• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1880-1884
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• 2008

Cleaning is required following CMP (chemical mechanical planarization) to remove particles. The minimization of particle residue is required with each successive technology generation, and the cleaning of wafers becomes more complicated. In copper damascene process for interconnection structure, it utilizes 2-steop CMP consists of Cu CMP and barrier CMP. Such a 2-steps CMP process leaves a lot of abrasive particles on the wafer surface, cleaning is required to remove abrasive particles. In this study, the buffing is performed various conditions as a cleaning process. The buffing process combined mechanical cleaning by friction between a wafer and a buffing pad and chemical cleaning by buffing solution consists of tetramethyl ammonium hydroxide (TMAH)/benzotriazole(BTA).

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04b
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• pp.43-44
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• 1997

세척제는 금속 표면에 도포되어 있는 왁스, 그리스, 방청유 등의 윤활유 및 금속 가공 중에 사용한 절삭유, 연마유 등의 유지성 물질을 제거하는 탈지 효과와 표면에 묻어 있는 오물을 제거하는 목적으로 우수한 세정력을 지니고 있다. 세척제는 현장의 세척조의 상태가 가동 시간이 길어짐에 따라 유분이 과포화하게 되고 한정된 계면활성제량 때문에 미처 Micelle을 형성하지 못한 광유중 일부는 에멀젼 내 Oil Drop 형태로 존재하고 나머지는 에멀젼층 위에 부유하게 된다. 따라서 세척제의 세정력을 유지하기 위하여는 주기적으로 세척액중의 유분을 제거하여야 한다. 본 연구에서는 한외여과막을 이용하여 세척수 중 존재하는 Oil 성분을 제거함으로써 세척수의 수명을 극대화시키고자 한다. 또한 한외여과시 동반되는 농도 분극화 현상을 줄이고 투과특성을 향상시키기 위하여 압축질소로 주기적으로 역세척하며 최적운전 조건을 확인하는데 있다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1329-1334
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• 2001

This paper deals with the application of a sound-ray method to the analysis of the sound field in an ultrasonic cleaner. In order to include the wave interference phenomenon, the method has been modified to consider the phase of sound rays, The improved algorithm has been implemented by developing a Visual C＋＋ program, The algorithm has been verified by comparing the analysis results of BEM reported earlier. It has been shown that the algorithm can be used to calculate ultrasonic fields in a cleaning- container with an object to be cleaned.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.769-777
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• 2002

Using four components - nonionic surfactants, water, hydrocarbon oil and an alcohol as cosurfactant, 12 types of cleaning agents were prepared, and their physical properties such as surface tension, viscosity, electroconductivity and phase stability were measured. As the formulated cleaning agents have low surface tensions(30.5-31.1 dyne/cm) and low viscosities (1.6-7.2 c.p.), they are satisfied with the general physical properties of water-in-oil(W/O) microemulsions for their industrial use. They showed a tendency that their temperature range for stable one-phase microemulsion decreased in accordance with the increase of alcohol/surfactant(A/S) ratio in the formulations. However, the temperature range of one-phase microemulsion was much more affected by hydrophilic lipophillic balance(HLB) value of the nonionic surfactant which increased its temperature range and it increased in accordance with the higher HLB value in the formulations. And the maximum content of water which can keep stable one-phase W/O microemulsion was measured at each sample. In addition, their temperature range for stable one-phase microemulsion was also measured. It was confirmed that the selection of surfactant type was very important for formulating a cleaning agent, since the W/O microemulsion system with the nonionic surfactant of the lower HLB value showed better cleaning efficacy that of the higher HLB value for abietic acid as a soil, which was used for preparing a rosin-type flux. In the formulated cleaning agents with the increase of A/S ratio in the formulations, however, there was no significant difference in cleaning efficacy. It was investigated that the differences of their cleaning efficacy was affected by the change of the condition of temperature and sonicating frequency as important factors in the industrial cleaning. That is, the higher, their cleaning temperature and the lower, their sonicating frequency, the more increased, their cleaning efficacy. Furthermore, using optical instruments like UV/Visable Spectrophotometer and FT-IR Spectrometer, their cleaning efficacy for abietic acid was measured. The removal of soil from the contaminated rinse water was measured by gravity separation method in the rinse bath. As a result, the cleaning agent system having the nonionic surfactant of HLB value 6.4 showed over 85% water-oil separation efficacy at over $25^{\circ}C$. Therefore, it was demonstrated in this work that the formulating cleaning agents were very effective for cleaning and economical in the possible introduction of water recycling system.

