• Electrical & Electronic Materials
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• v.6 no.2
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• pp.115-120
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• 1993

본 연구에서는 dry oxide와 wet oxide로 MOS capacitor를 제작하여 avalanche 전자주입 실험으로 산화막의 캐리어 트랩핑특성을 조사하였다. dry oxide에서는 avalanche 전자주입 시 전자 trapping이 주도적으로 일어났다. wet oxide에서는 주입 초기에 전자 trapping이 주도적이다가 hole trapping이 주도적으로 바뀌게 되는 turn-around 현상이 일어났다. 주입시간이 길어지면 다시 전자 trapping이 주도적으로 되는 또 한번의 turn-around 현상이 일어났다. 산화막의 트랩 parameter를 결정하기 위해 실험결과를 기초로 하여 종류가 다른 여러 트랩을 가지는 계에 대한 캐리어 트랩핑 이론식을 세워서 실험결과와 curve-fitting한 결과 실험치와 잘 일치하는 곡선을 얻었다.

• Proceedings of the IEEK Conference
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• summer
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• pp.343-347
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• 2004

High oxidation temperature of SiC shows a tendency of carbide formation at the interface which results in poor MOSFET transfer characteristics. Thus we developed oxidation processes in order to get low interface charge densities. N-type 6H-SiC MOS capacitors were fabricated by different oxidation processes: dry, wet, and dry­reoxidation. Gate oxidation and Ar anneal temperature was $1150^{\circ}C.$ Ar annealing was performed after gate oxidation for 30 minutes. Dry-reoxidation condition was $950^{\circ}C,$ H2O ambient for 2 hours. Gate oxide thickness of dry, wet and dry-reoxidation samples were 38.0 nm, 38.7 nm, 38.5 nm, respectively. Mo was adopted for gate electrode. To investigate quality of these gate oxide films, high frequency C- V measurement, gate oxide leakage current, and interface trapped charge densities (Dit) were measured. The interface trapped charge densities (Dit) measured by conductance method was about $4\times10^{10}[cm^{-1}eV^{-1}]$ for dry and wet oxidation, the lowest ever reported, and $1\times10^{11}[cm^{-1}eV^{-1}]$ for dry-reoxidation

• Korean Journal of Materials Research
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• v.12 no.5
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• pp.327-333
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• 2002

In order to obtain the oxidation layer for SiC MOS, the oxide layers by thermal oxidation process with dry and wet method were deposited and characterized. Deposition temperature for oxidation layer was $1100^{\circ}C$~130$0^{\circ}C$ by $O_2$ and Ar atmosphere. The oxide thickness, surface morphology, and interface characteristic of deposited oxide layers were measurement by ellipsometer, SEM, TEM, AFM, and SIMS. Thickness of oxidation layer was confirmed 50nm and 90nm to with deposition temperature at $1150^{\circ}C$ and $1200{\circ}C$ for dry 4 hours and wet 1 hour, respectively. For the high purity oxidation layer, the necessity of sacrificial oxidation which is etched for the removal of the defeats on the wafer after quickly thermal oxidation was confirmed.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.9
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• pp.145-151
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• 1998

In this study, the experimental and analytic investigation with cold air system has been performed for improving the working environment of the conventional grinding fluid. Very simple cold air system was developed which could replace by the conventional grinding fluid system. The identification of heat of grinding Bone is very important for precision grinding. The experimental data was analysed to investigate the heat which was transferred to the workpiece. It was found that 45∼55％ of the total energy for dry grinding, 22∼28％ for wet grinding, and 32∼35％ for cold air system are conducted to the workpiece in grinding with cubic boron nitride wheel. Cubic boron nitride wheel could reduce the residual stress and thermal demage comparing with aluminium oxide wheel, because cubic boron nitride wheel has very high extreme thermal conductivity.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.29-32
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• 2001

In this paper, the thermal oxidation behaviors and the electrical characteristics of the thermal oxide grown on SiC are discussed. For these studies the oxide layers with various thickness were on SiC in wet $O_2$ or dry $O_2$ at l15$0^{\circ}C$ and the MOS capacitors using the 350$\AA$ gate oxide grown in wet $O_2$ were fabricated and electrically characterized. It was found from the experimental results that the oxidation rate of SiC with the Si-face and with the carbon-face were about 10% and 50% of oxidation rate of Si. The C-V measurement results of the SiC oxide showed abnormal hysterisis properties which had ever been not observed for the Si oxide. And the hysterisis behavior was seen more significant when initial bias voltage was more negative or more positive. The hysterisis property of the SiC oxide was believed to be due the substantial amount of the deep level traps to exist at the interface between the oxide and the SiC substrate. The leakage of the SiC oxide was found to be one order larger than the Si oxide, but the breakdown strength was almost equal to that of the Si oxide.

