• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.183-184
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• 2006

The simulation on the mechanism of terahertz NSOM(near-field scanning optical microscopy) have been investigated. Based on experimental results, we have demonstrated the antenna effects on the coupling between a metal tip and substrate for an emission-type terahertz NSOM. It has been found that the lateral resolution can be estimated by a simplified model using an infinitesimal dipole in the substrate.

• Journal of the Korean Vacuum Society
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• v.8 no.2
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• pp.172-179
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• 1999

The axial distributions of plasma density in a helical resonator plasma with the external magnetic field have been measured using Langmuir probes. Net RF power is set to 200W and chamber pressure is varied from 0.4 mTorr to 100mTorr there are three kinds of eternal magnetic field structure applied on the helical resonator plasma. One is a uniform magnetic field, the second is a positive gradient magnetic field and the third is a negative gradient magnetic field. In the three magnetic field structures, the negative gradient magnetic field is found to show the highest increase in plasma density on the substrate compared with other magnetic structures. Plasma density profile in helical resonator is well consistent with electromagnetic field pattern obtained by computer simulation. It is also found that axial magnetic fields do not affect plasma density distribution in the plasma reactor region, but induce the increase of plasma density in the process chamber region. In order to avoid the nonuniformity of radial density profile, weak magnetic fields under 100G are applied.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.175-178
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• 2000

The resonance characteristic of microstrip antenna with an airgap between the substrate layer and ground plane is investigated. The study is performed by using a rigorous Green’s function formulation in the spectral domain and Galerkin’s moment method calculation. The numerical convergence using sinusoidal basis functions, the unknown surface current distribution in the rectangular patch, is discussed. Numerical result for the effects of airgap and patch length on the complex resonant frequencies of the rectangular microstrip structure are also presented

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.82-83
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• 2008

AI doped ZnO (AZO) films, and intentionally Zn added AZO (ZAZO) films were prepared on Corning glass by rf magnetron sputtering, and the electrical, optical, and structural properties of the as-deposited films together with the air annealed films were investigated. The resistivity of the AZO films increased with increasing substrate temperature and having minimum resistivity at $150^{\circ}C$. At the high temperature, the ZAZO films showed improved electrical properties better than the AZO films due.to increase in both the carrier concentration and.the Hall mobility. Upon air annealing at $500^{\circ}C$, the resistivity of both AZO and ZAZO films increased substantially, but the relative amount of degradation was smaller for films deposited at $450^{\circ}C$ than the films deposited at $150^{\circ}C$.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1148-1151
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• 2009

A self-designed, written in labview, Organic Light-Emitting Diode junction temperature measuring program was used to calculate the internal junction temperature for devices during operation, and an infrared thermometer was used to measure the backside temperature of the device substrate, to discuss the effects of the junction and substrate temperature difference to the characteristics of the device.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.710-712
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• 2007

The effects of stress on the IZO/PC substrate and the electro-optical properties of a flexible LCD with microstructure in bending were investigated. It showed that the IZO/PC substrate and the periodic cross spacers are good enough to be employed in the application of the ECB or polarization rotation LC mode.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.1
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• pp.48-52
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• 1986

An efficient numerical technique and computer program has been developed for the determination of the resonant frequencies and field coefficients of cylindrical dielectric disc resonators in a configuration which models the various effects present in real technical applications. it accounts for the influences due to shielding, plannar circuit substrate, dielectric support and a dielectric post used to tune out fabrication tolerances.

• Journal of computational fluids engineering
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• v.12 no.4
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• pp.14-19
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• 2007

We present a direct numerical simulation technique and some preliminary results of the capillary spreading of a droplet containing particles on the solid substrate. We used the level-set method with the continuous surface stress for description of droplet spreading with interfacial tension and employed the discontinuous Galerkin method for the stabilization of the interface advection equation. The distributed Lagrangian-multipliers method has been combined for the implicit treatment of rigid particles. We investigated the droplet spreading by the capillary force and discussed effects of the presence of particles on the spreading behavior. It has been observed that a particulate drop spreads less than the pure liquid drop. The amount of spread of a particulate drop has been found smaller than that of the liquid with effectively the same viscosity as the particulate drop.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.2
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• pp.101-106
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• 2009

The disjoining pressure is an important physical property in modeling the small-scale transport phenomena on thin film. It is a very useful definition in characterizing the non-continuum effects that are not negligible in heat and mass transport of the film thinner than submicro-scales. We present the calculated values of disjoining pressure of He, Kr and Xe thin films absorbed on graphite substrate using Molecular Dynamics Simulation (MD). The disjoining pressure is accurately calculated in the resolution of a molecular scale of the film thickness. The characteristics of the pressure are discussed regarding the molecular nature of the fluid system such as molecular diameter and intermolecular interaction parameters. The MD results are also compared with those based on the continuum approximation of the slab-like density profile and the results on other novel gases in the previous study. The discrepancies of the continuum model with MD results are shown in all three configurations and discussed in the view point of molecular features.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.180-182
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• 2002

Copper thin films are prepared by a chemical vapor deposition technology for multi-level metallzations in ULSI fabrication. The copper films were deposited on TiN/Si substrates in helium atmosphere with the substrate temperature between $120^{\circ}C$ and $300^{\circ}C$. In order to get more reliable metallizations, effects on the post-annealing treatment to the electrical properties of the copper films have been investigated. The Cu films were annealed at the $5\times$10^{-6}$ Torr vacuum condition, and the electrical resistivity and the nano-structures were measured for the Cu films. The electrical resistivity of Cu films shown to be reduced by the post-annealing. The electrical resistivity of 2.2 $\mu$$\Omega$.cm was obtained for the sample deposited at the substrate temperature of $180^{\circ}C$ after vacuum annealed at $300^{\circ}C$. The resistivity variations of the films was not exactly matched with the size of the nato-structures of the copper grains, but more depended on the deposition temperature of the copper films.