• Journal of electromagnetic engineering and science
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• 제17권4호
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• pp.169-177
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• 2017

The role of electromagnetic (EM) waves in magnetic fusion plasma-ranging from radio frequency (RF) to microwaves-has been extremely important, and understanding of EM wave propagation and related technology in this field has significantly advanced magnetic fusion plasma research. Auxiliary heating and current drive systems, aided by various forms of high-power RF and microwave sources, have contributed to achieving the required steady-state operation of plasmas with high temperatures (i.e., up to approximately 10 keV; 1 eV=10000 K) that are suitable for future fusion reactors. Here, various resonance values and cut-off characteristics of wave propagation in plasmas with a nonuniform magnetic field are used to optimize the efficiency of heating and current drive systems. In diagnostic applications, passive emissions and active sources in this frequency range are used to measure plasma parameters and dynamics; in particular, measurements of electron cyclotron emissions (ECEs) provide profile information regarding electron temperature. Recent developments in state-of-the-art 2D microwave imaging systems that measure fluctuations in electron temperature and density are largely based on ECE. The scattering process, phase delays, reflection/diffraction, and the polarization of actively launched EM waves provide us with the physics of magnetohydrodynamic instabilities and transport physics.

• 한국전기전자재료학회논문지
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• 제14권8호
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• pp.634-639
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• 2001

We investigated the etching characteristics of chromium films by using Cl$_2$/O$_2$ gas mixtures with electron cyclotron resonance plasma. In order to examine the chemical etch characteristics of Cr films by using Cl$_2$/O$_2$ gas plasma, we obtained the etch rate with various gas mixing ratios. By X-ray photoelectron spectroscopy, the surface reaction on the chromium films during the etch was examined. From narrow scan analyses of Cr, Cl, and O, it was confirmed that a chromium oxychlorie (CrCl$_{x}$O$_{y}$) layer was formed on the surface by the etch using Cl$_2$/O$_2$ gas mixtures. We observed a new characteristic emission line during the etch of chromium films using Cl$_2$/O$_2$ gas mixtures by an optical emission spectroscopy. It was found that the peak intensity of this emission line had a tendency compatible with the etch rate. The origin of this emission line was discussed in detail. At the same time, the etched profile was also examined by scanning electron microscope.e.e.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.55.2-55.2
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• 2009

A polymer electrolyte membrane (PEM) fuel cell has been getting large interest as a typical issue in useful applications. The PEMFC is composed of a membrane, catalyst and the bipolar plate. SnOx:F films on SUS316 stainless steel were prepared as a function of substrate with using electron cyclotron resonance-metal organic chemical vapor deposition (ECR-MOCVD) in order to achieve the corrosion-resistant and low contact resistance bipolar plates for PEM fuel cells. The SnOx:F films coated on SUS316 substrate at surface plasma treatment for excellent stability, before/after heat treatment for good crystalline structure and microwave power for were characterized by X-ray diffraction (XRD), auger electron microscopy (AES) and field emission-scanning electron microscopy (FE-SEM). The SnOx:F film coated on SUS316 substrate with various process parameters were able to observe optimum interfacial contact resistance (ICR) and corrosion resistance. It can be concluded that fluorine-doping content plays an important function in electrical property and characteristic of corrosion-protective film.

• 한국자기학회지
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• 제12권6호
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• pp.201-205
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• 2002

경사형 모서리접합을 이용한 터널링 자기저항(tunneling magnetoresistance; TMR) 특성을 연구하였다. 박막 증착과 식각은 스퍼터링과 사이크로트론 전자공명 (electron cyclotron resonance; ECR) 장치를 각각 사용하였다. Si$_3$N$_4$ 장벽층을 이용한 접합의 다층구조는 NiO(60)/Co(10)/NiO(60)/Si$_3$N$_4$(2-6)/NiFe(10) (nm)이었다. 상하부 반강자성체 NiO에 삽입된 wedged 형태의 고정층 Co와 장벽층 Si$_3$N$_4$위에 경사진 비대칭 구조에서 자유층 NiFe간의 접합에서 일어나는 특이한 스핀의존 터널링 현상이 관찰되었다. 외부자장이 0Oe일 때와 접합경계선에 수직방향으로 90Oe일 때 측정한 접합소자의 전류전압특성 곡선이 현저하게 구별되어 나타났다. TMR의 인가 전압의존성은 $\pm$10 V일 때도 약 -10%을 유지하는 매우 안정된 자기저항 특성을 보여주었다.

• 한국결정성장학회지
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• 제6권3호
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• pp.351-359
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• 1996

