• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.5
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• pp.201-206
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• 2004

In order to investigate the optimum conditions for the effective ozone formation in a dielectric barrier discharge, measurements of ozone concentration were carried out for various conditions such as the gap length, the dielectric material and the operating gas. It was found that the optimum discharge conditions differed exceedingly in the types of operating gases and dielectric materials. In dry air, dielectric material with low dielectric constant and thermal conductivity, which might contribute to the restriction of the gas temperature rise in the discharge region, proved effective in obtaining both high ozone yield and concentration. The optimum gap length was considered to be in the range of 600-800 mm. In oxygen, using a quartz glass disk as a dielectric material, the required condition to obtain the high ozone yield and concentration was expanded.

• Journal of IKEEE
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• v.25 no.1
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• pp.1-9
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• 2021

In this paper, a 4H-SiC UMOSFET was studied which is suitable for high voltage and high current applications. In general, SiO2 is a material most commonly used as a gate dielectric material in SiC MOSFETs. However, since the dielectric constant value is 2.5 times lower than 4H-SiC, it suffers a high electric field and has poor characteristics in the SiO2/SiC junction. Therefore, the static characteristics of a device with high-k material as a gate dielectric and a device with SiO2 were compared using TCAD simulation. The results show BV decreased, VTH decreased, gm increased, and Ron decreased. Especially when the temperature is 300K, the Ron of Al2O3 and HfO2 decreases by 66.29% and 69.49%. and at 600K, Ron decreases by 39.71% and 49.88%, respectively. Thus, Al2O3 and HfO2 are suitable as gate dielectric materials for high voltage SiC MOSFET.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.245-248
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• 1997

The dielectric resonators(DRs) with dielectric properties are widely used in microwave integrated circuit(MICs) and monolithic microwave integrated circuits(MMICS). The variational method as numerical simulation scheme would be applied to calculate the resonant frequencies(fr) and Q-factors of microwave dielectric resonators. The dielectric resonator with a cylindrical “puck” structure of high dielectric material is modeled in this simulation. The parameters, such as the diameter, the height, and the dielectric constant of dielectric resonator, would determine the resonant frequency and the Q-factor. The relationship between these parameters would effect each other to evaluate the approximate resonant frequency. This simulation method by the variational formula is very effective to calculate fr, and Q-factor. in high frequency microwave dielectric resonator The error rate of the simulation results and the measured results would be considered to design the microwave dielectric resonators.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1453-1456
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• 2009

Transparent sol-gel hybrid dielectric material (hybrimer) coating films were fabricated by spin coating and photo or thermal curing of sol-gel derived oligosiloxane resins. Hybrimer coating films are suitable as the passivation layer of TFT in AMLCD due to low dielectric constant, small loss tangent, low leakage current density, high transmittance and thermal stability.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1092-1095
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• 2005

The effect of the dielectric constant (${\varepsilon}$) of bonding materials in screen-printed carbon nanotube cathode on field enhancement factor was investigated using the ANSYS software for high-efficient CNT-cathodes. The field enhancement factor increased with decreasing the dielectric constant and reaching a maximum value when the dielectric constant is 1, the value for a vacuum. This indicates that the best bonding materials for screen-printing CNT cathodes should have a low dielectric constant and this can be used as criteria for selecting bonding materials for use in CNT pastes for high-efficient CNT-cathodes

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.48-48
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• 2010

In this paper, we have investigated temperature dependence of dielectric breakdown voltage at epoxy with added nano-filler(MgO), which is used as a filler of epoxy additives for HVDC(high voltage direct current) submarine cable insulating material with high thermal conductivity and restraining tree to improve electrical properties of epoxy resin in high temperature region. In order to find dispersion of the specimen, the cross sectional area of nano-composite material is observed by using the SEM(Scanning Electron Microscope) and it is conformed that each specimen is evenly distributed without the cohesion. As a result, it is confirmed that the strength of breakdown of all specimen at 50 [$^{\circ}C$] decreased more than that of the dielectric breakdown strength at room temperature. When temperature increases from 50 [$^{\circ}C$] to 100 [$^{\circ}C$], we have confirmed that breakdown strength of virgin specimen decreases, but specimens with added MgO show constant dielectric breakdown strength.

