• 한국정밀공학회지
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• 제28권2호
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• pp.193-201
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• 2011

Clamp type transferring mechanism for package substrate's wet processes was newly developed instead of conventional roller type transferring mechanism. Clamp type transferring mechanism has the advantages of reducing the panel deflection and of minimizing the contact problem between the panel and the transferring mechanism. Individual clamp of the mechanism has two distinct mechanical functions which are perfectly fixing a panel during the transferring and generating adequate tension for the panel. To determine the mechanical parameters of the clamp, panel deflection simulation was conducted and the result was verified by the panel deflection measurement. Also, fixing angle of a clamp could be determined by the free body force analysis of individual clamp. Finally clamp type transferring mechanism was actually manufactured and the transferring performance was verified during the water spraying condition of the package substrate's wet processes.

• Progress in Superconductivity
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• 제12권1호
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• pp.68-73
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• 2010

Y123 films have been deposited on $LaAlO_3$ (100) single-crystal and IBAD substrates by spray pyrolysis method using nitrate precursors. Ultrasonic atomization was adopted to decrease the droplet size, spraying angle and its moving velocity toward substrate for introducing the preheating tube furnace in appropriate location. A small preheating tube furnace was installed between spraying nozzle and substrate for fast drying and enhanced decomposition of precursors. C-axis oriented films were obtained on both LAO and IBAD substrates at deposition temperature of around $710{\sim}750^{\circ}C$ and working pressures of 10~15 torr. Thick c-axis epitaxial film with the thickness of $0.3{\sim}0.6\;{\mu}m$ was obtained on LAO single-crystal by 10 min deposition. But the XRD results of the film deposited on IBAD template at same deposition condition showed that the buffer layers of the IBAD metal substrate was affected by long residence of metal substrate at high temperature for YBCO deposition.

• 반도체디스플레이기술학회지
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• 제7권4호
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• pp.1-5
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• 2008

There is a need to enlarge the mother glass substrate in OLED to raise its productivity and to realize OLED TV. On the other hand, some difficulties may arise regarding the deflection of a large glass substrate during its handling operation due to its thinness $(0.5\sim0.7t)$, which is not even enough to allow it to stand its own mass. This thesis proposes a conceptual plan for the application of the clamping- and bending-end conditions to the glass substrate handler. To verify proposed plan, the non-contact 3 dimensional measuring instrument is developed. The composition of the 3 dimensional measuring instrument measures shape of the product using X-Y stage robot and laser distance sensor. X-Y stage robot and laser distance sensor are controlled by LabVIEW language. To calibrate measuring instrument, the direction conversion of the Euler angle was used. In order to confirm deflection of the glass substrate, the experiment was carried out at the bending end boundary condition and the proposed effect was verified.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.77-80
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• 2001

Crystallographic and magnetic characteristics of CoCr-based magnetic thin film for perpendicular magnetic recording media were influenced on preparing conditions. In these, there is that substrate temperature was parameter that increases perpendicular coercivity of CoCrTa magnetic layer using recording layer. While preparation of CoCr-based doublelayer, by optimizing substrate temperature, we expect to increase perpendicular anisotropy of CoCr magnetic layer and prepare ferromagnetic recording layer with a good quality by epitaxial growth. CoCrTa/Si doublelayer showed a good dispersion angle of c-axis orientation $\Delta$$\theta$$_{50}$ caused by inserting amorphous Si underlayer which prepared at underlayer substrate temperature 250C. Perpendicular coercivity was constant, in-plane coercivity was controlled a low value about 2000e. This result implied that Si underlayer could restrain growth of initial layer of CoCrTa thin film, which showed bad magnetic properties effectively without participating magnetization patterns of magnetic layer. In case of CoCrTa/Si that prepared with ultra thin underlayer, crystalline orientation of CoCrTa was improved rather underlayer thickness 1nm, it was expected that amorphous Si layer played a important role in not only underlayer but also seed layer.t also seed layer.r.

• 대한금속재료학회지
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• 제50권8호
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• pp.557-562
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• 2012

Self-organized ruthenium (Ru) dots were fabricated by $400^{\circ}C$ RTA (rapid thermal annealing) and ALD (atomic layer deposition). The dots were produced under the $400^{\circ}C$ RTA conditions for 10, 30 and 60 seconds on all Si(100)/200 nm-SiO2, glass, and glass/fluorine-doped tin oxide (FTO) substrates. Electrical sheet resistance, and surface microstructure were examined using a 4-point probe and FE-SEM (field emission scanning electron microscopy). Ru dots were observed when a 30 nm-Ru layer on a Si(100)/200 nm-SiO2 substrate was annealed for 10, 30 and 60 seconds, whereas the dots were only observed on a glass substrate when a 50 nm-Ru layer was annealed on glass. For a glass/FTO substrate, RTA <30 seconds was needed for 30 nm Ru thick films. Those dots can increase the effective surface area for silicon and glass substrates by up to 5-44%, and by 300% for the FTO substrate with a < $20^{\circ}$ wetting angle.

• 전기전자학회논문지
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• 제20권2호
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• pp.177-180
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• 2016

본 연구에서는 4H-SiC(0001)기판 위에서 형성되는 나노구조화를 제어하기 위해 상지층과 하지층으로 구성된 이중층 금속을 증착하고 두께, 열처리 시간을 변화하였다. 또한 표면에너지와 응집현상의 상관관계를 분석하기 위해 SiC와는 다른 표면에너지를 갖는 Glass와 Si기판에도 같은 조건으로 실험하였다. FE-SEM을 통하여 금속이 나노구조화를 형성하는 두께가 Ag=20nm, Ti=2nm임을 확인 했으며 두께가 두꺼울 수록 나노 입자가 형성되지 않았다. 세기판의 표면에너지를 구하기 위해 접촉각 측정기를 통해 정접촉각법으로 측정하였다. 그 결과 표면에너지 값이 가장 높은 Glass(53.89 mN/m) 기판에서 나노 입자가 가장 고르게 분포된 형태를 보였으며 SiC(41.13 mN/m)에서 나노구조화 되는 양상을 보였고, Si(32.96 mN/m)에서는 NPs 형성이 되지 않았다. 표면에너지가 작을수록 나노 입자형성이 고르게 분포되는 현상을 Young equation으로 분석하였다.

