• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.7
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• pp.382-386
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• 2004

A study has been made of surface modification of organic materials by ion implantation to increase the surface electrical properties. The substrate used were PET(polyethylene teraphtalate). N$^{＋}$, Ar$^{＋}$ implantation was peformed at energies of 40 keV and 50 keV with fluences from $5{\times}10^{15}$, $1{\times}10^{16}$,$7{\times}10^{16}$, $1{\times}10^{17}$/ ions/$cm^2$. UV/Vis, FT-IR and XPS spectroscopy measured for surface structure changes. Surface resistance decrease of implanted polymers was affected by ion implantation energy, ion species and ion dose rate. Surface conductivity of PET increased $2{\times}10^{9}$/∼$2{\times}10^{10}$/$\Omega$/sq by ion implantation. Result of various spectroscopy analysis, the cause of increasing PET surface conductivity was expected to breaking C=O bonds. It was formation carbon network structure by promote cross-linking and create C-C, C=C bonds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.99-102
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• 1999

A mixture which was made from organic gel, glass powder and ceramic powder was masklessly etched for fabrication of barrier rib of PDP(Plasma Display Panel) by focused Ar$^{+}$ laser( λ =514 nm) and Nd:YAG(λ =532, 266 nm) laser irradiation at the atmosphere. The depth of the etched grooves increases with increasing a laser fluence and decreasing a scan speed. Using second harmonic of Nd:YAG laser, the threshold laser fluence was 6.5 mJ/$\textrm{cm}^2$ for the sample of PDP barrier rib softened at 12$0^{\circ}C$. The thickness of 130 ${\mu}{\textrm}{m}$ of the sample on the glass was clearly removed without any damage on the glass substrate by fluence of 19.5 J/$\textrm{cm}^2$....

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.279-286
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• 2000

Magnetic field dependence of magnetization reversal in Co/Pt multilayers has been quantitatively investigated. Serial samples of Co/Pt multilayers have been prepared by dc-magnetron sputtering under various Ar pressure. Magnetization reversal was monitored by magnetization viscosity measurement and direct domain observation using a magneto-optical microscope system, and the wall-motion speed and the nucleation rate R were determined using a domain reversal model based on time-resolved domain reversal patterns. Both and R were found to be exponentially dependent on the reversing applied field. From the exponential dependencies, the activation volumes of the wall motion and nucleation could be determined based on a thermally activated relaxation model, and the wall-motion activation volume was revealed to be slightly larger than the nucleation activation volume.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.576-580
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• 2006

The $(Sr_{0.85}Ca_{0.15})TiO_3(SCT)$ thin films were deposited on Pt-coated electrode $(Pt/TiN/SiO_2/Si)$ using RF sputtering method according to the deposition condition. The crystallinity of SCT thin films were increased with increase of deposition temperature in the temperature range of $100{\sim}500[^{\circ}C]$. The optimum conditions of RF power and $Ar/O_2$ ratio were 140[W] and 80/20, respectively. Deposition rate of SCT thin films was about $18.75[{\AA}/min]$ at the optimum condition. The composition of SCT thin films deposited on Si substrate is close to stoichiometry (1.102 in A/B ratio). The maximum dielectric constant of SCT thin film as obtained by annealing at $600^{\circ}C$.

• Journal of the Korean Institute of Landscape Architecture
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• v.22 no.4
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• pp.1-21
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• 1995

Parks in Kwang Ju ar determined by the development of a housing project under the regulations of land development rather than the planning approach of park provision. This study tries to identify who is the provider of parks, to estimate the size of urban parks per person in the area of the housing project, to look at the spatial allocation patterns of park provision and to identify the character profiles of users and the social profile of an ares(Dong). This research has produced the following major conclusions : 1. The city government should set up a master plan of park provision to control park delivery system to avoid maldistribution. 2. A positive discrimination policy should be introduced to disadvantaged areas in terms of park provision. 3. The null hypothesis - there is no relationship between distance and park Use - is rejected by the correlation rate of 0.4984. 4. The ratio of parks per a person ; 10.43㎡/person in 1990 has decreased to 10.41㎡ /person in 1994. This means that the increase of parks in terms of quantity could not catch up the increase of population.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1990.10a
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• pp.105-107
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• 1990

In this study, we prepared plasma polymerized thin films as changing the composition rate of the Ar/CO$_2$, 0 to 100%, for analysing the influence of CO$_2$ gas in plasma polymerization. Power source was the RF frequence (13.56MHz), the monomers were styrene and MMA (Methyl-methacrylate), and substrates were glass and KBr(or NaCl) for IR spectroscopy. The molecular structure of plasma polymerized organic thin films was examined by IR, FT-IR, Gas chromatography and so forth.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1732-1734
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• 2003

An MgO thin film sputtering system for the PDP (Plasma Display Panel) applications has been developed. This system was manufactured with a vertical In-Line type of 42 inch, which has the length of 520 mm and the width of 900 mm. A reactive magnetron discharge for this sputtering was generated using an unipolar pulsed power supply which has functions of constant voltage (Max. 500 V) and current (Max. 15 A) control, frequency of $10{\sim}100$ kHz and duty ratio of $10{\sim}60$ %. The experiment was conducted under various conditions : $3{\sim}10$ mTorr of pressure, the ratio of $O_2$/Ar = $0.1{\sim}0.5$, 50 % of duty and power of $0.5{\sim}1.7$ kW. From the experiment, the deposition rate of a static state and a moving state were measured to be about 45 nm/min and 6 nm m/min at the distance of 50 mm between the target and the substrate, respectively.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1271-1273
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• 1993

$SiO_2$ and SiON films are formed by Laser CVD for inter-level dielectrics in submicron VLSI. This technique is noticeable that film formation can be done at low temperatures, below $300^{\circ}C$ with less damage. An ArF Excimer Laser with wave length of 193nm is used to excite and dissociate reactant gases. After film formation growth rate, refractive index, I-V curve, and step coverage characteristics of the films were evaluated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.134-135
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• 2007

Growth of cubic SiC has been carried out on oxided Si substrate using atmospheric pressure chemical vapor deposition (APCVD). Hexamethyldisilane (HMDS) was used as the single precursor and nonflammable mixture of Ar and $H_2$ was used as carrier gas. Epitaxial growth had performed depositions under the various $H_2$ conditions which were adjusted from 0 to 100 seem. The effects of $H_2$ was characterized by surface roughness, thickness uniformity, films quality and elastic modulus. Thickness uniformity and films quality were performed by SEM. Surface roughness and elastic modulus were investigated by AFM and Nano-indentor, respectively. According to the $H_2$ flow rate, Poly 3C-SiC thin film quality was improved not only physical but also mechanical properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.316-319
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• 2000

By RF magnetron sputtering ZnGa$_2$O$_4$thin films were prepared on Si(100) wafer in terms of RF power, substrate temperatures and Ar/O$_2$flow rate. Crystallographic orientation was characterized by x-ray diffraction(XRD). Surface morphology and microstructure were observed by scanning electron microscope(SEM). Photoluminescence(PL) measurement was employed to observe the emission spectra of ZnGa$_2$O$_4$films. The influences of various deposition parameters on the properties of grown films were studied. PL spectrum of ZnGa$_2$O$_4$thin films showed broad band luminescence spectrum.