Retentivity of RRAM Devices Based on Metal / YBCO Interfaces

ABSTRACTThe retention time of the resistive state is a key parameter that characterizes the possible utilization of the RRAM devices as a non – volatile memory device. The understanding of the mechanism of the time relaxation process of the information state may be essential to improve their performances. In this study we examine RRAM devices based on metal / YBCO interfaces in order to comprehend the physics beneath the resistive switching phenomenon.Our experimental results show that after producing the switching of the resistance from a low to a high state, or vice versa, the resistance evolves to its previous state in a small but noticeable percentage. We have measured long relaxation effects on the resistance state of devices composed by metal (Au, Pt) / ceramic YBCO interfaces in the temperature range 77 K – 300 K. This time relaxation can be described by a stretched exponential law that is characterized by a power exponent n = 0.5, which is temperature independent, and by a relaxation time τ that increases with increasing the temperature. These characteristics point out to a non-thermally assisted diffusion process that could be associated with oxygen (or vacancy) migration and that produces the growth of a conducting (or insulating) fractal structure.

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Investigation of Switching Phenomenon in Metal-Tantalum Oxide Interface

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2015.11133 ◽

2015 ◽

Vol 15 (10) ◽

pp. 7564-7568 ◽

Cited By ~ 5

Author(s):

Abbas Yawar ◽

Mi Ra Park ◽

Quanli Hu ◽

Woo Jin Song ◽

Tae-Sik Yoon ◽

...

Keyword(s):

Low Voltage ◽

Tantalum Oxide ◽

High Resistance State ◽

Amorphous Layer ◽

Memory Device ◽

Ohmic Conduction ◽

Oxide Interface ◽

Bipolar Switching ◽

Switching Phenomenon ◽

Resistance State

To investigate the nature of the switching phenomenon at the metal-tantalum oxide interface, we fabricated a memory device in which a tantalum oxide amorphous layer acted as a switching medium. Different metals were deposited on top of the tantalum oxide layer to ensure that they will react with some of the oxygen contents already present in the amorphous layer of the tantalum oxide. This will cause the formation of metal oxide (MOx) at the interface. Two devices with Ti and Cu as the top electrodes were fabricated for this purpose. Both devices showed bipolar switching characteristics. The SET and RESET voltages for the Ti top electrode device were ∼+1.7 V and ∼−2 V, respectively, whereas the SET and RESET voltages for the Cu top electrode device were ∼+0.9 V and ∼−0.9 V, respectively. In the high-resistance state (HRS) conduction, the mechanisms involved in the devices with Ti and Cu top electrodes were space-charge limited conduction (SCLC) and ohmic, respectively. On the other hand, in the low-resistance state (LRS), the Ti top electrode device undergoes SCLC at a high voltage and ohmic conduction at a low voltage, and the Cu top electrode again undergoes ohmic conduction. From the consecutive sweep cycles, it was observed that the SET voltage gradually decreased with the sweeps for the Cu top electrode device, whereas for the Ti top electrode device, the set voltage did not vary with the sweeps.

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Front Cover: Stabilization of Pristine Low Resistive State in a Ruthenium(II)-Polymer of a Hexadentate Schiff Base Ligand: Synthesis, Characterization, and Application as Non-Volatile Memory Device (Eur. J. Inorg. Chem. /2020)

European Journal of Inorganic Chemistry ◽

10.1002/ejic.202000739 ◽

2020 ◽

Author(s):

Deepa Oberoi ◽

Parveen Dagar ◽

Uday Shankar ◽

Satyajit Sahu ◽

Anasuya Bandyopadhyay

Keyword(s):

Schiff Base ◽

Schiff Base Ligand ◽

Memory Device ◽

Resistive State ◽

Front Cover ◽

Non Volatile Memory ◽

Volatile Memory ◽

Ligand Synthesis

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Stabilization of Pristine Low Resistive State in a Ruthenium(II)-Polymer of a Hexadentate Schiff Base Ligand: Synthesis, Characterization, and Application as Non-Volatile Memory Device

European Journal of Inorganic Chemistry ◽

10.1002/ejic.202000303 ◽

2020 ◽

Author(s):

Deepa Oberoi ◽

Parveen Dagar ◽

Uday Shankar ◽

Satyajit Sahu ◽

Anasuya Bandyopadhyay

Keyword(s):

Schiff Base ◽

Schiff Base Ligand ◽

Memory Device ◽

Resistive State ◽

Non Volatile Memory ◽

Volatile Memory ◽

Ligand Synthesis

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Polymer-based non-volatile resistive random-access memory device fabrication with multi-level switching and negative differential resistance state

Organic Electronics ◽

10.1016/j.orgel.2021.106228 ◽

2021 ◽

pp. 106228

Author(s):

Sobia Ali Khan ◽

Mehr Khalid Rahmani ◽

HyungWon Kim ◽

Muhammad Farooq Khan ◽

Changhun Yun ◽

...

