• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
• /
• pp.834-837
• /
• 2004

BST thin films were etched with inductively coupled $CF_4(C1_2+Ar)$ Plasmas. The maximum etch rate of the BST thin films was 53.6 nm/min for a 10 % $CF_4$ to the $Cl_2/Ar$ gas mixture at RF power of 700 W, DC bias of -150 V, and chamber pressure of 2 Pa. Small addition of $CF_4$ to the $Cl_2/Ar$ mixture increased chemical effect. Consequently, the increased chemical effect caused the increase in the etch rate of the BST thin films. To clarify the etching mechanism, the surface reaction of the BST thin films was investigated by X-ray photoelectron spectroscopy.

• Bulletin of the Korean Chemical Society
• /
• 제12권1호
• /
• pp.87-92
• /
• 1991

A dual capillary column system is described for the simultaneous measurement of retention index (RI) and area ratio (AR) values of each peak on two capillary columns of different polarity, DB-5 & DB-1701. Both capillary columns were connected to a common splitless injector via a deactivated fused-silica capillary tubing of 1 m length and a 'Y' splitter, the dead volume effect of which was found to be negligible. RI and AR were measured with high reproducibility(${\leq}$0.05% RSD) and with high accuracy (<10% RE), respectively. When applied to the test samples of the organic acid mixture, each acid was positively identified by the combined computer RI library search-AR comparison.

• 암석학회지
• /
• 제23권4호
• /
• pp.385-391
• /
• 2014

한반도 중부 전곡 지역 한탄강 유역에는 제4기 시기에 분출한 현무암질 암석들이 화산대지 및 하식절벽으로서 분포한다. 국내 최초로 도입된 다검출기 불활성기체 질량분석기와 레이저 가열장치를 이용하여 전곡 지역에서 산출하는 현무암질 암석의 $^{40}Ar-^{39}Ar$ 연대를 측정하였다. 전곡읍 은대리 지역 하식절벽의 현무암들은 하부에서 상부로 가면서 $0.54{\pm}0.07Ma$, $0.48{\pm}0.01Ma$, $0.12{\pm}0.01Ma$의 연대를 나타내며 전곡리 지역의 현무암에서 $0.43{\pm}0.04Ma$의 연대가 얻어진다. 이 결과는 0.12-0.54 Ma 사이에 전곡 지역에 단속적인 화산암의 분출이 있었을 가능성을 시사한다.

• 한국정밀공학회지
• /
• 제28권1호
• /
• pp.19-23
• /
• 2011

Recently, focused ion beam (FIB) applications have been investigated for the modification of VLSI circuit, the MEMS processing, and the localized ion doping, A multi aperture FIB system has been introduced as the demands of FIB applications for high speed and large area processing increase. A liquid metal ion source has problems, a large angular divergence and a metal contamination into a substrate. In this study, a gas ion source was introduced to replace a liquid metal ion source. The gas ion source generated inductively coupled plasma (ICP) in a quartz tube (diameter: 45 mm). Ar gas fed into the quartz was ionized by a 2 turned radio frequency antenna. The Ar ions were extracted by 2 extraction grids. The maximum extraction voltage was 10 kV. A numerical simulation was used to optimize the design of extraction grids and to predict an ion trajectory. As a result, the maximum ion current density was 38 $mA/cm^2$ and the spread of ion energy was 1.6 % for the extraction voltage.

• 한국전기전자재료학회논문지
• /
• 제22권12호
• /
• pp.1028-1032
• /
• 2009

In this study, the influences of silicon-based gas barrier films fabricated by using a facing target sputtering(FTS) system on the gas permeability for flexible displays have been investigated. Under these optimum conditions on the $SiO_x$ film with oxygen concentration($O_2/Ar+O_2$) of 3.3% and the $SiO_xN_y$ film with nitrogen concentration($N_2/Ar+O_2+N_2$) of 30% deposited by the FTS system, it was found that the films were grown about 4 times higher deposition rate than that of the conventional sputtering system and showed high transmittance about 85% in the visible light range. Particularly, the polyethylene naphthalate(PEN) substrates with the $SiO_x$ and/or $SiO_xN_y$ films showed the enhanced properties of decreased water vapor transmission rate (WVTR) over $10^{-1}\;g/m^2{\cdot}day$ compared with the PEN substrate without any gas barrier films, which was due to high packing density in the Si-based films with high plasma density by FTS process and/or the denser chemical structure of Si-N bond in the $SiO_xN_y$ film.

