• Korean Journal of Materials Research
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• v.16 no.10
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• pp.619-623
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• 2006

Selective vapor deposition of conductive poly(3,4-ethylenedioxythiophene) (PEDOT), thin films has been carried out on self assembled monolayers patterned oxide substrate. Since the 3,4-ethylenedioxythiophene(EDOT) monomer can be polymerized only in the presence of oxidant such as $FeCl_3$, the PEDOT thin film is selectively deposited on patterned $FeCl_3$, which only adsorbs on the partly removed SAMs region due to the inability of $FeCl_3$ to adsorb on SAMs. Therefore, the partly removed SAMs can act as an adsorption layer for the $FeCl_3$ and also as a glue layer for the deposition of PEDOT, resulting in the significantly increased adhesion of PEDOT to $SiO_2$ substrate. The use of UV lithography and Cr patterned quartz mask provided the formation of SAMs patterns on oxide substrates, which allowed for the selective deposition of conductive PEDOT thin films.$^{oo}The$ new process was successfully developed for the selective deposition of PEDOT thin films on SAMs patterned oxide substrate, providing a new way for the patterning of vapor phase deposition of PEDOT thin films with accurate alignment and addressing the inherent adhesion issues between PEDOT and dielectrics.

• Journal of the Korean Vacuum Society
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• v.4 no.S1
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• pp.190-195
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• 1995

The feature scale model for selective chemical vapor deopsition process was proposed and the simulation was performed to study the selectivity and uniformity of deposited thin film using Monte Carlo method and string algorithm. The effect of model parameters such as sticking coefficient, aspect ratio, and surface diffusion coefficient on the deposited thin film pattern was improved for lower sticking coefficient and higher aspect ratio. It was revealed that the selectivity loss ascrives to the surface diffusion. Different values of sticking coefficients on Si and on SiO2 surface greatly influenced the deopsited thin film profile. In addition, as the lateral wall angle decreased, the selectively deposited film had improved uniformity except the vicinity of trench wall. The optimum eondition for the most flat selective film deposition pattern is the case with low sticking coefficient and slightly increased surface diffusion coefficient.

• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.167-170
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• 2016

Various piezoelectric nanostructures have been extensively studied for competitive energy harvesting applications. Here, GaN nanowires grown by a nonconventional magnetic field-assisted chemical vapor deposition process were investigated to characterize the piezoelectric energy harvesting characteristics. As a controlling parameter, only the growth time was changed from 15 min to 90 min to obtain different crystallinity and morphology of the nanowires. Energy harvesting characteristics were found to depend largely on the growth time. A longer growth time tended to lead to an increased output current, which is reasonable when considering the enhanced charge potentials and crystallinity. A maximum output current of ~14.1 nA was obtained for the 90 min-processed nanowires.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.4
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• pp.307-320
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• 1989

This paper presetns new design of the Modified Chemical Vapor Deposition(MCVD) system for optical fiber preform fabrication. It contains a glass working lathe, raw material supplier and exhaust gas treatment apparatus as fundamental instruments for MCVD process, graded index fiber design, characteristic of process and the experimenta arrangement to measure the refractive index profile of MCVD preforms, respectively. From the investigation results, it is shown that an ideal graded index fiber preform does not exhibit a center dip or bump.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.983-989
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• 2012

The purpose of this paper is to decide the optimum synthesis conditions of polycrystalline diamond films according to the ratio of gas mixture. Diamond films were deposited with cyclo-hexane as a carbon precursor by the microwave plasma enhanced chemical vapor deposition process. The optimum oxygen ratio to cyclo-hexane was reached about 125 % under the fixed 0.3% c-hexane in hydrogen. Oxygen plays a role in etching the graphitic components of carbon sp2 bond effectively. By OES measurement, the best synthesis conditions found out about 12.5 % and 15.75 %, which is the emission intensity ratios of CH(B-X) and $H{\beta}$ on $H{\alpha}$, respectively. Also, the electron temperature was similar about 5,000 to 5,200 K in this work.

