• Journal of the Korean Vacuum Society
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• v.2 no.3
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• pp.355-359
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• 1993

전자빔증착기를 이용하여 적외선영역에서 직접천이형 에너지갭을 갖는 III-V족 2원 화합물 반도체인 InSb 박막을 제작하여 전기, 자기적 특성을 조사하였다. 기판온도 $350^{\circ}C$에서 증착된 박막을 $425^{\circ}C$의 온도에서 30분 동안 아닐링한 박막은 In2O3 피크가 없어지고, InSb 피크만 나타났으며, 이대의 격자상수 $\alpha$0는 $6.49AA$이었다. 기판온도 35$0^{\circ}C$까지는 InSb 박막의 결정화가 일어나 전자 이동도가 증가하고 비저항은 감소하여다. 자계 0.5~9kG범위에서 van der Pauw 방법으로 홀효과를 측정하여 전기, 자기적 특성을 조사하였다. 최적의 조건에서 증착된 박막의 전도형은 n형이었고, 실온에서 캐리어 농도 및 이동도는 각각 2.55$\times$1016cm-3, 2.83$\times$104$ extrm{cm}^2$/V.sec이었다. 자계가 증가할수록 자계저항은 증가하였고, 9kG에서 자계저항은 1.98이었다.

• Journal of Magnetics
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• v.10 no.4
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• pp.149-151
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• 2005

The electric properties of a single crystal bismuth telluride doped with a small concentration of Erbium, $Bi_{z-x}Er_xTe_3$ with x = 0.002, are investigated as a function of temperature. The resistivity was obtained by using the van der Pauw method. The measured electrical resistivity is 78 ${\mu}{\Omega}cm$ at 4.2 K. The charge density of $Bi_{z-x}Er_xTe_3$ is found to be $2{\times}10^{19}/cm^3$ at 4.2 K. It turns out that $Bi_{z-x}Er_xTe_3$ is a p-type semiconductor. It is discussed that the high mobility and less density support that $Bi_{z-x}Er_xTe_3$ is a potential sensor with high energy resolution. Comparison with an established material (i.e. Au:Er alloy) is also discussed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.1
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• pp.26-29
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• 2006

Transparent ZnO thin films were prepared by KrF pulsed laser deposition (PLD) technique and applied to a bottom-gate type thin film transistor device as an active channel layer. A high conductive crystalline Si substrate was used as an metal-like bottom gate and SiN insulating layer was then deposited by LPCVD(low pressure chemical vapour deposition). An aluminum layer was then vacuum evaporated and patterned to form a source/drain metal contact. Oxygen partial pressure and substrate temperature were varied during the ZnO PLD deposition process and their influence on the thin film properties were investigated by X-ray diffraction(XRD) and Hall-van der Pauw method. Optical transparency of the ZnO thin film was analyzed by UV-visible phometer. The resulting ZnO-TFT devices showed an on-off ration of $10^6$ and field effect mobility of 2.4-6.1 $cm^2/V{\cdot}s$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.498-499
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• 2007

금속 비저항의 측정방법은 4단자 방법을 비롯한 van der Pauw 방법, Four-Point Probe(FPP) 방법, eddy current 방법 등이 사용되고 있으며, 시료의 혈상과 크기에 따라서 그 측정방법은 각각 다르다. 본 연구에서는 그 중 4단자 방법에 의한 정밀측정방법과 측정불확도 평가에 관하여 고찰하였다. 4단자 방법은 시료가 바(bar)나 봉(rod) 형상이면 측정이 가능하며, 시료의 정밀가공과 측정기술을 통하여 측정 불확도를 줄일 수 있다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.95-98
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• 1999

ZnO thin films on (001) sapphire substrates have been deposited by pulsed laser deposition technique using a Nd:YAG laser with the wavelength of 355 nm. In order to investigate the effect of the deposition conditions on the properties of ZnO thin films at an oxygen pressure of 350 mTorr, the experiment has been Performed at various substrate temperatures in the range of 20$0^{\circ}C$ to $700^{\circ}C$. According to XRD, (002) textured ZnO films of high crystalline quality have been obtained and the intensity of UV emission was the highest at 40$0^{\circ}C$ substrate temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.349-352
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• 2004

The $CdS_{1-x}Se_x$ thin films were grown on the GaAs(100) wafers by a Hot Wall Epitaxy method(HWE). The temperatures the source and the substrate temperature are $580^{\circ}C\;and\;440^{\circ}C$ respectively. The crystalline structure of thin films was investigated by double crystal X-tay diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. In order to explore the applicability as a photoconductive cell, we measured the sensitivity($\gamma$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.157-158
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• 2006

$CdS_{0.69}Se_{0.31}$ single crystal grown by sublimation method. Hall effect measurement were carried out by the Van der Pauw method. The measurement values under the temperature were found to be carrier density $n\;=\;1.95\;{\times}\;10^{23}m^3$, Hall coefcient $RH\;=\;-3.21\;{\times}\;10^{-5}m^3/c$, conductivity ${\sigma}\;=\;362.41\;{\Omega}^{-1}m^{-1}$, and Hall mobility ${\mu}\;=\;1.16\;{\times}\;10^{-2}m^2/v.s$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.136-137
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• 2006

The stochiometric mix of evaporating materials for the $ZnGa_2Se_4$ single crystal thin films were prepared from horizental furnace. To obtains the single crystal thin films, $ZnGa_2Se_4$ mixed crystal were deposited on throughly etched Si(100) by the Hot Wall Epitaxy (HWE) system. The temperates of the source and the substrate were $590^{\circ}C$ and $450^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction(DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility dependence on temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.599-600
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• 2005

The measurement method of electrical conductivity of the metal use a generally DC technique. Traceability to national standards in many countries is achieved using DC measurement technique and recently it's interested in AC technique. As a results for AC technique, the properties of electrical conductivity of non-ferrous and ferrous metals is decreasing at low frequency level.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.214-214
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• 2012

화학기상증착법을 통해 대면적 합성이 가능해진 그래핀의 개발로 인해 그래핀에 관한 연구가 활발히 진행되었다. 특히, 플라즈마 처리에 관한 연구를 통해 그래핀의 도핑이 가능하다는 것이 밝혀졌고 이는 곧 그래핀 내의 전하 농도를 변화시킬 것으로 예상된다. 따라서 본 연구에서는 Van der Pauw 방법을 통해 플라즈마 처리에 따른 그래핀 내의 전하 농도와 면저항을 측정하고 이를 통해 이동도를 계산하는 실험을 진행하였다.