• 환경위생공학
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• 제4권2호
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• pp.1-14
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• 1989

There is increasing concern that depletion of the ozone layer may have important health consequences. Each $1\%$ decline in ozone concentration is expected to cause a $2\%$ increase in ultraviolet radiation this in turn has been suggested to lead to up to a $4-6\%$ increase in certain kinds of skin cancer. In Colorado state, malignant melanoma patients increased form 7.4 cases per 100,000 to 12.6 per 100,000 in the general population between 1979 and 1985. In Australia, 4,000 new melanomas are diagnosed each year and 800 people die every year from melanoma. Strong international controls CFCs production are necessary to lower the destruction of ozone in the stratosphere. Only then will the increase in ultraviolet radiation to the skin be halted and the incidence and mortality from melanomas be reduced.

• Bulletin of the Korean Chemical Society
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• 제15권7호
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• pp.590-592
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• 1994

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 하계학술발표회
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• pp.98-99
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• 2003

PIN photodiode has been used in solid-state detector for x-ray detection as a photosensor of visible light from scintillator. Since the light from CWO is short wavelength having peak at 490nm, the light is absorbed within a very shallow layer near the surface of the photodiode before arriving at the depletion layer and does not contribute to the signal. In designing the PIN photodiode, it is important to make the p-layer as shallow as possible. (omitted)

• Transactions on Electrical and Electronic Materials
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• 제12권4호
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• pp.148-151
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• 2011

We designed and fabricated aluminium gallium nitride (AlGaN)/GaN high electron mobility transistors (HEMTs) with stable reverse blocking characteristics established by employing a selective fluoride plasma treatment on the drainside gate edge region where the electric field is concentrated. Implanted fluoride ions caused a depolarization in the AlGaN layer and introduced an extra depletion region. The overall contour of the depletion region was expanded along the drift region. The expanded depletion region distributed the field more uniformly and reduced the field intensity peak. Through this field modulation, the leakage current was reduced to 9.3 nA and the breakdown voltage ($V_{BR}$) improved from 900 V to 1,400 V.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 하계학술발표회
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• pp.220-221
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• 2003

We optimized the structure of a fully depleted optical thyristor (DOT) to achieve the faster switching speed and the lower power consumption by the depletion of charge at the lower negative voltage. The fabricated optical thyristor shows sufficient nonlinear s-shape I-V characteristics with the switching voltage of 2.85 V and the complete depletion voltage of -8.73 V. In this paper, using a finite difference method (FDM), we calculate the effects of parameters such as doping concentration and thickness of each layer to determine the optimized structure in the view of the fast and low-power-consuming operation.

• 대한전자공학회논문지SD
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• 제37권1호
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• pp.1-7
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• 2000

본 논문에서는 반절연성 GaAs 기판위에 $Al_2O_3$ 절연막이 제이트 절연막으로 이용된 공핍형보드 n형 채널 GaAs MOSFET(depletion mode n-channel GaAs MOSFET)를 제조하였다. 반절연성 GaAs 기판위에 1 ${\mu}$m의 GaAs 버퍼층, 1500 ${\AA}$의 n형 GaAs층, 500 ${\AA}$의 AlAs층, 그리고 50 ${\AA}$의 캡층을 차례로 성장시키고 습식열산화 시켰으며, 이를 통하여 AlAs층은 완전히 $Al_2O_3$층으로 변환되었다. 제조된 MOSFET의 I-V, $g_m$, breakdown특성 측정 등을 통하여 AlAs/GaAs epilayer/S${\cdot}$I GaAs 구조의 습식열산화는 공핍형 모드 GaAs MOSFET를 구현하기에 적합함을 알 수 있다.

• 한국주조공학회지
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• 제15권3호
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• pp.272-282
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• 1995

Iron-based metal matrix composites have been recently investigated for the use of inexpensive abrasion resistance material. This paper carried out to investigate the in-situ reaction effects on the microstructural characteristics and the formation mechanism of tungsten carbides in a white cast iron matrix. The specimens of Fe-3.2%C-2.8%Si alloy cast-bonded with tungsten wire were cast in the metal mold and isothermally heat treated at $950^{\circ}C$ up to 48 hours. The typical microstructure of heat treated specimens showed the reaction layer of WC at the interface of tungsten wire and the carbon depletion zone between the WC layer and the matrix. During the formation of WC layer, if the carbon supply is insufficient due to the decarburization of matrix or the isolation of matrix by cast-bonded W wires, the reaction layer develops coarse hexagonal crystalline WC. From the microstructural investigation, it was found that the volume of WC layer and the carbon depletion zone increased linearly with the isothermal heat treating time. This results supported that the formation rate of WC in the white cast iron matrix is controlled by the interfacial reaction with a constant reaction rate.

• 대한전자공학회논문지
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• 제23권4호
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• pp.484-489
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• 1986

A device with variable stepped oxide layer along the edge region of Schottky junction have been designed and fabricated. The effect of this stepped oxide layer in the edge region improves the breakdown voltage as a result of the by increase of the depletion layer width, and decreases the leakage current as compared to the effect of conventional field oxide layer, when the reverse voltage was applied. Experimental results shown that the Schottky diode with the the reverse voltage was applied. Experimenal results show that the Schottky diode with the optimal stepped oxide layer maintains nearly ideal I-V characteristics and excellent breakdown voltage(170V) by reducing the edge effect inherent in metal-semiconductor contacts. The optimal conditions of stepped oxide layer are 1700\ulcornerin thickness and 10\ulcorner in length.

• 반도체디스플레이기술학회지
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• 제17권4호
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• pp.66-69
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• 2018

This study was researched the electrical properties of semiconductor devices such as ITO, $SiO_2$, $V_2O_5$ thin films. The films of ITO, $SiO_2$, $V_2O_5$ were deposited by the rf magnetron sputtering system with mixed gases of oxygen and argon to generate the plasma. All samples were cleaned before deposition and prepared the metal electrodes to research the current-voltage properties. The electrical characteristics of semiconductors depends on the interface's properties at the junction. There are two kinds of junctions such as ohmic and schottky contacts in the semiconductors. In this study, the ITO thin film was shown the ohmic contact properties as the linear current-voltage curves, and the electrical characteristics of $SiO_2$ and $V_2O_5$ films were shown the non-linear current-voltage curves as the schottky contacts. It was confirmed that the electronic system with schottky contacts enhanced the electronic flow owing to the increment of efficiency and increased the conductivity. The schottky contact was only defined special characteristics at the semiconductor and the interface depletion layer at the junction made the schottky contact which has the effect of leakage current cutoff. Consequently the semiconductor device with shottky contact increased the electronic current flow, in spite of depletion of carriers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.155-158
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• 1988

The fabrication of devices using plans technology could lend to n serious degradation in the breakdown voltage as a result of high electric field at the edges. An elegant approach to reducing the electric field at the edge is by using field limiting ring. The presence of surface charge has n strong influrence on the depletion layer spreading at the surface region because this charge complements the charge due to the ionized acceptors inside the depletion layer. Surface charge of either polarity can lower the breakdown voltage because it affects the distribution of electric field st the edges. In this paper we discuss the influrences of fixed oxide charge on the breakdown voltage of the p+/n junction with field limiting ring(or without field limiting ring).