• Journal of Surface Science and Engineering
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• v.29 no.3
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• pp.149-156
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• 1996

Conducting diamond-like carbon films are synthesized using Triode Magnetron Sputtering-Plasma Enhanced Chemical Vapor Deposition(TMS-PECVD), and are examined by four point probe, microhardeness tester, and scanning electron miscroscopy(SEM). As the target bias and Ar/CH$_4$, ratio increase, the electrical resitivity and microhardness of the films are found to decrease, and also, their surface morphologies tend to be rough. While the resistivities of the films are shown to increase in proportion to the increase of the substrate bias, the microhardness of the films is shown to be maximun value(1600kg/$\textrm{mm}^2$) at a certain substrate bias(-70V). We can obtain the conducting diamond-like carbon films with the microhardness of 1600(kg/$\textrm{mm}^2$) and electrical resitivity of 16($\Omega$cm) at the process condition such as target bias -400V, substrate bias -70V, and Ar/$CH_4$ ratio 20.

• Journal of Surface Science and Engineering
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• v.40 no.2
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• pp.59-62
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• 2007

Metal containing hydrogen free nanocrystalline structured carbon (Me:nc-C) films were synthesized by closed-field unbalanced magnetron sputtering system (CFUBM). The aim of this study was to determine the relationship between the microstructure and physical properties of Me:nc-C films as a function of the concentration of materials. The film structures were examined by x-ray photoelectron spectroscopy and high resolution transmission electron microscopy. The physical properties of the Me:nc-C films were evaluated by using a 4-point probe. The fraction of graphite clusters was found to be increased by containing titanium and the electrical resistivity decreased with increasing amount of containing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.688-692
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• 2004

In this paper, zinc oxide (ZnO) films with c-axis (002) orientation have been successfully deposited on the Al/Si substrate by rf magnetron sputtering method. The deposited films were characterized by substate temperature. Physical and structural properties of the deposited films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurement. Electrical Properties of the deposited films were investigated by 4-poing probe and LCR meter measurement. The optimal condition in this experimental result was found at foot of the substrate temperature and shown good film quality for FBAR application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1042-1045
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• 2004

ITO thin films ($\sim150nm$) are deposited on glass substrates by different deposition condition. The sheet resistance of ITO thin films measured by using a four probe station. The microstructure of these films is determined using a X-ray diffractometer (XRD) and a scanning electron microscope (SEM) and a atomic force microscope (AEM). The sheet resistance of ITO thin films compared $s_11$ values by using a near field scanning microwave microscope.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.110-110
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• 2009

본 연구에서는 전산유체역학적 방법을 이용하여 레이저-GMA 하이브리드 용접에서 용융풀 거동에 대한 3차원 과도해석을 수행하였다. 철강재의 주요 합금원소 중 하나인 크롬의 용융풀에서의 거동을 구현하기 위해 크롬에 대해 추가적인 보전 방정식을 도입하였다. 이를 이용하여 합금원소 분포에 대한 용접 변수별 영향을 해석적으로 분석하였으며 이를 EPMA(Electron Probe Micro Analyzer)를 통해 분석한 시험결과와도 비교하였다. 결과적으로 용접변수 중 선행 조건이 합금원소 분포에 구별할만한 영향을 미침을 알 수 있었고 이는 용융풀의 거동을 지배하는 주요 유동 패턴의 상이함에 기인한 것으로 보여진다.

• Bulletin of the Korean Chemical Society
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• v.11 no.5
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• pp.460-463
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• 1990

The normal and fluorinated high-Tc superconducting materials, $YBa_2Cu_3O_{7-x}F_y$with $0.25{\leq}x{\leq}0.55\;and\;0.00{\leq}y{\leq}0.30$, were synthesized to investigate the dopping effect of fluorine atom on the superconductivity of Y123 and studied by X-ray diffraction analysis and electron probe microanalysis, resistivity and thermopower measurements, and polarized micro-Raman spectroscopy. The reproducible micro-Raman spectra were recorded and analyzed. The coherent assignments could be suggested for the spectra of normal and fluorinated samples. The fluorine atoms introduced were found to be substituted for oxygen in pyramidal Cu-O units rather than in Cu-O chains. The unit cell parameters were decreased upon the substitution of oxygen by fluorine atom. From the decreasing cell parameters and Tc, the increasing thermopower, and the possible assignments of the vibrational modes, it could be suggested that the dopping of fluorine atom localizes the superconducting electrons in Y123.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.05a
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• pp.12-17
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• 2003

