• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.715-718
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• 2002

This paper investigated that resonant frequencies of microstrip patch antenna were agile when piezoelectric materials were used as the antenna substrates. When the bias is applied on them, thickness of the substrate is varied according. to the piezoelectric phenomenon. The microstrip patch antenna using Quartz substrate was fabricated and designed by Ensemble v 7.0 simulator. We fabricated the microstrip antennas using Quartz(Y-cut) as its substrate. When the operating frequencies of the microstrip antenna were 7.045GHz, 7.773GHz 8.18GHz the frequency shifts versus electric field, Emax=4[kV/cm], were 21MHz, 26MHz and 28MHz, respectively.

• 한국결정성장학회지
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• 제10권1호
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• pp.30-35
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• 2000

부상응고법은 액상 받침 재료 위에 용융 재료를 띄워서 응고시키는 방법으로 판유리 제조가 대표적이며, 이러한 방법을 이용하여 Si 판재를 얻기 위한 실험을 하였다. 본 연구에서는 액상받침재료에 요구되는 물리 화학적인 성질을 고려하여 3원계 산화물 상태도를 조사한 후, 적절한 액상받침재료로 50 wt% $SiO_2$- 2l wt% $A1_2$$O_3$-29 wt% MnO를 이용하였다. 실험결과 본 연구에서 이용한 받침재료는 온도와 밀도, Si의 반응성 면에서 적절한 성질을 나타내었으나, 유동도 및 계면 장력면에서 문제점을 나타내었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.303-303
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• 2007

Photo-imageable thick-film lithography technology was developed for the fabrication of embedded passives such as inductors and capacitors. In this study, photo-imageable dielectric and conductor pastes have apoted a negative type. Sodalime glass wafer, alumina substrate and zero-shrinkage LTCC green tapes were used as substrates. In result, The lithographic patterns were designed as lines and spaces for conductor material, or via-holes for ceramic, LTCC, materials. The scattering and reflection of UV-beam on the substrate had negative effects on fine patterning. The patterning performance was varied with the exposing and developing process conditions, and also varied with the substrate materials. Fine resolution of less then $50/50{\mu}m$ in line and space was obtained, which is difficult in screen printing method.

• 한국재료학회지
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• 제22권10호
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• pp.508-512
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• 2012

ZnO thin films were grown on a sapphire substrate by RF magnetron sputtering. The characteristics of the thin films were investigated by ellipsometry, X-ray diffraction (XRD), atomic force microscopy (AFM), photoluminescence (PL), and Hall effect. The substrate temperature and growth time were kept constant at $200^{\circ}C$ at 30 minutes, respectively. The RF power was varied within the range of 200 to 500 W. ZnO thin films on sapphire substrate were grown with a preferred C-axis orientation along the (0002) plan; X-ray diffraction peak shifted to low angles and PL emission peak was red-shifted with increasing RF power. In addition, the electrical characteristics of the carrier density and mobility decreased and the resistivity increased. In the electrical and optical properties of ZnO thin films under variation of RF power, the crystallinity improved and the roughness increased with increasing RF power due to decreased oxygen vacancies and the presence of excess zinc above the optimal range of RF power. Consequently, the crystallinity of the ZnO thin films grown on sapphire substrate was improved with RF sputtering power; however, excess Zn resulted because of the structural, electrical, and optical properties of the ZnO thin films. Thus, excess RF power will act as a factor that degrades the device characteristics.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.167-170
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• 1995

LiCoO$_2$is a electrode material of Li ion Cell which is expected as the cell with a very high electric charge density. The recent study is mainly to focused on a high power secondary cell. If very thin Li ion Cell can be made in the scale of IC substrate it can be a electric souse in IC chip , micro machine or very thin electrical display etc. LiCoO$_2$thin film can be made by CVD, Laser ablation, E-Beam, ton Beam process, sputtering etc. But to make the material with a high quality for a cell is difficult as the electrode in cell have the fitable ratio in components and a lattice structure of bulk etc. In this study, LiCoO$_2$is made by R.F magnetron sputtering with the variance of substrate temperature and oxygen partial pressure etc. In the substrate temperature of 600$^{\circ}C$ and the oxygen rate of 10%, we can acquire the good thin film LiCoO$_2$compared wish a bulk material.

