scholarly journals Electrically programmable magnetoresistance in $$\text{AlO}_{x}$$-based magnetic tunnel junctions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jhen-Yong Hong ◽  
Chen-Feng Hung ◽  
Kui-Hon Ou Yang ◽  
Kuan-Chia Chiu ◽  
Dah-Chin Ling ◽  
...  
Keyword(s):  
Resistive Switching ◽  
Magnetic Tunnel Junction ◽  
High Resistance State ◽  
Resistive State ◽  
Bipolar Resistive Switching ◽  
Spin Dependent Transport ◽  
Electric And Magnetic Fields ◽  
Potential Applications ◽  
Resistance State ◽  
Dependent Transport

AbstractWe report spin-dependent transport properties and I–V hysteresis characteristics in an $$\text{AlO}_{x}$$ AlO x -based magnetic tunnel junction (MTJ). The bipolar resistive switching and the magnetoresistances measured at high resistance state (HRS) and low resistance state (LRS) yield four distinctive resistive states in a single device. The temperature dependence of resistance at LRS suggests that the resistive switching is not triggered by the metal filaments within the $$\text{AlO}_{x}$$ AlO x layer. The role played by oxygen vacancies in $$\text{AlO}_{x}$$ AlO x is the key to determine the resistive state. Our study reveals the possibility of controlling the multiple resistive states in a single $$\text{AlO}_{x}$$ AlO x -based MTJ by the interplay of both electric and magnetic fields, thus providing potential applications for future multi-bit memory devices.

Two modes of bipolar resistive switching characteristics in asymmetric TaOx-based ReRAM cells

MRS Advances ◽  
2019 ◽  
Vol 4 (48) ◽  
pp. 2601-2607
Author(s):  
Toshiki Miyatani ◽  
Yusuke Nishi ◽  
Tsunenobu Kimoto
Keyword(s):  
Resistive Switching ◽  
High Resistance State ◽  
Opposite Polarity ◽  
Electrical Characteristics ◽  
Forming Process ◽  
Initial State ◽  
Bipolar Resistive Switching ◽  
Change Mechanism ◽  
Resistance State ◽  
Switching Characteristics

ABSTRACTImpacts of a forming process on bipolar resistive switching (RS) characteristics in Pt/TaOx/Ta2O5/Pt cells were investigated. We found that the forming resulted in a transition from an initial state to a particular high resistance state (HRS) in most of the Pt/TaOx/Ta2O5/Pt cells. Evaluation of electrical characteristics after the transition to the particular HRS revealed that two modes of bipolar RS with the conventional polarity based on valence change mechanism and with the opposite polarity could be selectively obtained by adjusting the magnitude of the applied voltage. Moreover, the cell resistance decreased gradually during set processes in the bipolar RS with the opposite polarity.

scholarly journals Effects of Sm2O3 and V2O5 Film Stacking on Switching Behaviors of Resistive Random Access Memories

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 318
Author(s):  
Lin ◽  
Wu ◽  
Chen
Keyword(s):  
Resistive Switching ◽  
Random Access ◽  
Single Layer ◽  
High Resistance State ◽  
Switching Behavior ◽  
Bipolar Resistive Switching ◽  
Compliance Behavior ◽  
Order Of Magnitude ◽  
Resistance State ◽  
Switching Characteristics

: In this work, the resistive switching characteristics of resistive random access memories (RRAMs) containing Sm2O3 and V2O5 films were investigated. All the RRAM structures made in this work showed stable resistive switching behavior. The High-Resistance State and Low-Resistance State of Resistive memory (RHRS/RLRS) ratio of the RRAM device containing a V2O5/Sm2O3 bilayer is one order of magnitude higher than that of the devices containing a single layer of V2O5 or Sm2O3. We also found that the stacking sequence of the Sm2O3 and V2O5 films in the bilayer structure can affect the switching features of the RRAM, causing them to exhibit both bipolar resistive switching (BRS) behavior and self-compliance behavior. The current conduction mechanisms of RRAM devices with different film structures were also discussed.

