• 한국자기공명학회논문지
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• 제27권4호
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• pp.28-34
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• 2023

We study the linear-nonlinear quantum transport theory of Wannier-Landau transition system in the confinement of electrons by a square well confinement potential. We use the projected Liouville equation method with the ensemble density projection technique. We select the dynamic value under a linearly oscillatory external field. We derive the dynamic value formula and the memory factor functions in three electron phonon coupling systems and electron impurity coupling systems of two transition types, the intra-band transitions and inter-band transitions. We obtain results that can be applied directly to numerical analyses. For simple example of application, we analyze the absorption power and line-widths of ZnO, through the numerical calculation of the theoretical result in the Landau system.

• 한국자기학회지
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• 제25권5호
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• pp.149-155
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• 2015

자성박막의 미세패턴 소자 제작을 위해 전자 사이크로트론 공명(electron cyclotron resonance; ECR) Ar 이온밀링 시스템을 제작하였다. 소자 식각에 적용한 ECR 이온밀링 시스템에서 주파수 2.45 GHz 파장 12.24 cm의 마이크로파 소스인 마그네트론은 전력 600 W에 의해 가동되어 파장의 정수배에 맞추어 만든 도파관을 통하여 전달되도록 설계하였다. 마이크로파 주파수와 공명시키기 위해 전자석으로 908 G의 자기장을 인가하였고, 알곤 개스를 cavity에 유입시켜서 방전된 이온들은 그리드 사이에 인가한 약 1000 V의 가속전압에 의한 에너지를 갖고 표면을 밀링한다. 이것을 이용하여 다층구조 GMR-SV(giant magnetoresistance-spin valve) 자성박막에 광 리소그래피, 이온밀링 및 전극제작 공정과정을 마치고 폭이 $1{\mu}m$에서 $9{\mu}m$까지의 소자들을 제작하여 광학현미경으로 소자 크기를 관찰하였다.

• 마이크로전자및패키징학회지
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• 제7권3호
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• pp.13-17
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• 2000

ECR (Electron Cyclotron Resonance) 식각 공정에 따른 층간 절연막 폴리이미드의 전기적 특성에 관하여 연구하였다. 알루미늄 식각시 일반적으로 사용되는 $Cl_2$플라즈마는 폴리이미드의 유전상수 값을 증가시킨 반면에 $SF_{6}$플라즈마의 경우는 높은 식각률과 유전상수 값의 감소를 가져왔다. 폴리이미드의 누설 전류는 ECR 식각 공정 후에 감소되었다. 다중 금속화 구조를 구현하는데 있어 $Cl_2$플라즈마를 사용하여 알루미늄을 식각하고 $SF_{6}$ 플라즈마를 사용하여 폴리이미드를 식각하는 것이 최적일 것으로 판단된다.

• 전자공학회논문지A
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• 제31A권4호
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• pp.63-69
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• 1994

The Ultrahigh Vacuum Electron Cyclotron Resonance Chemical Vapor Deposition(UHV-ECRCVD) system whose base pressure is 1${\times}10^{9}$ torr has been constructed. In-situ cleaning prior to the epitaxial growth was carried out at 56$0^{\circ}C$ by ECR generated uniform hydrogen plasma whose density is $10^{10}/cm{3}$. The natural oxide was effectively removed without damage by applying positive DC bias(+10V) to the substrate. RHEED(Reflection High Energy Electron Diffraction) analysis has been used to confirm the removal of the surgace oxide and the streaky 2$\times$1 reconstruction of the Si surface, and the suppression of the substrate damage is anaylized by X-TEM(cross-sectional Transmission Electron Microscopy). Surface cleaning technique by ECR hydrogen plasma confirmed good quality epitaxial growth at low temperature.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1996년도 제11회 학술발표회 논문개요집
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• pp.159-160
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• 1996

• Journal of Astronomy and Space Sciences
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• 제39권2호
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• pp.35-42
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• 2022

