• 대한전자공학회논문지
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• 제26권11호
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• pp.1631-1636
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• 1989

A space charge model for semiconductor reduced gas sensors has been roposed and applied to gas sensing mechanism. SnO2-x and SnO2-x/Pt thin film were deposited by vacuum evaporating method. And Hall effect and gas sensitivity characteristics of these sensors were measured. From the space charge model and carrier concentration, the number of the adsorbed gas atom on the solid surface was calculated quantitatively. The gas sensing model was compared with CO gas sensitivities of the fabricated thin film gas sensors.

• Nuclear Engineering and Technology
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• 제29권6호
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• pp.451-458
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• 1997

Signal shapes from a closed-ended coaxial HPGe detector are investigated by numerical methods. The detector used in this study has a volume of 72 ㎤ with relative efficiency of 15%. The electric field and potential distributions in the detector are determined by solving the Poisson equation at the depletion and operating bias. Hence the time dependent signal shapes induced on the electrode are obtained from the energy balance consideration and tv solving the equation of motion for the charge carriers. For various initial positions of a charge carrier pair, the collection times of induced charge vary in the range of 70 - 404 nsec.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.327-330
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• 2004

It is shown that the hot carrier degradation due to enhanced hot holes trapping dominates PMOSFETs lifetime both in thin and thick devices. Moreover, it is found that in 0.13 ${\mu}m$ CMOSFET the PMOS lifetime under CHC (Channel Hot Carrier) stress is lower than the NMOSFET lifetime under DAHC (Drain Avalanche Hot Carrier) stress. Therefore. the interface trap generation due to enhanced hot hole injection will become a dominant degradation factor. In case of thick MOSFET, the degradation by hot carrier is confirmed using charge pumping current method and highly necessary to enhance overall device lifetime or circuit lifetime in upcoming nano-scale CMOS technology.

• 한국세라믹학회지
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• 제36권12호
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• pp.1374-1380
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• 1999

The cause of Scond Harmonic Generation (SHG) in thermally poled silica glass is suggested basedon the electrical and dielectric relaxation measurements. The absorption currents as functions of time were measured for various types of silica glasses and analyzed by the theory of Space Charge Polarization. Space charge polarization occurs when an ionic conducting material is subjected to dc electric field with blocking electrode. Thermal poling performed to induce SHG in silica glass is basically identical to the process generating space charge polarization. Hence it was found that gene-ration removal reproduction and temperature dependence of SHG in poled silica is directly related to those of space charge polarization. It turned out that the fundamental parameters governing the SHG in poled silica are charge carrier concentration and mobility. Based on the theory of space charge polarization and experimental results of electrical rela-xation the method to increase the intensity of SHG is proposed.

• Journal of Pharmaceutical Investigation
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• 제41권6호
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• pp.323-329
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• 2011

In order to develop new protein carrier replacing poly(DL-lactic acid-co-glycolic acid) (PLGA) microspheres, succinylated pullulan acetate (SPA) was investigated to fabricate a long term protein delivery carrier. SPA microspheres loaded with lysozyme (Lys) as a model protein drug were prepared by a water/oil/water (W/O/W) double emulsion method. An acidity test of SPA copolymers after hydrolysis was performed to estimate the change of protein stability during releasing proteins from the microspheres. There was no pH change of SPA copolymers, but pH of PLGA polymers after hydrolysis was significantly decreased to around pH 2, indicating that the long-term stability of proteins released from SPA microspheres can be guaranteed. Loading efficiency of proteins into SPA microspheres was three times higher than those into conventional PLGA microspheres, indication of inducing stronger charge interaction between proteins and succinyl groups in SPA microspheres. Although initial burst behaviors were monitored in Lys-loaded SPA microspheres due to relatively strong hydrophilic succinyl segments in SPA microspheres, initial burst issues would be circumvented if the ratio of charge density of succinyl moieties and hydrophobic acetate groups is harmonically controlled. Therefore, in this study, a new attempt of protein delivery system was made and functional SPA was successfully confirmed as a new protein carrier.

