• Proceedings of the Membrane Society of Korea Conference
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• 1996.06a
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• pp.121-147
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• 1996

Since 1980, the water quality of ultra-pure water has been rapidly improved, and presently ultra-pore water producing equipment for 64Mbit is in operation. Table 1 shows the degree of integration of DRM and required water quality exlmple. The requirements of the ultra-pure water for 64Mbit are resistivity: 18.2 MQ/cm or higher, number of particulates: 1 pc/ml or less (0.05 $\mu$m or larger). bacteria count: 0.1 pc/l or less. TOC (Total Organic Carbon, index of organic snbstance) : 1ppb or less, dissolved oxygen: 5ppb or less, silica: 0.5ppb or less, heavy metal ions: 5ppb or less. The effect of metals on the silicon wafer has been well known, and recently it has been reported that the existence of organic substance in ultra-pure water is closely related to the device defect, drawing attention. It is reported that if organic substance sticks to the natural oxidation film, the oxide film remaims on the organic substance attachment in the hydrofluoric acid treatment (removal of natural oxidation film). The organic substance forms film on the silicon wafer, and harmful elements such as metals and N.P.S., components contained in the organic substance and the bad effect due to the generatinn of silicon carbide cannot be forgotten. In order to remove various impurities in raw water, many technological develoments (membrane, ion exchange, TOC removal, piping material, microanalysis, etc.) have been made with ultra-pure water producing equipment and put to practical use. In this paper, technologies put to practical use in recent ultra-pure vater producing equimeut are introduced.

• Journal of the Semiconductor & Display Technology
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• v.9 no.1
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• pp.55-59
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• 2010

In this study, we developed nonvolatile residue (NVR) real-time monitoring system to measure the nonvolatile residue particle in ultra pure water (UPW). This device has a capability of measuring 4 different channels, i.e., 10 nm, 30 nm, 50 nm, and 100 nm. Until now, the light scattering method to detect RAE(residue after evaporation) was the only choice. However, this method can detect RAE larger than ca. 50 nm. In ultra pure water, RAE particles are usually very small and hard to detect with conventional laser scattering devices. To detect very small RAEs, a new system is developed and tested. The system consists of an atomizer that generates RAE particles and a four channel condensation particle counter (CPC). During the several months' operation in manufacturing line, the system was successfully tested and showed reliable results.

• Membrane Journal
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• v.6 no.3
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• pp.141-156
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• 1996

For ultra-pure water, the removal of various impirities is required, and the requirement level is rising year by year. To cope with this problem, various removing technologies and system technologies have been developed and the introduction of new materials for the piping, etc. to form the system have been positively made. For the element technologies to be used for ultra-pure water production, their range will be expanded from the technological and economic viewpoints. Therefore, it is absolutely necessary to develop trace analysis evaluation technologies for ultra-pure water. Especially to raise the analytical level of heavy metals and organic substances is important. It is also important to establish individual analysis methods of organic substances. It is expected that the analytical methods will be established and new treating methods will be put to practical use in the near future.

• International Journal of Quality Innovation
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• v.6 no.3
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• pp.173-189
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• 2005

A life-cycle assessment (LCA) is based on the attention given to the environmental protection and concerning the possible impact while producing, making, and consuming products. It includes all environmental concerns and the potential impact of a product's life cycle from raw material procurement, manufacturing, usage, and disposal (that is, from cradle to grave). This study assesses the environmental impact of the ultra pure water process of semiconductor manufacturing by a life-cycle assessment in order to point out the heavy environmental impact process for industry when attempting a balanced point between production and environmental protection. The main purpose of this research is studying the development and application of this technology by setting the ultra pure water of semiconductor manufacturing as a target. We evaluate the environmental impact of the Precoat filter process and the Cation/Anion (C/A) filter process of an ultra pure water manufacturing process. The difference is filter material used produces different water quality and waste material, and has a significant, different environmental influence. Finally, we calculate the cost by engineering economics so as to analyze deeply the minimized environmental impact and suitable process that can be accepted by industry. The structure of this study is mainly combined with a life-cycle assessment by implementing analysis software, using SimaPro as a tool. We clearly understand the environmental impact of ultra pure water of semiconductor used and provide a promotion alternative to the heavy environmental impact items by calculating the environmental impact during a life cycle. At the same time, we specify the cost of reducing the environmental impact by a life-cycle cost analysis.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.06a
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• pp.149-153
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• 1996

