• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1994-1996
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• 1996

This paper presents the fabrication and testing of a polysilicon piezoresistive accelerometer with p+ silicon diaphragm by simple process such as two step photolithography for the RIE process to form the cantilevers and a deep anisotropic etch process for the complete fabrication of the accelerometer. The fabricated accelerometer consists of a seismic mass and four cantilevers on which polysilicon piezoresistors are formed. The measurement of the output signal from the bridge circuit of the fabricated accelerometer is carried out with the HP 3582A spectrum analyzer. The analysis of the experimental result is showed in terms of the sensitivity and the resonant frequency. At atmospheric condition, the measurement values of the sensitivity and the resonant frequency are $11\;{\mu}V/Vg$ and 475 Hz, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.489-490
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• 2006

To establish fabrication techniques for nano structure understanding of focused ion beam (FIB) milling process is required. In this study the mathematical model containing the factors related to FIB milling is developed to acquire the optimal fabrication condition. Then, the model is verified by comparison with various nano pattern fabricated in actual FIB system. Consequently, it is demonstrated that the nano patterns with the smallest pitch can be fabricated using developed FIB milling model.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.224-229
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• 1996

Performance characteristics of single cell in phosphoric acid fuel cell were studied for various electrode fabrication parameters such as teflon content, electrode structure, thickness of electrocatalyst layer, platinum content and electrode area. The performance of single cell was decided from the measured voltage-current through a load change. The electrode of 40wt.% teflon exhibited high initial performance of single cell, but in the long term operation, the cell performance of 45 wt.% teflon was better. Also the single cell appeared good performance in case of electrodes with duplicate structure, thin electrocatalyst in thickness, more platinum content, and small area. These results of cell performance were discussed as related to the electrolyte flooding, formation of 3 phase boundary area, internal resistance of electrode, and microstructure of electrode.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.91-94
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• 2001

Powder Metallurgy method have been used to fabricate TiC base composite with ferrous binder. TiC base composite has versatile hardness and is usable as sintered, or after heat treatment as required by the given applications. Smooth, round TiC grains impart high wear resistance and lubricity as well known characteristics of this composite. Annealed composite can be formed by conventional machining and be hardened up to 70 H$\_$R/C in vacuum. The optimizing fabrication process enables this composite to improve mechanical properties in heat, wear and corrosion environments. This study has examine the relationship between fabrication condition and mechanical property in TiC-Cr-Mo-Fe Composite.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04a
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• pp.35-38
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• 2004

Ozone is useful oxidizing gas for the fabrication of oxide thin films. Accordingly researching on oxidizing gas is required. In order to obtain high quality oxide thin films, higher ozone concentration is necessary. In this paper oxidation property was evaluated relation between oxide gas pressure and inverse temperature(CuO reaction). The obtained condition was formulated by the fabrication of Cu metal thin film by co-deposition using the Ion Beam Sputtering method. Because the CuO phase peak appeared at the XRD evaluation of the CuO thin film using ozone gas, this study has succeeded in the fabrication of the CuO phase at $825^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.587-588
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• 2005

Ozone is useful oxidizing gas for the fabrication of BSCCO thin films. In order to obtain high quality oxide BSCCO thin films, higher ozone concentration is necessary. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In this paper oxidation property was evaluated relation between oxide gas pressure and inverse temperature(CuO reaction). The obtained condition was formulated by the fabrication of Cu metal thin film by co-deposition using the Ion Beam Sputtering method. Because the CuO phase peak appeared at the XRD evaluation of the CuO thin film using ozone gas, this study has succeeded in the fabrication of the CuO phase at $825^{\circ}C$.

• Journal of the Semiconductor & Display Technology
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• v.16 no.4
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• pp.16-19
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• 2017

For the economical and environmental-friendly fabrication of polisher, Mo mask layer were sputtered on glass substrate instead of Cr mask material. Mo mask layers were sputtered by pulsed-DC sputtering and Photoresist patterns were formed on Mo mask layer for different develop times and optimized. After Mo mask layer were patterned and exposed glass was wet etched by HF solution for different etching times, the remaining Mo mask was stripped by using Al etchant. Develop time of 30 sec and HF wet etching time of 3 min were selected as optimized process condition and applied to the fabrication of polisher.

• Journal of the Korean Ceramic Society
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• v.40 no.4
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• pp.385-392
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• 2003

Sol-gel preparation technique using a chemical reaction of metal alkoxides has been widely used for the fabrication of various materials including ceramics. However, its mechanism has been studied till now because a number of chemical ways are possible from various alkoxides and additives. In this study, the mechanism of hydrolysis, condensation, and polymerization of alkoxides were investigated from the fabrication of lead-zirconate-titanate (PbZr$\_$x/Ti$\_$l-x/O$_3$; PZT) thin film that is used as various micro-actuator, transducer, and sensor because of its high electro-mechanical coupling factors and thermal stability. Furthermore, the fabrication process and characteristics of self-patternable PZT film using photosensitive stabilizer were studied in order to resolve the problem of physical damage and properties degradation during dry etching for device fabrication. Using an optimum condition to prepare the self-patternable PZT film, more than 5000 ${\AA}$ thick self-patternable PZT film could be fabricated by three times coating. The PZT film showed 28.4 ${\mu}$c/cm$^2$ of remnant polarization (Pr) and 37.0 kV/cm of coercive field (E$\_$c/).

• Journal of the Korean Ceramic Society
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• v.29 no.6
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• pp.419-430
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• 1992

Fabrication possibility of low-shrinkage alumina without oxidation and wetting agent was presented on the basis of observation about oxidation behavior, microstructure and physical characteristics of such reaction agents free Al2O3-Al system. The composition less than Al 10w/o where Al can act as a sintering agent for Al2O3 was excluded. Under the condition of present experiments oxidation of Al2O3-Al system was dependent not on holding time but mainly on oxidation temperature. In thes case of Al powder not comminuted effectively during powder mixing of Al2O3-Al, columnar structure which would act as a hindrance to the densification during sintering developed more during oxidation with higher Al contents, and which made the fabrication of low-shrinkage Al2O3 ceramics impossible. If Al powder was comminuted effectively due to co-mixed Al2O3 characteristics, densification was improved because of no columnar structure and made the fabrication of sintered body with -2.7% dimensional change and 81% relative density possible. As a result, it is possible to fabricate dense low-shrinkage Al2O3 ceramics without oxidation and wetting agent under conditions such as smaller particle size of Al, Al contents below 50v/o, higher green density of Al2O3-Al compact and the use of Al2O3 powder used for high-density ceramics.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.3
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• pp.431-453
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• 2013

The principal purpose of this paper is to present a novel two phases rational scenario applied in constructing an offshore monopod platform; in which the two phases are the all-ground horizontal construction phase and the post-construction phase. Concerning the all-ground construction phase, a brief investigation of its different stages, i.e., pre-fabrication, fabrication, pre-assembling, positioning, assembling, and surface finishing is introduced. The important practical aspects of such construction phase are investigated without going into the nitty-gritty of the details involved therein. Concerning the post-construction phase, a clear investigation of its sequential stages, i.e., lifting, moving and up-righting is introduced. A finite element model (FEM) of the monopod platform is created to perform the structural analysis necessary to decide the suspension points/devices and the handling scenario during the various stages of the post-construction phase on a rational wise. Such structural analysis is performed within the framework of the three dimensional quasi-static modeling and analysis aiming at simulating the realistic handling condition, and hence introducing a reliable physical interpretation of the numerical results. For the whole effort to be demonstrated efficiently, the results obtained are analyzed, the conclusions are presented, and few related recommendations are suggested.