A5055686260- Phase-change materials and chalcogenides
- Semiconductor materials and devices
- Ferroelectric and Piezoelectric Materials
- Chalcogenide Semiconductor Thin Films
- Transition Metal Oxide Nanomaterials
- Liquid Crystal Research Advancements
- Advanced Memory and Neural Computing
- Electronic and Structural Properties of Oxides
- Acoustic Wave Resonator Technologies
- Advanced Sensor and Energy Harvesting Materials
- Organic Light-Emitting Diodes Research
- Ferroelectric and Negative Capacitance Devices
- Thin-Film Transistor Technologies
- Organic Electronics and Photovoltaics
- Advanced MEMS and NEMS Technologies
- Semiconductor materials and interfaces
- Advanced Materials and Mechanics
- Photonic and Optical Devices
- Microwave Dielectric Ceramics Synthesis
- Metal and Thin Film Mechanics
- Advancements in Semiconductor Devices and Circuit Design
- Gas Sensing Nanomaterials and Sensors
- Dielectric materials and actuators
- Conducting polymers and applications
- Luminescence and Fluorescent Materials
Electronics and Telecommunications Research Institute
2008-2019
Government of the Republic of Korea
2017
Daejeon University
2014-2017
Tokyo Institute of Technology
1990-1991
A low power PRAM using a data-comparison write (DCW) scheme is proposed. The consumes large because currents are required during long time. At first, the DCW reads stored data operation. And then, it writes an input only when and different. Therefore, can reduce consumption to half. 1K-bit test chip with 128×8bits implemented 0.8μm CMOS technology 0.5μm GST cell.
A phase-change material of Sb/sub 65/Se/sub 35/ was newly proposed for the nonvolatile memory applications. The fabricated device using showed a good electrical threshold switching characteristic in dc current-voltage (I-V) measurement. programming time set operation decreased from 1 μs to 250 ns when introduced place conventionally employed Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sb Te...
We report the thickness and annealing temperature dependence of structural, morphological, compositional, electrical properties including ferroelectric characteristics Pb(Zr0.52Ti0.48)O3 thin films deposited by a sol-gel method. The were in range 0.12–0.36 μm 520–670 °C, respectively. crystalline structure growth behavior have been studied x-ray diffraction, scanning electron microscopy, atomic force microscopy. It is demonstrated that weak ac electric field permittivity terms Rayleigh law...
Organic–inorganic hybrid-type nonvolatile memory thin-film transistors using an organic ferroelectric gate insulator and oxide semiconducting active channel are a very promising solution to the devices having both features of low-cost high-performance, which embeddable into next-generation flexible transparent electronics. In this paper, we discuss some important issues for proposed device, such as device structure design, process optimization array integration. Promising feasible...
Abstract Graphene has attracted considerable attention as a next-generation transparent conducting electrode, because of its high electrical conductivity and optical transparency. Various optoelectronic devices comprising graphene bottom such organic light-emitting diodes (OLEDs), photovoltaics, quantum-dot LEDs electrochemical cells, have recently been reported. However, performance using top electrodes is limited, the lamination process through which positioned layer these conventional...
This letter reports on the performance improvement of phase-change memory (PCM) cells by applying silicon-germanium (SiGe) alloys as resistive heating layers. The in situ doped polycrystalline Si0.75Ge0.25 films, lying under holes filled with a Ge2Sb2Te5 (GST) material pore-style configuration, promoted temperature rise and phase transition GST. SiGe layer caused drastic reduction both set reset currents compared to conventional TiN heater material. threshold voltages PCM were almost uniform...
The crystallization behavior of antimony(Sb)-excess was examined. Sb-excess GST showed and melting temperatures 205 550°C, respectively, slightly higher lower values than stoichiometric compounds. It also a substantially different compared to the composition. resulting GeSbTe thin film grain growth dominated behavior.
Poly(vinylidene fluoride trifluoroethylene) and ZnO were employed for nonvolatile memory thin film transistors as ferroelectric gate insulator oxide semiconducting channel layers, respectively. It was proposed that the thickness of layer be carefully controlled realizing lower programming voltage, because serially connected capacitor by formation a fully depleted had critical effect on off voltage. The fabricated transistor with Al/P(VDF–TrFE) (80 nm)/Al2O3 (4 nm)/ZnO (5 nm) exhibits...
