• Title/Summary/Keyword: emission spectroscopy

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Revealing ionized gas kinematics at the center of nearby Seyfert galaxies

  • Kim, Eun Chong;Woo, Jong-Hak
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.43.2-43.2
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    • 2014
  • We investigate the ionized gas kinematics at the center of 6 nearby Seyfert galaxies, using the integral field spectroscopy data from the Calar Alto Legacy Integral Field spectroscopy Area survey Data Release 1. To understand the kinematic nature of the ionized gas in the narrow-line regions (NLRs), we measured the flux, velocity, and velocity dispersion of the [OIII] $5007{\AA}$ and Ha $6563{\AA}$ emission lines, after subtracting a best-fit stellar population model representing the stellar features. At the same time, we measured stellar velocity as a reference for the systemic velocity, and stellar velocity dispersion. We spatially resolved the velocity structure of the ionized gas using each emission line and compared it to that of stars. In this poster we present the flux, velocity, and velocity dispersion maps of the ionized gas and stars, and discuss the nature of the ionized gas outflows in the central kiloparsec scale.

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Neural Network Modeling of Actinometric Optical Emission Spectroscopy Information for Mo nitoring Plasma Process (플라즈마 공정 감시를 위한 Actinometric 광방사분광기 정보의 신경망 모델링)

  • Kwon, Sang-Hee;Bo, Kwang;Lee, Kyu-Sang;Uh, Hyung-Soo;Kim, Byung-Whan
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.177-178
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    • 2007
  • 플라즈마 공정은 집적회로 제작을 위한 미세 박막의 증착과 패턴닝에 핵심적으로 이용되고 있다. 본 연구에서는 플라즈마공정감시와 제어에 응용될 수 있는 모델을 제안한다. 본 모델은 광방사분광기 (Optical emission spectroscopy-OES)정보와 역전파 신경망을 이용해서 개발하였다. 제안된 기법은 Oxide 식각공정에서 수집한 데이터에 적용하였으며, 체계적인 모델링을 위해 공정데이터는 통계적 실험계획법을 적용하여 수집되었다. Raw OES 정보대신, Actinometric OES 정보를 이용하였으며, 신경망의 예측성능은 유전자 알고리즘을 이용해서 증진시켰다. OES의 차수를 줄이기 위해 주인자 분석 (Principal Component Analysis-PCA)을 세 종류의 분산(100, 99, 98%)에 대해서 적용하였다. 최적화한 모델의 예측에러는 323 $\AA/min$이었다. 이전에 PCA를 적용하고 은닉층 뉴런의 함수로 최적화한 모델의 예측에러는 570 $\AA/min$이었으며, 개발된 모델은 이에 비해 43% 증진된 예측 성능을 보이고 있다.

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Emission Spectroscopy of Unstable Molecules using a Fourier Transform Spectrometer (Fourier Transform 분광기를 이용한 불안정한 분자의 방출분광학)

  • Sang Kuk Lee;Un Sik Kim
    • Journal of the Korean Chemical Society
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    • v.37 no.4
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    • pp.371-377
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    • 1993
  • Fourier Transform UV/VIS spectrometer has been modified for emission spectroscopy with the technique of supersonic expansion, in which the unstable molecular radical $CH_3S$ has been generated in a jet by a high voltage DC discharge. The fluorescence spectra of the supersonically cooled radical have been recorded on a Fourier Transform UV/VIS spectrometer. The ratio of signal to noise of the spectra has been improved substantially. Also the rotational structure has been clearly resolved for $CH_3S$ molecular radical.

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A Study on the Dielectric Barrier Discharges Plasmas of Flat Atmospheric Pressure Using an AC Pulse Voltage (교류 펄스 전압을 이용한 평판형 대기압 유전격벽방전 플라즈마의 특성 분석)

  • Lee, Jong-Bong;Ha, Chang-Seung;Kim, Dong-Hyun;Lee, Ho-Jun;Lee, Hae-June
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.5
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    • pp.717-720
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    • 2012
  • Various types of dielectric-barrier-discharge (DBD) devices have been developed for diverse applications for the last decade. In this study, a flat non-thermal DBD micro plasma source under atmospheric pressure has been developed. The flat-panel type plasma is generated by bipolar pulse voltages, and driving gas is air. In this study, the plasma source was investigated with intensified charge coupled device (ICCD) images and Optical Emission Spectroscopy (OES). The micro discharges are generated on the crossed electrodes. For theoretical analysis, 2-dimensional fluid simulation was performed. The plasma source can be driven in air, and thus the operation cost is low and the range of application is wide.

A Study on Pumping Effect of Oxygen in Polysilicon Gate Etching

  • Kim, Nam-Hoon;Shin, Sung-Wook;Bin, Shin-Seok;Yu chang-Il kim;Chang, Eui-Goo
    • Transactions on Electrical and Electronic Materials
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    • v.1 no.2
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    • pp.1-6
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    • 2000
  • This article presents the experiments and considerations possible about gate etching in polysilicon when oxygen gas is added in chamber, We propose the novel study with optical emission spectroscopy in polysilicon etching. It is shown that added oxygen gases play an important role in enhencement of density in chlorine gases as a scavenger of silicon from SiCl$\_$x/. And a small amount of Si-O bonds are deposited and then the deposited thin film protect silicon dioxyde against reaction chlorine with silicon in SiO$_2$. Consequently, we can improve the selectivity of polysilicon the silicon dioxide, which is clearly explained in this model.

