Effects of Electric Fields on the Switching Properties Improvements of RRAM Device With a Field-Enhanced Elevated-Film-Stack Structure

Chuang, Kai-Chi; Lin, Kuan‐Yu; Luo, Jun-Dao; Li, Weishuo; Chu, Chien Wei; Cheng, Hsiu‐Fung

doi:10.1109/jeds.2018.2832542

Cited by 8 publications

(3 citation statements)

References 18 publications

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“…Therefore, using photolithography, nine ReRAM structures with an operational area of 25×8 μm 2 are fabricated to overlap with the waveguide path. The resulting ReRAM structure resembles the elevated-film-stack (EFS) ReRAM structure previously reported in [8]. This EFS structure with enhanced local electric fields can improve the uniformity of ReRAM devices while at the same time reducing operating voltages.…”

Section: Introductionsupporting

confidence: 64%

Lithium niobate long-period waveguide gratings integrated with bismuth ferrite (BiFeO3) resistive random access memory

Chuang,

Chang,

Huang

2024

Oxide-Based Materials and Devices XV

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We report the miniaturization of Ag/BiFeO3/ITO resistive random access memory (ReRAM) in the form of long-period waveguide grating, all fabricated entirely on z-cut lithium niobate (LiNbO3) substrate. The electric characterization vividly reveals a selector-like threshold-switching (TS) characteristic. It is well accepted that there are two filament formation mechanisms governing the operation of Ag/BiFeO3/ITO ReRAM, a two-side TS characteristic is typically generated when the positive and negative bias voltages are applied during the cycles. It is reasonable to believe the TS characteristic exists because the Joule heat produced during device operation cannot be dissipated effectively, resulting in the rupture of the conductive filament. To mitigate this shortcoming, replacing the BiFeO3 (BFO) layer of the original grating shape with a planar-layer structure is beneficial for heat dissipation, and this, in turn, would help to improve the characteristics of the ReRAM device by delivering the memory-switching characteristics as intended. As already mentioned, this ReRAM structure with the ITO bottom electrode fabricated over the lithium niobate waveguide can jointly serve as the long-period waveguide grating. Furthermore, when the Ag/BFO/ITO ReRAM structure's device area shrinks to 200 μm 2 , the growth path of the silver conductive filament is confined immediately above the lithium niobate waveguide. The corresponding spectral measurement shows that as the increasing number of ReRAM grating fingers are in the set state (silver conductive filaments formed), the energy of the transmission dips would decrease gradually in return, and during the reset state, the energy of the transmission dip would rise accordingly.

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Section: Introductionsupporting

confidence: 64%

Lithium niobate long-period waveguide gratings integrated with bismuth ferrite (BiFeO3) resistive random access memory

Chuang,

Chang,

Huang

2024

Oxide-Based Materials and Devices XV

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“…Over the past decade, several approaches employing “edge effects” have been developed to improve the switching uniformity and reliability of RRAM devices. For instance, Liu and co-workers embedded nanoparticles in the switching matrix to regulate its microstructure and distribution of the internal electric field, ,, whereas Ryoo et al used staggered active layers to achieve the same target. , Although the resultant devices show enhanced performance in comparison with that of the controlled samples, there are still rooms for further optimization since the placement of the nanoparticles nor the wrinkle patterns of the staggered layers cannot be controlled exactly during thin film deposition. Multiple nanoscale conductive filaments may be formed throughout the entire device area with a typical size of 100 nm to 10 μm, the random evolution of which can still lead to deteriorated switching uniformity.…”

Section: Resultsmentioning

confidence: 99%

Controlled Construction of Atomic Point Contact with 16 Quantized Conductance States in Oxide Resistive Switching Memory

Chen

Liu

Xue

et al. 2019

ACS Appl. Electron. Mater.

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A resistive switching device with controlled formation and evolution of conductive filament possesses great capability of being miniaturized to atomic scale for the construction of high-density memory arrays and even in-memory computing architectures. Although the switching mechanism based on ion migration and electrochemistry has been clarified, precise control of the evolution dynamics is still a challenge that hinders the direct application of the memory devices. In this contribution, we propose an effective scanning probe microscope tip-assisted approach for the performance modulation of oxide-based resistive switching devices. The directional migration of oxygen anions inside the hafnium oxide nanofilm is regulated by using the voltage-biased scanning probe microscope (SPM) tip as a microelectrode, so that a single filament would be formed deliberately inside the switching matrix to greatly improve the stability and reliability of the memory device. The variations of the switching parameters, e.g. programming voltages and ON/OFF resistances, have been reduced by at least 33%. More importantly, the elaborate tuning of the filament dimension also gives rise to single atomic point contact in the resistive switching device, producing at least 16 half-integer multiples of quantized conductance states that can be used for multilevel data storage and high-order neuromorphic computing paradigm.