ECR (electron cyclotron resonance) 플라즈마원이 장착되어 있는 화학선에피탁시 (chemical beam epitaxy : CBE) 장치를 사용하여 InAs 양자점 구조형성에 미치는 수소플라즈마의 효과에 대하여 조사하였다. 자기조직화(self-organized)에 의해 GaAs 기판위에서 InAs 양자점의 형성을 RHEED(reflection high energy electron diffraction)로 관측한 결과 수소가스 및 수소플라즈마의 영향을 받지 않은 상태에서는 1.9 ML(monolayer)의 InAs 층성장(layer growth) 후에 형성되는데 비해 수소플아즈마를 조사한 상태에서는 약 2.6 ML의 InAs 층성장(layer growth) 후에 형성되는데 비해 수소플아즈마를 조사한 상태에서는 약 2.6 ML의 InAs층이 성장된 후 뒤늦게 이루어짐을 확인하였다. 기판의 온도 $370^{\circ}C$에서 동일한 조건으로 형성시킨 InAs 양자점의 밀도 및 크기는 수소플라즈마의 영향을 받지 않은 경우 $1.9{\times}10^{11}cm^{-2}$ 및 17.7 nm에서 수소플라즈마를 쪼인 경우 $1.3{\times}10^{11}cm^{-2}$ 및 19.4 nm로 양자점 형성 다소 완화되는 것으로 나타났다. 또한, 수소플아즈마에 의한 InAs 양자점의 PL(photoluminescence) 신호의 적색이동(red shift)과 반치폭 증가로부터 양자점 크기의 증가와 균일성이 다소 감소되는 모습을 알 수 있었다. 이와같은 수소플라즈마의 영향은 GaAs 기판과 InAs 사이의 부정합 변형환화 효과에의해 InAs의 충성장을 강화시키는 원자상 수소의 작용때문인 것으로 고려되었다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 The IMAPS-Korea Workshop 2001 Emerging Technology on packaging
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• pp.110-113
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• 2001

ECR(electron cyclotron resonance) 플라즈마 식각 장비를 이용하여 SF$_{6}$/Ar과 Cl$_2$/Ar 플라즈마 가스에 대한 Platinum (이하 Pt) 박막의 식각 특성을 연구하였다. Pt 박막의 경우 Cl$_2$ 가스 혼합물에 대한 식각 특성은 많이 보고가 되어 왔으나 상대적으로 Fluorine 계열의 가스 혼합물에 의한 시각 연구는 미비하였다. 본 연구에서는 SF$_{6}$/Ar과 Cl$_2$/Ar 플라즈마 가스를 이용한 Pt 박막의 식각 특성을 비교 분석하고 각각의 가스와 Pt 박막과의 반응을 분석, 식각 특성을 개선하고자 하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.70.1-70.1
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• 2015

The facility for RAON superconducting heavy-ion accelerator at a beam power of up to 400 kW will be produced rare isotopes with two electron cyclotron resonance (ECR) ion sources. Highly charged ions generated by the ECR ion source will be injected to a superconducting LINAC to accelerate them up to 200 MeV/u. During the acceleration of the heavy ions, a good vacuum system is required to avoid beam loss due to interaction with residual gases. Therefore ultra-high vacuum (UHV) is required to (i) limit beam losses, (ii) keep the radiation induced within safe levels, and (iii) prevent contamination of superconducting cavities by residual gas. In this work, a RAON vacuum design for all the accelerator system will be presented along with Monte Carlo simulation of vacuum levels in order to validate the vacuum hardware configuration, which is needed to meet the baseline requirements.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(3)
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• pp.225-230
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• 1996

탄화규소(SiC)가 도포된 핵연료 제조를 위해 고온 연소 합성법(Self-propagating High Temperature Synthesis, SHS)이 적용되었으며, 반응물로 규소(Si) 분말, 규소 박막 (Si-thin film), 흑연 분말과 카본(C) 화이버가 사용되었다. 규소 박막은 프라즈마가 강화된 화학증착법(a microwave pulsed electron cyclotron resonance plasma enhanced chemical vapor deposition)으로 준비되었다. 그 결과 규소와 탄소의 고온 연소 합성반응 생성물은 반응물이 분말이거나 박막에 관계없이. 탄화규소(SiC)가 합성되었으며, 생성물의 형상(morphology)은 초기 탄소의 형상에 의존하였다. 본 연구를 통해 고온 연소 합성법이 탄화규소와 탄소가 도포된 핵연료 제조에 적용 가능함을 알 수 있었다.

• 전자공학회논문지A
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• 제29A권10호
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• pp.35-41
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• 1992

Ultra-thin silicon nitride films were fabricated with ECR(Electron cyclotron Resonance) nitrogen plasma at room temperature. Film thickness was about 50$\AA$ after nitridation for 1min at microwave power of 1000W, RF power of 500W, and NS12T pressure of ${\times}10^{-3}$ torr. 50$\AA$ fo nitride film was grown within 1 min and no appreciable growth occured thereafter. Dielectric breakdown strength and leakage current density in Al/SiN/Si structure were measured to be about 7-11 MV/cm and ${\times}10^{-10}~5{\times}10^{-10}A/cm^{2}$, respectively. Observed linear relationship in 1n(J/E)-vs-E$^{1/2}$ and no polarity-dependence of the leakage current indicated that the Poole-Frenkel emission is mainly responsible for the conduction in this nitrided silicon films.

• 마이크로전자및패키징학회지
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• 제8권1호
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• pp.39-43
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• 2001

$SiC_{x}N$_{y}$ film is deposited by electron cyclotron resonance plasma chemical vapor deposition system using $SiH_4$(5% in Ar), $CH_4$ and $N_2$. Ternary phase $SiC_{x}N$_{y}$ thin film deposited at the microwave power of 600 W and substrate temperature of 700 contains considerable amount of strong C-N bonds. Change in $CH_4$flow rate can effectively control the residual film stress, and typical surface roughness of 34.6 (rms) was obtained. Extreme]y high hardness (3952 Hv) and optical transmittance (95% at 633 nm) was achieved, which is suitable for a LIGA mask membrane application.