• 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 Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.60-65
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• 2002

The purpose of this study is to measure and compare the output power characteristics and optical gain for selenium vapour laser depending on the He gas purity. The purity of the He gas was improved with a special He-filter. During the measurement the individual wavelengths were selected with a birefringent filter. The result shows that compared with those of laser without He-filter, the output-coupling power and small signal gain of laser with He-filter increase in the most of the lines. Especially, the output-coupling power and small signal gain for the strong lines (497.6 nm, 499.3 nm, 506.9 nm, 517.6 nm, 522.8 nm, 530.5 nm), blue(460.4 nm, 464.8 nm) and red(644.4 nm 649.1 nm) lines lies notably higher.

• Fire Science and Engineering
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• v.32 no.5
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• pp.52-56
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• 2018

The damage caused by fires is fatal as opposed to the damage caused by heat, and toxic gas generated by fires can be protected against by using a wet towel. In this study, we quantified the filtration effect of gas generated by an actual fire using a wet towel. In order to confirm the filtration effect of the wet towel on three harmful gases ($CO_2$, HCl, HCN), gases passed through a filter using FT-IR were analyzed in realtime. HCl and HCN, which are gases, were filtered by a wet towel, and the detection time of each gas was delayed. Therefore, it was confirmed that evacuation time can be secured by using a wet towel in the case of toxic gas, especially water-soluble gases in an actual fire.

• Journal of environmental and Sanitary engineering
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• v.22 no.2
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• pp.9-20
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• 2007

The incineration process has commonly used for wastes amount reduction and thermal treatments of pollutants as the technologies accumulated. However, the process is getting negative public images owing to matter of hazardous pollutants emission. Specially dioxins became a main issue and were mostly emitted from municipal solid wastes incineration. In this reason, pyrolysis/gasification/melting process is presented as an alternative of incineration process. The pyrolysis/gasification/melting process, a novel technology, is middle of verification of commercial plant and development of technologies in Korea. But the survey about the pollutant emission from the process, and background data in these facilities is necessary. So in this survey, t is investigated that the behavior of chlorobenzenes and chlorophenols in plasma type pyrolysis/gasification/melting plant of pilot scale. We investigated discharging behavior of each phase of chlorobenzene through each process in the plsasma type pyrolysis/gasification/melting process. From this result, it was found that about 99 percent of particle-phase chlorobenzene was removed, but on the other hand gas-phase chlorobenzene was increased by about 600 percent through heat exchanger, flue gas cooling, system and semi dry absorption bag filter(SDA/BF). Also, this investigation presented that di-chlorobenzene(DCB) tri-chlorobenzene(TCB), tetra-chlorobenzene(TeCB), penta-chlorobenzene (PCB), except mono-chlorobenzene(MCB) and hexa-chlorobenzene(HCB) were increased through the flue gas cooling system and the semi dry absorption bag filter(SDA/BF). It was investigated that concentration of particle-phase chlorophenol was decreased by about 66 percent, but on the other hand, concentration of gas-phase chlorophenol was increased by about 170 percent through heat exchanger, flue gas cooling system, and semi dry absorption bag filter(SDA/BF). Also, it was found that di-chlorophenol(DCP), tri-chlorophenol(TCP), and penta-chlorophenol(PCP) were increased through the flue gas cooling system, and the semi dry absorption bag filter(SDA/BF). It can be considered that small-scale pilot facility and short investigation period might cause the concentration increase through the flue gas cooling system and the semi dry absorption bag filter(SDA/BF). A further study on real-scale pilot facility and accurate investigation may be required.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.369-370
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• 2000

석유화학공업단지, 도장공업, 유기용제 제조공정에서 휘발성유기화합물인 가스상 물질이 다양하게 배출되어진다. VOCs 제거하기 위해서 흡착, 연소, 광촉매, 코로나방전에 의한 플라즈마기술 등이 제어기술로 응용되고 있다. 또한 Bio필터를 이용한 휘발성 유기화합물의 제어기술은 비용절감을 위해서 이용되어왔지만, 생물학적 제어기술을 효과적으로 적용하기 위해서는 가스의 농도, 물리적 특성, 온도변화, 함수율 등의 영향인자에 따라서 재거효율이 민감하게 반응하는 특성 때문에 여러 가지 단점을 내포하고 있다. (중략)

• Journal of the Korean institute of surface engineering
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• v.42 no.5
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• pp.216-219
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• 2009

