• Journal of the Korean Vacuum Society
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• v.18 no.2
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• pp.97-101
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• 2009

In the modem semiconductor industry, the progress that consumes the most capital and labor is cleansing process. Cleansing process is to remove impurities that can affect the operation of the device and deteriorate its function. Especially, Photoresist (PR) progress that etches the device always requires cleansing at the end of the progress. Also, HDI-PR (High-Dose Ion-implanted Photoresist) created from PR progress is difficult to remove. Thus, in modem IC cleansing, many steps of cleansing are used, including dry and wet cleansing. In this paper, we suggested to combine existing dry-cleansing and wet-cleansing, each represented by plasma cleansing and stripper solution, as Plasma Liquid-Vapor Activation (PLVA). This PLVA method enhances the effect of existing cleansing solution, and decreases the amount of solution and time required to strip. We stripped HDI-PR by activated solution and measured surface hardness and Young's modulus by Nano-indenter. Nano-indenter is the equipment that determines the hardness and the modulus of elasticity by indenting nano-sized tip with specific shape into the surface and measuring weight and z-axis displacement. We measured the change of surface hardness and Young's modulus before and after the cleansing. As a result, we found out that the surface hardness of the sample sharply decreased after the cleansing by plasma-activated PR stripper solution. It can be considered that if physical surface-cleansing process is inserted after this, more effective elimination of HDI-PR is possible.

• Clean Technology
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• v.11 no.3
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• pp.129-139
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• 2005

Fluoride-type cleaning agents such as TFEA (2,2,2-trifluoroethanol) and HFE (hydrofluoroether) are noticed to be next generation cleaning agents alternative to CFCs since they do not destruct ozones in the stratosphere due to no containment of chloride in the molecule, have lower global warming potential compared to HFCs and HCFCs, and are thermally stable compounds. Thus, the physical properties and cleaning agents were measured and compared with those of CFC-113, 1,1,1-TCE and HCFC-141b which are ozone destruction substances. They were also compared and evaluated with those of IPA and methanol which are currently employing as alternative cleaning agents. And TFEA-based cleaning agents consisted of TFEA and alcohols or HFEs were formulated, their physical properties and cleaning abilities were measured and their utilization as alternative cleaning agents was evaluated. As a result, TFEA and HFEs have lower cleaning ability for their removal of various soils compared to chloride-type cleaning agents, but theyshow excellent cleaning ability for Fluoride-type soils. And it is observed that the formulated cleaning agents of TFEA and alcohols or HFEs caused to increase cleaning ability of flux and unsoluble cutting oil more than 100% compared to their individual component. Therefore, the fluoride-type cleaning agents are expected to be utilized for development of environmental-friendly non aqueous cleaning agents with excellent cleaning ability if they are formulated with proper solvents or additives.

• Resources Recycling
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• v.29 no.6
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• pp.57-64
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• 2020

In this study, removal of OCA and organic impurities for recycling LCD touch panel glass was conducted by mechanical and chemical dissolution methode. Cut mill and oscillation mill were used for mechanical crushing of touch panel, and water, ethanol, dichloromethane were used to remove OCA and organic impurities. As a result of TGA, when applied only dicloromethane in the process, the efficiency of organic removal was to be best. In addition, removal effect of organic impurities increased as the cleaning temperature increased. As a result of zeta potential analysis to confirm the dispersion degree of touch panel glass in the solvent, the absolute value of the zeta potenial of water with the lowest cleaning effect was lower than other solvents, and it was confirmed that efficiency of organic removal is affected not only by the chemical dissolution properties but also the physical dispersion properties in the solvent.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.981-987
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• 2011

Biologically treated water contains a large quantity of organic matters and microorganisms which can cause various problems to membrane. The membrane fouling occurred by these reasons is hard to control by single physical cleaning. This study analyzes the efficiency of aeration with chemical backwashing and foulants removal during chemical backwashing. The cleaning efficiency improves when the chemical concentration is high and the contact time of chemical is long. Chemical backwashing with aeration shows exceptional cleaning efficiency which leads the physical cleaning is required during chemical backwashing since it forms flow inside the membrane submerged tank. From the foulants removal analysis, the particles such as turbidity and TOC removal rate increase when the aeration is applied. Dissolved matter of DOC and UV254 removal is dependent on higher chemical concentration. According to FTIR analysis, one of major foulants, the polysaccharide is controlled by the chemical backwashing with aeration condition.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.605-612
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• 2016

