• Title/Summary/Keyword: High Density Plasma

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Effects of Human Plasma Lipid Transfer Protein on the Distribution of Lipids Between Lipoprotein Fractions of Rat Plasma (인체의 혈장에서 분리한 지질전이단백질이 흰쥐의 혈장 Lipoprotein 의 지질분포에 미치는 영향)

  • 최영선
    • Journal of Nutrition and Health
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    • v.19 no.5
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    • pp.296-303
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    • 1986
  • Rat lipoprotein-deficient plasma possessed a lipid tramsfer inhibitory activity when it was added to purified human plasma lipid transfer protien, while it lacked a lipid transfer activity. Incubation of whole rat plasma with partially purified human lipid transfer protein resulted in big changes in lipid distribution of rat plasma lipoproteins. There w was a 4-fold increase in cholesteryl ester(CE) and 4 47 % reduction in triglyceride(TG) in very low density lipoproteins after 2싹lour incubation. In high density lipoprotein $2(HDL_2)$ there was a 9­fold increase in TG and 33 % reduction in CEo HDL3 had 82 % reduction in CE. The result indi­c cates that the absence of the lipid transfer activity in rat plasma can be ascribed not to the inability of rat lipoproteins to serve as substrates but to the lack of 야Ie lipid transfer protein in rat plasma. Th­e erefore, species differences in lipid transfer betwe­e en lipoproteins should be taken into consideration to interpret results of studies on lipoprotein m.eta­b bolism using rats.

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A Study of Machining Optimization of Parts for Semiconductor Plasma Etcher (반도체 플라즈마 식각 장치의 부품 가공 연구)

  • Lee, Eun Young;Kim, Moon Ki
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.4
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    • pp.28-33
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    • 2020
  • Plasma etching process employs high density plasma to create surface chemistry and physical reactions, by which to remove material. Plasma chamber includes silicon-based materials such as a focus ring and gas distribution plate. Focus ring needs to be replaced after a short period. For this reason, there is a need to find materials resistant to erosion by plasma. The developed chemical vapor deposition processing to produce silicon carbide parts with high purity has also supported its widespread use in the plasma etch process. Silicon carbide maintains mechanical strength at high temperature, it have been use to chamber parts for plasma. Recently, besides the structural aspects of silicon carbide, its electrical conductivity and possibly its enhanced life time under high density plasma with less generation of contamination particles are drawing attention for use in applications such as upper electrode or focus rings, which have been made of silicon for a long time. However, especially for high purity silicon carbide focus ring, which has usually been made by the chemical vapor deposition method, there has been no study about quality improvement. The goal of this study is to reduce surface roughness and depth of damage by diamond tool grit size and tool dressing of diamond tools for precise dimensional assurance of focus rings.

Study on Argon Metastable and 4p State Neutral Atoms in Magnetized ICP and Helicon Plasmas Measured by Laser Induced Fluorescence and Plasma Emission

  • Seo, Byeong-Hun;Yu, Sin-Jae;Kim, Jeong-Hyeong;Seong, Dae-Jin;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.579-579
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    • 2013
  • We study on Argon metastable and 4p state neutral atom density in magnetized ICP Helicon plasmas by Laser Induced Fluorescence and plasma emission. The results show that metastable density is too low at the center of chamber due to significant neutral depletion. Otherwise, 4p state is high at the center of chamber because electron density is very high. Power and pressure dependence of metastable and 4p state neutral atom have been spatially measured in the radial direction of cylindrical chamber.

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RF Power Conversional System for Environment-friendly Ferrite Core Inductively Coupled Plasma Generator (환경친화형 페라이트 코어 유도결합 플라즈마 고주파 전력 변환 장치)

  • Lee, Joung-Ho;Choi, Dae-Kyu;Kim, Soo-Seok;Lee, Byoung-Kuk;Won, Chung-Yuen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.8
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    • pp.6-14
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    • 2006
  • This paper is a study about a proper method of plasma generation to cleaning method and a high frequency power equipment circuit to generation of plasma that used cleaning of chamber for TFT-LCD PECVD. The high density plasma required for cleaning causes a possibility of high density plasma more than $1{\times}10^{11}[EA/cm^3]$. It apply a ferrite core of ferromagnetic body to a existing ICP form. In case of power transfer equipment on 400[kHz] high frequency to generation of plasma it makes certain a stable switching operation in condition of plasma through using a inverter form for general purpose HB. And it demonstrates the performance of power transfer equipment using methods of measurement which use a transformer of series combination the density of plasma and the rate of dissolution of $NF_3$ in condition of $A_r\;and\;NF_3$.

