance.

Uncovering the Indium Filament Formation and Dissolution in Transparent ITO/SiNx/ITO Resistive Random Access Memory

“…In these RRAMs with an ITO electrode, different switching mechanisms such as composition modulation, electron trapping/detrapping, and oxygen ion migration were reported, − ,,, which did not involve the ITO electrode. In our previous work (i.e., ITO/hBN/graphene and ITO/SiO x /Au RRAMs), , the indium (In) filaments were found to be responsible for the bipolar resistive switching behaviors, indicating that the ITO electrode can generate conductive filaments due to the In–O bond break and indium diffusion under an electric field. However, the memory devices’ behaviors and switching mechanisms are always uncertain due to their different electrical operations, different structures, and different material systems .…”

ZnO Based Resistive Random Access Memory Device: A Prospective Multifunctional Next-Generation Memory

“…24(c) and (d). Also, Qian et al [242] elaborates a transmittance of ∼ 82% at ∼ 600 nm obtained in ITO/SiO x /ITO as shown in Fig. 24(e) and (f).…”

“…Fabrication parameters strongly regulate the growth and conduction properties of TCO [254], [255]. Nevertheless, some studies have shown that the modification and manipulation of the TCO electrodes may trigger the oxygen vacancy concentration, thus, enhancing the device performance [242], [256], [257]. Various methods were proposed to deposit ZnO switching layer on TCO electrodes, like the solution-processed (sol-gel) method [167], [189], [246], [258]- [260], high-power pulse laser deposition (PLD) [238], [261]- [263], atomic layer deposition (ALD) [264], thermal-roll lamination technique [265], hydrothermal growth [266], RF magnetron sputtering [53], [151], [202], [205], [267]- [270], metal-organic chemical vapor deposition [271]- [273].…”

Design of a Controllable Redox‐Diffusive Threshold Switching Memristor

“…Electrodes in conventional electronic devices are usually used to transport paths for carriers as an auxiliary role, however, they significantly influence the switching behaviors in memristor devices. [ 2 ] On the one hand, the common electrode materials can be classified into five categories based on composition, including simple substance electrodes (most metals), alloy electrodes (e.g., Cu–Te, [ 12 ] Ag–Cu [ 13 ] ), silicon‐based electrodes (e.g., n‐Si, [ 14 ] p‐Si [ 15 ] ), nitride‐based electrodes (e.g., TiN, [ 16 ] TaN [ 17 ] ) and oxide‐based electrodes (e.g., ITO, [ 18 ] Nb‐doped SrTiO 3 [ 19 ] ). On the other hand, the common electrodes can be sorted into four types based on their functions in switching behaviors, including inert electrodes (IE, e.g., Pd, [ 20 ] Pt, [ 21 ] Ir [ 22 ] ) which has almost no effect on switching, relatively active electrodes (e.g., Ti, [ 23 ] W, [ 24 ] Ta [ 25 ] ) which is helpful for the formation of vacancy‐based CFs, active electrodes (AE, e.g., Ag, [ 26 ] Cu [ 27 ] ) which can act as the source of metallic CFs, and other electrodes for specific purposes (e.g., ITO, [ 28 ] FTO, [ 29 ] PEDOT:PSS [ 30 ] ).…”