A surface acoustic wave (SAW) filter structure was fabricated employing $4{\mu}m$ thick nanocrystalline diamond (NCD) and $2.2{\mu}m$ thick ZnO films on Si wafer. The NCD film was deposited in an $Ar/CH_4$ gas mixture by microwave plasma chemical vapor deposition method. The ZnO film was formed over the NCD film in an RF magnetron sputter using ZnO target and $Ar/O_2$ gas. On the top of the two layers, copper film was deposited by the RF sputter and inter digital transducer (IDT) electrode pattern (line/space : $1.5/1.5{\mu}m$) was defined by the photolithography including a lift-off etching process. The fabricated SAW filter exhibited the center frequency of 1.66 GHz and the phase velocity of 9,960 m/s, which demonstrated that a giga Hertz SAW filter can be realized by utilizing the nanocrystalline diamond thin film.

• 열병합발전
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• s.68
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• pp.14-18
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• 2009

• Journal of the Korean Ceramic Society
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• v.39 no.2
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• pp.210-215
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• 2002

Optical Band-pass Filter(BPF) for the selected wavelength of 4300 nm was designed and fabricated on Si wager by alternately depositing Ge and $SiO_2$ thin layers by an electron beam evaporation technique. The fabricated BPF showed the optical transmittance characteristics of 58.2% with FWHM(Full Width at Half Maximum) of 204 nm at 4300 nm, but showed the transmittance less than 5% due to the reflectance over all the wavelength ranges except 4300 nm band. The $CO_2$ sensitivity of BPF was investigated with the transmittance as a function of $CO_2$ gas concentration using a sensing cell attached to FT-IR instrument. The transmittance of BPF was almost linearly decreased with increasing of $CO_2$ concentration in the range of from 500 to 5000 ppm. The sensing structure using double BPFs showed higher slop of transmittance vs $CO_2$ concentration, and thus higher gas sensitivity than that using a single BPF, even though the former had relatively lower transmittance.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.75-80
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• 2018

The problem of water shortages and water related disasters caused by climate change has increased the seriousness of water problems and the importance of water treatment technology capable of securing clean water is expanding. In this study, we analyzed not only the water pollutant generated by the filtration system technology of various water treatment technologies but also the indirect greenhouse gas emissions generation, and analyzed the influence on the environment. The subjects of study are Fabric Filter, Reverse Osmosis System and Pressurized Microfiltration Device which are widely used for water treatment and we analyzed the impact on the environment using the Life Cycle Assessment (LCA) method using the electricity amount necessary for use, the water purification efficiency, the throughput per ton and the cost. The amount of greenhouse gas generated when the Pressurized Microfiltration Device operates for 1 year is $2.15E+04kg\;CO_2-eq$., Fabric Filter is $3.29E+04kg\;CO_2-eq$., and Reverse Osmosis System is $1.68E+05kg\;CO_2-eq$. As a result of analyzing the amount of greenhouse gas generated at the time of purifying 1 ton of the Pressurized Microfiltration Device and the conventional filtration system, the Pressurized Microfiltration Device was $20.5g\;CO_2-eq$., Fabric Filter was $34.7g\;CO_2-eq$., and Reverse Osmosis System was $191.7g\;CO_2-eq$. The amount of greenhouse gas generated was calculated to be 41.0% less than that of the Fabric Filter by the Pressurized Microfiltration Device and 89.3% less than the Reverse Osmosis System. From the viewpoint of climate change, it is necessary to select a filtration system that takes climate change into account, not from the viewpoint of water quality removal efficiency and economic efficiency according to future water treatment applications, and it is necessary to select a water treatment filtration system more researches and improvements will be made for.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1067-1070
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• 1999

Anesthesia gas to pour to patients affects the flow and volume as the pressure difference of an oxygen and an anesthesia gas. An anesthesia gas, being injurious and polluting an environment, must control the pressure of an oxygen gas because of being used by closing up tight. But a pressure sensor to use for measuring an oxygen gas appears other pressure as the characteristic and the error difference of elements to use for implementing an system. A medical machine such as an anesthesia ventilator must be accurate because of using for the person's body. So we intend to implement an system for a sensor pressure measurement not to be change regardless of an environment. This papers is the target that a sensor pressrue measurement to be changed in environment is equal to actual sensor pressure measurement. So an implemented system is using analog filter and digital filter to reduce a noise. And we are using auto-zeroing and calibration to correct a sensor pressure which is changed in environment. Through such a process we increase the accuracy and the confidence of an anesthesia ventilator by controlling the flow of an anesthesia gas.