• Journal of Soil and Groundwater Environment
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• v.8 no.3
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• pp.56-60
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• 2003

The optimal operation conditions of electrofloatation for oil-water separation of soil flushing effluent including electrolyte and pH were investigated. The reactor (200 ${\times}$ 10 ${\times}$ 15 cm) for the experiment was constructed by using acrylic plate. Diesel concentration was 1,000 mg/L in the 1 % mixed surfactant solution ($POE_5$: $POE_{14}$ 1: 1). Titanium coated electrode was used as cathode and stainless steel electrode as anode. Reaction time was 62 minutes (reaction time: 60 min., flotation time: 2 min.) and voltage was 6 V. The separation efficiency of electrofloatation was improved to 40% by electrolyte addition. Furthermore, NaCl (1N) added as electrolyte was showed enhanced efficiency compared to NaOH (1N). While, the effect of both NaCl and NaOH was sequentially increased in the range of 0.2∼1.0% (0.02∼0.1 M). The equilibrium time was found as 20 min. in the range of 0.4∼1.0% (0.04∼0.1M) for both of them.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.75-79
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• 2015

DIWS system was introduced to treat HCl gas from the scrubber of iron and steel industry according as the regulation of air quality is expected to be changed to 2ppm. pH of condensed water at stack was increased to 6.0. While 13.3ppm of inflow HCl was introduced to DIWS system, the average exhaust gas was 0.43ppm with 96.9% of removal efficiency. Compared with HCl data of TMS, the stable removal efficiency was shown in DIWS system, but the phenomenon of data hunting was also observed with different types of TMS apparatus.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1306-1311
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• 2009

In recent semiconductor manufacturing clean rooms, in order to improve clean room air quality, air washers are used to remove airborne gaseous contaminants such as $NH_3$, SOx and organic gases from the outdoor air introduced into clean room. Meanwhile, there is a large amount of exhaust air from a clean room. From an energy conservation point of view, heat recovery is therefore useful for reducing the outdoor air conditioning load for a clean room. Therefore it is desirable to recover heat from the exhaust air and use it to reheat the outdoor air. In the present study, numerical analysis and experiment was conducted to simulate the amount of energy reduction of exhaust air heat recovery type air washer system. The present numerical results showed good agreement with the results of the experimental data.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.905-909
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• 2003

This paper describes a shower type ultrasonic cleaning system using particle acceleration, developed for better effectiveness in washing out agricultural chemicals from fruits or vegetables, compared to the existing bath type ultrasonic cleaning system. The shower type system consists of a signal generator, a transducer, and a spouting nozzle, mainly. The system has been tested based on the method recommended by Korea Food and Drug Administration. It is found that shower type system shows better performance and cost-effectiveness than the bath type system that is commercially available .

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.2005-2010
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• 2004

Ultrasonic cleaning is performed by cavitation which is caused by the change of the sound pressure due to the vibration in a cleaning tank. In this study, experiments on electric power and sound pressure with various temperatures, dissolved oxygen and the level of the fluid was done in order to find out how the changes in a cleaning tank affect cavitation. As a result of a series of experiments, we found that transducer impedance changes periodically in response to the variances of fluid and have a direct influence on cleaning efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.2
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• pp.114-118
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• 2009

PVA (polyvinyl alcohol) brush cleaning method is a typical cleaning method for semiconductor cleaning process especially post-CMP cleaning. PVA brush contacts with the wafer surface and abrasive particle, generating the contact rotational torque of the brush, which is the removal mechanism. The brush rotational torque can overcome theoretically the adhesion force generated between the abrasive particle and wafer by zeta potential. However, after CMP (chemical mechanical polishing) process, many particles remained on the wafer because the brush was contaminated in previous post-CMP cleaning step. The abrasive particle on the brush redeposits to the wafer. The level of the brush contamination increased according to the cleaning run time. After cleaning the brush, the level of wafer contamination dramatically decreased. Therefore, the brush cleanliness effect on the cleaning performance and it is important for the brush to be maintained clearly.