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A Diagnostic Study of Pulsed Plasma Process for Reactive Deposition (반응성 증착용 펄스 플라즈마 공정의 진단)

  • Joo, Jung-Hoon
    • Journal of the Korean institute of surface engineering
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    • v.45 no.4
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    • pp.168-173
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    • 2012
  • A real-time monitoring of an immersed antenna type inductively coupled plasma (ICP) was done with optical emission spectroscopy (OES) to check the reports that sputtered atom density is decreasing as the ICP power is increased. At 10 mTorr pressure of Ar, Mg was sputtered by a bipolar pulsed power supply into 2 MHz ICP which has an insulator covered 2.5 turn antenna. Emitted light was collected in two different positions: above the target and inside the ICP region. With 100 W of Mg sputtering power, the intensities of Mg I (285.06 nm), Mg II (279.48 nm), Ar I (420.1 nm) were increased constantly with ICP power from 100 W to 600 W. At 500 W, the intensity of $Mg^+$ exceeded that of Mg under PID controlled discharge voltage of 180 V. The ratio of Mg II/Mg I was increased from 0.45 to 2.71 approximately 6 times.

The Application of Time-Resolved Laser Induced Fluorescence Spectroscopy in the Complexation Studies of Eu(III) and Cm(III) with Humic Substances

  • Joong Gill Choi;Oum Ka Won;Chang Yeoul Choi;Hichung Moon;Hyun Sang Shin;Park, Seung Min;Paul Joe Chong
    • Bulletin of the Korean Chemical Society
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    • v.14 no.1
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    • pp.72-78
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    • 1993
  • The application of time-resolved laser induced fluorescence spectroscopy (TRLIF) to the complexation studies of Eu(III) and Cm(III) with humic substances is described. Using this method, three different spectroscopic characteristics(excitation spectra, emission spectra, and lifetimes) of these aquo ions and their complexes can be directly measured. By observing shifts in the wavelength and changes in the lifetime and intensities of the fluorescence emission, the information on the complexation behavior of humic substances with these trivalent metal cations in an aqueous solution, as well as energy transfer mechanisms, can be obtained. In addition, this method allows precise spectroscopic quantification of the complexation processes at very low concentrations of both components.

Semi-Supervised Learning for Fault Detection and Classification of Plasma Etch Equipment (준지도학습 기반 반도체 공정 이상 상태 감지 및 분류)

  • Lee, Yong Ho;Choi, Jeong Eun;Hong, Sang Jeen
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.4
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    • pp.121-125
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    • 2020
  • With miniaturization of semiconductor, the manufacturing process become more complex, and undetected small changes in the state of the equipment have unexpectedly changed the process results. Fault detection classification (FDC) system that conducts more active data analysis is feasible to achieve more precise manufacturing process control with advanced machine learning method. However, applying machine learning, especially in supervised learning criteria, requires an arduous data labeling process for the construction of machine learning data. In this paper, we propose a semi-supervised learning to minimize the data labeling work for the data preprocessing. We employed equipment status variable identification (SVID) data and optical emission spectroscopy data (OES) in silicon etch with SF6/O2/Ar gas mixture, and the result shows as high as 95.2% of labeling accuracy with the suggested semi-supervised learning algorithm.

Analysis of First Wafer Effect for Si Etch Rate with Plasma Information Based Virtual Metrology (플라즈마 정보인자 기반 가상계측을 통한 Si 식각률의 첫 장 효과 분석)

  • Ryu, Sangwon;Kwon, Ji-Won
    • Journal of the Semiconductor & Display Technology
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    • v.20 no.4
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    • pp.146-150
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    • 2021
  • Plasma information based virtual metrology (PI-VM) that predicts wafer-to-wafer etch rate variation after wet cleaning of plasma facing parts was developed. As input parameters, plasma information (PI) variables such as electron temperature, fluorine density and hydrogen density were extracted from optical emission spectroscopy (OES) data for etch plasma. The PI-VM model was trained by stepwise variable selection method and multi-linear regression method. The expected etch rate by PI-VM showed high correlation coefficient with measured etch rate from SEM image analysis. The PI-VM model revealed that the root cause of etch rate variation after the wet cleaning was desorption of hydrogen from the cleaned parts as hydrogen combined with fluorine and decreased etchant density and etch rate.

Green Synthesis of Dual Emission Nitrogen-Rich Carbon Dot and Its Use in Ag+ Ion and EDTA Sensing

  • Le Thuy Hoa;Jin Suk Chung;Seung Hyun Hur
    • Korean Chemical Engineering Research
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    • v.61 no.3
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    • pp.463-471
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    • 2023
  • Nitrogen-rich carbon dots (NDots) were synthesized by using uric acid as carbon and nitrogen sources. The as-synthesized NDots showed strong dual emissions at 420 nm and 510 nm with excitation at 350 nm and 460 nm, respectively. The physicochemical analyses such as X-ray photoelectron spectroscopy, Transmission electron microscopy and Fourier transform infrared spectroscopy were used to analyze the chemical, physical and morphological structures of NDots. The as-synthesized NDots exhibited wide linear range (0-100 µM) and very low detection limit (124 nM) in Ag+ ion sensing. In addition, Ag+ saturated NDots could be used as an EDTA sensor by the EDTA induced PL recovery.