• 반도체디스플레이기술학회지
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• 제4권4호
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• pp.13-17
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• 2005

The behavior of ozone in $NH_4OH$ was investigated to evaluate the solution as a cleaning chemical of the silicon wafer. The solubility of ozone in DI(Deionized) water increased as the oxygen flow-rate decreased and ozone generator power increased. Ozone in DI water showed solubility of 100 ppm or higher at room temperature. Ozone concentration was stabilized at the range of ${\pm}2ppm$ by controlling oxygen flow rate and ozone generator power. On the contrary, the solubility of ozone in $NH_4OH$ was very low and strongly depended on the concentration of $NH_4OH$ and pH. The redox potential of ozone was saturated within 10 minutes in DI water and decreased rapidly with the addition of $NH_4OH$. The behavior of ozone in $NH_4OH$ is well explained by redox potential calculation.

• 대기
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• 제29권1호
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• pp.53-59
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• 2019

The quality of troposphere ozone in three reanalysis datasets is evaluated with longterm ozonesonde measurement at Pohang, South Korea. The Monitoring Atmospheric Composition and Climate (MACC), European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERAI) and Modern Era Retrospective-Analysis for Research and Applications version 2 (MERRA2) are particularly examined in terms of the vertical ozone structure, seasonality and long-term trend in the lower troposphere. It turns out that MACC shows the smallest biases in the ozone profile, and has realistic seasonality of lower-tropospheric ozone concentration with a maximum ozone mixing ratio in spring and early summer and minimum in winter. MERRA2 also shows reasonably small biases. However, ERAI exhibits significant biases with substantially lower ozone mixing ratio in most seasons, except in mid summer, than the observation. It even fails to reproduce the seasonal cycle of lower-tropospheric ozone concentration. This result suggests that great caution is needed when analyzing tropospheric ozone using ERAI data. It is further found that, although not statistically significant, all datasets consistently show a decreasing trend of 850-hPa ozone concentration since 2003 as in the observation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.264-267
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• 2002

An ozone condensation system is evaluated from the viewpoint of an ozone supplier for oxide thin film growth. Ozone is condensed by the adsorption method and its concentration is analyzed by three methods; ultraviolet absorption, thermal decomposition and Q-mass analyzing methods. Thermal decomposition method is found to be available to the concentration evaluation from dilution to highly condensed ozone. The highest ozone concentration condensed by the adsorption method is evaluated to be 97 mol%

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.1089-1092
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• 2003

This paper has been studied on wafer cleaning and photoresist striping in semiconductor fabrication processes using ozone solved deionized water. In this work, we have developed high concentration ozone generating system and high contact ratio ozone solving system to get high efficiency DIO$_3$. Through this study, we obtained 11% ozone gas concentration, 99.5% of ozone efficiency and 51% of solubility in deionized water.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.590-593
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• 2003

금속 산화물 박막 제작에 유효한 산화가스로 오존가스를 채택했다. 고품질의 산화 박막을 얻기 위해 고농도 오존이 필요하여 오존 농축 시스템을 구축 및 평가하였다. 이 장치는 실리카겔로 오존의 선택 흡착을 이용해, 농축 공정 시작 후 유입 농도 8.5 mol%가 검출되는 2.5 h에서 농축이 완료되고, 진공 배기로 고농도 오존가스를 생성하였으며, 성막 장치까지 가스가 공급되는 몇 분 동안은 자연분해 효과를 무시할 수 있었다.

• 한국대기환경학회지
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• 제25권1호
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• pp.57-74
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• 2009

In order to clarify the vertical ozone distribution in planetary boundary layer of coastal area with complex terrain, an observation campaign was carried out around Gwangyang Bay with dense pollutant emission sources during two days from June, 4 2007. For this observation are Radiosonde, SODAR(SOnic Detection And Ranging) and Tethered ozone sonde were employed. The surface meteorological and photochemical observation data provided by AWS (Automatic Weather System) and AQMS (Air Quality Monitoring System) were also applied for analysis. Synoptic condition is strongly associated with lower level ozone distribution in complex terrain coastal area. Since mesoscale circulation induced by difference of characteristics of land and sea and orographic forcing is predominant under calm synoptic condition, vertical distribution of ozone is complicate and vertical ozone concentration greatly fluctuated. However in second day when synoptic influence become strong, ozone concentration in lower levels is vertically uniform regardless of observation level. This results in vertical observation indicates that vertical ozone distribution is often determined by synoptic condition and also affects surface ozone concentration.