• 한국세라믹학회지
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• 제41권10호
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• pp.788-791
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• 2004

입자크기가 수 nm인 고농도 은 나노 졸을 이용하여 잉크젯 기법으로 은 미세라인을 형성하고자 하였다. 고분자전해질을 사용하여 합성한 $10wt\%$ 농도의 은 나노 졸의 입자크기는 10nm 이하였으며, 은 나노 졸을 이용한 미세 라인의 인쇄특성은 은 나노 졸의 접촉각에 매우 깊은 관계를 갖고 있었다. 순수한 ITO 기판에서 은 나노 졸은 높은 접촉각을 나타내었으며, dot 형상이 나타났다. 그러나 100ppm의 Polyethylenimine(PEI)을 코팅한 ITO 기판은 젖음성이 크게 개선되었으며, 잉크젯 기법을 이용하여 $60\~100{\mu}m$의 선폭을 갖는 은 나노 졸의 미세라인 형성이 가능함을 확인할 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.277-277
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• 2013

The epitaxial graphene on the 4H- or 6H-SiC(0001) surface has been intensively studied due to the possibility of wafer-scale growt. However the existence of interface layer (zero layer graphene) and its influence on the upper graphene layer have been considered as one of the main obstarcles for the industrial application. Among various methods tried to overcome the strong interaction with the substrate through the interface layer, it has been proved that the hydrogen intercalation successfully passivate the Si dangling bond of the substrate and can produce the quasi-free standing epitaxial graphene (QFEG) layers on the siC(0001) surface. In this study, we report the results of the angle-resolved photoemission spectroscopy (ARPES) and Raman spectroscopy for the QFEG layers produced by ex-situ and in-situ hydrogen intercalation.From the ARPES measurement, we confirmed that the Dirac points of QFEG layers exactly coincide with the Fermi level. The band structure of QFEG layer are sustainable upon thermal heating up to 1100 K and robust against the deposition of several metals andmolecular deposition. We also investigated the strain of the QFEG layers by using Raman spectroscopy measurement. From the change of the 2D peak position of graphene Raman spectrum, we found out that unlike the strong compressive strain in the normal epitaxial graphene on the SiC(0001) surface, the strain of the QFEG layer are significantly released and almost similar to that of the mechanically exfoliated graphene on the silicon oxide substrate. These results indicated that various ideas proposed for the ideal free-standing graphene can be tested based on the QFEG graphene layers grown on the SiC(0001) surface.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.335-335
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• 2011

Instability of a thin film attached to a compliant substrate often leads to emergence of exquisite wrinkle patterns with length scales that depend on the system geometry and applied stresses. However, the patterns that are created using the current techniques in polymer surface engineering, generally have low aspect ratio of undulation amplitude to wavelength, thus, limiting their application. Here, we present a novel and effective method that enables us to create wrinkles with a desired wavelength and high aspect ratio of amplitude over wavelength as large as to 2.5:1. First, we create buckle patterns with high aspect ratio of amplitude to wavelength by deposition of an amorphous carbon film on a surface of a soft polymer poly(dimethylsiloxane) (PDMS). Amorphous carbon films are used as a protective layer in structural systems and biomedical components, due to their low friction coefficient, strong wear resistance against, and high elastic modulus and hardness. The deposited carbon layer is generally under high residual compressive stresses (~1 GPa), making it susceptible to buckle delamination on a hard substrate (e.g. silicon or glass) and to wrinkle on a flexible or soft substrate. Then, we employ glancing angle deposition (GLAD) for deposition of a high aspect ratio patterns with amorphous carbon coating on a PDMS surface. Using this method, pattern amplitudes of several nm to submicron size can be achieved by varying the carbon deposition time, allowing us to harness patterned polymers substrates for variety of application. Specifically, we demonstrate a potential application of the high aspect wrinkles for changing the surface structures with low surface energy materials of amorphous carbon coatings, increasing the water wettability.

• 한국재료학회지
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• 제8권10호
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• pp.956-960
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• 1998

XPS와 glancing angle XRD, AES 및 AFM을 사용하여 $330^{\circ}C$-$800^{\circ}C$사이의 진공분위기에서 열처리할 때, Co/Nb이중층과 $SiO_2$기판 사이의 계면반응을 조사하였다. $600^{\circ}C$에서 Co와 Nb는 서로 활발하게 확산하여, $700^{\circ}C$이상에서는 두 층사이의 충역전이 완전히 일어났다. 그 때 Nb 중간층과 $SiO_2$기판 사이의 반응에 의하여 계면에 일부 NbO가 형성되었으며, 표면에서는 분위기 중의 산소에 의하여 $Nb_2O_5$가 생성되었다. Nb와 기판간의 반응에 의하여 유리된 Si는 $600^{\circ}C$이상에서 잔류 Co 및 Nb와 반응하여 실리사이드를 형성하였다. Co/Nb 이중층 구조는 $800^{\circ}C$에서 열처리한 후 면저항이 급증하기 시작하였는데, 이것은 Co층이 기판과 바로 접하게 되어 계면에너지를 줄이기 위해 응집되기 때문이다.