Bipolar resistive switching characteristics of samarium oxide solid electrolyte thin films for non-volatile memory applications

2019 ◽  
Vol 12 (03) ◽  
pp. 1950023
Author(s):  
Mei Ji ◽  
Yangjiang Wu ◽  
Zhengzhong Zhang ◽  
Ya Wang ◽  
Hao Liu
Keyword(s):  
Thin Films ◽  
Solid Electrolyte ◽  
Resistive Switching ◽  
High Resistance State ◽  
High Yield ◽  
Bipolar Resistive Switching ◽  
Non Volatile Memory ◽  
Resistance State ◽  
Volatile Memory ◽  
Oxide Solid Electrolyte

In this paper, we report the bipolar resistive switching behaviors in Ag/Sm2O3/Pt structures where the Sm2O3 thin films act as solid electrolyte layer of electrochemical metallization memory (ECM) devices. The memory devices show reproducible and stable bipolar resistive switching over 1000 cycles with a resistance ratio (high-resistance state to low-resistance state) of over 4 orders of magnitude and stable retention for over 104[Formula: see text]s at room temperature. Moreover, the benefits of high yield and multilevel storage possibility make the device promising in the next generation non-volatile memory application.

scholarly journals Gradually Tunable Conductance in TiO2/Al2O3 Bilayer Resistors for Synaptic Device

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 440
Author(s):  
Hojeong Ryu ◽  
Sungjun Kim
Keyword(s):  
Resistive Switching ◽  
Strong Electric Field ◽  
Single Layer ◽  
High Resistance State ◽  
Forming Process ◽  
Initial State ◽  
Conduction Model ◽  
Bipolar Resistive Switching ◽  
Trap Assisted Tunneling ◽  
Resistance State

In this work, resistive switching and synaptic behaviors of a TiO2/Al2O3 bilayer device were studied. The deposition of Pt/Ti/TiO2/Al2O3/TiN stack was confirmed by transmission electron microscopy (TEM) and energy X-ray dispersive spectroscopy (EDS). The initial state before the forming process followed Fowler-Nordheim (FN) tunneling. A strong electric field was applied to Al2O3 with a large energy bandgap for FN tunneling, which was confirmed by the I-V fitting process. Bipolar resistive switching was conducted by the set process in a positive bias and the reset process in a negative bias. High-resistance state (HRS) followed the trap-assisted tunneling (TAT) model while low-resistance state (LRS) followed the Ohmic conduction model. Set and reset operations were verified by pulse. Moreover, potentiation and depression in the biological synapse were verified by repetitive set pulses and reset pulses. Finally, the device showed good pattern recognition accuracy (~88.8%) for a Modified National Institute of Standards and Technology (MNIST) handwritten digit database in a single layer neural network including the conductance update of the device.

scholarly journals Nonideal resistive and synaptic characteristics in Ag/ZnO/TiN device for neuromorphic system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jongmin Park ◽  
Hojeong Ryu ◽  
Sungjun Kim
Keyword(s):  
Resistive Switching ◽  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Bipolar Resistive Switching ◽  
Applied Pulse ◽  
Negative Effect ◽  
Endurance Tests ◽  
Resistance State ◽  
The Impact

AbstractIdeal resistive switching in resistive random-access memory (RRAM) should be ensured for synaptic devices in neuromorphic systems. We used an Ag/ZnO/TiN RRAM structure to investigate the effects of nonideal resistive switching, such as an unstable high-resistance state (HRS), negative set (N-set), and temporal disconnection, during the set process and the conductance saturation feature for synaptic applications. The device shows an I–V curve based on the positive set in the bipolar resistive switching mode. In 1000 endurance tests, we investigated the changes in the HRS, which displays large fluctuations compared with the stable low-resistance state, and the negative effect on the performance of the device resulting from such an instability. The impact of the N-set, which originates from the negative voltage on the top electrode, was studied through the process of intentional N-set through the repetition of 10 ON/OFF cycles. The Ag/ZnO/TiN device showed saturation characteristics in conductance modulation according to the magnitude of the applied pulse. Therefore, potentiation or depression was performed via consecutive pulses with diverse amplitudes. We also studied the spontaneous conductance decay in the saturation feature required to emulate short-term plasticity.