• 한국대기환경학회지
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• 제9권1호
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• pp.107-115
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• 1993

This study was carried out to find the characteristics of surface ozone concentration data obtained during 1988-1991 by the Korea Ministry of Environment. Seasonal data (spring, summer, autumn and winter) wre obtained in May, August, November and February respectively at Kwanghwamun in Seoul. The pollutants analyzed in this study are $SO_2, TSP, CO, NO, NO_2 and NO_2/NO$. Atmospheric factors such as solar radiation, wind speed, relative humidity, cloud amount and atmospheric temperature are also analyzed. The influence of pollutants and atmospheric factors that affect ozone concentration were analyzed by statistical method. The results are summarized as follows : 1. The ozone concentration varied seasonally. The maximum values were 23 ppb in spring, 33 ppb in summer, 16 ppb in autumn and 13 ppb in winter. So the seasonal ozone value was highest in Summer. 2. Te diurnal concentration of ozone was highest during 2-4 P. M. and was very low in the morning and evening. 3. The maximal correlation coefficients of each season between ozone concentration and the influencing pollutants or atmospheric factors asr as follows ; a. spring, r = 0.44(solar radiation) b. summer, r = -0.59(relative humidity) c. autumn, r = -0.55(relative humidity) d. winter, r = -0.58($NO_2$) 4. The major factor affecting the ozone concentration in spring was solar radiation, Relative humidity was the first affecting factor in summer, autumn and $NO_2$ concentration was dominant in winter.

• 한국환경과학회지
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• 제20권3호
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• pp.405-416
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• 2011

In order to clarify the impact of regional warming on the ozone concentration according to the differences in meteorological contribution in each city over the South-Eastern part of the Korean Peninsula, several numerical experiments were carried out. WRF - CMAQ model was used to access the ozone differences in each case, during the episode day. Meteorological contributions estimated by WRF command a reasonable feature on the dispersion of ozone concentrations in each city according to regional warming. This causes a difference in estimated ozone concentration. A higher ozone concentration difference tend to be forecasted in coastal cities than in upcountry city. Therefore, the emission reduction policy according to the regional warming should consider the characteristics of meteorological contribution of each city.

• 한국전기전자재료학회논문지
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• 제16권2호
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• pp.163-167
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• 2003

Ozone is strong and useful oxidizing gas for the fabrication of oxidation thin films. In order to obtain high quality thin film, the ozone concentration must be increased. An ozone condensation system is evaluated in the viewpoint of an ozone supplier for oxidation thin film growth. Ozone is condensed by the adsorption method and ozone concentration reaches 8.5 mol% by 2.5 h after the beginning of the ozone condensation is negligible if the condensed ozone is transferred between the ozone condensation system and the film growth chamber within a few minutes. CuO peak which is the result of the obtained Cu-films using condensed ozone appears by XRD patterns.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권5호
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• pp.201-206
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• 2004

In order to investigate the optimum conditions for the effective ozone formation in a dielectric barrier discharge, measurements of ozone concentration were carried out for various conditions such as the gap length, the dielectric material and the operating gas. It was found that the optimum discharge conditions differed exceedingly in the types of operating gases and dielectric materials. In dry air, dielectric material with low dielectric constant and thermal conductivity, which might contribute to the restriction of the gas temperature rise in the discharge region, proved effective in obtaining both high ozone yield and concentration. The optimum gap length was considered to be in the range of 600-800 mm. In oxygen, using a quartz glass disk as a dielectric material, the required condition to obtain the high ozone yield and concentration was expanded.