• 전자공학회논문지D
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• 제35D권4호
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• pp.53-60
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• 1998

The purpose of this paper is to meausre the electrophotographic characteristics of double-layered organic photoreceptor and to evaluate an application for the laser beam printer drum. The characte carrier generation layer(CGL) of double-layered photoreceptor was fabricated with .tau.-H$_{2}$Pc which has high photosensitivity in the near-infrareed region(thickness is about 0.3.mu.m), and Oxadiazole derivative was chosen as a charge carrier transport layer(CTL) because of its high hole mobility. To observe the electrophotographic characteristics of the photoreceptor, we measured the charge acceptance, dark-decay ratio, residual potential after light irradiation. From the result of this study, proper thickness of CTL was about 10.mu.m. Also it's realized that electrophotographic characteristics of the photoreceptor were depend on the thickness of the CTL and the initial surface potential.

• 대한전자공학회논문지
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• 제25권7호
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• pp.780-790
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• 1988

We have studied the hot-carrier-induced degradation caused by the high channel electric field due to the decrease of the gate length of MOSFET used in VLSI. Under DC stress, the condition in which maximum substrate current occures gave the worst degradation. Under AC dynamic stress, other conditions, the pulse shape and the falling rate, gave enormous effects on the degradation phenomena, especially at 77K. Threshold voltage, transconductance, channel conductance and gate current were measured and compared under various stress conditions. The threshold voltage was almost completely recovered by hot-injection stress as a reverse-stress. But, the transconductance was rapidly degraded under hot-hole injection and recovered by sequential hot-electron stress. The Si-SiO2 interface state density was analyzed by a charge pumping technique and the charge pumping current showed the same trend as the threshold voltage shift in degradation process.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2012년 춘계학술대회
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• pp.371-380
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• 2012

Although all costs concerned in transportation be separated by region and each terms and conditions of Incoterms that state cleary them who have to pay the charges. But, almost lcl exporters donot want to pay their charges the carriers at loading port eventhough they make the contracts with the importer as FOB and CFR of Incoterms. And the carrier have been do not bill the FOB charges to the shipper. Now, there are no more Incoterms in LCL transportation. So, the importer have been payed loading port charges twice, first, the contract with the shipper, secondly, through the destination charge. These problems make decreasing of trading volume and increasing of logistics costs. We suggest every traders and carriers separate the costs as per the price terms and conditions of incoterms and bill/receive the costs separated the trader who have to pay the charges as per their price terms. It will bring mutual success in the world and increasing trade.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.492-496
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• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e,g. As, Cl). In this paper, We investigated dopants(As, Cl) composition rate to improve dark resistivity and transport properties of charge carrier in amorphous selenium using by direct X-ray conversion material. Alloying a-Se with As inhibits the recrystallization of a-Se but introduces undesirable deep hole traps. then doping with Cl(in the ppm range) compensates for the deep hole traps. We investigated their composition rate in various doping conditions and then obtained optimum dopant composition rate. The result was Se-As 0.3%-Cl 30 ppm and X-ray Sensitivity was 0.57 pc/pixel$.$mR at 137 $\mu\textrm{m}$ x 137 $\mu\textrm{m}$ Pixel area.

• 마이크로전자및패키징학회지
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• 제22권4호
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• pp.111-115
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• 2015

실리콘 태양전지의 효율을 향상하기 위해서는 소수 캐리어의 높은 수명이 필수조건이다. 따라서, 이를 달성하기 위한 실리콘 표면결함을 없애줄 수 있는 부동화(passivation) 기술이 매우 중요하다. 일반적으로 PECVD 법이나 열산화 공정을 통해 얻어진 $SiO_2$ 박막이 부동화 층으로 많이 사용되나 1000도에 이르는 고온 공정과 낮은 열적 안정성이 문제로 여겨진다. 본 연구에서는 원자층 증착법을 이용하여 400도 미만의 저온 공정을 통해 $Al_2O_3$ 부동화 박막을 형성하였다. $Al_2O_3$ 박막은 고유의 음의 고정 전하밀도로 인해 낮은 표면 재결합속도를 보이는 것으로 알려져 있다. 본 연구에서는 질소 도핑을 통해 높은 음의 고정 전하 밀도를 얻고 이를 통해 좀 더 향상된 실리콘 표면 부동화 특성을 얻고자 하였다.