• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1309-1312
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• 2005

A multi-chemical supply system is developed and applied to a wet station, which uses the multi-chemical process in one bath. To control the concentration of two chemicals, control logic of a supply pump is programmed using the programable logic controller (PLC). By using the multi-chemical supply system, wet station with single bath is applied to cleaning process using multi chemicals such as buffed oxide etchant (BOE) and standard clean 1 (SC-1). The concentration of each chemical is measured in the bath to verify the multi-chemical supply system. The control range in the each chemical concentration is measured to 1.33weight% in NH4OH and 0.23weight% in H2O2. The multi-chemical supply system can be movable and usable as an independent module of fixed wet station. By simply midifying the PLC, a multi-chemical supply system can be developed for a wet station.

• Journal of the Semiconductor & Display Technology
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• v.4 no.3 s.12
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• pp.29-33
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• 2005

As the integrated devices become more and more sophistcated, the diameter of wafers increased up to 300 mm and strict level of cleaning is necessary to remove the particulates on the surface of wafer. Therefore we need a new type of wet-station which can reduce DI water and chemical in the cleaning process. Moreover, it is important to control the temperature and the concentration of chemical in the wet-station. In the conventional chemical supply system, it is difficult not only to fit the mixing rate of chemicals in cleaning process, but also to fit the quantity and temperature. Thus, we propose a new chemicals supply system, which overcomes above problems by the analysis of fluid and thermal transfer on chemical supply system.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.05a
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• pp.157-162
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• 2005

The wafer's size has been increased up to 300mm according as the devices have been integrated sophisticatedly. For this process to make 300mm-wafer, it is required strict level which removes the particulates on the surface of wafer. Therefore we need new type wet-station which can reduce DI water and chemical in the cleaning process. Moreover, it is very important to control the temperature and the concentration of chemical wet-stat ion. The chemical supply system which is used currently is not only difficult to make a fit mixing rate of chemical in cleaning process, but also it is difficult to make fit quantity and temperature. We propose new chemical supply system, which overcomes the problems via analysis of fluid and thermal transfer on chemical supply system,

• Korean Journal of Heritage: History & Science
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• v.46 no.1
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• pp.228-237
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• 2013

Paper relics are affected by a number of complex physical, chemical, biological and artificial damaging factors due to the vulnerability of organic materials. Wet cleaning is a conservation treatment method for removing pollutants from paper artefacts. This study was carried out in order to analyse the effect of wet cleaning on Hanji (Traditional Korean paper made from mulberry trees) which is the main material used in Korean paper relics (historical paper documents). For this study, the color change and folding endurance of artificially degraded paper was analysed before and after immersion wet cleaning. The result showed that washing each twice in 30 minutes is the most appropriate method for obtaining cleaning efficiency and material stability.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.11
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• pp.99-104
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• 1993

We analyzed the D.I. water used in wet cleaning process of semiconductor device manufacturing both at the D.I. water plant and at the wafer cleaning bath to detect the impurity source of D.I. water contamination. This shows that the quantity of impurity is related to the resistivity of D.I. water, and we found that the cleanliness of the wafer surface processed in D.I. water bath was affected by the degree of the ionic impurity contamination. So we evaluated the cleaning effect as different method for Fe ion, having the best adsoptivity on wafer surface. Moreover the temperature effect of the D.I. water is investigated in case of anion in order to remove the chemical residue after wet process. In addition to the control of D.I. water resistivity, chemical analysis of impurity control in D.I. water should be included and a suitable cleaning an drinsing method needs to be investigated for a high yielding semiconductor device.

• Bulletin of the Korean Chemical Society
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• v.18 no.7
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• pp.737-740
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• 1997

The influence of cyclic treatments with H2O2/DIW (1 : 10) and HF/DIW (1 : 100) on the roughness of silicon surface in the wet chemical processing was investigated by atomic force microscopy (AFM). During the step of the SC-1 cleaning, there is a large increase in roughness on the silicon surface which will result in the poor gate oxide breakdown properties. The roughness of the silicon wafer after the SC-1 cleaning step was reduced by cyclic treatments of hydrogen peroxide solution and hydrofluoric acid solution instead of HF-only cleaning. AFM images after each step clearly illustrated that the average roughness of silicon surface after three times treatments with H2O2 and HF solutions was reduced by 10 times compared with that after the SC-1 cleaning step.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.149-152
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• 2004

Generally the wafer is increased by 300mm. We are desired that the wafer is prevented from pollutions of metal contaminant on surface of wafer. We have to develop new wafer cleaning process of IC Manufacturing that can reduce DI water and chemical by removal of the wafer cleaning process step. Moreover, it is difficult to control temprature and density of chemical in spite of rapidly increasing automation of system. We design smart module controller for new generation of semiconductor wet station with intelligent algorithm using data that is taken by computer simulation for optimal system.

