• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.113-114
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• 2005

We present the effect of substrate temperature on the structural and optical properties of ZnO films grown on sapphire substrate by pulsed laser deposition. Growing at higher substrate temperature results in an increase in the surface roughness. The optimum c-axis orientation of the ZnO films occurs at the substrate temperature of 700$^{\circ}C$ The decay time shows a rapid increase in the substrate temperature from 400$^{\circ}C$ to 500$^{\circ}C$ and falls down gradually as the substrate temperature is approached to 700$^{\circ}C$.

• Progress in Superconductivity
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• v.12 no.1
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• pp.32-35
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• 2010

Potassium doped $BaFe_2As_2$ superconducting thin films by using an ex situ pulsed laser deposition technique were fabricated in various conditions to find out an optimal growth condition. Controlled conditions were annealing temperature, annealing time, and mass of potassium. The $Ba_{1-x}K_xFe_2As_2$ thin films which has most good quality is fabricated at a condition of annealing temperature at $700^{\circ}C$, annealing time of 60 minutes, and 0.6 g of potassium lumps. In this condition we were able to fabricate good quality films with high transition temperature of ~ 39 K.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.100-104
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• 2013

A superhydrophobic mesh is a unique structure that blocks water, while allowing gases, sound waves, and energy to pass through the holes in the mesh. This mesh is used in various devices, such as gas- and energy-permeable waterproof membranes for underwater sensors and electronic devices. However, it is difficult to fabricate micro- and nano-structures on three-dimensional surfaces, such as the cylindrical surface of a wire mesh. In this research, we successfully produced a superhydrophobic water-repellent mesh with a high contact angle (> $150^{\circ}$) for nanofibrous structures. Conducting polymer (CP) composite nanofibers were evenly coated on a stainless steel mesh surface, to create a superhydrophobic mesh with a pore size of $100{\mu}m$. The nanofiber structure could be controlled by the deposition time. As the deposition time increased, a high-density, hierarchical nanofiber structure was deposited on the mesh. The mesh surface was then coated with Teflon, to reduce the surface energy. The fabricated mesh had a static water contact angle of $163^{\circ}$, and a water-pressure resistance of 1.92 kPa.

• Carbon letters
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• v.6 no.2
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• pp.96-100
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• 2005

Taguchi methodology has been applied to get an idea about the parameters related to the chemical vapour deposition technique, which influences the formation of semiconducting carbon thin film of a desired band gap. L9 orthogonal array was used for this purpose. The analysis based on Taguchi methodology suggests that amongst the parameters selected, the temperature of pyrolysis significantly controls the magnitude of band gap (46%). Sintering time has a small influence (30%) on the band gap formation and other factors have almost no influence on the band gap formation. Moreover this analysis suggests that lower temperature of pyrolysis (${\leq}$ $750^{\circ}C$) and lower time of sintering (${\leq}$ 1 h) should be preferred to get carbon thin film with the desired band gap of 1.2eV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.289-292
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• 1998

The methastable state diamond films have been deposited on Si substrates using MWPCVD. Effects of each experimental parameters of MWPCVD including CH$_4$ concentrations, Oxygen additions, Operating pressure, deposition time, etc. on the growth rate and crystallinity were investigated. The best crystallinity of the finn at 3% methane concentration addition of oxygen to the CH$_4$-$H_2O$ mixture gave an improved film crystallinity at 50% oxygen concentration. Upon increasing the operating pressure and time, the growth rate and crystallinity were increased simultaneously.

• Journal of the Semiconductor & Display Technology
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• v.19 no.2
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• pp.16-21
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• 2020

How accurately reproducible energy is delivered to the wafer in the process of making thin films using PE-CVD (Plasma enhanced chemical vapor deposition) during the semiconductor process. This is the most important technique, and most of the reaction on the wafer surface is made by thermal energy. In this study, we studied the method of monitoring the change of thermal energy transferred to the wafer surface by monitoring the temperature change according to the change of the thin film formed on the showerhead facing the wafer. Through this research, we could confirm the monitoring of wafer thin-film which is changed due to abnormal operation and accumulation of equipment, and we can expect improvement of semiconductor quality and yield through process reproducibility and equipment status by real-time monitoring of problem of deposition process equipment performance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.365-366
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• 2007

High quality cathode with high deposition rate of thin films and long target life time is required for manufacturing TFT-LCD and semiconductor. We developed WV(wide view) sputtering cathode with wide erosion area and high deposition rate. Ti thin film thickness variation in WV cathode is below 5% for 380 kWh target life time. Al thin film thickness using normal cathode is decreased about 20%. By using WV cathode, target using efficiency was improved 40%. in comparison with normal cathode.

• Journal of the Korean institute of surface engineering
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• v.22 no.3
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• pp.135-144
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• 1989

Aluminium Oxide was deposited with a C.V.D.-technique on various substrates. The effects of various treating condition such as temperature, time, heat resistance and composition of substrates were investigated in order to understand the relationship of structure, property and process. Grain size depends upon the activity of adsorption siite and coarsened with increasing temperature and time. Deposition rate decreases in order of electrolytic iron, carbon steel STS430 and STS304, since the active site for adsorption of reactant was more decreased for Cr and Ni than Fe. Oxidation resistance of alumina coated specimens improved markedely and that of stainless steel was prominent.

• Journal of Magnetics
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• v.5 no.4
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• pp.124-129
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• 2000

$Sm_2Fe_{17}N_x$ film magnets were prepared using a $Sm_2Fe_{17}$ target in a $N_2$ gas atmosphere using a Nd-YAG pulsed laser ablation technique. The effect of nitrogen pressure, deposition temperature, pulse time and film thickness on the structure and magnetic properties of $Sm_2Fe_{17}N_x$ film were studied. Increasing the nitrogen pressure up to 5 atm led to the formation of complete $Sm_2Fe_{17}N_x$ compound. Optimized magnetic properties with the nitrogenation temperature in the range 500-53$0^{\circ}C$ could be obtained by extending the nitrogenation time up to 4 hours. Relatively low coercivities of 400~600 Oe were found in $Sm_2Fe_{17}N_x$films 50~100 m thick, while a $4\piM_s$ of 10$\sim$12 kG could be achieved. In-plane anisotropy, which was the basic goal in this study, was achieved by controlling the nitrogenation parameters.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.818-822
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• 2008

The purpose of this study is to develop realistic painting simulation in real-time as well as to represent the thickness of the deposited paint on the surface. The Gaussian model is used for a painting deposition model to calculate the thickness of paints. For a painting simulation, rather than implementing particle systems, we propose a new heuristic algorithm for painting process based on a few number of rays. After we find the collision points of the rays with an environment, we compute the painted area using flood-fill searching method on the texture map and visualize paint effects. We analyzed time complexity of our method to verify that our system is suitable for real-time VR applications.