• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1489-1496
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• 2009

Amorphous indium-gallium-zinc-oxide thin-film-transistors (TFTs) were modeled successfully. Dependence of TFT characteristics on structure, thickness, and equilibrium electron-density of the active layer was studied. For mono-active-layer TFTs, a thinner active layer had higher field-effect mobility. Threshold voltage showed the smallest absolute value for the 20 nm active-layer. Subthreshold swing showed almost no dependence on active-layer thickness. For the double-active-layer case, better switching performances were obtained for TFTs with bottom active layers with higher equilibrium electron density. TFTs with thinner active layers had higher mobility. Threshold voltage shifted in the minus direction as a function of the increase in the thickness of the layer with higher equilibrium electron-density. Subthreshold swing showed almost no dependence on active-layer structure. These data will be useful in optimizing the structure, the thickness, and the doping ratio of the active layers of oxide-semiconductor TFTs.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.44-51
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• 2004

오늘날 대부분의 에너지를 전기에 의존함에 따라 전력사용이 급증하고 부하가 대용량화되어 및 정적 전력공급이 중요한 문제로 대두되었다. 이러한 추세에 따라 송ㆍ배전 설비도 점차 대용량화 및 고전압화 되고 신뢰성을 요구하게 되며, 각종 배전 설비의 제조기술이 더욱 복합 다양하게 발전하고 있다. 그 중 전력계통에서 뇌 혹은 개폐서지 등의 과전압을 흡수ㆍ억제하여, 전력설비와 계통보호를 위해 설치하는 것이 피뢰기이다. 따라서 어떻게 과전압을 낮게 억제할 수 있을까 하는 것이 피뢰기의 가장 중요한 성능이라고 말할 수 있다. (중략)

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.11
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• pp.1-7
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• 2009

In this paper, a simple analytical model for deriving the threshold voltage of a short-channel intrinsic-body SDG SOI MOSFET is suggested. Using the iteration method, both Laplace equations in intrinsic silicon body and gate oxide are solved two-dimensionally. Obtained potential distributions in both regions are expressed in terms of fourth and fifth-order of the coordinate perpendicular to the silicon channel direction. Making use of them, the surface potential is obtained to derive the threshold voltage in a closed-form. Simulation results show the fairly accurate dependencies of the threshold voltage on the various device parameters and applied bias voltages.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.7
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• pp.9-16
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• 2008

In this paper, a simple analytical model for deriving the threshold voltage of a short-gate SOI MESFET is suggested. Using the iteration method, the Poisson equation in the fully depleted silicon channel and the Laplace equation in the buried oxide region are solved two-dimensionally, Obtained potential distributions in each region are expressed in terms of fifth-order of $\chi$, where $\chi$ denotes the coordinate perpendicular to the silicon channel direction. From them, the bottom channel potential is used to describe the threshold voltage in a closed-form. Simulation results show the dependencies of the threshold voltage on the various device geometry parameters and applied bias voltages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.793-798
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• 2012

In this paper, dependence of subthreshold current has been analyzed for doping distribution and channel structure of double gate(DG) MOSFET. The charge distribution of Gaussian function validated in previous researches has been used to obtain potential distribution in Poisson equation. Since DGMOSFETs have reduced short channel effects with improvement of current controllability by gate voltages, subthreshold characteristics have been enhanced. The control of current in subthreshold region is very important factor related with power consumption for ultra large scaled integration. The deviation of threshold voltage has been qualitatively analyzed using the changes of subthreshold current for gate voltages. Subthreshold current has been influenced by doping distribution and channel dimension. In this study, the influence of channel length and thickness on current has been analyzed according to intensity and distribution of doping.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1422-1428
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• 2014

This paper has analyzed threshold voltage roll-off for bottom gate voltages of asymmetric double gate(DG) MOSFET. Since the asymmetric DGMOSFET is four terminal device to be able to separately bias for top and bottom gates, the bottom gate voltage influences on threshold voltage. It is, therefore, investigated how the threshold voltage roll-off known as short channel effects is reduced with bottom gate voltage. In the pursuit of this purpose, off-current model is presented in the subthreshold region, and the threshold voltage roll-off is observed for channel length and thickness with a parameter of bottom gate voltage as threshold voltage is defined by top gate voltage that off-currnt is $10^{-7}A/{\mu}m$ per channel width. As a result to observe the threshold voltage roll-off for bottom gate voltage using this model, we know the bottom gate voltage greatly influences on threshold voltage roll-off voltages, especially in the region of short channel length and thickness.

• Proceedings of the Korean Magnestics Society Conference
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• 2006.06a
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• pp.100-101
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• 2006

• 전기의세계
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• v.45 no.11
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• pp.16-20
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• 1996

본 글에서는 신경섬유에 활동전압들이 전달될 때 새성되는 활동의존 막흥분성의 변화가 신경계에서의 정보처리와 어떠한 관련성이 있는가를 알아보기로 한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.128-133
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• 2008

This paper describes underwater discharge phenomena and breakdown characteristics in case that the standard lightning impulse voltage is injected to the needle and spherical electrodes installed in the hemisphere water tank. The objective of this work is to understand the basic features related to transient ground impedance against lightning surges. The discharge luminous images were observed and the dependence of breakdown voltage on the polarity of applied voltage and water resistivity were investigated. As a consequence, streamer corona is initiated at the tip of needle and spherical electrodes and is propagated toward grounded tank with stepwise extension. The breakdown voltage characteristics measured as a function of water resistivity showed V-shaped curves. Breakdown voltage and time curve of needle electrode is higher than that of spherical electrode.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04a
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• pp.13-17
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• 2004

펜틸시아노비페놀(PCB) 액정셀은 저주파 영역에서 유전율이 대단히 크게 나타나는 현상이 보인다. 그 원인은 액정셀 내의 불순물 이온의 거동이라고 생각된다. 액정셀 내에 존재하는 불순물 이온의 거동을 관찰하기 위하여 PCB 액정셀의 유전 분산특성을 측정하여 온도의존성, 막 두께 의존성, 직류전압 의존성등을 측정하였다.