• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.737-744
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• 2011

탄화수소 계열의 점화원과 달리 선행 연구된 스팀 플라즈마 점화기를 이용한 알루미늄 분말의 지속 연소 성공을 바탕으로, 고온의 플라즈마를 이용한 알루미늄 분말의 점화 특성을 알아보기 위해 산화제가 없는 환경을 조성하여 점화 특성 확인 실험을 수행하였다. 아르곤 플라즈마를 이용하여 이전의 연소 실험과 동일한 4500 K의 온도 조건 및 이송 가스를 이용한 입자 공급 조건을 조성하여 실험을 수행하였으며, 플라즈마의 온도는 방출분광법을 사용하여 측정하였고 점화 특성은 SEM 촬영과 EDS 분석을 통해 비교 분석하였다. 고온의 플라즈마 제트 내부를 통과한 알루미늄 분말은 탄화수소 계열의 점화원과 다르게 급격한 기화로 인한 점화 촉진 효과를 확인 할 수 있었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.152-155
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• 2003

Ashing of photoresist was investigated in dielectric barrier discharges in atmospheric pressure by changing applied voltage, frequency, flow rate. we analyzed the plasma by Optical Emission Spectroscopy(OES) to monitor the variation of active oxygen species. Another new peaks of oxygen radical is observed by addition of argon gas. This may explain the increase in ashing rate with argon addition. With the results of Optical Emission Spectroscopy(OES), we can find the optimized ashing conditions. MIS capacitor for monitoring charging damage by the plasma was also studied. The results suggest the dielectric barrier discharges(DBD) can be an efficient, alternative Plasma source for general surface processing.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.262-262
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• 2010

반도체 제조공정 중 식각공정(Etching)은 웨이퍼표면으로부터 화학적, 물리적으로 불필요한 물질들을 선택적으로 제거하는 방법이다. 식각공정 중 하나인 플라즈마 식각(Plasma etching) 공정에서 오버식각(over-etching) 과언더식각(under-etching) 되는것을피하기위해서통계적인방법을기준으로식각종료점(endpoint)를 결정한다. 본 논문의 목표는 통계적인 분석방법을 이용하지 않고 실시간 식각 데이터(realtime etching data)를 사용해서 식각 종료점을 검출하는 것이다. 식각 데이터는 시계열 데이터(time-series data)이기 때문에 간단한 구조와 적은 계산량으로 빠른 수렴속도와 좋은 안정도를 가진 Radial Basis Function Neural Network's (RBF-NN) 를 이용하여 시계열 모델(time-series model)을 구현 하였다. 광학방사분광기(Optical Emission Spectroscopy: OES)로부터 나온 6개의 데이터 세트중에서 4개의 데이터 세트는 RBF-NN을 학습하는데 사용되고 2개의 데이터 세트는 모델의 성과를 시험해 보기 위하여 사용하였다. 학습을 위한 데이터들은 Matrix화 시켜서 목표값을 설정하여 학습시킨다. 실험한 결과 학습한 RBF-NN 모형이 식각 종료점(endpoint)를 정확하게 검출된다는 것을 보여준다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.473-473
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• 2010

Plasma is widely used in various commercial etchers and chemical vapor deposition. Unfortunately, real-time plasma process monitoring is still difficult. Some methods of plasma diagnosis is improved, however, it is possible for real-time plasma diagnosis to use non-intrusive probe only. In this research, the object is to investigate the suitability of using impedance analysis and optical emission spectroscopy (OES) for real-time plasma process monitoring. It is assumed that plasma system is a equivalent circuit. Therefore, V-I probe is used for measuring impedance, which can be a new non-intrusive probe for plasma diagnosis. From impedance data, we tried to analyse physical properties of plasma. And OES, the other method of plasma diagnosis, is a typical non-intrusive probe for analyzing chemical properties. The amount of the OES data is typically large, so this poses a difficulty in extracting relevant information. To solve this problem, principal component analysis (PCA) can be used. For fundamental information, Ar plasma and $O_2$ plasma are used in this experiment. This method can be applied to real-time endpoint and fault detections.

• 반도체디스플레이기술학회지
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• 제21권2호
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• pp.74-84
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• 2022

As the semiconductor industry develops, the difficulty of newly required process technology becomes difficult, and the importance of production yield and product reliability increases. As an effort to minimize yield loss in the manufacturing process, interests in the process defect process for facility diagnosis and defect identification are continuously increasing. This research observed the plasma condition changes in the multi oxide/nitride layer deposition (MOLD) process, which is one of the 3D-NAND manufacturing processes through optical emission spectroscopy (OES) and monitored the result of whether the change in plasma characteristics generated in repeated deposition of oxide film and nitride film could directly affect the film. Based on these results, it was confirmed that if a change over a certain period occurs, a change in the plasma characteristics was detected. The change may affect the quality of oxide film, such as the film thickness as well as the interfacial surface roughness when the oxide and nitride thin film deposited by plasma enhenced chemical vapor deposition (PECVD) method.

