scholarly journals Nano-Graphitic based Non-Volatile Memories Fabricated by the Dynamic Spray-Gun Deposition Method

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 95 ◽  
Author(s):  
Paolo Bondavalli ◽  
Marie Martin ◽  
Louiza Hamidouche ◽  
Alberto Montanaro ◽  
Aikaterini-Flora Trompeta ◽  
...  
Keyword(s):  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Deposition Method ◽  
Metal Insulator Metal ◽  
Oxidized Carbon ◽  
Resistance State ◽  
Scientific Group ◽  
First Time ◽  
Spray Gun

This paper deals with the fabrication of Resistive Random Access Memory (ReRAM) based on oxidized carbon nanofibers (CNFs). Stable suspensions of oxidized CNFs have been prepared in water and sprayed on an appropriate substrate, using the dynamic spray-gun deposition method, developed at Thales Research and Technology. This technique allows extremely uniform mats to be produced while heating the substrate at the boiling point of the solvent used for the suspensions. A thickness of around 150 nm of CNFs sandwiched between two metal layers (the metalized substrate and the top contacts) has been achieved, creating a Metal-Insulator-Metal (MIM) structure typical of ReRAM. After applying a bias, we were able to change the resistance of the oxidized layer between a low (LRS) and a high resistance state (HRS) in a completely reversible way. This is the first time that a scientific group has produced this kind of device using CNFs and these results pave the way for the further implementation of this kind of memory on flexible substrates.

Effect of Ar-plasma treatment of ITO layer on resistive memory properties of a Ti/ITO point-contact structure

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940042
Author(s):  
Chih-Yi Liu ◽  
Wan-We Chih ◽  
Chao-Kai Weng ◽  
Wei-Chen Tien ◽  
Chang-Sin Ye
Keyword(s):  
Plasma Treatment ◽  
Point Contact ◽  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Text Structure ◽  
Forming Process ◽  
Metal Insulator Metal ◽  
Resistance State ◽  
Ar Plasma

A Ti/ITO structure was used as a point-contact resistive random access memory to simplify the procedures for conventional metal/insulator/metal structures. After the forming process, a [Formula: see text] interface was formed to fabricate a [Formula: see text] structure. The [Formula: see text] structure can be reversibly switched between a high-resistance state and a low-resistance state by using dc voltages at different polarities. The resistive switching was determined by the formation and rupture of oxygen-vacancy filaments. However, the high-forming current resulted in circuit design complexity and reliability concerns. An Ar-plasma treatment was adopted to modify the ITO surface. The Ar-plasma treatment lowered the forming current and improved memory reliability. The Ar-treated sample exhibited an endurance of more than 800 cycles through dc operation and a retention time longer than [Formula: see text] at [Formula: see text], making it suitable for nonvolatile memory applications.

Resistive Switching Characteristics in TiO2 ReRAM with Top Electrode of Co Selectively Formed on SAMs Printed Patterns

2007 ◽  
Vol 124-126 ◽  
pp. 603-606
Author(s):  
Sang Hee Won ◽  
Seung Hee Go ◽  
Jae Gab Lee
Keyword(s):  
Resistive Switching ◽  
Random Access ◽  
Atomic Layer ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Tio2 Thin Films ◽  
Selective Deposition ◽  
Precise Control ◽  
Resistance State ◽  
Switching Characteristics

Simple process for the fabrication of Co/TiO2/Pt resistive random access memory, called ReRAM, has been developed by selective deposition of Co on micro-contact printed (μ-CP) self assembled monolayers (SAMs) patterns. Atomic Layer Deposition (ALD) was used to deposit TiO2 thin films, showing its ability of precise control over the thickness of TiO2, which is crucial to obtain proper resistive switching properties of TiO2 ReRAM. The fabrication process for Co/TiO2/Pt ReRAM involves the ALD of TiO2 on sputter-deposited Pt bottom electrode, followed by μ-CP with SAMs and then selective deposition of Co. This results in the Co/TiO2/Pt structure ReRAM. For comparison, Pt/TiO2/Pt ReRAM was produced and revealing the similar switching characteristics as that of Co/TiO2/Pt, thus indicating the feasibility of Co replacement with Pt top electrode. The ratios between the high-resistance state (Off state) and the low-resistance state (On state) were larger than 102. Consequently, the selective deposition of Co with μ-CP, newly developed in this study, can simplify the process and thus implemented into the fabrication of ReRAM.

