• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.185-188
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• 2001

Chemical mechanical polishing(CMP) process is widely used for global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP Process, deionized water (DIW) pressure, purified $N_2$ (P$N_2$) gas, slurry filter and high spray bar were installed. Our experimental results show that DIW pressure and P$N_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter. Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.199-205
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• 2015

This study is about ionic water generator filter Recently, a lot of people feel deep interest in health and drinking water. And there are various types of water. Ionic water generator is a system with special function, and can be classified as a medical device and should be manufactured after approval from the Food and Drug Administration. Basically ionized water is different from the packaged and stored water. When the tap water or ground water passes through the various filters of ionic water generator, it turns to the purified water of pH7 ~ 7.5 and we can electrolyze that water into anion and cation by diaphragm. And in negative electrode side, we can get alkaline water with calcium ($Ca^+$), potassium ($K^+$), magnesium ($Mg^+$), sodium ($Na^+$) for body. In general, we can change pH value from 5 to 9 of ionizer by controlling the level of electrolysis voltage in the ionizer. In general, 1stage (pH8), 2stage (pH8.5), 3stage (pH9), 4stage (pH9.5) are used as the alkaline ionized water, -1Stage (pH6.0), -2 stage (pH5.0) are used as the acidic water. But in early stage, the water that passed through filter was weakly alkaline water and that was problem. Therefore, when filter condition is stable, the pH and ORP value of water is different with the early one. the initial setting pH value of the ionizer was confirmed that changes significantly. In order to resolve this problem we need to wash filter for some period time and neutralize by acidification treatment of the filter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.185-188
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• 2001

Chemical mechanical polishing(CMP) process is widely used for global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP process, deionized water (DIW) pressure, purified $N_2 \; (PN_2)$ gas, slurry filter and high spray bar were installed. Our experimental results show that DIW pressure and $PN_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter. Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.332-336
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• 2014

A non-electric water purification system using the Korean traditional ceramic ware Onggi, was demonstrated as an appropriate technology to solve water shortages in under developed regions. Generally, Onggi is produced using large size raw materials that are sintered at low temperature, resulting in a porous body that shows air and water permeability. An Onggi filter was prepared using a spinning wheel with the addition of rice bran to the body to increase porosity. The porosity of the obtained Onggi filter was 25.1%; the water permeability was 85.1 $L/m^2h$. Turbidity and TDS of the purified water using Onggi filter were decreased by 97.7% and 29.1%, respectively.

• Journal of environmental and Sanitary engineering
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• v.23 no.2
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• pp.55-63
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• 2008

All over the world, the existing process of water purification needs more flocculants and chlorine due to a gradual decline in the quality of source water. Therefore, the problem of the remaining aluminium and DBPs in purified water is on the rise. To solve this problem, the process of membrane filter has recently come into the spotight. This study reaches the following conclusions concerning TMP variation in order to solve the dropping of flux throgh a membrane filter when operating a membrane filter system in the process of water purification. 1. In case that a cohesion-precipitation process was introduced to pre-treatment of a membrane filter, initial TMP was very satisfactory(0.27kg/cm) in producing the constantly safe quality of water, $0.04{\sim}0.1$(mean 0.05) NTU by pouring 2mg/l of PACI(10% $Al_2O_3$) used for the existing process of water purification in high-density turbidity at a dry or flood season and at occurrence of high algae. 2. As flux increased at 0.5m/day.m, TMP increased 0.05 kgf/cm. 3. As filtering, operation mode of PVDF MF membrane filtering was 48 minutes and 1 cycle of back washing was 42 minutes, flux was increased 1.5m/day.m and TMP increased $0.25{\sim}0.27kgf/cm$. Without back washing, TMP increased 0.03 kgf/cm per a cycle.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.5
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• pp.191-195
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• 2002

Chemical mechanical Polishing (CMP) process is widely used for the global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP process, deionized water (DIW) pressure, purified $N_2$ ($PN_2$) gas, point of use (POU) slurry filler and high spray bar (HSB) were installed. Our experimental results show that DW pressure and P$N_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• Journal of Animal Environmental Science
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• v.1 no.1
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• pp.77-82
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• 1995

