• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.09a
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• pp.183-187
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• 2005

Thin films of diblock copolymers may be suitable for semiconductor device applications since they enable patterning of ordered domains with dimensions below photolithographic resolution over wafer-scale area. We obtained nanometer-scale cylindrical structure of dibock copolymer of polystyrene-block-poly(methylmethacrylate), PS-b-PMMA, also demonstrate pattern transfer of the nanoporous polymer using both reactive ion etching. The size of fabricated naonoholes were about 10 nm. Fabricated nanopattern surface was observed by field emission scanning electron microscope (FESEM).

• Electronics and Telecommunications Trends
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• v.33 no.6
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• pp.34-40
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• 2018

Traditionally, many researchers have conducted research on terahertz technology utilizing optical devices such as lasers. However, nanometer-scale electronic devices using silicon or III-V compound semiconductors have received significant attention regarding the development of a terahertz system owing to the rapid scaling down of devices. This enables an operating frequency of up to approximately 0.5 THz for silicon, and approximately 1 THz for III-V devices. This article reviews the recent trends of terahertz monolithic integrated circuits based on several electronic devices such as CMOS, SiGe BiCMOS, and InP HBT/HEMT, and a particular quantum device, an RTD.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.3
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• pp.215-222
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• 2022

Artificial neuromorphic devices are considered the key component in realizing energy-efficient and brain-inspired computing systems. For the artificial neuromorphic devices, various material candidates and device architectures have been reported, including two-dimensional materials, metal-oxide semiconductors, organic semiconductors, and halide perovskite materials. In addition to conventional electrical neuromorphic devices, optoelectronic neuromorphic devices, which operate under a light stimulus, have received significant interest due to their potential advantages such as low power consumption, parallel processing, and high bandwidth. This article reviews the recent progress in optoelectronic neuromorphic devices using various active materials such as two-dimensional materials, metal-oxide semiconductors, organic semiconductors, and halide perovskites

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.253.1-253.1
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• 2007

• ETRI Journal
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• v.29 no.1
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• pp.124-126
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• 2007

In this letter, we study the impact of single event upsets (SEUs) in space or defense electronic systems which use memory devices such as EEPROM, and SRAM. We built a microcontroller test board to measure the effects of protons on electronic devices at various radiation levels. We tested radiation hardening at beam current, and energy levels, measured the phenomenon of SEUs, and addressed possible reasons for SEUs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.627-628
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• 2005

In recent years, the rapid growth of portable electronic device market requires higher density characteristics of batteries. The speed at which portability and mobility is advancing hinges much on the battery. What is important is this energy source that engineers design handled devices around the battery, rather than the other way around. Much improvement has been made in reducing the power consumption of portable devices. Currently, the most popular secondary battery is Li-ion battery. Li-ion has won the limelight and become the most prominent battery. This paper reviews the prospect and future of the Li-ion battery.

• The Journal of the Acoustical Society of Korea
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• v.14 no.4
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• pp.64-73
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• 1995

We developed a surface acoustic wave (SAW) computer aided design (CAD) for mobile communication using Kaier window function. The systems are composed of modules for designing apodization weighted IDT-uniform IDT, withdrawal weighted IDT-withdrawal weighted IDT, and resonator type. The design of SAW bandpass with center frequencies from 222MHz to 343MHz were simulated by the developed CAD system. Although the method proposed in this paper is formulated primarily for SAW filters, it is equally applicable to finite impulse response (FIR) digital filter design.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3304-3306
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• 1999

In this study, we used the sputtering method with single target to obtain the thick and uniform PZT($PbZrTiO_3$) films for micromached IR sensor application. Then, we investigated the etching characteristics and conditions which is necessary process to fabricate the IR sensor. We tested the C-axis orientation and P-E loop of the deposited PZT films with the XRD and RT66A, respectively. Also we investigated the surface of the films by the AFM and SEM analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.8
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• pp.1369-1375
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• 2016

A rapid progress of the next-generation non-volatile memory device has been made in recent years. Metal/insulator/Metal multi-layer structure resistive RAM(ReRAM) has attracted a great deal of attention because it has advantages of simple fabrication, low cost, low power consumption, and low operating voltage. This paper describes the working principle of the ReRAM device, a review of fabrication techniques, and characteristics of flexible ReRAM devices using graphene oxide as an insulating layer and ReRAM devices using multi-layered insulator. The switching characteristics of the above ReRAM devices have been compared. The oxidized graphene could be employed as an insulator of next generation ReRAM devices.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.5
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• pp.682-687
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• 2014

We have performed reverse gate bias stress tests on AlGaN/GaN-on-Si Heterostructure FETs (HFETs). The shift of threshold voltage ($V_{th}$) and the reduction of on-current were observed from the stressed devices. These changes of the device parameters were not permanent. We investigated the temporary behavior of the stressed devices by analyzing the temperature dependence of the instabilities and TCAD simulation. As the baseline temperature of the electrical stress tests increased, the changes of the $V_{th}$ and the on-current were decreased. The on-current reduction was caused by the positive shift of the $V_{th}$ and the increased resistance of the gate-to-source and the gate-to-drain access region. Our experimental results suggest that electron-trapping effect into the shallow traps in devices is the main cause of observed instabilities.