A5101944465- Advanced Memory and Neural Computing
- Transition Metal Oxide Nanomaterials
- Ferroelectric and Negative Capacitance Devices
- Phase-change materials and chalcogenides
- Semiconductor materials and devices
- Microstructure and mechanical properties
- Powder Metallurgy Techniques and Materials
- Metallurgy and Cultural Artifacts
- X-ray Diffraction in Crystallography
- Microstructure and Mechanical Properties of Steels
- Crystallography and Radiation Phenomena
- Semiconductor materials and interfaces
- Radiation Shielding Materials Analysis
- Advancements in Photolithography Techniques
- Advanced Electron Microscopy Techniques and Applications
- Electronic and Structural Properties of Oxides
- Diamond and Carbon-based Materials Research
- Neuroscience and Neural Engineering
- Advanced X-ray Imaging Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Electron and X-Ray Spectroscopy Techniques
- CCD and CMOS Imaging Sensors
- Fusion materials and technologies
- Thin-Film Transistor Technologies
- ZnO doping and properties
Pohang University of Science and Technology
1996-2019
Pohang Accelerator Laboratory
2001
Northwestern University
1986
In this letter, simple binary Ovonic threshold switching (OTS) material with outstanding selector device performance has been demonstrated. Even its composition and easy fabrication process, the OTS showed excellent such as high-OFF resistance (> 1 G <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> at 0.1 V), low-ON (< k 2.0 extremely sharp slope mV/dec), fast operating...
The scaling and 3-D integration issues of NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> with threshold switching characteristics were investigated for ReRAM selector device. To avoid the process problems Pt electrode, we tested devices conventional electrodes (TiN W). By adopting 10nm-thick TiN bottom electrode low thermal conductivity, could significantly reduce current insulator-metal transition (I-M-T) due to heat confinement...
We demonstrated binary Ovonic threshold switching (OTS) materials (ZnTe, GeTe, and SiTe) the composition dependent electrical properties. Among those materials, amorphous SiTe-film deposited at room-temperature (RT) process showed excellent OTS properties such as high off resistance (∼20GΩ 0.2V), low on (<1kΩ 1.2V), selectivity (∼10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> ), extreme SS (<1mV/dec), fast operating speed (2ns...
We have experimentally demonstrated a strong correlation between the electrical properties of Zn1-xTex Ovonic threshold switching (OTS) selector device and material analysed by X-ray diffraction (XRD), spectroscopic ellipsometry, photoelectron spectroscopy (XPS). The key parameters determining performances were investigated. By comparing experimental data with calculation results from various analytical models previously developed for OTS materials, shown to be dependent on parameters;...
We have investigated the analogue memory characteristics of an oxide-based resistive-switching device under electrical pulse to mimic biological spike-timing-dependent plasticity synapse characteristics. As a synaptic device, TiN/Pr0.7Ca0.3MnO3-based exhibiting excellent was used control weight by applying various amplitudes and cycles. Furthermore, potentiation depression with same spikes can be achieved negative positive pulses, respectively. By adopting complementary...
A 3D high-density switching device is realized utilizing titanium oxide, which the most optimum material, but not practically demonstrated yet. The 1S1R (one ReRAM with developed device) exhibits memory characteristics a significantly suppressed sneak current, can be used to realize applications.
Current overshoot has severe effects on the reliability of resistive random access memory (RRAM). It is well known that current during SET process caused by parasitic capacitance. In this letter, we observed a different type RESET process. The was confirmed to have endurance RRAM. We also demonstrated relation between and intrinsic capacitive elements each state Finally, an optimized pulse shape proposed minimize experimentally verified significantly improve variability in typical RRAM...
The effects of stack and defect engineering metal-oxide layers on resistive switching uniformity were investigated to obtain random access memory (ReRAM) with excellent reliability. Uniform switching, parameters, such as set voltage (Vset), reset (Vreset), low-resistance state, high-resistance retention characteristics, significantly improved by engineering. Furthermore, the initial forming operation, which is a nuisance, was removed realize cross-point ReRAM.
We have investigated various Te-based binary materials for Ovonic Threshold Switch (OTS) selector application. found that both Te composition and difference in atomic radius of elements composing the telluride film are key control parameters to maximize OTS characteristics such as low leakage current (<;5 nA device area 30 nm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), good switching endurance (10...
We demonstrate a selector device with excellent performances (J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MAX</sub> > 10 <sup xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> A/cm xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , switching speed <; 20ns) at the 30nm cell size. Furthermore, these promising characteristics were achieved in fully CMOS compatible stack (W/Ta xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O...
In this study, the effect of oxygen profile and thickness multiple-layers TiOx on tunnel barrier characteristics was investigated to achieve high non-linearity in low-resistance state current (ILRS). To form multiple-layer TiOx, engineering terms attempted using deposition thermal oxidation times. It modified defect distribution for effective suppression ILRS at off-state (½VRead). By inserting resistive random access memory, a non-linear exhibited with significantly lowered ½VRead.
TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> based Insulator-Metal-Transition (IMT) devices with TiN electrode were investigated for selector application. To maximize heat confinement, we adopted localized filament by breaking stoichiometric ALD xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layer. Using Ti xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> target and...
Retention of the low resistance state (LRS) in resistive random access memory (ReRAM) significantly decreases at increasing electrical stress due to barrier lowering ion migration and Joule heating. The LRS failure rate under externally applied bias could be modeled by adopting an Arrhenius equation for migration. Accelerated retention voltage is explained combination two effects: 1) external electric field 2) thermal energy enhancement through local Based on this model, improved methodology...
For uniform switching of resistive random access memory, narrower physical gap between an electrode and remained conducting filament can be effective method, which also leads to degradation ON/OFF ratio. To overcome a trade-off the uniformity ratio, additional layer was intentionally inserted. Consequently, improved parameters achieved without
Reliability characteristics (retention and endurance) of RRAM are critical for its practical realization need to be improved. In this work, we confirmed the trade-off between retention endurance by using various top electrode thickness conditions. To improve both characteristics, proposed a new method high-pressure hydrogen annealing. Finally, obtained improved in HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X</sub> based devices after...
In this paper, the effect of titanium oxide-based tunnel barrier on non-linearity and switching uniformity resistive random access memory has been investigated with object achieving excellent device reliability for cross-point array applications. To form oxide, its thickness was engineered using deposition time. The effectively controls current flow in devices a tunneling mechanism that modifies devices. behavior because most bias is applied to owing dominant resistance state. addition, can...
Abstract In the synchrotron radiation‐excited total reflection x‐ray fluorescence (SR‐TXRF) determination of surface contaminants on Si wafers, minimum detection limit is intrinsically determined by background spectrum. The absolute counts spectra for whole energy range concerned was calculated under usual SR‐TXRF experimental conditions and compared with measurements. limits near wafers within a few atomic layers were evaluated from spectrum signal given conditions. Copyright © 2001 John...