• Journal of Electrical Engineering and Technology
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• v.1 no.2
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• pp.233-236
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• 2006

A 3-D numerical simulation of a buried-channel CCD (Charge Coupled Device) with a deep depletion has been performed to investigate its electrical and physical behaviors. Results are presented for a deep depletion CCD (EEV CCD12; JET-X CCD) fabricated on a high-resistivity $(1.5k\Omega-cm)\;65{\mu}m$ thick epi-layer, on a $550{\mu}m$ thick p+ substrate, which is optimized for X-ray detection. Accurate predictions of the Potential minimum and barrier height of a CCD Pixel as a function of mobile electrons are found to give good charge transfer. The depletion depth approximation as a function of gate and substrate bias voltage provided average errors of less than 6%, compared with the results estimated from X-ray detection efficiency measurements. The result obtained from the transient simulation of signal charge movement is also presented based on 3-Dimensional analysis.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.8
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• pp.907-918
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• 2006

In this study capacitance and dielectric loss factor were measured with low-voltage signal and the simulation of equivalent circuits for the data was conducted. As the result it was shown that the equivalent circuit model considered the grain-boundary structure with semiconducting layer, dielectric layer and depletion layer was well approximated with the observed data. Various parameters were determined by a optimum curve-fitting method and could be used to analyze the characteristics of varistor. It also seems that the proposed equivalent circuit model will be adopted for other BL type varistors.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.163.2-163.2
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• 2014

We report catalytic decomposition of few-layer graphene on an $Au/SiO_x/Si$ surface wherein oxygen is supplied by dissociation of the native $SiO_x$ layer at a relatively low temperature of $400^{\circ}C$. The detailed chemical evolution of the graphene covered $SiO_x/Si$ surface with and without gold during the catalytic process is investigated using a spatially resolved photoelectron emission method. The oxygen atoms from the native $SiO_x$ layer activate the gold-mediated catalytic decomposition of the entire graphene layer, resulting in the formation of direct contact between the Au and the Si substrate. The notably low contact resistivity found in this system suggests that the catalytic depletion of a $SiO_x$ layer could realize a new way to micromanufacture high-quality electrical contact.

• Polymer(Korea)
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• v.39 no.3
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• pp.370-381
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• 2015

In the system of poly(vinyl alcohol) (PVA)/dimethyl sulfoxide, the refractive index of polymer was very well matched to that of solvent and thus its scattered intensity could be minimized. After adding small amount of polystyrene latex particle (nominal diameter 200 nm), diffusion behavior of only probe particle was investigated against the concentration of polymer matrix by means of dynamic light scattering. The polymer concentration dependence of its reduced diffusion coefficient was able to be analysed with the stretched exponential function of the reduced concentration $C[{\eta}]$. In very dilute concentration regime, the depletion layer kept constant but at the early semi-dilute regime of $1{\leq}C[{\eta}]{\leq}2.5$, the concentration-dependent exponent of depletion layer ${\delta}$ was appeared to be -0.8 which was very close to theoretical one of -0.85. However it was also observed at the higher concentration that its layer thickness decreased more abruptly than theoretical expectation and this phenomenon was ascribed to Oosawa type attractive interaction between adjacent latex particles.

• Polymer(Korea)
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• v.36 no.5
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• pp.628-636
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• 2012

The polymer concentration dependence of depletion layer was investigated by means of dynamic light scattering after the very small amount of polystyrene spherical latex particles was added into the matrix solution of poly(vinyl alcohol)(PVA)/dimethyl sulfoxide. At the dilute regime, the magnitude of depletion layer kept constant at the level of $63{\pm}3%$ of the radius of gyration of the corresponding PVA chain. Next, at the early semi-dilute regime of $1.5{\leq}C[{\eta}]{\leq}3$, polymer concentration dependence of the layer thickness ${\delta}$ was obtained as ${\delta}{\sim}C^{-0.8}$, and this experimental value was very close to theoretical one of -0.75. However it was observed above $C[{\eta}]$ >3 that its thickness decreased abruptly, and this was ascribed to aggregation effect of latex particles which was driven by Oosawa type attractive interaction.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.65-69
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• 2002

An Al film deposited on the Kovar alloy substrate was anodically-bonded to the borosilicate glass, and the bond interfaces was closely investigated by transmission electron microscopy. Al oxide was found to form a layer ~l0 nm thick at the bond interface, and fibrous structure of the same oxide was found to grow epitaxially in the glass from the oxide layer. The fibrous structure grew with the bonding time. The mechanism of the formation of this fibrous structure is proposed on the basis of the migration of Al ions under the electric field. Penetration of Al into glass beyond the interfacial Al oxide was not detected. The comparison of the amount of excess oxygen ions generated in the alkali depletion layer with that incorporated in the Al oxide suggests that the growth of the alkali-ion depletion layer is controlled by the consumption of excess oxygen to form the interfacial Al oxide.