• Journal of Powder Materials
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• v.27 no.4
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• pp.305-310
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• 2020

In this study, partially dry transfer is investigated to solve the problem of fully dry transfer. Partially dry transfer is a method in which multiple layers of graphene are dry-transferred over a wet-transferred graphene layer. At a wavelength of 550 nm, the transmittance of the partially dry-transferred graphene is seen to be about 3% higher for each layer than that of the fully dry-transferred graphene. Furthermore, the sheet resistance of the partially dry-transferred graphene is relatively lower than that of the fully dry-transferred graphene, with the minimum sheet resistance being 179 Ω/sq. In addition, the fully dry-transferred graphene is easily damaged during the solution process, so that the performance of the organic photovoltaics (OPV) does not occur. In contrast, the best efficiency achievable for OPV using the partially dry-transferred graphene is 2.37% for 4 layers.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.1
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• pp.26-32
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• 1979

Dry oxidation and wet oxidation processes of silicon have been examined experimentally. The oxidation temperatures were 1.10$0^{\circ}C$, 1.15$0^{\circ}C$, and 1.200 $^{\circ}C$, and oxygen flow rate was changed from 0.2 liter/min to 2.8 liter/min. From the experimental measurements, oxidation temperaturel time and oxygen flow rate have been tabutated for oxide layers 0.1$\mu$ - 1.0$\mu$ in thickness. The quality of the grown oxide layer has been investigated In terms of the dielectric constant, breakdown voltage, fixed surface charge densify (Qss/q) and mobile charge density (Q /q). From these measurements, it is concluded that the quality of the oxide layer is sufficient to expect the normal operation of MOS transistors.

• Corrosion Science and Technology
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• v.7 no.4
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• pp.224-232
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• 2008

During the hot rolling process, steels develop an oxide scale on their surface. This scale can affect the mechanical properties of the rolled steel and its surface aspect. The main problem comes from the mechanical integrity of the oxide scales which could delaminate or crack, leading eventually to later oxide incrustation within the steel. The objective of the present work is to qualify the mechanical integrity of the iron oxide scales during the hot rolling process. The laboratory experiments use a four point bending test to simulate the mechanical solicitation which takes place during the rolling sequence of the steel slabs. The oxide scales grow on a mild steel at $900^{\circ}C$ under wet or dry atmosphere and the oxidized steel is then mecahnically tested at $900^{\circ}C$ or $700^{\circ}C$. The high temperature four point bending tests are completed with microstructural observations and with the record of acoustic emission to follow in-situ the mechanical damages of the oxide scales. The results show the role of water vapor which promotes the scale adherence, and the role of the temperature as the oxide are more damaged at $700^{\circ}C$ than at $900^{\circ}C$.

• Resources Recycling
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• v.11 no.4
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• pp.3-10
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• 2002

The characteristics of dry and wet milled powder prepared by 1 cycle OREOX (oxidation and reduction of oxide fuels) treatment were investigated using the simulated spent fuel pellet. Sintered pellets simulating spent nuclear fuel burned in reactor were fabricated from $UO_2$ powder using as a starting material in fabrication of nuclear fuel. The 1 cycle OREOX-treated powder was prepared by only one path of oxidation md reduction of the simulated pellet. Powder having average particle size of less than 1 $\mu\textrm{m}$ could be easily obtained by dry milling, but not be achieved by wet milling. And, specific surface area of dry milled pow-der was higher than that of wet milled powder. Dry milled powder formed loose agglomerate, while wet milled powder showed the shape of irregular and angular particles. Dry milled powder provided higher green density, resulting in higher sintered density of higher than 95% TD and average grain size of larger than 8 $\mu\textrm{m}$ satisfying the standard specification of sintered pellets.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.491-492
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• 2006

The horizontal high energy rotor ball mill ($Simoloyer^{(R)}$) is used to break and activate dry solids. It is used for dry-milling and in the vertical mount for wet-milling in leaching processes. Technical electric arc furnace (EAF) dust with high contents of zinc oxide, zinc ferrite and magnetite is efficiently separated by ambient temperature leaching. The process shows promise for industrial application