Membrane bioreactors (MBRs) employ a process of biological treatment that is based on a membrane that has the advantages of producing high-quality treated water and possessing a compact footprint. However, despite these advantages, the occurrence of "fouling" during the operation of these reactors causes the difficulty of maintenance. Hence, in this study, three physical cleaning methods, namely, backwashing, air scrubbing, and mechanical cleaning ball was performed to identify optimum operating conditions through laboratory scale experiments, and apply them in a pilot plant. Further, the existing MBR process was compared with these methods, and the field applicability of a combination of these physical cleaning methods was investigated. Consequently, MCB, direct control of cake fouling on the membrane surface was found to be the most effective. Moreover, as a result of operating with combination of the physical cleaning process in a pilot plant, the TMP increasing rate was found to be - 0.00007 MPa/day, which was 185% higher than that obtained using the existing MBR process. Therefore, assuming fouling only by cake filtration, about one year of operation without chemical cleaning is considered to be feasible through the optimization of the physical cleaning methods.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.451-456
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• 1994

Alkyl polyglucosides (APG), so called natural nonionic surfactants, are prepared with glucose from corn starch and fatty alcohol from palm and/or coconut oil. When we studied on interfacial properties of APG, surface and interfacial tension, cmc, foaming and effectiveness, according to degree of polymerization of glucose unit (D.P.=1.2~1.8) and alkyl chain length, the former hardly affects but the latter greatly affects on them. The order of detergency for fatty acid soils decreased as followings ; APG 0814> APG 1214> APG 10> APG 0810> APG 08, and the samples with lowest interfacial tension and maximum adsorption had a better detergency.

• Journal of Korean Physical Therapy Science
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• v.26 no.2
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• pp.46-50
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• 2019

Background: The purpose of present study is to effect of arm swing on uphill road gait in healthy adults. Design: Cross-sectional study. Methods: This study was Participated in 15 healthy subjects. The subjects were allowed to walk uphill, about 10m from the line drawn on the floor. The subject stood at the starting line and started by pressing the start button with the signal "start", and I pressed Stop at the last incoming point. Walking with and without arm swing was measured twice in random draws. Results: Walking path with arm swing showed good results in walking path duration, cadence, speed, stride length, and Gait cycle duration rather than uphill walk without arm swing. Conclusion: As a results of this study, The arm swing is important in getting uphill.

• Korean Journal of Materials Research
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• v.8 no.9
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• pp.837-842
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• 1998

As the size of the integrated circuit is scaled down the importance of Si cleaning has been emphasized. One of the major concerns is abut the removal of metallic impurities such as Cu and Fe on Si surface. In this study, we intentionally contaminated Cu and Fe on the Si wafers and cleaned the wafer by cleaning splits of the chemical mixture of $\textrm{H}_2\textrm{O}_2$ and HF and the combination of HF treatment with UV/$\textrm{O}_3$ treatment. The contamination level was monitored by TXRF. Surface microroughness of the Si wafers was measured by AFM. The Si wafer surface was examined by SEM. AES analysis was carried out to analyze the chemical composition of Cu impurities. The amount of Cu impurities after intentional contamination was abut the level of $\textrm{10}^{14}$ atoms/$\textrm{cm}^2$. The amount of Cu was decreased down to the level of $\textrm{10}^{10}$ atoms/$\textrm{cm}^2$ by cleaning splits. The repeated treatment exhibited better Cu removal efficiency. The surface roughness caused by contamination and removal of Cu was improved by repeated treatment of the cleaning splits. Cu were adsorbed on Si surface not in a thin film type but in a particle type and its diameter was abut 100-400${\AA}$ and its height was 30-100${\AA}$. Cu was contaminated on Si surface by chemical adsorption. In the case of Fe the contamination level was $\textrm{10}^{13}$ atoms/$\textrm{cm}^2$ and showed similar results of above Cu cleaning. Fe was contaminated on Si surface by physical adsorption and as a particle type.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.04a
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• pp.46-47
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• 1996