• Tribology and Lubricants
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• v.31 no.6
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• pp.239-244
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• 2015

Chemical mechanical polishing (CMP) is one of the most important processes for enabling sub-14 nm semiconductor manufacturing. Moreover, post-CMP defect control is a key process parameter for the purpose of yield enhancement and device reliability. Due to the complexity of device with sub-14 nm node structure, CMP-induced defects need to be fixed in the CMP in-situ cleaning module instead of during post ex-situ wet cleaning. Therefore, post-CMP in-situ cleaning optimization and cleaning efficiency improvement play a pivotal role in post-CMP defect control. CMP in-situ cleaning module normally consists of megasonic and brush scrubber processes. And there has been an increasing effort for the optimization of cleaning chemistry and brush scrubber cleaning in the CMP cleaning module. Although there have been many studies conducted on improving particle removal efficiency by brush cleaning, these studies do not consider the effects of brush contamination. Depending on the process condition and brush condition, brush cross contamination effects significantly influence post-CMP cleaning defects. This study investigates brush cross contamination effects in the CMP in-situ cleaning module by conducting experiments using 300mm tetraethyl orthosilicate (TEOS) blanket wafers. This study also explores brush pre-treatment in the CMP tool and proposes recipe effects, and critical process parameters for optimized CMP in-situ cleaning process through experimental results.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.2
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• pp.181-191
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• 2011

This study examines the effects of Evening primrose on colors, color fastness, and the antimicrobial activity of dyed fabrics. The results are as follows. The dyeing conditions of Evening primrose on cotton and mercerized cotton were optimized at $50^{\circ}C$, 60 minutes, and 200% (o.w.f.). In addition, Evening primrose dyeing on silk was determined at $90^{\circ}C$, 60 minutes and 200% (o.w.f.). The pre-mordant concentration of chemicals of cotton, mercerized cotton and silk was optimized at 1% (o.w.f.). The post-mordant concentration on mercerized cotton, silk and cotton was determined at 1% (o.w.f.) and 3% (o.w.f.), respectively. The mordant methods (such as pre-mordant and post-mordant) were slightly affected on the hue of dye-fabrics. Wet cleaning fastness of cotton was improved by post-mordant; otherwise, the wet cleaning fastness of mercerized cotton and silk was improved by a pre-mordant. The dry cleaning fastness of cotton and silk was excellent regardless of mordant methods. The dry cleaning fastness of mercerized cotton was improved by a post-mordant compared to a pre-mordant. The antimicrobial activity of Evening primrose-dyed fabrics was shown at 99.9%. The excellent antimicrobial activity of dyed fabrics remained after the mordant as well as wet and dry cleaning.

• Journal of Industrial Technology
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• v.15
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• pp.175-185
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• 1995

Under the new environmental regulations announced by the government, utilities will have to cut their sulfur dioxide emissions by 60% from 1991 levels by the year of 1999. Sulfur dioxide emissions can be reduced prior to combustion by physical, chemical or biological coal cleaning. The new technology of high gradient magnetic separation (HGMS) offers the potential of economic separatoins of a variety of fine, weakly magnetic minerals including inorganic sulfur and many ash-forming minerals from coals. In the present paper, magnetic separation tests have been conducted on Korean anthracite and high-sulfur Chinese coal to investigate the feasibility of these techniques for reducing sulfur content from coals. In wet magnetic separation, the studied operating parameters include particle size, pH, matrix types, feed solids content, feed rate, number of cleaning stages and etc. The results shows that for wet separation, 60~70% of total sulfur was removed from coals with over 80% combustible recovery, on the other hand, for dry separation, 47.6% of total sulfur was removed from coals with 75% recovery.