Impact of resistive switching parameters on resistive random access memory crossbar arrays

2020 ◽  
Vol 34 (12) ◽  
pp. 2050115
Author(s):  
Liping Fu ◽  
Sikai Chen ◽  
Zewei Wu ◽  
Xiaoyan Li ◽  
Mingyang You ◽  
...  
Keyword(s):  
Resistive Switching ◽  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
High Density ◽  
Access Memory ◽  
Storage Density ◽  
Crossbar Array ◽  
Resistance State ◽  
Potential Impact

Sneak current issue of RRAM-based crossbar array is one of the biggest hindrances for high-density memory application. The integration of an addition selector to each cell is one of the most familiar solutions to avoid this undesired cross-talk issue, and resistive switching parameters would affect on the storage density. This paper investigates the potential impact of different resistive switching parameters on crossbar arrays with one-diode one-resistor (1D1R) and one-selector one-resistor (1S1R) architectures. Results indicate that 1S1R architecture is a more scalable technology for high-density crossbar array than 1D1R, and the storage density of 1D1R- and 1S1R-based crossbar array shows little dependence on resistance values of high-resistance state and low-resistance state, which gives a guideline for choosing appropriate selectors for RRAM crossbar array with specific parameters.

Annealing Effect of Al2O3 Tunnel Barriers in HfO2-Based ReRAM Devices on Nonlinear Resistive Switching Characteristics

2015 ◽  
Vol 15 (10) ◽  
pp. 7569-7572 ◽  
Author(s):  
Sukhyung Park ◽  
Kyoungah Cho ◽  
Jungwoo Jung ◽  
Sangsig Kim
Keyword(s):  
Resistive Switching ◽  
Conduction Mechanism ◽  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Tunnel Barrier ◽  
Tunnel Barriers ◽  
Retention Characteristics ◽  
Resistance State ◽  
Switching Characteristics

In this study, we demonstrate the enhancement of the nonlinear resistive switching characteristics of HfO2-based resistive random access memory (ReRAM) devices by carrying out thermal annealing of Al2O3 tunnel barriers. The nonlinearity of ReRAM device with an annealed Al2O3 tunnel barrier is determined to be 10.1, which is larger than that of the ReRAM device with an as-deposited Al2O3 tunnel barrier. From the electrical characteristics of the ReRAM devices with as-deposited and annealed Al2O3 tunnel barriers, it reveals that there is a trade-off relationship between nonlinearity in low-resistance state (LRS) current and the ratio of the high-resistance state (HRS) and the LRS. The enhancement of nonlinearity is attributed to a change in the conduction mechanism in the LRS of the ReRAM after the annealing. While the conduction mechanism before the annealing follows Ohmic conduction, the conduction of the ReRAM after the annealing is controlled by a trap-controlled space charge limited conduction mechanism. Additionally, the annealing of the Al2O3 tunnel barriers is also shown to improve the endurance and retention characteristics.

scholarly journals Effect of Annealing Environment on the Performance of Sol–Gel-Processed ZrO2 RRAM

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 947 ◽  
Author(s):  
Seunghyun Ha ◽  
Hyunjae Lee ◽  
Won-Yong Lee ◽  
Bongho Jang ◽  
Hyuk-Jun Kwon ◽  
...  
Keyword(s):  
Sol Gel ◽  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Access Memory ◽  
Environment Effect ◽  
Bipolar Switching ◽  
Non Volatile Memory ◽  
Retention Characteristics ◽  
Resistance State

We investigate the annealing environment effect on ZrO2-based resistive random-access memory (RRAM) devices. Fabricated devices exhibited conventional bipolar-switching memory properties. In particular, the vacuum-annealed ZrO2 films exhibited larger crystallinity and grain size, denser film, and a relatively small quantity of oxygen vacancies compared with the films annealed in air and N2. These led to a decrease in the leakage current and an increase in the resistance ratio of the high-resistance state (HRS)/low-resistance state (LRS) and successfully improved non-volatile memory properties, such as endurance and retention characteristics. The HRS and LRS values were found to last for 104 s without any significant degradation.

scholarly journals Multilevel Bipolar Electroforming-Free Resistive Switching Memory Based on Silicon Oxynitride

2020 ◽  
Vol 10 (10) ◽  
pp. 3506
Author(s):  
Nayan C. Das ◽  
Se-I Oh ◽  
Jarnardhanan R. Rani ◽  
Sung-Min Hong ◽  
Jae-Hyung Jang
Keyword(s):  
Resistive Switching ◽  
Random Access ◽  
Charge Trapping ◽  
High Resistance State ◽  
Memory Device ◽  
Resistive Random Access Memory ◽  
Silicon Oxynitride ◽  
Set Switching ◽  
Resistance State ◽  
Switching Characteristics

Resistive random-access memory (RRAM) devices are fabricated by utilizing silicon oxynitride (SiOxNy) thin film as a resistive switching layer. A SiOxNy layer is deposited on a p+-Si substrate and capped with a top electrode consisting of Au/Ni. The SiOxNy-based memory device demonstrates bipolar multilevel operation. It can switch interchangeably between all resistance states, including direct SET switching from a high-resistance state (HRS) to an intermediate-resistance state (IRS) or low-resistance state (LRS), direct RESET switching process from LRS to IRS or HRS, and SET/RESET switching from IRS to LRS or HRS by controlling the magnitude of the applied write voltage signal. The device also shows electroforming-free ternary nonvolatile resistive switching characteristics having RHRS/RIRS > 10, RIRS/RLRS > 5, RHRS/RLRS > 103, and retention over 1.8 × 104 s. The resistive switching mechanism in the devices is found to be combinatory processes of hopping conduction by charge trapping/detrapping in the bulk SiOxNy layer and filamentary switching mode at the interface between the SiOxNy and Ni layers.