scholarly journals Irregular Resistive Switching Behaviors of Al2O3-Based Resistor with Cu Electrode

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 653
Author(s):  
Hojeong Ryu ◽  
Sungjun Kim
Keyword(s):  
Resistive Switching ◽  
Photoelectron Spectroscopy ◽  
Complementary Metal Oxide Semiconductor ◽  
High Resistance State ◽  
Oxide Semiconductor ◽  
Bipolar Resistive Switching ◽  
Thin Film Layer ◽  
Film Layer ◽  
Resistance State ◽  
Al2o3 Thin Film

In this work, we examined the irregular resistive switching behaviors of a complementary metal–oxide–semiconductor (CMOS)-compatible Cu/Al2O3/Si resistor device. X-ray photoelectron spectroscopy (XPS) analysis confirmed the chemical and material compositions of a Al2O3 thin film layer and Si substrate. Bipolar resistive switching occurred in a more stable manner than the unipolar resistive switching in the device did. Five cells were verified over 50 endurance cycles in terms of bipolar resistive switching, and a good retention was confirmed for 10,000 s in the high-resistance state (HRS) and the low-resistance state (LRS). Both high reset current (~10 mA) and low reset current (<100 μA) coexisted in the bipolar resistive switching. We investigated nonideal resistive switching behaviors such as negative-set and current overshoot, which could lead to resistive switching failure.

Resistive switching of multiferroic BiCoO3 nanoflowers

2015 ◽  
Vol 08 (01) ◽  
pp. 1550001 ◽  
Author(s):  
Bai Sun ◽  
Qiling Li ◽  
Yonghong Liu ◽  
Peng Chen
Keyword(s):  
Resistive Switching ◽  
High Resistance ◽  
Hydrothermal Process ◽  
High Resistance State ◽  
Bipolar Resistive Switching ◽  
Low Resistance ◽  
Current Voltage ◽  
Extreme Change ◽  
Resistance State ◽  
Switching Characteristics

Multiferroic BiCoO 3 nanoflowers were synthesized by a hydrothermal process. The BiCoO 3 nanoflowers show superior bipolar resistive switching characteristics. The typical current–voltage (I–V) characteristics of the Ag / BiCoO 3/ Ag structures exhibit an extreme change in resistance between high resistance state (HRS) or "OFF" state and low resistance state (LRS) or "ON" state with ON/OFF ratio ~ 105.

scholarly journals Bipolar resistive switching on Ti/TiO2/NiCr memory cells

2017 ◽  
Vol 30 (4) ◽  
pp. 65-68
Author(s):  
Eric Hernandez Rodriguez ◽  
Alfredo Marquez Herrera ◽  
Miguel Melendez Lira ◽  
Enrique Valaguez Velazquez ◽  
Martin Zapata Torres
Keyword(s):  
Thin Films ◽  
Resistive Switching ◽  
Rf Sputtering ◽  
High Resistance State ◽  
Switching Behavior ◽  
Emission Model ◽  
Tio2 Thin Films ◽  
Bipolar Resistive Switching ◽  
Metal Insulator Metal ◽  
Resistance State

