• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.374-374
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• 2012

Nowadays, Active Matrix Organic Light-Emitting Diodes (AM-OLEDs) are the superior display device due to their vivid full color, perfect video capability, light weight, low driving power, and potential flexibility. One of the advantages of AM-OLED over Liquid Crystal Display (LCD) lies in its flexibility. The potential flexibility of AM-OLED is not fully explored due to its sensitivity to moisture and oxygen which are readily present in atmosphere, and there are no flexible encapsulation layers available to protect these. Therefore, we come up with a new concept of Inorganic-Organic hybrid thin film as the encapsulation layer. Our Inorganic layer is Al2O3 and Organic layer is F-Alucone. We deposited these layers in vacuum state using Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) techniques. We found the results are comparable to commercial requirement of 10-6 g/m2 day for Water Vapor Transmission Rate (WVTR). Using ALD and MLD, we can control the exact thin film thickness and fabricate more dense films than chemical or physical vapor deposition methods. Moreover, this hybrid encapsulation layer potentially has both the flexibility of organic layers and superior protection properties of inorganic layer.

• 대한기계학회논문집B
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• 제29권8호
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• pp.956-962
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• 2005

A three-dimensional computation was conducted to make a study about effects of the inlet boundary layer thickness on the total pressure loss in a low-speed axial compressor operating at the design condition ($\phi=85\%$) and near stall condition($\phi=65\%$). Differences of the tip leakage flow and hub corner-stall induced by the inlet boundary layer thickness enable the loss distribution of total pressure along the span to be altered. At design condition, total pressure losses for two different inlet boundary layers are almost alike in the core flow region but the larger loss is generated at both hub and tip when the inlet boundary layer is thin. At the near stall condition, however, total pressure loss fer the thick inlet boundary layer is found to be greater than that for the thin inlet boundary layer on most of the span except the region near hub and casing. Total pressure loss is scrutinized through three major loss categories in a subsonic axial compressor such as profile loss, tip leakage loss and endwall loss using Denton's loss model, and effects of the inlet boundary layer thickness on the loss structure are analyzed in detail.

• Korean Chemical Engineering Research
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• 제55권4호
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• pp.483-489
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• 2017

The loss of the sulfur cathode material through dissolution of the polysulfide into electrolyte causes a significant capacity reduction of the lithium-sulfur cell during the charge-discharge reaction, thereby debilitating the electrochemical performance of the cell. We addressed this problem by using a chemical and physical approach called reduction of polysulfide dissolution through direct coating functional inorganic (graphene oxide) or organic layer (polyethylene oxide) on electrode, since the deposition of external functional layer can chemically interact with polysulfide and physically prevent the leakage of lithium polysulfide out of the electrode. Through this approach, we obtained a composite electrode for a lithium-sulfur battery (sulfur: 60%) coated with uniform and thin external functional layers where the thin external layer was coated on the electrode by solution coating and drying by a subsequent heat treatment at low temperature (${\sim}80^{\circ}C$). The external functional layer, such as inorganic or organic layer, not only alleviates the dissolution of the polysulfide electrolyte during the charging/discharging through physical layer formation, but also makes a chemical interaction between the polysulfide and the functional layer. As-formed lithium-sulfur battery exhibits stable cycling electrochemical performance during charging and discharging at a reversible capacity of 700~1187 mAh/g at 0.1 C (1 C = 1675 mA/g) for 30 cycles or more.

• 한국전기전자재료학회논문지
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• 제35권2호
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• pp.172-177
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• 2022

The quench voltage of the second-generation superconducting wire is affected by the resistivity characteristics of the stabilization layer. The specific resistance of the stabilization layer can be changed by the deposition process using RF magnetron sputtering. In this paper, a thin film made of a homogeneous material (Ag) and a dissimilar material (Cu) was deposited on the stabilization layer of the second-generation superconducting wire through RF magnetron sputtering. We found that the specific resistance was reduced by increasing the thickness of the stabilization layer. The reduction in the resistivity of the stabilization layer led to a decrease in the quench voltage of the second-generation superconducting wire. We suggest that various characteristic changes of the second-generation superconducting wire can be expected through the successful change in the resistivity of the stabilization layer of the proposed deposition process.