Temperature Dependence of Electrical Properties of NiO Thin Films for Resistive Random Access Memory

2008 ◽  
Vol 1071 ◽  
Author(s):  
Ryota Suzuki ◽  
Jun Suda ◽  
Tsunenobu Kimoto
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Electrical Properties ◽  
Temperature Dependence ◽  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Temperature Range ◽  
Temperature Application ◽  
Resistance State

AbstractTemperature dependence of electrical properties in NiO thin films for ReRAM applications has been investigated. I-V measurements have been carried out in the temperature range from 100K to 523K. The resistance in the high resistance state (HRS) is almost independent of temperature below 250K, whereas it decreases with an activation energy of 300 meV above 250K. Hopping conduction and band conduction may be dominant in the low- and high-temperature range, respectively. Admittance spectroscopy on the NiO/n+-Si structure¡¡reveals the existence of a high density of traps, which may contribute to the conduction in HRS. In the low resistance state (LRS), however, the resistance slightly increased in the whole temperature range and the trend is similar to that of metallic Ni film, indicating the metallic Ni defects is related to the conduction in LRS. The Pt/NiO/Pt structure demonstrated stable resistance switching even at temperature as high as 250°C or higher. Since other competitive nonvolatile memories will face severe difficulty in high-temperature operation, the present ReRAM shows promise for high-temperature application.

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 Alloyed High-k-Based Resistive Switching Memory in Contact Hole Structures

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 451
Author(s):  
Byeongjeong Kim ◽  
Chandreswar Mahata ◽  
Hojeong Ryu ◽  
Muhammad Ismail ◽  
Byung-Do Yang ◽  
...  
Keyword(s):  
Resistive Switching ◽  
High Resistance ◽  
Random Access ◽  
High Resistance State ◽  
Memory Device ◽  
Resistive Random Access Memory ◽  
Long Term Memory ◽  
Pulse Input ◽  
Low Resistance ◽  
Resistance State

Resistive random-access memory (RRAM) devices are noticeable next generation memory devices. However, only few studies have been conducted regarding RRAM devices made of alloy. In this paper, we investigate the resistive switching behaviors of an Au/Ti/HfTiOx/p-Si memory device. The bipolar switching is characterized depending on compliance current under DC sweep mode. Good retention in the low-resistance state and high-resistance state is attained for nonvolatile memory and long-term memory in a synapse device. For practical switching operation, the pulse transient characteristics are studied for set and reset processes. Moreover, a synaptic weight change is achieved by a moderate pulse input for the potentiation and depression characteristics of the synaptic device. We reveal that the high-resistance state and low-resistance state are dominated by Schottky emissions.

High Total-Dose Proton Radiation Tolerance in TiN/HfO2/TiN ReRAM Devices

2012 ◽  
Vol 1430 ◽  
Author(s):  
Xiaoli He ◽  
Robert E. Geer
Keyword(s):  
Resistive Switching ◽  
Random Access ◽  
High Resistance State ◽  
Resistive Random Access Memory ◽  
Switching Behavior ◽  
Radiation Tolerance ◽  
Proton Radiation ◽  
Performance Parameters ◽  
Trap Assisted Tunneling ◽  
Resistance State

ABSTRACTThe resistive switching properties of CMOS compatible TiN/HfO2/TiN resistive-random-access-memory (ReRAM) devices have been investigated after exposure to 1 MeV proton radiation. The HfO2-based ReRAM devices were found to have high total-ionizing-dose (TID) radiation tolerance up to 5 Grad(Si). TiN/HfO2/TiN ReRAM performance parameters include high-resistance state (HRS) resistance, low-resistance state (LRS) resistance, set and reset voltages. HfO2-based ReRAM devices exhibited no degradation in these performance parameters following proton irradiation exposure with TID from 105 to 109 rad(Si). Furthermore, the HfO2-based ReRAM devices exhibited more uniform resistive switching behavior with increased TID. Based on this radiation response it is proposed that the resistive switching mechanism in TiN/HfO2/TiN – trap-assisted tunneling associated with Hf-rich conducting filament formation – may be reinforced through proton exposure which acts to stabilize the formation/rupture of Hf-rich filaments. The high radiation tolerance of HfO2-based ReRAM devices suggests such devices may be potentially attractive for aerospace and nuclear applications.

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