We investigated the electric-field-induced resistance-switching behavior of metal-insulator-metal (MIM) cells based on TiO2 thin films fabricated by the reactive RF-sputtering technique. MIM cells were constructed by sandwiched TiO2 thin films between a pair of electrodes; Ti thin films were employed to form an ohmic bottom contact and NiCr thin films were employed to form Schottky top electrodes obtaining Ti/TiO2/NiCr MIM cells. Schottky barrier height for the TiO2/NiCr junction was determined according to the thermionic emission model by using the Cheung´s functions. SEM and Raman analysis of the TiO2 thin films were carried out to ensure the quality of the films. Current-Voltage (I-V) sweeps obtained at room temperature by the application of dc bias showed a bipolar resistive switching behavior on the cells. Both low resistance state (ON state) and high resistance state (OFF state), of Ti/TiO2/NiCr cells are stable and reproducible during a successive resistive switching. The resistance ratio of ON and OFF state is over 103 and the retention properties of both states are very stable after 105 s with a voltage test of 0.1 V.

scholarly journals Резистивное переключение в структурах металл-оксид-полупроводник с наноостровками GeSi на подложке кремния

2020 ◽  
Vol 90 (10) ◽  
pp. 1741
Author(s):  
С.В. Тихов ◽  
В.Г. Шенгуров ◽  
С.А. Денисов ◽  
И.Н. Антонов ◽  
А.В. Круглов ◽  
...  
Keyword(s):  
Resistive Switching ◽  
High Resistance ◽  
High Resistance State ◽  
Metal Electrode ◽  
Semiconductor Interface ◽  
Bipolar Resistive Switching ◽  
Low Resistance ◽  
Resistance State ◽  
Intrinsic Photosensitivity ◽  
Mos Structures

The self-assembled GeSi nanoislands built into the semiconductor-insulator interface of the MOS-structures based on Si(001) with SiOx and ZrO2(Y) oxide layers deposited by magnetron sputtering have been shown to initiate bipolar resistive switching without preliminary electroforming. The current-voltage curves and electrical parameters of the MOS-structures in the high-resistance state and in the low-resistance state have been studied. A change in the built-in charge in the dielectric near the insulator-semiconductor interface during resistive switching is established and associated with the formation and destruction of conductive filaments. The light-stimulated resistive switching of MOS-structures with ZrO2(Y) layer from the high-resistance to the low-resistance state is observed, which is associated with an increase in the conductivity of the space-charge region in the Si substrate due to interband optical absorption in Si, which causes a voltage redistribution between Si and ZrO2(Y) layer. A difference in the shape of the small signal photo-voltage spectra of MOS-structures is found in the spectral region of intrinsic photosensitivity of Si in the high and low resistance states due to the leakage of photo-excited charge carriers from Si to the metal electrode through filaments.

scholarly journals Bias Polarity Dependent Threshold Switching and Bipolar Resistive Switching of TiN/TaOx/ITO Device

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1531
Author(s):  
Hojeong Ryu ◽  
Beomjun Park ◽  
Sungjun Kim
Keyword(s):  
Resistive Switching ◽  
Indium Tin Oxide ◽  
Conduction Mechanism ◽  
High Resistance State ◽  
Positive Bias ◽  
Ohmic Conduction ◽  
Pulse Operation ◽  
Bipolar Resistive Switching ◽  
Threshold Switching ◽  
Resistance State

In this work, we demonstrate the threshold switching and bipolar resistive switching with non-volatile property of TiN/TaOx/indium tin oxide (ITO) memristor device. The intrinsic switching of TaOx is preferred when a positive bias is applied to the TiN electrode in which the threshold switching with volatile property is observed. On the other hand, indium diffusion could cause resistive switching by formation and rupture of metallic conducting filament when a positive bias and a negative bias are applied to the ITO electrode for set and reset processes. The bipolar resistive switching occurs both with the compliance current and without the compliance current. The conduction mechanism of low-resistance state (LRS) and high-resistance state (HRS) are dominated by Ohmic conduction and Schottky emission, respectively. Finally, threshold switching and bipolar resistive switching are verified by pulse operation.

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