• 한국표면공학회지
• /
• 제36권6호
• /
• pp.480-490
• /
• 2003

Effects of plasma-nitriding on the pitting corrosion of Fe-30at%Al-5at%Cr alloy containing Ti, Hf, and Zr were investigated using potentiostat in 0.1M HCl. The specimen was casted by the vacuum arc melting. The subsequent homogenization was carried out in Ar gas atmosphere at $1000^{\circ}C$ for 7days and phase stabilizing heat treatment was carried out in Ar gas atmosphere at $500^{\circ}C$ for 5 days. The specimen was nitrided in the $N_2$, and $H_2$, (1:1) mixed gas of $10^{-4}$ torr at $480^{\circ}C$ for 10 hrs. After the corrosion tests, the surface of the tested specimens were observed by the optical microscopy and scanning electron microscopy(SEM). For Fe-30at%Al-5Cr alloy, the addition of Hf has equi-axied structure and addition of Zr showed dendritic structure. For Fe-30at%Al-5Cr alloy containing Ti, plasma nitriding proved beneficial to decrease the pitting corrosion attack by increasing pitting potential due to formation of TiN film. Addition of Hf and Zr resulted in a higher activation current density and also a lower pitting potential. These results indicated the role of dendritic structure in decreasing the pitting corrosion resistance of Fe-30Al-5Cr alloy. Ti addition to Fe-30Al-5Cr decreased the number and size of pits. In the case of Zr and Hf addition, the pits nucleated remarkably at dendritic branches.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.74-74
• /
• 2009

Titanium nitride has been used as hardmask for semiconductor process, capacitor of MIM type and diffusion barrier of DRAM, due to it's low resistivity, thermodynamic stability and diffusion coefficient. Characteristics of the TiN film are high intensity and chemical stability. The TiN film also has compatibility with high-k material. This study is an experimental test for better condition of TiN film etching process. The etch rate of TiN film was investigated about etching in $BCl_3/Ar/O_2$ plasma using the inductively coupled plasma (ICP) etching system. The base condition were 4 sccm $BCl_3$ /16 sccm Ar mixed gas and 500 W the RF power, -50 V the DC bias voltage, 10 mTorr the chamber pressure and $40\;^{\circ}C$ the substrate temperature. We added $O_2$ gas to give affect etch rate because $O_2$ reacts with photoresist easily. We had changed $O_2$ gas flow rate from 2 sccm to 8 sccm, the RF power from 500 W to 800 W, the DC bias voltage from -50 V to -200 V, the chamber pressure from 5 mTorr to 20 mTorr and the substrate temperature from $20\;^{\circ}C$ to $80\;^{\circ}C$.

• 열처리공학회지
• /
• 제22권5호
• /
• pp.267-274
• /
• 2009

Titanium Chromium Nitrided (TiCrN) coatings were deposited on stainless steel 316 L and Si (100) wafer by inductively coupled plasma assisted D.C. magnetron sputtering at the various sputtering power on Cr target and $N_2/Ar$ gas ratio. Increasing the sputtering power of Cr target, XRD patterns were changed from TiCrN to nitride $Cr_2Ti$. The maximum hardness was $Hk_{3g}$ 3900 at $0.3\;N_2/Ar$ gas ratio. The thickness of the TiCrN films increased as the Cr target power increased, and it showed over $Hk_{5g}3100$ hardness at 100 W, 150 W. TiCrN films were deposited by the ICP assisted DC magnetron sputtering shown good wear resistance as the $N_2/Ar$ gas ratio was 0.1, 0.3.