• Journal of Powder Materials
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• v.13 no.6 s.59
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• pp.455-461
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• 2006

High temperature dielectric constants of the various ceramic materials have been measured using cavity perturbation method. The measurements were applied to refractory, traditional and fine ceramic powder compacts from room temperature to $1200^{\circ}C$. Calibration constant in the equation suggested by Hutcheon et al., was determined from the dielectric constants of reference specimen (teflon and alumina) at room temperature. From these results, informations on the refectory materials were obtained for the microwave kiln design and understanding of the microwave heating effects of ceramics have been improved.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.52-62
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• 2004

In this paper we look at the effect of Fringe-Enhanced-Barrier-lowering (FEBL) for high-K dielectric MOSFETs and the dependence of FEBL on various technological parameters (spacer dielectrics, overlap length, dielectric stack, S/D junction depth and dielectric thickness). We show that FEBL needs to be contained in order to maintain the performance advantage with scaled high-K dielectric MOSFETs. The degradation in high-K dielectric MOSFETs is also identified as due to the additional coupling between the drain-to-source that occurs through the gate insulator, when the gate dielectric constant is significantly higher than the silicon dielectric constant. The technology parameters required to minimize the coupling through the high-K dielectric are identified. It is also shown that gate dielectric stack with a low-K material as bottom layer (very thin $SiO_2$ or oxy-nitride) will be helpful in minimizing FEBL. The circuit performance issues with high-K MOS transistors are also analyzed in this paper. An optimum range of values for the dielectric constant has been identified from the delay and the energy dissipation point of view. The dependence of the optimum K for different technology generations has been discussed. Circuit models for the parasitic capacitances in high-K transistors, by incorporating the fringing effects, have been presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.163-166
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• 2002

We investigated structural and electrical properties of Metal-Oxide-Semiconductor(MOS) structure using Hafnium $oxide(HfO_{2})$ as high-k gate dielectric material. $HfO_{2}$ films are ultrathin gate dielectric material witch have a thickness less than 2.0nm， so it is spotlighted to be substituted $SiO_{2}$ as gate dielectric material. In this paper We have grown $HfO_{2}$ films with pt electrode on P-type Silicon substrate by RF magnetron sputtering system using $HfO_{2}$ target and oserved the property of semiconductor-oxide interface. Using pt electrode, it is necessary to be annealed at ${300^{\circ}C}$. This process is to increase an adhesion ratio between $HfO_{2}$ films with pt electrode. In film deposition process, the deposition time of $HfO_{2}$ films is an important parameter. Structura1 properties are invetigated by AES depth profile, and electrical properties by Capacitance-Voltage characteristic. Interface trap density are measured to observe the interface between $HfO_{2}$ with Si using High-frequency(1MHz) C-V and Quasi - static C-V characteristic.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.978-983
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• 2014

The polymer nano composite possess good priority recently for engineering applications. Especially the electrical insulating materials attract the high performance of nano composites. In this work the ballmill synthesiation process of nano sized Alumina ($Al_2O_3$), the preparation of new nano composite material with an content of enamel and synthesized Alumina as 1wt%, 3wt% and 5wt%. Experimental investigation has been carried out for the prepared nano composites materials with respect to dielectric parameter measurements such as dielectric loss (tan ${\delta}$), dielectric constant (${\varepsilon}$), dielectric strength under various temperature. The partial discharge level also measured for all the samples and the PD inception voltage is also observed and compared. Weight loss of the material has been analyzed through TGA. It has been experimentally proved that 3wt% of Alumina nano filler added enamel has significant improvement in the dielectric and thermal properties.