In order to investigate the purification effects of livestock waste water, Modified Activated-Sludge Process(MASP) containing marine silica and volcanic ash-rock as the contact media and Sawdust-Soil Filter Method were used. The results obtained are as follows: 1. MASP which treated two metric tons' livestock waste water a day decreased BOD by 97.5% from 4,400.0mg/I to 108.8mg/I and SS by 98.0% from 5,335.0mg/I to 111.0mg/I. 2. MASP decreased BOD by 93.9% from 2,549.1mg/I to 156.6mg/I and SS by 96.3% from 3,521.9mg/I to 132.0mg/I when ten metric ton's livestock waste water was treated a day. 3. BOD and SS were decreased by 83.4% from 45.1mg/I to 7.5mg/I and by 83.4% from 47.5mg/I to 7.9mg/I when the supernatant layer treated by MASP was purified by Sawdust-Soil Filter Method.

• Membrane Journal
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• v.25 no.6
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• pp.503-514
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• 2015

In this study, water purification system without coagulant was consisted of F/A and membrane to produce purified water which only uses physical treatment without coagulant. Because the use of coagulant has a possibility remaining of hazardous aluminum with our health. Especially, the Filtralite was reviewed the possibility to remove turbidity and organic material. It was found that the turbidity removal rate of Filtralite was 83~84%. It show that Filtralite has similar efficiency to sand-filter. But Filtralite has higher 50% removal rate of organic material than sand-filter due to well-developed pore on the surface of it. So, Filtralite could be used to substitute the sand-filter for the F/A process due to higher removal rate. And also coupled with activated carbon in F/A process, TMP was increased by TOC value. To prevent increasing TMP, media that has outstanding organic adsorption ability should be used.

• Journal of Environmental Science International
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• v.15 no.1
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• pp.21-31
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• 2006

Aquatic plants grow in water with photosynthesis and purify water quality as taking organic and inorganic matter in water. Polluted water in stagnant stream channel where nutritive salts load is great can be purified by activities of aquatic plants. Aquatic plants should be fixed to bed easily to plant and sustainable environment is needed. So in this study, Mattress/Filter system is suggested to plant aquatic plant in stagnant stream channel. In the result of study, coverage of Phragmites australis, Zizania latifolia and Typha angustifolia which planted in mattress was $78\%,\;62\%\;and\;82\%$ and numbers of species in each mattress system were 7, 11, 3. The evenness index of each mattress system was 0.86, 0.91 and 0.79 and diversity index of each mattress system was 1.67. 2.18 and 0.87. Removal rates of phosphorus at Phragmites australis, Zizania latifolia and Typha angustifolia which planted in mattress were $68.7\%,\;62.7\%,\;55.3\%$ and removal rates of nitrogen of them were $79.8\%,\;74.7\%,\;64.9\%$. The removal rate of nitrogen was greater than phosphorus at all system and both removal rates were greater at Phragmites australis than at Zirania latifolia and at Typha angustifolia the rate was the least. Removal rates of $PO_4^{-3},\;NH_4-N,\;NO_{3-}N$ at Phragmites australis were $57.4\%,\;52.8\%,\;47.8\%$ and at Zizania latifolia were $82.6\%,\;77.2\%,\;67.5\%$ and at Typha angustifolia were $80.6\%,\;73.7\%,\;64.3\%$. It seems that removal effect is great by the planted mattress system.

• Journal of Korean Society of societal Security
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• v.3 no.2
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• pp.47-55
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• 2010

It was developing of portable hybrid water purification system for clean water production in the disaster area. because there are no way to supply a drinking water to the victims of calamity. currently, the government has been supplying bottled water to victims. but it is a limit to the reserves. It is composed of a filter, a feed pump, a solar-cell, a controller, and a case and is possible supplying a drinking water not to limit time and a place. Field test was carried out to developed portable water purification system and the purified water was satisfied a criterion for a drinking water.