• Journal of Electrochemical Science and Technology
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• 제1권1호
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• pp.45-49
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• 2010

$Li_2PtO_3$ thin film electrodes, which might be possible candidate for the cathode materials for implantable batteries, were synthesized using an electrostatic spray deposition (ESD) technique onto a platinum foil substrate. Single phase $Li_2PtO_3$with a structure similar to layered $LiCoO_2$ structure were synthesized by spraying a precursor solution of $CH_3CO_2Li2H_2O$ in ethanol onto a Pt substrate at temperatures ranging from 200 to $400^{\circ}C$ followed by annealing at above $600^{\circ}C$. Lithium carbonate was the only major phase at temperatures up to $500^{\circ}C$. The X-ray diffraction (XRD) peaks of the Pt foil substrate and lithium carbonate disappeared at temperatures >$600^{\circ}C$. The volumetric capacity of the $Li_2PtO_3$ thin film synthesized using the ESD technique was approximately 817 mAh/$cm^3$, which exceeded that of $LiCoO_2$ (711 mAh/$cm^3$).

• 한국재료학회지
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• 제19권11호
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• pp.625-630
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• 2009

Embedding of active devices in a printed circuit board has increasingly been adopted as a future electronic technology due to its promotion of high density, high speed and high performance. One responsible technology is to embedded active device into a dielectric substrate with a build-up process, for example a chipin-substrate (CiS) structure. In this study, desmear treatment was performed before Cu metallization on an FR-4 surface in order to improve interfacial adhesion between electroless-plated Cu and FR-4 substrate in Cu via structures in CiS systems. Surface analyses using atomic force microscopy and x-ray photoemission spectroscopy were systematically performed to understand the fundamental adhesion mechanism; results were correlated with peel strength measured by a 90o peel test. Interfacial bonding mechanism between electrolessplated Cu and FR-4 substrate seems to be dominated by a chemical bonding effect resulting from the selective activation of chemical bonding between carbon and oxygen through a rearrangement of C-C bonding rather than from a mechanical interlocking effect. In fact, desmear wet treatment could result in extensive degradation of FR-4 cohesive strength when compared to dry surface-treated Cu/FR-4 structures.

• 한국전기전자재료학회논문지
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• 제23권11호
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• pp.859-863
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• 2010

Evolution of surface morphology of ${\alpha}-Al_2O_3$ substrate was investigated as a function of annealing temperature and time. Commercial (0001) ${\alpha}-Al_2O_3$ single crystal substrates were annealed in the range of $600-1000^{\circ}C$ in air. At $600^{\circ}C$, step-terrace structure started to be formed on the substrate. However, the surface roughness on the terrace was still considerable and a number of islands were observed on the step edges as well as the terraces. As the annealing temperature increased, the islands were absorbed into the step edges. Thus the terraces were smoother and the step edges were more straightened. Well-defined surface with a step height of 0.2 nm was formed above $900^{\circ}C$. On the other hand, when the substrate was annealed at a fixed temperature of $1000^{\circ}C$, the change of surface morphology was observed for the substrate annealed for 10 min. After the annealing for 30 min, the surface on which any islands could not survive was observed.

• 한국전기전자재료학회논문지
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• 제23권10호
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• pp.776-781
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• 2010

CdSe films were deposited on glass substrates (CdSe/glass) by thermal evaporation. Substrate temperature was lowered by cooling substrate holder with liquid nitrogen. Substrate temperatures were $200^{\circ}C$, $0^{\circ}C$ and $-40^{\circ}C$. The crystallographic properties and surface morphologies of the CdSe/glass films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optical and electrical properties of the films were investigated by dependence of energy gap, photosensitivity and resistivity on the substrate temperature. CdSe/glass showed energy gap of ~1.72 eV regardless of substrate temperature. The resistivity of the films decreased to $0.5{\Omega}cm$ by lowering the substrate temperature to $-40^{\circ}C$. The CdSe/glass films prepared at $0^{\circ}C$ showed the highest photosensitivity among the films in this study.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.202-205
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• 2002

Polycrystalline silicon thin film transistors (poly-Si TFTs) are used in a wide variety of applications, and will figure prominently future high-resolution, high-performance flat panel display technology However, it was very difficult to fabricate high performance poly-Si TFTs at a temperature lower than 300$^{\circ}C$ for glass substrate. Conventional process on a glass substrate were limited temperature less than 600$^{\circ}C$ This paper proposes a high temperature process above 750$^{\circ}C$ using a flexible molybdenum substrate deposited hydrogenated amorphous silicon (a-Si:H) and than crystallized a rapid thermal processor (RTP) at the various temperatures from 750$^{\circ}C$ to 1050$^{\circ}C$. The high temperature annealed poly-Si film illustrated field effect mobility higher than 30 $\textrm{cm}^2$/Vs, achieved I$\sub$on//I$\sub$off/ current ratio of 10$^4$ and crystall volume fraction of 92%. In this paper, we introduce the new TFTs Process as flexible substrate very promising roll-to-roll process, and exhibit the properties of high temperature crystallized poly-Si Tn on molybdenum substrate.