Keyword(s):

Negative Differential Resistance ◽

Random Access ◽

Random Access Memory ◽

Differential Resistance ◽

Memory Device ◽

Resistive Random Access Memory ◽

Device Fabrication ◽

Access Memory ◽

Resistance State ◽

Multi Level

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Gradually Modified Conductance in the Self-Compliance Region of an Atomic-Layer-Deposited Pt/TiO2/HfAlOx/TiN RRAM Device

Metals ◽

10.3390/met11081199 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1199

Author(s):

Hojeong Ryu ◽

Sungjun Kim

Keyword(s):

Photoelectron Spectroscopy ◽

Depth Profiling ◽

Atomic Layer ◽

High Resistance State ◽

Long Term Potentiation ◽

Memory Device ◽

Bipolar Resistive Switching ◽

Term Potentiation ◽

Resistance State ◽

Neuromorphic System

This study presents conductance modulation in a Pt/TiO2/HfAlOx/TiN resistive memory device in the compliance region for neuromorphic system applications. First, the chemical and material characteristics of the atomic-layer-deposited films were verified by X-ray photoelectron spectroscopy depth profiling. The low-resistance state was effectively controlled by the compliance current, and the high-resistance state was adjusted by the reset stop voltage. Stable endurance and retention in bipolar resistive switching were achieved. When a compliance current of 1 mA was imposed, only gradual switching was observed in the reset process. Self-compliance was used after an abrupt set transition to achieve a gradual set process. Finally, 10 cycles of long-term potentiation and depression were obtained in the compliance current region for neuromorphic system applications.

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Hysteresis Behavior of the Donor–Acceptor-Type Ambipolar Semiconductor for Non-Volatile Memory Applications

Micromachines ◽

10.3390/mi12030301 ◽

2021 ◽

Vol 12 (3) ◽

pp. 301

Author(s):

Young Jin Choi ◽

Jihyun Kim ◽

Min Je Kim ◽

Hwa Sook Ryu ◽

Han Young Woo ◽

...

Keyword(s):

Organic Semiconductor ◽

Field Effect ◽

Field Effect Transistor ◽

Memory Device ◽

Non Volatile Memory ◽

Device Applications ◽

Donor Acceptor ◽

Effect Transistor ◽

Volatile Memory ◽

Memory Applications

Donor–acceptor-type organic semiconductor molecules are of great interest for potential organic field-effect transistor applications with ambipolar characteristics and non-volatile memory applications. Here, we synthesized an organic semiconductor, PDPPT-TT, and directly utilized it in both field-effect transistor and non-volatile memory applications. As-synthesized PDPPT-TT was simply spin-coated on a substrate for the device fabrications. The PDPPT-TT based field-effect transistor showed ambipolar electrical transfer characteristics. Furthermore, a gold nanoparticle-embedded dielectric layer was used as a charge trapping layer for the non-volatile memory device applications. The non-volatile memory device showed clear memory window formation as applied gate voltage increases, and electrical stability was evaluated by performing retention and cycling tests. In summary, we demonstrate that a donor–acceptor-type organic semiconductor molecule shows great potential for ambipolar field-effect transistors and non-volatile memory device applications as an important class of materials.

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Hydrothermal Synthesis of Lead Titanate Epitaxial Film for Non-Volatile Memory Device Application

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.652-654.1846 ◽

2013 ◽

Vol 652-654 ◽

pp. 1846-1850

Author(s):

Thin Thin Thwe ◽

Than Than Win ◽

Yin Maung Maung ◽

Ko Ko Kyaw Soe

Keyword(s):

Electron Microscopy ◽

Silicon Dioxide ◽

Lead Titanate ◽

Conduction Mechanism ◽

Epitaxial Film ◽

Memory Device ◽

X Ray Diffraction ◽

X Ray ◽

Non Volatile Memory ◽

Scanning Electron

Hydrothermal synthesized lead titanate (PbTiO3¬) powder was prepared in a Teflon-lined stainless steel bomb at different bath temperatures. X-ray diffraction was performed to examine the phase assignment and crystallographic properties of hydrothermal synthesized lead titanate powder. Silicon dioxide (SiO2) was thermally deposited and adapted as intermediate layer on p-Si (100) substrates for MFIS (Metal/Ferroelectric/ Insulator/Semi-conductor) design. The microstructures of PbTiO3 film for both MFS and MFIS designs were observed by scanning electron microscopy (SEM). Charge conduction mechanism was also interpreted by C-2-V relationship. Polarization and electric field characteristics were measured by Sawyer-Tower circuit and good hysteresis nature was formed for both structures of the films. The loop of MFIS was wider than that of MFS cell. Also, the higher value of polarization (Ps=3.21E-03µC/cm2) for MFIS could be explained on the basis of higher dipole moment in this SiO2 buffer layer.

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