• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.74-79
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• 2022

In this study, the plasma corrosion resistance and the change in the number of contamination particles generated using the plasma etching process and cleaning process of coating parts for semiconductor plasma etching equipment were investigated. As the coating method, atmospheric plasma spray (APS) was used, and the powder materials were Y₂O₃ and Y₃Al₅O₁₂ (YAG). There was a clear difference in the densities of the coatings due to the difference in solubility due to the melting point of the powdered material. As a plasma environment, a mixed gas of CF₄, O₂, and Ar was used, and the etching process was performed at 200 W for 60 min. After the plasma etching process, a fluorinated film was formed on the surface, and it was confirmed that the plasma resistance was lowered and contaminant particles were generated. We performed a surface cleaning process using piranha solution(H₂SO₄(3):H₂O₂(1)) to remove the defect-causing surface fluorinated film. APS-Y₂O₃ and APS-YAG coatings commonly increased the number of defects (pores, cracks) on the coating surface by plasma etching and cleaning processes. As a result, it was confirmed that the generation of contamination particles increased and the breakdown voltage decreased. In particular, in the case of APS-YAG under the same cleaning process conditions, some of the fluorinated film remained and surface defects increased, which accelerated the increase in the number of contamination particles after cleaning. These results suggest that contaminating particles and the breakdown voltage that causes defects in semiconductor devices can be controlled through the optimization of the APS coating process and cleaning process.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.11
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• pp.1193-1201
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• 2013

Improved far field type(improved type) megasonic applicable to the cleaning equipment of single wafer processing type has been developed. In this study, to improve the uniformity of acoustic pressure distribution(APD), we utilize far field with relatively uniform APD, piezoelectric ceramic with a triangle hole in its center to prevent standing wave resulted from radial mode, and reflected wave from the wall of waveguide. On the basis of these methods, two analysis models of improved type were designed to which piezoelectric ceramic of different shape of electrode attached, and APD were analyzed by means of finite element method, and then one of them was selected by analysis results, finally, the selected model was fabricated. Test results show that the fabricated is better in the uniformity of APD than the imported and the conventional, also the fabricated shows high particle removal efficiency of 92.3% using DI water alone as a cleaning solution.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.747-750
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• 2007

This study proposes that chlorine residue after metal etch as the source of metal corrosion, and charges should be removed by optimizing etch, PR strip and cleaning condition. Charges distributed along the metal line acts as a source of tungsten (W) plug corrosion when associated with following cleaning solution. In cleaning process after metal etch and PR strip, chemical selection is significantly important in terms of metal corrosion. Optimal corrosion preventive PH, no metal attack (choice of optimal inhibitants), high by product removal efficiency and optimal de ionized water treatment condition is critical to the metal corrosion prevention.

• Journal of Construction Engineering and Project Management
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• v.5 no.2
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• pp.44-52
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• 2015

Various approaches have been used in crack preparations and each of the approaches has advantages and disadvantages. Although the routing method has been widely used and seems to be the best approach among the approaches, it is not a complete solution for crack preparation. This paper compares and evaluates a pneumatic crack cleaning device (CCD) developed by Robotics and Intelligent Construction Automation group at Georgia Tech, over existing devices. Surveys were conducted to discover factors that affect the performance of crack/joint preparation work. Then, data for such information were collected via field tests for devices such as router, heat lancer, air blower and CCD. Performed field test results and follow-up interviews demonstrated that the utilization of CCD has potential to offer improvements in productivity, safety, and maintenance cost. An analytic hierarchical procedure (AHP) and economic analyses were conducted. The AHP analysis considered three factors including safety, quality and productivity while the economic analyses examined the alternatives in various ways. The results indicated that the CCD was ranked first and second for the AHP analysis and economic analysis, respectively. In conclusion, the field tests and results revealed that the utilization of CCD achieved satisfactorily in performance, quality, safety and control, and showed that it has high potential in crack cleaning practice.

• Journal of the Semiconductor & Display Technology
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• v.4 no.4 s.13
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• pp.13-17
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• 2005

The behavior of ozone in $NH_4OH$ was investigated to evaluate the solution as a cleaning chemical of the silicon wafer. The solubility of ozone in DI(Deionized) water increased as the oxygen flow-rate decreased and ozone generator power increased. Ozone in DI water showed solubility of 100 ppm or higher at room temperature. Ozone concentration was stabilized at the range of ${\pm}2ppm$ by controlling oxygen flow rate and ozone generator power. On the contrary, the solubility of ozone in $NH_4OH$ was very low and strongly depended on the concentration of $NH_4OH$ and pH. The redox potential of ozone was saturated within 10 minutes in DI water and decreased rapidly with the addition of $NH_4OH$. The behavior of ozone in $NH_4OH$ is well explained by redox potential calculation.

