• Korean Journal of Materials Research
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• v.21 no.9
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• pp.482-485
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• 2011

$La_{0.6}Sr_{0.4}MnO_3$ (LSMO) thin films, which are known as colossal magnetoresistance materials, were prepared on fused silica thin films by conventional RF magnetron sputtering, and the interfacial reactions between them were investigated by rapid thermal processing. Various analyses, namely, X-ray diffraction, transmission electron microscopy combined with energy adispersive X-ray spectrometry, and secondary ion mass spectrometry, were performed to explain the mechanism of the interfacial reactions. In the case of an LSMO film annealed at $800^{\circ}C$, the layer distinction against the underplayed $SiO_2$ was well preserved. However, when the annealing temperature was raised to $900^{\circ}C$, interdiffusion and interreaction occurred. Most of the $SiO_2$ and part of the LSMO became amorphous silicate that incorporated La, Sr, and Mn and contained a lot of bubbles. When the annealing temperature was raised to $950^{\circ}C$, the whole stack became an amorphous silicate layer with expanded bubbles. The thermal instability of LSMO on fused silica should be an important consideration when LSMO is integrated into Si-based solid-state devices.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.959-961
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• 1999

ZnO thin films are deposited by using an RF magnetron sputtering system. Structural and electrical properties are analyzed as a function of deposition conditions, such as RF power, Ar/($Ar+O_2$) ratio, and substrate temperature. The c-axial growth of ZnO is observed to be preferable to the $SiO_2$/Si substrate, rather than the Si substrate. By adding the oxygen gas during deposition, the electrical resistivity of films is increased, but the c-axial growth is inhibited. A pizoelectric resonator of Al/ZnO/Al is also fabricated to estimate the electric-mechanical coupling coefficient($k^2$) of ZnO film. The value of $k^2$ obtained from our work is about 10.14 %.

• Journal of IKEEE
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• v.28 no.3
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• pp.285-289
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• 2024

Utilizing Aerosol Deposition technology, we deposited Ga₂O₃ films onto 4H-SiC substrates with thicknesses of 1 and 5㎛. Subsequently, we analyzed the impact of oxide film thickness variation on the electrical characteristics of diodes. Experimental findings revealed that thicker films exhibited device operation at lower voltages, whereas thinner films demonstrated comparatively steeper current flow. This underscores the critical importance of controlling film thickness for optimizing the smooth electrical characteristics of the film.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.112.1-112
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• 1998

• Journal of Surface Science and Engineering
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• v.43 no.3
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• pp.127-131
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• 2010

Adhesion of DLC film is very significant property that exhibits wear resistance, chemical inertness and high hardness when being deposited to metal substrate. This study was considered that change adhesion of DLC film produced by Plasma Enhanced Chemical Vapor Deposition can be presented through inserting interlayer (Cr, Si-C:H). The thickness of interlayer was result of changing adhesion and residual stress. It was showed that the maximum 12 N of adhesion is on DLC film of Cr interlayer, and that a tendency is to be increased residual stress depend on the thickness. DLC film of Si-C:H interlayer represented 16 N of adhesion at $1{\mu}m$, whereas adhesion is decreased when the thickness is increased. For the interlayer at multi-layer, it was the best that adhesion of Cr/Si-C:H/DLC film was 33 N. Si-C:H interlayer at DLC film controled adhesion of the whole film. It was relaxed the internal stress of DLC film produced by inserting Cr, Si-C:H interlayer.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.2
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• pp.70-74
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• 2009

Effect of the processing variables on the formation of $Pb(Sc_{1/2}Nb_{1/2})O_3$(hereafter PSN) thin layers prepared on Pt(111)/Ti/$SiO_2$/Si substrates using the sol-gel and the spin coating method has been studied. After each deposition, the coated films were heated at $370^{\circ}C$ for 5 min. Then they were finally sintered at temperature range of $600{\sim}700^{\circ}C$ by RTA(rapid thermal annealing). The final multilayered films showed a (111) preferred orientation. On a while, the layer-by-layer crystallization of multilayered amorphous thin films without the intermediate heating exhibited a (100) preferred orientation. In case of heat treatment in the tube furnace with the heating rate of $4^{\circ}C/min$, (100) and (111) oriented thin layers were formed simultaneously. The microstructure of the deposited films were dense and crack-free with thickness of 300nm, irrespective of the processing variables.