• 방사성폐기물학회지
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• 제21권1호
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• pp.43-53
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• 2023

Sulfide concentrations critically affect worker safety and the integrities of underground facilities, such as deep geological repositories for spent nuclear fuel. Sulfide is highly sensitive to oxygen, which can oxidize sulfide to sulfate. This can hinder precise measurement of the sulfide concentration. Hence, a literature review was conducted, which revealed that two methods are commonly used: the methylene blue and sulfide ion-selective electrode (ISE) methods. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used for comparison with the two methods. The sulfide ISE method was found to be superior as it yielded results with a higher degree of accuracy and involved fewer procedures for quantification of the sulfide concentration in solution. ICP-OES results can be distorted significantly when sulfide is present in solution owing to the formation of H₂S gas in the ICP-OES nebulizer. Therefore, the ICP-OES must be used with caution when quantifying underground water to prevent any distortion in the measured results. The results also suggest important measures to avoid problems when using ICP-OES for site selection. Furthermore, the sulfide ISE method is useful in determining sulfide concentrations in the field to predict the lifetime of disposal canisters of spent nuclear fuel in deep geological repositories and other industries.

• 천문학논총
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• 제27권4호
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• pp.271-274
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• 2012

We present the result of systematic AKARI IRC infrared $2.5-5{\mu}m$ spectroscopy of >100 nearby luminous infrared galaxies, to investigate the energetic roles of starbursts and optically-elusive buried AGNs. Based on (1) the equivalent widths of the $3.3{\mu}m$ PAH emission features, (2) the optical depths of absorption features, and (3) continuum slopes, we can disentangle emission from starbursts and AGNs. We find that the energetic importance of buried AGNs increases with increasing galaxy infrared luminosities, suggesting that the AGN-starburst connections (and thereby possible AGN feedback to host galaxies) are luminosity dependent.

• Journal of the Optical Society of Korea
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• 제16권1호
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• pp.76-79
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• 2012

$Tb_3Al_5O_{12}:Ce$ (TAG:Ce) thin films were successfully deposited by a pulsed laser ablation method on a quartz substrate, and low-temperature post-annealing effects on luminescent properties were investigated in detail. TAG:Ce thin films were analyzed by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The as-deposited films were amorphous, and post-annealing above $700^{\circ}C$ was required for crystallization. The post-annealed TAG:Ce thin films showed strong and broad emission bands around 542 nm and excitations at 451 nm, which all corresponded to transitions between the 4f ground level to the $5d^1$ excited levels of Ce ion.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 춘계학술대회 논문집
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• pp.247-247
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• 2009

3차원 반도체 패키징에서 관통전극 Through Silicon Via (TSV)를 형성하기 위하여 이온과 래디컬의 활성도 조절이 가능한 pulsating inductively coupled plasma (ICP) 식각을 수행하였다. 본 식각공정에서는 펄스주파수 ($50{\sim}500Hz$)와 듀티 싸이클 ($20{\sim}99%$)을 조절하여, 플라즈마 내 이온과 래디컬들의 활성도 변화를 발생시켰다. 플라즈마 공정변수에 따라 식각형태가 달라짐을 S.E.M을 이용하여 확인했으며, 이온(SFx+, O+)과 래디컬 ($SF^*$, $F^*$, $O^*$)의 농도 및 활성도 변화를 측정하기 위하여 광학적 기술인 optical emissin spectroscopy와 전기적 특성 측정 기술인 Langmuir probe 시스템을 직접 제작 설치하여 펄스플라즈마를 진단하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.302-305
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• 2007

During the CareBeijing campaign in September 2006, Imaging Differential Optical Absorption Spectroscopy (IDOAS) measurements were made over the city of Beijing, China using a spatial resolution of 146 pixels horizontally and 61 pixels vertically, each with a field of view of $0.133^{\circ}$ and $0.072^{\circ}$ in the horizontal and vertical directions, respectively. Using Fraunhofer reference spectra (FRS) for the evaluation of data for two consecutive days, the diurnal variation of $NO_2$ distributions was determined from data measured every single hour from 08:00 until 16:00 on September 9 and 10. Both days presented a fairly clear sky with high visibility. The setup allowed detailed images of the low surface $NO_2$ distribution over Beijing. Images with less than a 30-min temporal resolution showed variation of plume dispersal in both horizontal and vertical directions. An in-situ measurement was also conducted. Results from both instruments are interpreted by considering local emission sources and wind conditions.