• Journal of Integrative Natural Science
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• v.4 no.4
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• pp.311-314
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• 2011

Application of self-assembled monolayers (SAMs) to the fabrication of organic thin film transistor has been recently reported very often since it can help to provide ohmic contact between films as well as to form simple and effective electrode pattern. Accordingly, quality of these ultra-thin films is becoming more imperative. In this study, in order to manufacture a high quality SAM pattern, a hydrophobic alkylsilane monolayer and a hydrophilic aminosilane monolayer were selectively coated on $SiO_2$ surface through the consecutive procedures of a micro-contact printing (${\mu}CP$) and dip-coating methods under extremely dry condition. On a SAM pattern cleaned with SC1 solution immediately after ${\mu}CP$, poly(3,4-ethylenedioxythiophene) (PEDOT) source and drain electrode array were very selectively and nicely vapour phase polymerized. On the other side, on a SC1-untreated SAM pattern, PEDOT array was very poorly polymerized. It strongly suggests that the SC1 cleaning process effectively removes unwanted contaminants on SAM pattern, thereby resulting in very selective growth of PEDOT electrode pattern.

• Corrosion Science and Technology
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• v.8 no.6
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• pp.209-216
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• 2009

In this study the effect of different surface finishing techniques on the pitting corrosion behaviour of a commercial 304 stainless steel alloy was investigated. Surface finishing methods were divided into two categories, i.e. mechanical and chemical. Mechanical treatment methods include power tooling such as grinding, emery paper brushing, stainless steel wire brushing and stainless steel shot blasting. Chemical treatment methods include chemical passivation (phosphoric acid, citric acid, nitric acid) and electro-cleaning (phosphoric acid and citric acid). Potentiodynamic polarization experiments were carried out in 3.5 wt. % NaCl solution at room temp. (20 $^{\circ}C$). The results showed that chemical treatment methods improved the corrosion resistance of stainless steel 304, measured in terms of pitting potential ($E_{pit}$). Corrosion resistance of the specimens was increased in the order of; electro-cleaning > manual passivation > mechanical cleaning. Surface of electro-cleaned specimens was smoother than rest of the surface treatment methods. Chrome content in chemically treated specimens was higher than in mechanically treated specimens as shown by EDX analysis.

• Journal of the Korean Society of Costume
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• v.57 no.9
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• pp.67-75
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• 2007

The purpose of this research is to conserve of golden decoration(Jikgeumdan) of Chima(skirt) and Jeogori(Korean jacket) of the costumes excavated from Hangju Gi' tomb(17th Century) of Joseon dynasty$(1392{\sim}1910)$ and to focus on the development of conservation skill to prevent flakings of gold leaves in gilt paper strips. Up to the present, in case of golden decorations of costumes excavated from tombs of Joseon dynasty, some of gold leaves in gilt paper strips of costumes were flaked away by deterioration of adhesives in tombs. However, most of gold leaves were flaked away and totally lost by wet cleaning for eliminating contaminants after excavation. In order to prevent flaking, preliminary experiments for re-adhesion of gold leaves have been carried out. Firstly, simulation was performed using gold leaf which was available in the market. Adhesives used in this research were water-soluble adhesives(hide glue(cow, rabbit), glue made from air bladders of sciaenoid fish and Primal AC-3444 of acrylic emulsion) and solvent-soluble adhesives(acrylic adhesive Paraloid B-67 and B-72). Because of difficulty in wetting and spreading of adhesive solutions into the interface between gold leaf and Korean paper, water-soluble adhesives were not proper for adhesion of gold leaf and Korean paper. Solvent-soluble adhesives were easily infiltrated into interface between gold leaf and Korean paper and the adhesive force was also satisfied. From this result, the researchers chose more flexible Paraloid B-72$(Tg\;40^{\circ}C)$ 1% solution than Paraloid B-67$(Tg\;50^{\circ}C)$ for adhesion of gold leaf and Korean paper. Secondly, using Paraloid B-72 1% solution, the estimations of re-adhesions of gold leaves in gilt paper strips of Jeogori were carried out. When Paraloid B-72 1% solution was injected three times into the interface between gold leaf and Korean paper, the re-adhesion was most effective. On the basis of the results in these preliminary experiments, re-adhesions of gold leaves in gilt paper strips of Chima and Jeogori were carried out on condition of three times injections of Paraloid B-72 1% solution before wet cleaning. After wet cleaning, the most of the gold leaves were survived, which was confirmed by both the examination with the naked eye and the microscopic examination.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2335-2337
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• 2001

In this paper, we address a new complete coverage navigation algorithm and guidance methodology for the cleaning robot. The proposed algorithm is based on the grid map. Six templates, excluding a Back-Trace(BT) template are used as the local navigation method. The effectiveness of the algorithm proposed in this paper is thoroughly demonstrated through simulations and the evaluation of parameters for the path execution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.617-620
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• 1999

To reduce the consumption of chemicals and ultra pure water(UPW) in cleaning process used in device manufacturing, we proposed wet processes that use electrolytic ionized water(EIW), which is generated by electrolysis of a diluted electrolyte solution or UPW and systemically investicate the EIW\`s characteristics. EIW\`s pH values are increased in cathode chamber and decreased in anode chamber according to the electrolysis time and its varied ratio is reduced with time increasement. The variation of pH and ORP is increased accordin to the applied voltage until critical voltage. But more than that voltage, the variation is decreased because of ion\`s scattering effect. When electrolyte is added, the effects of electrolysis is increased because electrolyte acts as catalyst. But when the density of electrolyte is increased more than critical value, ion\`s flowage is obstructed and the effects of electrolysis is decreased.