• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.32-36
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• 1992

An ECR plasma apparatus is designed and constructed. The gradient of magnetic field in microwave cavity was adjusted to provide an ECR plasma stream by electro magnetic lenz system. Employing a yoke arround the electro magnets, the magnetic field intensity was increased by 50% with the same electric current. Characteristics of the ECR plasma discharged in the apparatus were investigated by Langmuir probe method. The variations of electron temperature and electron density along chamber axis were analysed.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.508-508
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• 2012

CST microwave studio is used to simulate the plasma profile of the 450mm CCP source. Standing wave effect becomes important at the high frequency as the electrode radius increases. To solve plasma non-uniformity problem, we designed multi electrode chamber to decreasing standing wave effect. Simulation showed the ratio of input power of each electrode is related with electric field strength. The multi electrode was constructed and measured by 2D probe arrays using floating harmonic method. Uniformity of 450 mm CCP was changed by the ratio of input power of each electrode. We described this dependence with circuit model.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.181-182
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• 2012

본 연구에서는 반도체 기술의 핵심으로 알려있는 플라즈마 표면 처리 공정을 이용하여 인위적으로 그래핀과 기능기 반응을 통한 도핑효과를 일으켜, 전계효과(Electric Field Effect)를 인가하였을 때 그래핀 내에서 발생하는 Electron & Hole carrier 들의 accumulation & Depletion 효과에 의한 Charge Density 변화를 Graphene Field Effect Transistors (GFETs) 소자의 전기적 특성 변화를 확인하였다. 특히, 그래핀 내 Conduction of electron을 높이기 위하여, $N_2+H_2$ 가스 조합을 플라즈마 방전가스로 사용하였으며, Optical Emission Spectroscopy (OES) 및 Langmuir-probe 측정을 통하여 합성가스의 ICP 방전 상태 및 효과를 예측하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.60-64
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• 2005

Discharge of the flat lamp lighting source research are requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important, distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single langmuir probe in flat lamp, we tested the discharge from 100 Torr to 300 Torr pressure, the Pulse is rectangular pulse with frequency 20kHz and Duty ratio 20%. Resultly, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

• Corrosion Science and Technology
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• v.4 no.1
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• pp.1-7
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• 2005

An alternating current (AC) corrosion on buried pipeline has been studied using coupon and ER probe. Coupons and ER probes were applied to the sites from high value of AC voltage to low value based on the survey of AC voltages on buried gas transmission pipeline over the country. Parameters such as AC current density of coupon, AC voltage, cathodic protection potential, soil resistivity and frequency were monitored continually. Corrosion induced by AC was observed even under cathodically protected condition that met cathodic protection criterion (; below -850 mV vs. CSE). Corrosion rate was affected mainly not by AC voltage but by both of frequency and AC current density. An experimental corrosion rate relation could be obtained according to effective AC current density, in which AC corrosion rate increased linearly with effective AC current density, and its slope was 0.619 in coupon method and 0.885 in ER probes.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.33-35
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• 2016

In this study, a new plasma source was used in the ALD process. Line type plasma sources were analyzed by electric and magnetic field simulation. And the results were compared with plasma density and electron temperature measurement results. As a result, the results of the computer simulation and the diagnosis results of plasma density and electron temperature showed similar tendency. At this time, the plasma uniformity is 95.6 %. $Al_2O_3$ thin film was coated on 6 inch Si-wafer, using this plasma source. The uniformity of the thin film was more than 98% and the thin film growth rate was 0.13 nm/cycle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.4
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• pp.422-425
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• 2004

In this study, the AZO thin films were prepared as a function of oxygen gas flow ratio at room temperature by FTS(Facing Targets Sputtering) apparatus using Zn:Al(metal)-Zn:Al(metal) or Zn(metal)-ZnO:Al(ceramic). The film thickness, crystalline and electric properties of AZO thin film was evaluated by $\alpha$-step, XRD and 4-point probe. In the results, the resistivity of AZO thin film was shown the lowest value about 8${\times}$10$^{-2}$ $\Omega$-cm(Zn:Al-Zn:Al), 3${\times}$10$^{-1}$ $\Omega$-cm(Zn-ZnO:Al) at the oxygen gas flow ratio 0.3. And the AZO thin film has good crystalline at oxygen gas flow ration 0.4, using Zn:Al-Zn:Al targets.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.426-429
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• 1999

In this paper, we have provided the measurement technique of the grounding mesh resistance by field measurements. The standard of measurement is specified in the IEEE Std 81.2-1991 and JEAC 5001-1988, which is the the fall-of-potential method by test-current injection, but this method is difficult to apply at field, where is small around a electric power substation of domestic. For the convenient measurement method, space of assistant probe and quantity of test-current injection are changed step for step. As the result, ' the proposed measurement technique of grounding mesh resistance is that the space of current and potential probes must be fixed at 150rn from a grounding mesh, the test-current injection has to keep 5A or more.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2064-2067
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• 2000

In our country, most region is composed of mountains and people have recently been displeased with the construction of the substations in their vicinity so the substations newly built are mainly constructed with GIS system in the small area that has high soil resistivity near mountain. Therefore, nowadays the design of substation grounding system has been difficult, and the additional considerations are needed. UC substation was also difficult to design the grounding system because of so small substation area and high soil resistivity. This paper shows the examples of reducing the grounding system resistance reasonably by using several ways. Designing the ground grid electrode in the access road, deep electric earth probe, changing the substation soil with the law level resistivity soil. This report deals with the computer simulation of the grounding system resistance about the ways illustrated above.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.111-116
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• 2004

An experiment was carried out to confirm the validity of time series evaluation of supersonic mixing condition by using catalytic reaction on a platinum wire. Geseous hydrogen was injected parallel to supersonic freestream (M$\infty$ $\approx$ 1.81) from a slit injector, which was located at backward facing step. Time series condition of supersonic mixing was evaluated by using W-type probe which has a platinum wire and reference wire (nickel wire). The evaluation was by simultaneously measuring each electric circuit which kept the temperature of wire constant. Investigations were also conducted for helium, air and no secondary injectant cases to compare with the hydrogen injectant case. The results indicated that it was possible to measure the time series behavior of air and hydrogen supersonic mixing layer or coherent motion of turbulence by using this evaluation.