• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.715-718
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• 2008

An in-line wet etch/cleaning system was established for the research and development in wet etch process. The system was equipped with a reverse moving system for the reduction in the size of the in-line wet etch/cleaning system and it was possible for the glass substrate to be moved back and forth and alternated in a wet etch bath. For the comparison of the effect of the normal motion and that of the alternating motion on the in-line wet etch process, indium tin oxide(ITO) pattern was obtained through both wet etch process conditions. The results showed that the alternating motion is not inferior to the normal motion in etch rate and in etch uniformity. It is concluded that the alternating motion is possible to be applied to the in-line etch process.

• Fashion & Textile Research Journal
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• v.12 no.1
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• pp.94-102
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• 2010

The dyeing of poly(trimethylene terephthalate)(PTT)/silk mixture fabrics can be accomplished by a two bath dyeing method with separate application of the disperse dyes on the PTT, reduction cleaning of the stained silk and then dyeing the silk with the acid dyes, or by one bath dyeing method with mixed dye ranges, possibly followed by a cleaning treatment. The two bath dyeing method has the advantage of better results with respect to dry cleaning fastness properties thanks to the possibility of an intermediate reduction clear. On the other hand, as compared with the two bath dyeing method, one bath dyeing method with a mixed dye range permits rapid and more reproducible dyeing, without the risk of great difference with respect to the shade of the strike on both substrates as well as savings of time, energy and water usage. This study was carried out to investigate dyeing characteristics of PTT/silk mixture fabrics with disperse dyes/acid dyes by one bath dyeing method in comparison with two bath dyeing method in the interests for rationalization of the dyeing process.

• Clean Technology
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• v.6 no.1
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• pp.79-84
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• 2000

In this study, to reduce the consumption of chemicals in cleaning processes, Si-wafers contaiminated with metallic impurities were cleaned with electrolyzed water(EW), which was generated by the electrolysis of a diluted electrolyte solution or ultra pure water(UPW). Electrolyzed water could be controlled for obtaining wide ranges of pH and ORP(oxidation-reduction potential). The pH and oxidation-reduction potential of anode water and cathode water were measured to be 4.7 and +1000mV, and 6.3 and -550mV, respectively. To analyze the amount of metallic impurities on Si-wafer surfaces, ICP-MS was introduced. Anode water was effective for Cu removal, while cathode water was more effective for Fe removal.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2002.11a
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• pp.117-119
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• 2002

A semiconductor cleaning technology has been based upon RCA cleaning which consumes vast amounts of chemicals and ultra pure water. This technology hence gives rise to many environmental issues, and some alternatives such as electrolyzed water are being studied. In this work, intentionally contaminated Si wafers were cleaned using the electrolyzed water. The electrolyzed waters were obtained in anode and cathode with oxidation reduction potentials and pH of -1050mV and 4.8, and -750mV and 10.0, respectively. The electrolyzed water deterioration was correlated with $CO_2$ concentration changes dissolved from air. Overflowing of electrolyzed water during cleaning particles resulted in the same cleanness as could be obtained with RCA clean. The roughness of patterned wafer surfaces after EW clean maintained that of as-received wafers. RCA clean consumed about $9\ell$ chemicals, while electrolyzed water clean did only $400m\ell$ HCl or $600m\ell$ $NH_4$Cl to clean 8" wafers in this study. It was hence concluded that electrolyzed water cleaning technology would be very effective for releasing environment, safety, and health(ESH) issues in the next generation semiconductor manufacturing.ring.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.72-75
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• 2023

Carbon neutrality has been emerged as important mission for all the manufacturing industry to reduce energy usage and carbon emission equivalent. Korean semiconductor and display manufacturing industries are also in huge interest by minimize the energy usage as well as to find a less global warming product gases in both etch and cleaning. In addition, Korean government is also investing long term research and development plan for the safe environment in various ways. In this paper, we revisit previous research activities on carbon emission equivalent and current research activities performed in semiconductor process diagnosis research center at Myongji University with respect to the reduction of NF3 usage for the PECVD chamber cleaning, and we present the analytical result of the exhaust gas with residual gas analysis in both 6 inches and 12 inches PECVD equipment. The presented result can be a reference study of the development of new substitution gas in near future to compare the cleaning rate of the silicon oxide deposition chamber.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.66-71
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• 2023

This paper describes a hybrid cleaning method of silicon wafer combining nano-bubble and ultrasound to remove sub-micron particles and contaminants with minimal damage to the wafer surface. In the megasonic cleaning process of semiconductor manufacturing, the cavitation induced by ultrasound can oscillate and collapse violently often with re-entrant jet formation leading to surface damage. The smaller size of cavitation bubbles leads to more stable oscillations with more thermal and viscous damping, thus to less erosive surface cleaning. In this study, ultrasonic energy was applied to the wafer surface in the DI water to excite nano-bubbles at resonance to remove contaminant particles from the surface. A patented nano-bubble generator was developed for the generation of nano-bubbles with concentration of 1×10⁹ bubbles/ml and nominal nano-bubble diameter of 150 nm. Ultrasonic nano-bubble technology improved a contaminant removal efficiency more than 97% for artificial nano-sized particles of alumina and Latex with significant reduction in cleaning time without damage to the wafer surface.

• The Journal of Advanced Prosthodontics
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• v.7 no.2
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• pp.151-159
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• 2015

PURPOSE. To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS. A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non- quantitatively. RESULTS. All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION. The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.

• Tribology and Lubricants
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• v.29 no.5
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• pp.304-309
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• 2013

Shark skin has functionalities such as self-cleaning and antifouling; it also exhibits excellent drag reduction owing to a hierarchical structure of microgrooves and nanometer-long chain mucus drag reduction interfaces around the shark body. In this study, the wettability of a shark skin surface and its replicas are evaluated. First, a shark skin template is taken from a real shark. Then, shark skin replicas are produced directly from a shark skin template, using a micromolding technique. The quantitative replication precision of the shark skin replicas is evaluated by comparing the geometry of the shark skin template to the replica using 2D surface profiles. Contact angles at the solid-air-water interfaces are evaluated for the shark skin template and its replicas under two conditions: with and without hydrophobic coating. The results show that the microriblets on shark skin improve the hydrophobic feature and play a critical role in self-cleaning.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.265-270
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• 2001

Nowadays, like any other areas we have asked that the concrete would get more and more properties to increase there performance. So, in this research we are intended to develop the Photocatalytic Concrete which is one of the High Performance Concrete with waste gas reduction and self-cleaning. The fundamental phenomena of the Photocatalytic Concrete were observed by the residue water-weight, SEM, flow and surface hardness(Pencil tester). As a result of this study, the Photocatalytic Concrete used Photocatalytic powder, OPC admixture and other materials can obtain its properties, also photocatalytic efficiency. Last of all, we are convinced of the Photocatalytic Concrete possibility and make an effort to develop its properties added a various study.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.8
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• pp.770-777
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• 2004

Fouling and cleaning tests are performed for a uniquely designed 7,000 ㎉/hr fluidized bed heat exchanger for exhaust gas heat recovery. Fuel rich condition is maintained in the combustor for a limited time period to generate soot that is to be deposited on the heat transfer surfaces (fouling) and 600 Um glass beads are circulated inside the heat exchanger system for cleaning and enhancing the heat transfer performance. According to the present experimental study, performance degradation mode could be monitored and the effect of particle circulation on the heat transfer improvement could be identified. Through the present study, it is demonstrated that circulating particles contribute not only to the fouling reduction in gas side, but also to the heat transfer enhancement of the unit, while other possible aging factors including water side corrosion seemed to contribute to the accumulated performance deterioration.