• Journal of the Korean Ceramic Society
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• v.44 no.10
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• pp.580-584
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• 2007

The ZrC layer instead of SiC layer is a critical and essential layer in TRISO coated fuel particles since it is a protective layer against diffusion of fission products and provides mechanical strength for the fuel particle. In this study, we carried out computational simulation before actual experiment. With these simulation results, Zirconium carbide (ZrC) films were chemically vapor deposited on $ZrO_2$ substrate using zirconium tetrachloride $(ZrCl_4),\;CH_4$ as a source and $H_2$ dilution gas, respectively. The change of input gas ratio was correlated with growth rate and morphology of deposited ZrC films. The growth rate of ZrC films increased as the input gas ratio decreased. The microstructure of ZrC films was changed with input gas ratio; small granular type grain structure was exhibited at the low input gas ratio. Angular type structure of increased grain size was observed at the high input gas ratio.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.5
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• pp.413-417
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• 1998

In this paper, we investigate frequency dependance of inductance of FeCoB amorphous magnetic films. $(Fe_{1-x}Co_x)_{79}Si_2B_{19}$ was used as the basic composition of amorphous magnetic film having near zero magnetostriction. The amorphous magnetic films were fabricated with x=0.94 and x=0.95 by using sputtering method at high frequency. The films were anneald under non-magnetic field and near crystallization temperatures(30min at $280^{\circ}C$, 30min and 1hr at $400^{\circ}C$, respectively). As the results of the experiments with the fabricated films, the lowest coercive force was 0.084[Oe] at 400[W] of the input power and the crystallization temperature was $360^{\circ}C$ . In the case 30min at 40$0^{\circ}C$ the inductance value in the low frequency with x=0.95 was higher by 488% than that with x=0.94. The quality factor Q was below 0.7 for all samples. We obtained the highest quality value at 400[KHz] with 30min at $280^{\circ}C$ and x=0.94. The value was about 0.62. Also, the quality factor value was about 0.35 at 1[MHz] with 30min at $280^{\circ}C$ and x=0.95.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.8
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• pp.706-710
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• 2007

Ti-containing amorphous carbon (a-C:Ti) films shows attractive mechanical properties such as low friction coefficient, good adhesion to various substrate and high wear resistance. The incorporation of titanium in a-C films is able to improve the electrical conductivity, friction coefficient and adhesion to various substrates. In this study, a-C:Ti films were depositied on Si wafer by closed-field unbalanced magnetron (CFUBM) sputtering system composed two targets of carbon and titanium. The tribological properties of a-C:Ti films were investigated with the increase of DC bias voltage from 0 V to - 200 V. The hardness and elastic modulus of films increase with the increase of DC bias voltage and the maximum hardness shows 21 GPa. Also, the coefficient of friction exhibites as low as 0.07 in the ambient. In the result, the a-C:Ti film obtained by CFUBM sputtering method improved the tribological properties with the increase of DC bias volatage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.589-592
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• 1999

This paper describes direct $\mu$C-Si/CaF$_2$/glass thin film growth by RPCVD system in a low temperature for thin film transistor (TFT), photovoltaic devices. and sensor applications. Experimental factors in a low temperature direct $\mu$ c-Si film growth are presented in terms of deposition parameters: SiH$_4$/H$_2$ ratio, chamber total pressure, substrate temperature, rf power, and CaF$_2$ buffer layer. The structural and electrical properties of the deposited films were studied by means of Raman spectroscopy, I-V, L-I-V, X-ray diffraction analysis and SEM. we obtain a crystalline volume fraction of 61%, preferential growth of (111) and (220) direction, and photosensitivity of 124. We achieved the improvement of crystallinity and electrical property by using the buffer layers of CaF$_2$ film.