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“…Resistive random access memory (RRAM) devices using transition metal oxides (TMOs) such as TiO x [1], ZrO x [2], AlO x [3]- [4], HfO x [5]- [6], and TaO x [7]- [8] as resistive switching layers (RSLs) have been proposed and considered as promising future alternatives to next-generation nonvolatile memory, owing to their advantages of fast writing ability and read access, low power consumption, highdensity integration, long retention time, and CMOS process compatibility [9]- [14]. Furthermore, a RRAM device with analog resistive switching can behave synaptic characteristics by applying consecutive voltage sweeps or pulses appropriately, and this kind of RRAM device is considered a promising candidate for neuromorphic applications.…”

Section: Introductionmentioning

confidence: 99%

Impact of the Stacking Order of HfO_x and AlO_x Dielectric Films on RRAM Switching Mechanisms to Behave Digital Resistive Switching and Synaptic Characteristics

Chuang

Chu

Yang

et al. 2019

IEEE J. Electron Devices Soc.

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Resistive random access memory (RRAM) devices with analog resistive switching are expected to be beneficial for neuromorphic applications, and consecutive voltage sweeps or pulses can be applied to change the device conductance and behave synaptic characteristics. In this paper, RRAM devices with a reverse stacking order of 6-nm-thick HfO x and 2-nm-thick AlO x dielectric films were fabricated. The device with TiN/Ti/AlO x /HfO x /TiN stacked layers exhibited digital resistive switching, while the other device with TiN/Ti/HfO x /AlO x /TiN stacked layers could demonstrate synaptic characteristics that were analog set and reset processes under consecutive positive and negative voltage sweeps or a train of potentiation and depression pulses. Moreover, this device could also implement synaptic learning rules, spike-timing-dependent plasticity (STDP). Varying temperature measurements and linear fittings of the measured data were conducted to analyze current conduction mechanisms. As a result, the variation of resistive switching behavior between these two devices is attributed to the varying effectiveness of the oxygen scavenging ability of the Ti layer when put into contact with either AlO x or HfO x . Moreover, AlO x functioned as a diffusion limiting layer (DLL) in the device with TiN/Ti/HfO x /AlO x /TiN stacked layers, and gradual modulation of the production and annihilation of oxygen vacancies is the cause of synaptic characteristics.INDEX TERMS Resistive random access memory (RRAM), bilayered dielectric films, synaptic characteristics, diffusion limiting layer (DLL), conductive filament (CF), spike-timing-dependent plasticity (STDP).

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Effects of Electric Fields on the Switching Properties Improvements of RRAM Device With a Field-Enhanced Elevated-Film-Stack Structure

Cited by 8 publications

References 18 publications

Lithium niobate long-period waveguide gratings integrated with bismuth ferrite (BiFeO3) resistive random access memory

Lithium niobate long-period waveguide gratings integrated with bismuth ferrite (BiFeO3) resistive random access memory

Controlled Construction of Atomic Point Contact with 16 Quantized Conductance States in Oxide Resistive Switching Memory

Impact of the Stacking Order of HfO_x and AlO_x Dielectric Films on RRAM Switching Mechanisms to Behave Digital Resistive Switching and Synaptic Characteristics

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Effects of Electric Fields on the Switching Properties Improvements of RRAM Device With a Field-Enhanced Elevated-Film-Stack Structure

Cited by 8 publications

References 18 publications

Lithium niobate long-period waveguide gratings integrated with bismuth ferrite (BiFeO3) resistive random access memory

Lithium niobate long-period waveguide gratings integrated with bismuth ferrite (BiFeO3) resistive random access memory

Controlled Construction of Atomic Point Contact with 16 Quantized Conductance States in Oxide Resistive Switching Memory

Impact of the Stacking Order of HfO x and AlO x Dielectric Films on RRAM Switching Mechanisms to Behave Digital Resistive Switching and Synaptic Characteristics

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Impact of the Stacking Order of HfO_x and AlO_x Dielectric Films on RRAM Switching Mechanisms to Behave Digital Resistive Switching and Synaptic Characteristics