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 ◽  
...  

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.

2020 ◽  
Vol 10 (10) ◽  
pp. 3506
Author(s):  
Nayan C. Das ◽  
Se-I Oh ◽  
Jarnardhanan R. Rani ◽  
Sung-Min Hong ◽  
Jae-Hyung Jang

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.


2007 ◽  
Vol 124-126 ◽  
pp. 603-606
Author(s):  
Sang Hee Won ◽  
Seung Hee Go ◽  
Jae Gab Lee

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.


2020 ◽  
Vol 34 (12) ◽  
pp. 2050115
Author(s):  
Liping Fu ◽  
Sikai Chen ◽  
Zewei Wu ◽  
Xiaoyan Li ◽  
Mingyang You ◽  
...  

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.


2015 ◽  
Vol 15 (10) ◽  
pp. 7569-7572 ◽  
Author(s):  
Sukhyung Park ◽  
Kyoungah Cho ◽  
Jungwoo Jung ◽  
Sangsig Kim

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.


Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1124 ◽  
Author(s):  
Chao-Feng Liu ◽  
Xin-Gui Tang ◽  
Lun-Quan Wang ◽  
Hui Tang ◽  
Yan-Ping Jiang ◽  
...  

The resistive switching (RS) characteristics of flexible films deposited on mica substrates have rarely been reported upon, especially flexible HfO2 films. A novel flexible Au/HfO2/Pt/mica resistive random access memory device was prepared by a sol-gel process, and a Au/HfO2/Pt/Ti/SiO2/Si (100) device was also prepared for comparison. The HfO2 thin films were grown into the monoclinic phase by the proper annealing process at 700 °C, demonstrated by grazing-incidence X-ray diffraction patterns. The ratio of high/low resistance (off/on) reached 1000 and 50 for the two devices, respectively, being relatively stable for the former but not for the latter. The great difference in ratios for the two devices may have been caused by different concentrations of the oxygen defect obtained by the X-ray photoelectron spectroscopy spectra indicating composition and chemical state of the HfO2 thin films. The conduction mechanism was dominated by Ohm’s law in the low resistance state, while in high resistance state, Ohmic conduction, space charge limited conduction (SCLC), and trap-filled SCLC conducted together.


2011 ◽  
Vol 687 ◽  
pp. 167-173 ◽  
Author(s):  
Chih Yi Liu ◽  
Po Wei Sung ◽  
Chun Hung Lai ◽  
Hung Yu Wang

SiO2thin films were fabricated as resistive layers of Cu/SiO2/Pt devices to investigate resistive switching properties. A thermal annealing was performed to allow for the diffusion of Cu ions into the SiO2thin films, leading to the formation of Cu-doped SiO2layers. Occurrence probabilities of the resistive switching and initial resistance-states of the devices were influenced by SiO2thickness, which was dependent on the Cu diffusion status within the SiO2layer. The resistive switching behaviors were characterized by the voltage sweeping mode and the current sweeping mode. The current sweeping mode provided a desired compliance current to well control the resistive switching from the high resistance-state to the low resistance-state (SET). Therefore, the large RESET (from the low resistance-state to the high resistance-state) current was not inherent in the device, due to poor control of the compliance current by the voltage sweeping mode. The current sweeping mode is a simple method to characterize the RESET current.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jongmin Park ◽  
Hojeong Ryu ◽  
Sungjun Kim

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.


2020 ◽  
Author(s):  
Shanming Ke ◽  
Shangyu Luo ◽  
Jinhui Gong ◽  
Liwen Qiu ◽  
Renhong Liang ◽  
...  

Abstract The resistive switching (RS) mechanism of hybrid organic-inorganic perovskites is an open question until now. Here, a switchable diode-like RS behavior in MAPbBr3 single crystals using Au (or Pt) symmetric electrodes is reported. Both the high resistance state (HRS) and low resistance state (LRS) are electrode-area dependent and light responsive. We propose an electric-field-driven inner p-n junction accompanied by a trap-controlled SCLC conduction mechanism to explain this switchable diode-like RS behavior in MAPbBr3 single crystals.


2015 ◽  
Vol 08 (01) ◽  
pp. 1550001 ◽  
Author(s):  
Bai Sun ◽  
Qiling Li ◽  
Yonghong Liu ◽  
Peng Chen

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.


2012 ◽  
Vol 1430 ◽  
Author(s):  
Xiaoli He ◽  
Robert E. Geer

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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