본 연구에서는 MICP Etching system 을 이용한 Via contact 및 Deep contact hole etch process 특성을 연구하였다. Langmuir probe 를 이용한 MICP source 의 Plasma density & electron temperature 측정하였고 탄소와 플로우르를 포함하는 혼합 Plasma 를 형성하여 RF frequency, wall temperature, chamber gap, gas chemistry 등의 변화에 따른 식각 특성을 조사하였다. Plasma density 는 1000w 에서 $10^{11}$/$cm^3$ 이상의 high density plasma와 uniform plasma 형성을 확인하였고 $CH_{2}F_{2}$와 CO의 적절한 혼합비를 이용하여 Oxide to PR 선택비가 10 이상인 고선택비 조건을 확보하였다. 고선택비 형성에 따라 Polymer 형성이 많이 되었고 이를 개선하기 위하여 반응 챔버의 온도 조절을 통하여 Polymer 증착 방지에 효과적인 것을 확인하였다. MICP source를 이용하여 탄소와 플로우르의 혼합 가스와 식각 챔버의 온도 조절에 의한 선택비 증가를 확보하여 High Aspect Ratio Contact Hole Etch 가능성을 확보하였다.

• Journal of the Semiconductor & Display Technology
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• v.8 no.3
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• pp.57-60
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• 2009

Transparent electrode ZnO:Al(AZO)films were deposited on a PES (polyethersulfone) polymer substrate for thin film solar cells applications. A PES substrate with a thickness of 0.2mm and transmittance > 90% in the visible range was used because it is light weight and can deform easily. AZO thin films were prepared at a fixed DC power, $PO_2\;=\;P(O_2)/[P(O_2)\;+\;P(Ar)]$, and various substrate temperatures. The properties of AZO thin films were examined by X-ray diffraction, UV/VIS spectroscopy, four-point probe, Hall measurements, and field emission scanning electron microscopy. The lowest resistivity of all the films was $4.493\;{\times}\;10^{-4}\;[\Omega-cm]$ and the transmittance was > 80% in the visible range.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.223-230
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• 1997

최근들어 그 활용도가 점점 증대되고 있는 DLU(Diamond-like Carbon) /Diamond 박막(thin film)의 합성기술을 개발하여 원자력분야에 응용하고자 시도하였다. 이를 위하여 13.56 MHz의 고주파(RF: radio-frequency)를 사용하는 플라즈마 화학증착(PECVD: Plasma Enhanced Chemical Vapor Deposition) 장치를 직접 제작하여 탄소함유(CH$_4$, $CO_2$...등) 기체로부터 기본적인 DLC 박막증착시험을 수행하였다. 실험은 진공증착기(vacuum chamber)내의 압력(pressure), 탄소함유 기체의 조성비, 그리고 바이어스전압(negative self-bias voltage)둥을 변화시키면서 수행하였다. 증착속도(deposition rate)는 증착층의 두께를 알파스템($\alpha$-step)으로 측정하여 결정하였으며, 이로부터 증착속도가 압력 및 바이어스 전압의 증가에 따라 증가함을 알 수 있었다. 또한 바이어스 전압 300V 이상에서 $CO_2$량 증가가 증착속도를 촉진시킨다는 사실도 확인하였다. 그리고 EPMA(electron probe micro-analyser) 및 Raman 스펙트럼분석을 통하여 증착층의 구조가 DLC 임을 확인하였다.

• Journal of the Optical Society of Korea
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• v.7 no.2
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• pp.47-52
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• 2003

Effect of soaking temperature on erbium doping of the optical fiber core during solution doping procedure, especially in the modified chemical vapor deposition (MCVD) process, was investigated. The concentration of dopants such as $Er^{3+} and Al^{3+}$ in the preforms and the optical fibers measured by the electron probe microanalysis (EPMA) and the optical spectrum analyzer (OSA) was found to increase with decreasing the soaking temperature. The increase in the concentration of the $Er^{3+}$ is attributed to the precipitation of the erbium due to the decrease in the solubility as well as the increase of capillary force and viscosity of the doping solution by decreasing the temperature.