• 한국분말재료학회지
• /
• 제27권2호
• /
• pp.139-145
• /
• 2020

The powder manufacturing process using the gas atomizer process is easy for mass production, has a fine powder particle size, and has excellent mechanical properties compared to the existing casting process, so it can be applied to various industries such as automobiles, electronic devices, aviation, and 3D printers. In this study, a modified A4032-xSn (x = 0, 1, 3, 5, and 10 wt.%) alloy with low melting point properties is investigated. After maintaining an argon (Ar) gas atmosphere, the main crucible is tilted; containing molten metal at 1,000℃ by melting the master alloy at a high frequency, and Ar gas is sprayed at 10 bar gas pressure after the molten metal inflow to the tundish crucible, which is maintained at 800℃. The manufactured powder is measured using a particle size analyzer, and FESEM is used to observe the shape and surface of the alloy powder. DSC is performed to investigate the change in shape, according to the melting point and temperature change. The microstructure of added tin (Sn) was observed by heat treatment at 575℃ for 10 min. As the content of Sn increased, the volume fraction increased to 1.1, 3.1, 6.4, and 10.9%.

• 한국자기학회지
• /
• 제11권4호
• /
• pp.146-150
• /
• 2001

스퍼터 증착시 수소 첨가가 NiFe/FeMn의 교환결합 자계 (H$_{ex}$)에 미치는 영향에 대하여 연구하였다. Si(100)/Ta(50 $\AA$)/NiFe(60 $\AA$)/FeMn(250 $\AA$)Ta(50 $\AA$)의 경우는 하지층 NiFe 증착시 수소 첨가량이 8%에서 H$_{ex}$과 H$_{c}$ 최적 특성을 보였다. Si(100)/Ta(50 $\AA$)/NiFe(60 $\AA$)/FeMn(250 $\AA$)/NiFe(70 $\AA$)/Ta(50 $\AA$) 시편에서 FeMn 증착 시에는 5% 수소 혼합개스에서 H$_{ex}$가 148 Oe로서 최적 특성을 보였다. 이는 수소 첨가에 의해 하지층 NiFe의 (111) 우선배항성 향상, 결정립 크기의 증가 및 음력이 감소하였으며 그에 따라 FeMn의 (111) 우선 배향성 및 결정립의 크기가 증가한 결과이다.다.결과이다.

• 한국표면공학회지
• /
• 제42권3호
• /
• pp.116-121
• /
• 2009

The 2-step low temperature plasma processes (the combined carburizing and post-nitriding) offer the increase of both surface hardness and thickness of hardened layer and corrosion resistance than the individually processed low temperature nitriding and low temperature carburizing techniques. The 2-step low temperature plasma processes were carried out for improving both the surface hardness and corrosion resistance of AISI 316L stainless steel. The influence of gas compositions on the surface properties during nitriding step were investigated. The expanded austenite (${\gamma}_N$) was formed on all of the treated surface. The thickness of ${\gamma}_N$ and concentration of N on the surface increased with increasing both nitrogen gas and Ar gas levels in the atmosphere. The thickness of ${\gamma}_N$ increased up to about $20{\mu}m$ and the thickness of entire hardened layer was determined to be about $40{\mu}m$. The surface hardness was independent of nitrogen and Ar gas contents and reached up to about 1200 $HV_{0.1}$ which is about 5 times higher than that of untreated sample (250 $HV_{0.1}$). The corrosion resistance in 2-step low temperature plasma processed austenitic stainless steels was also much enhanced than that in the untreated austenitic stainless steels due to a high concentration of N on the surface.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.581-582
• /
• 2005

In order to apply the discharge plasma processing. to industrial areas, the control of the chemical reaction mechanism is necessary. The hybrid plasma reactor was designed for the effective treatment of wastewater and hazardous volatile organic substances. This plasma reactor was similar to the barrier discharge, and surface discharge on the dielectric surface was propagated to the water surface strongly for the heterogeneous chemical reaction at the interface between the working gas and the water surface. The discharge emission in this discharge reactor was mainly $N_2$ second positive band in the case of $N_2$ or air gas atmosphere, and intensities from OH radicals in Ar gas atmosphere were stronger than in $N_2$ or air gas atmosphere. From this result, it is necessary to apply Ar gas for the effective generation of OH radicals in this plasma reactor.

• 한국결정성장학회지
• /
• 제4권4호
• /
• pp.370-377
• /
• 1994

비이송식DC 플라즈마 토치를 제작하고 이를 이용하여 질화규소 분말을 제조하였다. Ar 가스를 사용하여 플라즈마를 발생시켯으며, 발생된 플라즈마 flame으로 반응가스 및 reactive quenching 가스를 도입하였다. 토치의 하단부에 2개의 slit를 장착하여 가스의 도입 위치를 변화시킬 수 있게 하였다. $SiCl_4와 NH_3$를 출발원료로 하여 질화규소 분말을 제조하였다. 얻어진 분말은 무정형이었으며, 반응부산물을 제거하고 $1420^{\circ}C$에서 질소 분위기하에서 가열함으로써 결정화된 질화규소 분말을 얻었다. XPD pattern 및 IR 스펙트럼으로부터 질화규소 분말을 확인하였고, TEM을 사용하여 전후의 형상을 관찰하였다.