• Transactions on Electrical and Electronic Materials
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• 제9권6호
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• pp.247-250
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• 2008

Hafnium dioxide ($HfO_2$) thin film as a gate dielectric for organic thin film transistors is prepared by plasma enhanced atomic layer deposition (PEALD). Mostly crystalline of $HfO_2$ film can be obtained with oxygen plasma and with water at relatively low temperature of $200^{\circ}C$. $HfO_2$ was deposited as a uniform rate of $1.2\;A^{\circ}$/cycle. The pentacene TFT was prepared by thermal evaporation method with hafnium dioxide as a gate dielectric. The electrical properties of the OTFT were characterized.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.250-250
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• 2009

Thin film of $SnO_2$ was fabricated from plasma enhanced atomic layer deposition technology with bubbler type injector system by using TEMASn (tetrakisethylmethylamino tin) precursor. Mostly crystalline of $SnO_2$ films can be obtained with oxygen plasma and with water at relatively low temperature of $150^{\circ}C$. $SnO_2$ was deposited as an uniform rate of $1.0A^{\circ}$/cycle. In order to obtain uniform film, a seed oxide material was used before TEMASn deposition in ALD process. The process parameters were controlled to obtain dense thin film by atomic deposition methodology. The morphology and characterization of thin film with optimized process condition will be discussed.

• 전산구조공학
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• 제9권4호
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• pp.165-172
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• 1996

들보나 아치, 판재 그리고 쉘과 같은 박판구조물의 경계부근의 매우 좁은 영역에는 경계층이 존재하는데, 이 영역에서 해는 급격하게 변화하는 특이 거동을 나타낸다. 유한요소법을 이용하여 이러한 물체의 거동을 해석하는 경우, 이런 특이성을 묘사하기 위해 유한요소 체눈패턴이 대단히 중요한 역할을 한다. 이 논문은 경계층에 대한 이론적 해석과 최적의 체눈패턴을 형성하기 위한 가이드를 제시한다. 또한 이론적인 결과를 입증하는 예제도 소개하고자 한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.471-471
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• 2013

Highly stable and high performance amorphous oxide semiconductor thin film transistors (TFTs) were fabricated using 4-mercaptophenol (4MP) doped ZnO by atomic layer deposition (ALD). The 4 MP concentration in ZnO films were varied from 1.7% to 5.6% by controlling Zn: 4MP pulses. The carrier concentrations in ZnO thin films were controlled from $1.017{\times}10^{20}$/$cm^3$ to $2,903{\times}10^{14}$/$cm^3$ with appropriate amount of 4MP doping. The 4.8% 4MP doped ZnO TFT revealed good device mobility performance of $8.4cm^2V-1s-1$ and on/off current ratio of $10^6$. Such 4MP doped ZnO TFTs were stable under ambient conditions for 12 months without any apparent degradation in their electrical properties. Our result suggests that 4 MP doping can be useful technique to produce more reliable oxide semiconductor TFT.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.283-288
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• 2004

We have fabricated MIM capacitors for MMIC applications, with capacitances as high as 600pF/$\textrm{mm}^2$ and excellent electrical properties of the insulator layer. Silicon nitride thin film is the desirable material for MMIC capacitor fabrication. Standard MIM capacitance in MMIC is 300pF/$\textrm{mm}^2$ with an insulator layer thickness of more than 2000$\AA$. However, capacitors with thin insulator layers have breakdown voltages as low as 20V. We have deposited insulator layers by PECVD in our MIM structure with an air bridge between the top metal and the contact pad. The PECVD process was optimized for fabricating the desired capacitors to be used in MMIC. Silicon nitride(Si$_{x}$N$_{y}$) thin films of about 1000$\AA$ thick show capacitances of about 600pF/$\textrm{mm}^2$, and breakdown voltages above 70V at 100nA.A.A.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.343-346
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• 1998

Ultra-thin gate oxide in MOS devices are subjected to high-field stress during device operation, which degrades the oxide and exentually causes dielectric breakdown. In this paper, we investigate the electrical properties of ultra-thin nitrided oxide (NO) and reoxidized nitrided oxide(ONO) films that are considered to be promising candidates for replacing conventional silicon dioxide film in ULSI level integration. We study vriations of I-V characteristics due to F-N tunneling, and time-dependent dielectric breakdown (TDDB) of thin layer NO and ONO depending on nitridation and reoxidation condition, and compare with thermal $SiO_{2}$. From the measurement results, we find that these NO and ONO thin films are strongly depending on its condition and that optimized reoxided nitrided oxides (ONO) films show superior dielectric characteristics, and breakdown-to-change ( $Q_{bd}$ ) performance over the NO films, while maintaining a similar electric field dependence compared to NO layer.