Effect of the Neutral Beam Energy on Low Temperature Silicon Oxide Thin Film Grown by Neutral Beam Assisted Chemical Vapor Deposition

  • So, Hyun-Wook;Lee, Dong-Hyeok;Jang, Jin-Nyoung;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.253-253
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    • 2012
  • Low temperature SiOx film process has being required for both silicon and oxide (IGZO) based low temperature thin film transistor (TFT) for application of flexible display. In recent decades, from low density and high pressure such as capacitively coupled plasma (CCP) type plasma enhanced chemical vapor deposition (PECVD) to the high density plasma and low pressure such as inductively coupled plasma (ICP) and electron cyclotron resonance (ECR) have been used to researching to obtain high quality silicon oxide (SiOx) thin film at low temperature. However, these plasma deposition devices have limitation of controllability of process condition because process parameters of plasma deposition such as RF power, working pressure and gas ratio influence each other on plasma conditions which non-leanly influence depositing thin film. In compared to these plasma deposition devices, neutral beam assisted chemical vapor deposition (NBaCVD) has advantage of independence of control parameters. The energy of neutral beam (NB) can be controlled independently of other process conditions. In this manner, we obtained NB dependent high crystallized intrinsic and doped silicon thin film at low temperature in our another papers. We examine the properties of the low temperature processed silicon oxide thin films which are fabricated by the NBaCVD. NBaCVD deposition system consists of the internal inductively coupled plasma (ICP) antenna and the reflector. Internal ICP antenna generates high density plasma and reflector generates NB by auger recombination of ions at the surface of metal reflector. During deposition of silicon oxide thin film by using the NBaCVD process with a tungsten reflector, the energetic Neutral Beam (NB) that controlled by the reflector bias believed to help surface reaction. Electrical and structural properties of the silicon oxide are changed by the reflector bias, effectively. We measured the breakdown field and structure property of the Si oxide thin film by analysis of I-V, C-V and FTIR measurement.

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Effects of Atmospheric Pressure Microwave Plasma on Surface of SUS304 Stainless Steel

  • Shin, H.K.;Kwon, H.C.;Kang, S.K.;Kim, H.Y.;Lee, J.K.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.268-268
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    • 2012
  • Atmospheric pressure microwave induced plasmas are used to excite and ionize chemical species for elemental analysis, for plasma reforming, and for plasma surface treatment. Microwave plasma differs significantly from other plasmas and has several interesting properties. For example, the electron density is higher in microwave plasma than in radio-frequency (RF) or direct current (DC) plasma. Several types of radical species with high density are generated under high electron density, so the reactivity of microwave plasma is expected to be very high [1]. Therefore, useful applications of atmospheric pressure microwave plasmas are expected. The surface characteristics of SUS304 stainless steel are investigated before and after surface modification by microwave plasma under atmospheric pressure conditions. The plasma device was operated by power sources with microwave frequency. We used a device based on a coaxial transmission line resonator (CTLR). The atmospheric pressure plasma jet (APPJ) in the case of microwave frequency (880 MHz) used Ar as plasma gas [2]. Typical microwave Pw was 3-10 W. To determine the optimal processing conditions, the surface treatment experiments were performed using various values of Pw (3-10 W), treatment time (5-120 s), and ratios of mixture gas (hydrogen peroxide). Torch-to-sample distance was fixed at the plasma edge point. Plasma treatment of a stainless steel plate significantly affected the wettability, contact angle (CA), and free energy (mJ/$m^2$) of the SUS304 surface. CA and ${\gamma}$ were analyzed. The optimal surface modification parameters to modify were a power of 10 W, a treatment time of 45 s, and a hydrogen peroxide content of 0.6 wt% [3]. Under these processing conditions, a CA of just $9.8^{\circ}$ was obtained. As CA decreased, wettability increased; i.e. the surface changed from hydrophobic to hydrophilic. From these results, 10 W power and 45 s treatment time are the best values to minimize CA and maximize ${\gamma}$.