막분리 공정의 공업적인 이용을 위해서는 막을 특정 용기에 적재한 모듈의 형태가 요구되는데 모듈의 형태에 따라 평판형(plate and frame), 나권형(spiral wound), 관형(tubular), 중공사형(hollow fiber)모듈 등이 있다. 이 중에서 관형 시스템은 내경이 12.5~25 mm, 길이 0.6~6.4 m에 이르는 비교적 큰 open channel로 되어 있으며 공급액 유로가 일반적으로 커서 전처리를 행하지 않고도 fouling이 적으며, 또한 막 표면의 세정이 약품에 의한 것 이외에 스폰지 볼 등에 의한 물리적 세정도 가능하므로 응용 범위가 넓다는 것이 특징이다. 한외여과 공정의 가장 큰 문제점은 농도분극 및 fouling 현상에 의한 플럭스 감소이다. 농도분극 현상은 경계층에서 용질의 대류,확산적인 전달에 기인하여 막 표면으로 갈수록 진해지는 용액층의 형성을 의미한다. 이 현상은 가역적인 과정으로서 감압함으로 원상태로 회복이 가능하며 조작 압력에서 정상상태가 되면 막투과 플럭스는 일정한 값을 유지한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.712-712
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• 2012

하 폐수 처리방류수를 물리적, 화학적 그리고 생물학적 기술을 이용하여 처리한 후 재활용수로 이용하고자 하는 새로운 노력들이 진행되고 있지만 국내의 경우 방류수 재활용 기술과 처리수의 재이용에 대한 평가기술이 선진국에 비해 초기 단계에 있어 이 분야에 대한 적극적인 기술개발이 요구된다. 막 분리 기술을 이용한 처리 수는 소독 등의 추가적인 처리 없이 살수용수나 수경용수로 이용이 가능하며, 잔류염소를 유지시킬 경우 화장실 세정용수로의 이용도 가능하며, 또한 후처리 기술을 조합하면 고급 공업용수 등으로 사용가능하므로 선진기술로서 수요조건에 맞게 전 후 처리를 조합한 수요자 맞춤형 재이용수 공정기술을 개발할 필요가 있다. 이에 효율적인 하 폐수 재이용을 이용하여 농업용수(축산 음용수, 첨단 수출원예용수, 첨단 농업용수, 농산업 클러스터 복합 곡물 용수), 원예용수(원예단지), 공업용수 등의 다양한 용도에 활용 가능한 수요자 맞춤형 모듈 및 공정 개발을 수행하였다. 개발된 공정은 AOP 및 막 세정 시스템을 이용한 새로운 공정으로, AOP 시스템은 전기 이온 모듈을 통해 OH 라디칼을 생성 및 염분 제거 효율을 극대화 하여 오염 물질을 산화시키는 공정이며, FDA 시스템은 탁도가 높은 원수가 과다 유입 될 경우 후단 여과 막의 부하를 줄이는 역할을 하며, 부유 물질을 여과 시킨다. 막 세정 시스템은 미세 입자를 구성된 기포를 이용하여 눈에 보이지 않는 곳 까지 세척하며, 살균 작용을 하며, 분리 막의 성능을 증대 시킨다. 이어 UF 분리 막 시스템은 원수의 미세불순물, 박테리아, 스케일 물질 등을 제거하며, NF 시스템을 통하여 미립자, 박테리아 유기 화합물 및 2가 염 제거를 하여 재이용수를 생산하는 공정을 개발하였다. 개발된 수요자 맞춤형 공정은 하수 재이용 기술의 이용 목적 및 수요자별로 맞춤형으로 운영이 가능하며, 개발된 세척 기술은 분리 막 세정 유지관리비 및 에너지를 저감 할 수 있으며, 현장 적용의 실증화 과정을 거쳐 공정 기술을 신뢰도를 향상하고, 보유 기술을 수요자 맞춤형으로 업그레이드함으로써 기술의 경쟁력 및 고품질의 하수 재이용 기술의 새로운 방향을 제시 할 수 있을 것으로 판단된다.