• Journal of Ceramic Processing Research
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• v.13 no.spc1
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• pp.42-46
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• 2012

The effect of the parameters for few-layered graphene growth by thermal CVD on nickel substrate was investigated. Graphene can be synthesized by using different strategies. Chemical vapor deposition (CVD) has known as one of the most attractive methods to produce graphene due to its good film uniformity, compatibility and large scale production. The control of parameters such as temperature, growth time and pressure in CVD process has been widely recognized as the most important process in graphene growth. Different carbon precursors, methane and acetylene, were introduced in the quartz tube with a variety of growth conditions. Raman spectroscopy was used to confirm the presence of a few- or multi-layered graphene.

• Transactions on Electrical and Electronic Materials
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• v.13 no.2
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• pp.69-72
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• 2012

In this study, deposition of low-dielectric constant SiOC(H) films by conventional plasma-enhanced chemical vapor deposition (PECVD) were investigated through various characterization techniques. The results show that, with an increase in the plasma power density, the relative dielectric constant (k) of the deposited films decreases whereas the refractive index increases. This is mainly due to the incorporation of organic molecules with $CH_3$ group into the Si-O-Si cage structure. It is as confirmed by FT-IR measurements in which the absorption peak at 1,129 $cm^{-1}$ corresponding to Si-O-Si cage structure increases with power plasma density. Electrical characterization reveals that even after fast thermal annealing process, the leakage current density of the deposited films is in the order of $10^{-11}$ A/cm at 1.5 MV/cm. The reliability of the SiOC(H) film is also further characterized by using BTS test.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.135.2-135.2
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• 2010

Carbon nanotube(CNT) has been spotlighted as a promising candidate for catalyst support material for PEMFC (proton exchange membrane fuel cell). The considerable properties of CNT include high surface area, outstanding thermal, electrical conductivity and mechanical stability. In this study, to fully utilize the properties of CNTs, we prepared directly oriented CNT on carbon paper as a catalyst support in the cathode electrode. The CNT layer was prepared by a chemical vapor deposition(CVD) process. And the Pt particles were deposited on the CNT oriented carbon paper by impregnation and eletro-deposition method. The potential advantages of directly oriented CNT on carbon paper can include improved thermal and charge transfer through direct contact between the electrolyte and the electrode and enhanced exposure of Pt catalyst sites during the reaction.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1119-1122
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• 2005

A selective deposition of Co thin films for thin film transistor gate electrode has been carried out by the growth with combination of micro-contact printing and metal organic chemical vapor deposition (MOCVD). This results in the elimination of optical lithography process. MOCVD has been employed to selectively deposit Co films on preformed OTS gate pattern by using micro-contact printing (${\mu}CP$). A hydrogenated amorphous silicon TFT with a Co gate selectively formed on SAMs patterned structure exhibited a subthreshold slope of 0.88V/dec, and mobility of $0.35cm^2/V-s$, on/off current ratio of $10^6$, and a threshold voltage of 2.5V, and thus demonstrating the successful application of the novel bottom-up approach into the fabrication of a-Si:H TFTs.

• Journal of the Korean Ceramic Society
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• v.31 no.5
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• pp.477-484
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• 1994

The yttria stabilized zirconia(YSZ) thin films for solid oxide fuel cell (SOFC) were fabricated by an electrochemical vapor deposition(EVD) technique using YCl3+ZrCl4+H2O gas system. The YSZ films were deposited under reduced pressure at the temperature of 1000~120$0^{\circ}C$ on the porous alumina substrates. The deposition rate, chemical composition and growth morphology were investigated by SEM, XRD, EDS. The growth rates of the films obeyed a parabolic rate law, representing that the growing process is controlled by an electrochemical transport through the YSZ film. The Y2O3 content of the films was about 10 mol%, equal to the composition of metal chloride reactant gases, approximately. The YSZ films were highly dense, the growing features showed columnar structure and surface morphologies were changed with the EVD conditions.