• Electrical & Electronic Materials
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• v.9 no.10
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• pp.1019-1026
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• 1996

In this study, we may be presented the carrier oscillation properties for the low-voltage varistor fabricated by a new method of three composition seed grain, in order to analyze the behavior of carriers at the its equivalent circuit model. The oscillation phenomena of carriers appeared from current-voltage characteristics under knee voltage is shown by the transient flow of nontrapped carriers group in the trap level of intergranular layer, surface state and/or depletion layer. In particularly, current oscillation phenomena is hardly shown in the high electric field. It is that the injected carriers from both electrodes are directly from the conduction band of forward biased ZnO grain through the intergranular layer into the reverse biased ZnO grain, because the trap level in the electric field above the knee voltage is mostly filled.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.5
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• pp.728-734
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• 2004

Environmentally friendly refrigerants with zero ozone layer depletion potential are required to be used in refrigerators and air conditioners due to the difficulties related to ozone layer depletion and global warming. A rigorous study for the system performance with new refrigerants having zero ozone layer depletion potential is inevitable before adopting that as a new fluid. The HFC(Hydrofluorocarbon) potential has been recommended as alternatives. In this paper. system performance in the heat pump facilities were studied using R-290, R-600a. R-1270 as an environment friendly refrigerant. R-22 as a HCFC's refrigerant. The experimental apparatus has been set-up as a conventional vapor compression type heat Pump system. The test section is a horizontal double pipe heat exchanger. A tube diameter of 12.70mm with 1.315mm wall thickness is used for this investigation. The test results showed that the COP of hydrocarbon refrigerants were superior to that of R-22 and the maximum increasing rate of COP was found in R-1270. The refrigeration capacity of hydrocarbon refrigerants were higher than that of R-22. The compressor work was obtained with the maximum value in R-1270 and the minimum one in R-22.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.709-714
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• 2018

This study researched the reasons for changing polarity in accordance with junction properties in an interface of semiconductors. The contact properties of semiconductors are related to the effect of the semiconductor's device. Therefore, it is an important factor for understanding the junction characteristics in the semiconductor to increase the efficiency of devices. For generation of various junction properties, carbon-doped silicon oxide (SiOC) was deposited with various argon (Ar) gas flow rates, and the characteristics of the SiOC was varied based on the polarity in accordance with the Ar gas flows. Tin-doped zinc oxide (ZTO) as the conductor was deposited on the SiOC as an insulator to research the conductivity. The properties of the SiOC were determined from the formation of a depletion layer by the ionization reaction with various Ar gas flow rates due to the plasma energy. Schottky contact was good in the condition of the depletion layer, with a high potential barrier between the silicon (Si) wafer and the SiOC. The rate of ionization reactions increased when increasing the Ar gas flow rate, and then the potential barrier of the depletion layer was also increased owing to deficient ions from electron-hole recombination at the junction. The dielectric properties of the depletion layer changed to the properties of an insulator, which is favorable for Schottky contact. When the ZTO was deposited on the SiOC with Schottky contact, the stability of the ZTO was improved by the ionic recombination at the interface between the SiOC and the ZTO. The conductivity of ZTO/SiOC was also increased on SiOC film with ideal Schottky contact, in spite of the decreasing charge carriers. It increases the demand on the Schottky contact to improve the thin semiconductor device, and this study confirmed a high-performance device owing to Schottky contact in a low current system. Finally, the amount of current increased in the device owing to ideal Schottky contact.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.2
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• pp.72-75
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• 2006

A CMOS compatible Super Junction LDMOS (SJ-LDMOS) structure, which reduces substrate-assisted depletion effects, is reported. The proposed structure uses a N-buffer layer between the pillars and P-substrate to achieve global charge balance between the pillars, the N-buffer layer and the P-substrate. The new structure features high breakdown voltage, low on-resistance, and reduced sensitivity to doping imbalance in the pillars.