• 방사성폐기물학회지
• /
• 제18권3호
• /
• pp.355-362
• /
• 2020

The corrosion behavior of the Inconel X-750 alloy was investigated for its potential application under a Cl₂-O₂ mixed gas flow in an Ar atmosphere. The corrosion rate was found to be negligible at temperatures up to 400℃ under a flow rate of 30 mL·min^-1 Cl₂ + 170 mL·min^-1 Ar, whereas an exponential increase was observed in the corrosion rate at temperatures greater than 500℃. The suppression of the corrosion reaction due to the presence of O₂ was verified experimentally at flow rates of 30 mL·min^-1 Cl₂ (4.96 g·m^-2·h^-1), 20 mL·min^-1 Cl₂ + 10 mL·min^-1 O₂ (2.02 g·m^-2 ·h^-1), and 10 mL·min^-1 Cl₂ + 20 mL·min^-1 O₂ (1.34 g·m^-2·h^-1) under a constant Ar flow rate of 170 mL·min^-1 at 600℃ for 8 h. The surface morphology analysis results revealed that porous surfaces with tunnel-type holes were produced under the Cl₂-O₂ mixed-gas condition. Furthermore, the effects of the Cl₂ flow rate on the corrosion rate were investigated, indicating that its impact was negligible within the range of 5-30 mL·min^-1 Cl₂ at 600℃.

• 한국재료학회지
• /
• 제19권7호
• /
• pp.376-381
• /
• 2009

Indium Tin Oxide (ITO) thin films on Polyethylene Terephtalate (PET) substrate were prepared by Roll-to-Roll sputter system with targets of 5 wt% and 10 wt% $SnO_2$ at room temperature. The influence of the chromaticity (b*) and transmittance properties of the ITO Films were investigated. The ITO thin films were deposited as a function of the DC power, rolling speed, and Ar/$O_2$ gas flow ratio, and then characterized by spectrophotometer. Their crystallinity and surface resistance were also analyzed by X-ray diffractometer and 4-point probe. As a result, the chromaticity (b*) and transmittance of the ITO films were broadly dependent on the thickness, which was controlled by the rolling speed. When the ITO films were prepared with the DC power of 300 W and the Ar/$O_2$ gas flow ratio of 30/1 sccm using 10 wt% $SnO_2$ target as a function of the rolling speeds 0.01 through 0.10 m/min, its chromaticity (b*) and transmittance were about -4.01 to 11.28 and 75.76 to 86.60%, respectively. In addition, when the ITO films were deposited with the DC power of 400W and the Ar/$O_2$ gas flow ratio of 30/2 sccm used in 5 wt% $SnO_2$ target, its chromaticity (b*) and transmittance were about -2.98 to 14.22 and 74.29 to 88.52%, respectively.

• 한국산학기술학회논문지
• /
• 제14권2호
• /
• pp.535-541
• /
• 2013

본 연구에서는 아연도금강관 용접에 용접 전류, 전압과 보호가스가 용접 비드 형상과 미세조직과 경도에 미치는 영향을 조사하였다. 전압, 전류과 보호가스 종류 및 조성의 변화가 용접 비드의 높이와 너비, 용입깊이에 영향을 미침을 확인하였다. 비드높이에는 보호가스 Ar 가스, 용입에는 $CO_2$ 가스, 그리고 비드너비에는 Ar+$O_2$ 가스가 가장 큰 영향을 미쳤다. 용접부의 경도에서는 Ar+10% $O_2$ 와 Ar+20% $CO_2$ 가스 사용 시 결정립계 페라이트와 다각형 페라이트가 생성되어 낮았으며, Ar+2% $O_2$ 가스를 사용했을 때는 아시큘러 페라이트와 베이나이트적 페라이트와 사이드플레이트 페라이트가 생성되어 경도가 높았다.