반도체 소자 제조 공정이 고 집적화 됨에 따라 습식 세정방법에 의한 세정공정의 중요성이 더욱 증가 되어지고 있으며, 특히 그 중에서 전체 세정공정의 약 절반을 차지하고 있는 Deionised water에 의한 rinsing 공정의 경우 ultrapure water의 quality가 최근 지속적으로 향상이 되어짐에 따라 많은 발전을 자져 왔다. 일반적으로 Deionised water에 함유하고 있는 TOC(total oxidisable components), bacteria, metallic impurity, desolved oxygen cencentration, colloidal material impurity (예를 들면 Silica, oraganic substrate)등은 ultra pure water의 quality를 결정하는데 매우 중요한 factor로 작용하고 있으며, 이러한 불순물들이 반도체 제조공정중 wafer surface에 흡착되어 졌을때 여러형태의 defect들을 유발한다고 알려져 있다. 그러나 pseudommonas, flavobacterlum, alcaligene등의 기 얄려진 bacteria들의 경우 Deionised water를 supply해주는 배관의 Inner surface에 잘 흡착 되지만 고온의 water 혹은 과산화수소수($H_{2}O_{2}$) 를 이용하여 주기적으로 처리 해줌으로 인하여 이에 대한 문제점을 어느정도 최소화 시킬수 있다. 위의 두가지 방법중 전자의 경우 chemical을 사용하지 않고, 유지 및 관리가 간편하며, 용존산소량을 줄일수 있다는 점에서 장점이 있으나, 전 ultra pure water의 system이 열적으로 안정해야 하고 경제적인 문제가 수반하는 단점을 가지고 있다. 후자의 경우, 미량의 과산화수소수 (1~10,000 ppm)를 이용해 처리 해주는 방법의 경우 경제적으로 큰 장점이 있고, 처리가 단순하다는 장점이 있으나 과산화수소수 자체에 포함하고 있는 높은 impurit level, 그리고 처리후 장시간의 flushing time을 가져야 한다는 단점등이 존재 하고 있다.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.237-249
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• 2013

Ultra-pure water (UPW), a highly treated water free of colloidal material and of a conductivity less than 0.06 ${\mu}S$, is an essential component required by modern industry. One of the methods for UPW production is the electrodialysis-ion exchange (ED/IE) system, in which the electrodialysis (ED) process is used as a preliminary demineralization step. The IE step can be replaced with electrodeionization (EDI) to decrease the volume of post-regeneration lyes. In this paper, the electrodialysis process carried out to relatively low diluate conductivity was investigated and the costs of UPW production were calculated. The optimal value of desalination degree by ED in the ED/IE and ED/EDI systems was estimated. UPW unit costs for integrated ED/IE and ED/EDI systems were compared to simple ion exchange and other methods for UPW production (RO-IE, RO-EDI). The minimal UPW unit costs in ED/EDI integrated system were estimated as $0.37/$m^3$ for feed TDS 600 mg/L and $0.36/$m^3$ for feed TDS 400 mg/L at 64 $m^3/h$ capacity, which was lower than in the comparable ED/IE integrated system ($0.42-0.44/$m^3$). The presented results suggest that an ED/EDI integrated system may be economically viable.

• 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.

• Journal of the Korean Professional Engineers Association
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• v.35 no.5
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• pp.58-61
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• 2002

• Korean Membrane Journal
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• v.2 no.1
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• pp.9-18
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• 2000

• Proceedings of the Membrane Society of Korea Conference
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• 1999.04a
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• pp.1-11
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• 1999