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The study of silicon etching using the high density hollow cathode plasma system

  • Yoo, Jin-Soo;Lee, Jun-Hoi;Gangopadhyay, U.;Kim, Kyung-Hae;Yi, Jun-Sin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1038-1041
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    • 2003
  • In the paper, we investigated silicon surface microstructures formed by reactive ion etching in hollow cathode system. Wet anisotropic chemical etching technique use to form random pyramidal structure on <100> silicon wafers usually is not effective in texturing of low-cost multicrystalline silicon wafers because of random orientation nature, but High density hollow cathode plasma system illustrates high deposition rate, better film crystal structure, improved etching characteristics. The etched silicon surface is covered by columnar microstructures with diameters form 50 to 100nm and depth of about 500nm. We used $SF_{6}$ and $O_{2}$ gases in HCP dry etch process. This paper demonstrates very high plasma density of $2{\times}10^{12}$ $cm^{-3}$ at a discharge current of 20 mA. Silicon etch rate of 1.3 ${\mu}s/min$. was achieved with $SF_{6}/O_{2}$ plasma conditions of total gas pressure=50 mTorr, gas flow rate=40 sccm, and rf power=200 W. Our experimental results can be used in various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications. In this paper we directed our study to the silicon etching properties such as high etching rate, large area uniformity, low power with the high density plasma.

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Box Cathode Sputtering Technologies for Organic-based Optoelectronics (유기물 광전소자 제작을 위한 박스 캐소드 스퍼터 기술)

  • Kim, Han-Ki
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.19 no.4
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    • pp.373-378
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    • 2006
  • We report on plasma damage free-sputtering technologies for organic light emitting diodes (OLEDs), organic thin film transistor (OTFT) and flexible displays by using a box cathode sputtering (BCS) method. Specially designed BCS system has two facing targets generating high magnetic fields ideally entering and leaving the targets, perpendicularly. This target geometry allows the formation of high-density plasma between targets and enables us to realize plasma damage free sputtering on organic layer without protection layer against plasma. The OLED with Al cathode prepared by BCS shows electrical and optical characteristics comparable to OLED with thermally evaporated Mg-Ag cathode. It was found that OLED with Al cathode layer prepared by BCS has much lower leakage current density ($1{\times}10^{-5}\;mA/cm^2$ at -6 V) than that $(1{\times}10^{-2}{\sim}-10^0\;mA/cm^2)$ of OLED prepared by conventional DC sputtering system. This indicates that BCS technique is a promising electrode deposition method for substituting conventional thermal evaporation and DC/RF sputtering in fabrication process of organic based optoelectronics.

Box Cathode Sputtering Technologies for Organic Optoelectronics (유기물 광전소자 제작을 위한 박스 캐소드 스퍼터 기술)

  • Kim, Han-Ki;Lee, Kyu-Sung;Kim, Kwang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.53-54
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    • 2005
  • We report on plasma damage free-sputtering technologies for organic light emitting diodes (OLEDs), organic thin rim transistor (OTFT) and flexible displays by using a box cathode sputtering (BCS) method. Specially designed BCS system has two facing targets generating high magnetic fields ideally entering and leaving the targets, perpendicularly. This target geometry allows the formation of high-density plasma between targets and enables us to realize plasma damage free sputtering on organic layer without protection layer against plasma. The OLED with top cathode prepared by BCS shows electrical and optical characteristics comparable to OLED with thermally evaporated Mg-Ag cathode. It was found that TOLED with ITO or IZO top cathode layer prepared by BCS has much lower leakage current density ($1\times10^{-5}$ mA/cm2 at -6V) than that ($1\times10^{-1}\sim10^{\circ}mA/cm^2$)of OLED prepared by conventional DC sputtering system. This indicates that BCS technique is a promising electrode deposition method for substituting conventional thermal evaporation and dc/rf sputtering in fabrication process of organic based optoelectronics.

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Gas and Magenetic Field Effect to Low Pressure Plasma

  • Bae, In-Sik;Na, Byeong-Geun;Seol, Yu-Bin;Yu, Sin-Jae;Kim, Jeong-Hyeong;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.557-557
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    • 2013
  • Plasma hardly grows in lowpressure because of lack of collision. But low pressure plasma has useful properties because it has typically low electron density. In here, thermal electron is used to make breakdown in low pressure easily. We changed magnetic field strength and gas to control electron density or temperature. IV characteristic and electron density of the discharge are examined and the characteristic of the discharge in presence of magnetic field is also examined. Results showed that depending on the ionization cross section of the gas, electron density is changed and proper strength of magnetic field is required for high electron density.

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