• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.231-241
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• 2001

The epoxy resin materials used in outdoor high voltage equipments are required to have the high electric performance because of the miniaturization. The frequence dependence of the permittivity and the loss tangent have important information. In this paper we describe the frequency dependence of the permittivity and the loss tangent for epoxy resin filled with silica and the influence of filler shapes on the dielectric properties. The increment of tan $\delta$ in the low frequency region is caused by the increment of both the electrical conductivity and the polarization due to the shape of filler and the water absorbed in and near the interface between fillers and resins. The result of charge current and discharge measure, electric conduction is increased according to voltage.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.671-674
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• 2006

Due to the stricter requests of the human perception of images, many industrial standards such as TCO'03 have been made to survey the Flat Panel Displays (FPD) nowadays. The angular-dependence luminance uniformity is an important item to evaluate the performance of FPD. In this article, we focus on the above test item base on TCO'03 standard in the case of vertical direction of ${\pm}15^{\circ}$. With controlling the driving voltage toward the liquid crystals of TN-type TFT-LCD, there exists a voltage-driving range which can achieve the value of the $L_{max}/L_{min}$ at ${\pm}15^{\circ}\;{\leq}1.7$ readily. Both experiment and simulation have been well analysis.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.5-8
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• 2001

This paper describes the development of SiC MOSFET model for high temperature applications. The temperature dependence of the threshold voltage and mobility of SiC MOSFET is quite different from that of silicon MOSFET. We developed the empirical temperature model of threshold voltage and mobility of SiC MOSFET and implemented into HSPICE. Using this model the MOSFET Id-Vds characteristics as a function of temperature are simillated. Also the SiC CMOS operational amplifieris designed using this model and the temperature dependence of the frequency response, transfer characteristics and slew rate as a function of temperature are analyzed.

• Progress in Superconductivity
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• v.3 no.2
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• pp.146-150
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• 2002

We performed the point contact spectroscopy on newly discovered superconductor $MgB_2$ thin films with Au tip. In the point contact spectroscopy of the metallic Sharvin limit, the differential conductance below the gap is twice as that above the gap by virtue of Andreev Reflection. After some surface cleaning processes of sample preparation such as ion-milling and wet etching, the obtained dI/dV versus voltage curves are relatively well fitted to the Blonder-Tinkham-Klapwijk (BTK) formalism. Gaps determined by this technique were distributed in the range of 3meV~ 8meV with the BCS value of 5.9meV in the weak coupling limit. We attribute these discrepancies to the symmetry of the gap parameter and the degradation of the surface of the sample. We also present the temperature dependence of the conductance vs voltage curve and thereby the temperature dependence of the gap.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.4
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• pp.157-163
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• 1984

The object of this paper is to investigte the gate controlled diode structure for ionic concentration measurement. It includes device fabrication, characterization, device physics and modeling of the gate controlled diode structure. The differences of turn on voltages and surface generation currents in the (100) and (111) silicon crystallographic orientation of the sample device were observed. Therefore the dependence of these two factors of the silicon crystallographic orientation was investigated. It was observed that drifts arose after extended immersion of the sample device in acid or base solutions. The surface generation-recombination velocity of both (100) and (111) increased. The increase in the interfacial traps for both surface, determined by the turn on voltage was directly proportional to the surface generation-recombination velocity increase.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.4
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• pp.563-570
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• 1990

A silicon pressure sensor made of a full bridge of diffused resistors was designed and fabricated using semiconductor integrated circuit process. Thin diaphragms with 30\ulcorner thickness were obtained using anisotropic wet chemical etching technique. Our device showed strong temperature dependence. Compensation networks are used to compensate for the temperature dependence of the pressure sensor. The bridge supply voltage having positive temperature coefficient by compensation networks was utilized against the negative temperature coefficient of bridge output voltage. The sensitivity fluctuation of pressure sensor before temperature compensation was -1700 ppm/\ulcorner, while it reduced to -710ppm\ulcorner with temperature compensation. Our result shows that the we could develop accurate and reliable pressure sensor over a wide temperature range(-20\ulcorner~50\ulcorner).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.425-428
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• 1996

Treeing deterioration which is one of the main cause of breakdown in insulating materials is affected by temperature, applied voltage and frequency. In this study, GN was introduced to improve impact strength of DGEBA/MDA system and the temperature dependence of AC treeing deterioration in this system was investigated. Dielectric breakdown strength decreased with the increment of temperature. As temperature increased, the growth rate of tree Increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.102-105
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• 1997

The thickness dependence of stress voltage oxide currents has been measured in oxides with thicknesses between 10nm and 80nm. The oxide currents were shown to be composed of stress current and transient current. The stress current was caused by trap assited tunneling through the oxide. The transient current was caused by the tunneling charging and discharging of the trap in the interfaces. The stress current was used to estimate to the limitations on oxide thicknesses. The transient current was used to the data retention in memory devices.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.310-314
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• 2011

This paper has presented doping profile dependent threshold voltage for DGMOSFET using analytical transport model based on Gaussian function. Two dimensional analytical transport model has been derived from Poisson's equation for symmetrical Double Gate MOSFETs(DGMOSFETs). Threshold voltage roll-off is very important short channel effects(SCEs) for nano structures since it determines turn on/off of MOSFETs. Threshold voltage has to be constant with decrease of channel length, but it shows roll-off due to SCEs. This analytical transport model is used to obtain the dependence of threshold voltage on channel doping profile for DGMOSFET profiles. Also we have analyzed threshold voltage for structure of channel such as channel length and gate oxide thickness.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.99-102
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• 2005

In the paper, a proposed VCO based on bondwire inductances and nMOS varactors was implemented in a standard $0.25\;{\mu}m$ CMOS process. Using the new drain current model and a propagation delay time model equations, the operation speed of CMOS gate will predict the dependence on the load capacitance and the depth of oxide, threshold voltage, the supply voltage, the channel length. This paper describes the result of simulation which calculated a gate propagation delay time by using new drain current model and a propagation delay time model. At the result, When the reverse bias voltage on the substrate changes from 0 voltage to 3 voltage, the propagation delay time is appeared the delay from 0.8 nsec to 1 nsec. When the reverse voltage is biased on the substrate, for reducing the speed delay time, a supply voltage has to reduce. The $g_m$ value of MOSFET is calculated by using new drain current model.