During their respective missions, the spacecraft Voyager and Cassini measured several Saturn magnetosphere parameters at different radial distances. As a result of information gathered throughout the journey, Voyager 1 discovered hot and cold electron distribution components, number density, and energy in the 6-18 Rs range. Observations made by Voyager of intensity fluctuations in the 20-30 keV range show electrons are situated in the resonance spectrum's high energy tail. Plasma waves in the magnetosphere can be used to locate Saturn's inner magnetosphere's plasma clusters, which are controlled by Saturn's spin. Electromagnetic electron cyclotron (EMEC) wave ring distribution function has been investigated. Kinetic and linear approaches have been used to study electromagnetic cyclotron (EMEC) wave propagation. EMEC waves' stability can be assessed by analyzing the dispersion relation's effect on the ring distribution function. The primary goal of this study is to determine the impact of the magnetosphere parameters which is observed by Cassini. The magnetosphere of Saturn has also been observed. When the plasma parameters are increased as the distribution index, the growth/damping rate increases until the magnetic field model affects the magnetic field at equator, as can be seen in the graphs. We discuss the outputs of our model in the context of measurements made in situ by the Cassini spacecraft.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.850-853
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• 1992

A cryogenic electron cyclotron resonance plasma etching system has been built to study wafer-temperature in the silicon etching characteristics. The wafer temperature was controlled from -150 to +30 $^{\circ}C$ during etching using the liquid nitrogen cooled helium gas. Although silicon was etched isotropically in $SF_6$ plasma at room temperatures, we found that it is possible to suppress the etch undercut in Si by reducing a substrate temperature without side wall passivation. In addition, the selectivity of silicon to photoresist was improved considerably at a low wafer temperature. Etch rates, anisotropy and selectivity to photo resist are measured as a function of the wafer temperature in the region of -125 $\sim$ 25$^{\circ}C$ and rf bias power of 20W $\sim$ 80W.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.242.1-242.1
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• 2014

The electron cyclotron resonance plasma source with a belt-type magnet assembly (BMA) is designed for effective plasma confinements. For characterizing the plasma source, the plasma parameters are measured by Langmuir probe. However, the plasma parameters and the motion of charged particles near the ECR zone are not easy to diagnostics, because of the high plasma density and temperature. Thus, as an alternative method, the electromagnetic simulation of the plasma source has been performed by using three-dimensional particle-in-cell and Monte Carlo collisional (PIC-MCC) simulation codes. For considering the limitation of simulation resources and time, the periodic boundary condition is applied and the coulomb collision is neglected. In this paper, we present the results of 3D PIC simulations of ECR plasmas with BMA and we compare them with the experimental results.

• 한국진공학회지
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• 제2권4호
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• pp.501-506
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• 1993

The spatial potential distribution of electron cyclotron resonance plasma is measured as a function of tehsubstrate DC bias by Langmuir probe method. It is observed that the substrate DC bias changes the slope of the plasma potential near the subsrate, resulting in changes in flux and energy of the impinging ions across plasma $_strate boundary along themagnetric field. The effect of the substrate DC bias on the low-temperature silicon homoepitaxy (below $560^{\circ}C$) is examine dby in situ reflection high energy electron diffraction (RHEED), cross-section transmission electron microscopy (XTEM),plan-view TEM and high resolution transmision electron microscopy(HRTEM). While the polycrystalline silicon layers are grow withnegative substrate biases, the single crystaline silicon layers are grown with negative substrate biases, the singel crystalline silicon layers are grown with positive substrate biases. As the substrate bias changes form negative to positive values, the growth rate decreases. It is concluded that the control of the ion energy during plasma deposition is very important in silicon epitaxy at low temperatures below $560^{\circ}C$ by UHV-ECRCVD.VD.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2001년도 추계 기술심포지움
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• pp.161-164
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• 2001