SrTa 2 O 6 (STO) thin films were prepared by plasma-enhanced atomic layer deposition (PEALD) with an alternating supply of reactant sources, Sr[Ta(C H 5 O) (C 4 10 NO)] {strontium bis-[tantalum penta-ethoxide dimethyllaminoethoxide]; Sr(Ta(OEt) ·dmae) } and plasma. It was observed that the uniform conformal STO successfully deposited using PEALD film thickness per cycle saturated at approximately 0.8 Å 300°C. Electrical properties on Pt/SiO /Si substrates various annealing temperatures...
Programmable metallization cell structure with a device diameter of 2μm composed Ag–Ge–Te chalcogenide films was prepared by cosputtering technique at room temperature. The 150nm thick Ag30(Ge0.3Te0.7)70 electrolyte switches 0.2V from an “off” state resistance Roff close to 106Ω “on” Ron more than four orders magnitude lower for this programming current. switching characteristics were closely related diffusion silver anode into silver-saturated GeTe films.
The phase transition characteristics and device performance of Si-doped Ge2Sb2Te5 thin films were studied for PRAM application. deposited by the RF-magnetron cosputtering system analyzed x-ray diffractometer (XRD), 4-point probe measurement photoelectron spectroscopy (XPS). difference in sheet resistance between amorphous crystalline states was higher than 104 Ω/□. In XPS spectrum, Si–Te binding confirmed. addition, positional change Si observed. activation energy transformation decreased...
We investigated the etching behaviors of GST, which has been mainly employed for realization phase-change type nonvolatile memory devices, using high-density helicon plasma system under various gas conditions. Our results provide etch rates GST thin films as a function mixing ratio when mixtures Ar/Cl 2 and Ar/CHF 3 were applied. It was found that selectivities to SiO TiN optimized at = 90/10 80/20, respectively. also confirmed there is no significant change in composition after process....
Recently, we have addressed that a formation mechanism of nanolens array (NLA) fabricated by using maskless vacuum deposition is explained as the increase in surface tension organic molecules induced their crystallization. Here, another research finite difference time domain simulations, not electric field intensities but transmitted energies electromagnetic waves inside and outside top-emitting blue light-emitting diodes (TOLEDs), without with NLAs, are obtained, to easily grasp effect NLA...
ABSTRACT We directly formed the organic ferroelectric P(VDF-TrFE) 70/30 copolymer film by spin coating for making MFS structure in silicon wafer. To understand crystallization behavior of copolymer, morphologies thin films were studied AFM and XRD. studies revealed that as grown annealed showed surface roughness greater than amorphous due to crystallization. The XRD spectrum subjected various annealing temperatures β -phase this phase content was maximum at 140°C annealing. capacitance shows...
To date, all deposition equipment has been developed to produce planar films. Thus lens arrays with a diameter of <1 mm have manufactured by combining other technologies, such as masks, surface treatment, molding etc. Furthermore, nano-lens array (NLA) sufficiently small (<1 μm) is necessary avoid image quality degradation in high resolution displays. In this study, an organic NLA made using conventional technique - without techniques reported. Very interestingly, grazing-incidence...
The electrical properties of metal/ferroelectric/insulator/semiconductor (MFIS) structures with various insulators were investigated. Layers Si 3 N 4 /SiO 2 (NO) formed by thermal oxidation and low pressure chemical vapor deposition (LPCVD) Al O layers deposited atomic layer (ALD) used as inter-dielectric layers. SrBi Ta 9 (SBT) films ferroelectric prepared metal organic decomposition (MOD). capacitance-voltage ( C – V ) curves including the memory window affected varying annealing...
We report on the electrical characterization of SrTa2O6 (STA) films as alternative gate dielectrics deposited directly Si by plasma-enhanced atomic layer chemical vapor deposition. The dielectric constant extracted from accumulation capacitance and fixed charge interface state for STA annealed in O2 ambient are about 20 6.54×10-8 C/cm2, respectively. trap density Dit at midgap obtained a quasistatic capacitance-voltage technique is estimated approximately to be low 1011 cm-2·eV-1 range...