• 한국재료학회지
• /
• 제28권5호
• /
• pp.301-307
• /
• 2018

A boron-doped diamond(BDD) electrode is attractive for many electrochemical applications due to its distinctive properties: an extremely wide potential window in aqueous and non-aqueous electrolytes, a very low and stable background current and a high resistance to surface fouling. An Ar gas mixture of $H_2$, $CH_4$ and trimethylboron (TMB, 0.1 % $C_3H_9B$ in $H_2$) is used in a hot filament chemical vapor deposition(HFCVD) reactor. The effect of argon addition on quality, structure and electrochemical property is investigated by scanning electron microscope(SEM), X-ray diffraction(XRD) and cyclic voltammetry(CV). In this study, BDD electrodes are manufactured using different $Ar/CH_4$ ratios ($Ar/CH_4$ = 0, 1, 2 and 4). The results of this study show that the diamond grain size decreases with increasing $Ar/CH_4$ ratios. On the other hand, the samples with an $Ar/CH_4$ ratio above 5 fail to produce a BDD electrode. In addition, the BDD electrodes manufactured by introducing different $Ar/CH_4$ ratios result in the most inclined to (111) preferential growth when the $Ar/CH_4$ ratio is 2. It is also noted that the electrochemical properties of the BDD electrode improve with the process of adding argon.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.41-43
• /
• 1999

Among the feffoelectric thin films that have been widely investigated for ferroelectric random access memory (FRAM) applications, SrBi$_2$Ta$_2$$O_{9}$ thin film is appropriate to memory capacitor materials for its excellent fatigue endurance. However, very few studies on etch properties of SBT thin film have been reported although dry etching is an area that demands a great deal of attention in the very large scale integrations. In this study, the a SrBi$_2$Ta$_2$$O_{9}$ thin films were etched by using magnetically enhanced inductively coupled Ar/CHF$_3$ plasma. Etch properties, such as etch rate, selectivity, and etched profile, were measured according to gas mixing ratio of CHF$_3$(Ar$_{7}$+CHF$_3$) and the other process conditions were fixed at RF power of 600 W, dc bias voltage of 150 V, chamber pressure of 10 mTorr. Maximum etch rate of SBT thin films was 1750 A77in, under CHF$_3$(Ar+CHF$_3$) of 0.1. The selectivities of SBT to Pt and PR were 1.35 and 0.94 respectively. The chemical reaction of etched surface were investigated by X-ray photoelectron spectroscopy (XPS) analysis. The Sr and Ta atoms of SBT film react with fluorine and then Sr-F and Ta-F were removed by the physical sputtering of Ar ion. The surface of etched SBT film with CHF$_3$(Ar+CHF$_3$) of 0.1 was analyzed by secondary ion mass spectrometer (SIMS). Scanning electron microscopy (SEM) was used for examination of etched profile of SBT film under CHF$_3$(Ar+CHF$_3$) of 0.1 was about 85˚.85˚.˚.

• 암석학회지
• /
• 제7권2호
• /
• pp.69-76
• /
• 1998

옥천대 남서부지역에 분포하는 화강편마암과 광주화강암에서 분리한 각섬석과 백운모의 40Ar/39Ar 분석자료는 다음과 같은 지구조적 의미를 가진다. 이들 시료의 40Ar/39Ar 분석치는 모두 뚜렷한 연령 스펙트럼을 보이며 특히 방출된 39Ar 가스의 60% 이상으로 만들어진 37Arca/39Ark과 38Arcl/39Ark 프라토우(plateau)가 뚜렷하다. 각섬석에 대한 36Ar/40Ar 대 39Ar/40Ar 의 대비도는 시료 HN-100을 제외하고는 모두 뚜렷한 연령 프라토우를 보여준다. 고온단계에서 37Arca/39Ark 값은 38Arcl/39Ark 값의 상대적인 증가에 따른 불규칙성은 판상광물 사이에 들어있던 알곤 가스의 방출에 의한 것으로 추정된다. HN-100은 40Ar/39Ar 전체 알곤가스 연령이 918 Ma로서 저온단계에서 알곤 방출이 있었고 고온단계에서 1360 Ma를 보인다. 전자는 대보운동에 의한 영향을 받은 시기이며, 후자는 선캠브리아기 화강편마암에 포획된 각섬석 결정이 폐쇄온도(약 $500\pm$$50^{\circ}C$)에 도달한 시기를 보여준다. 광주화강암류의 세 암상(각섬석 흑운모 화강섬록암, 흑운모 화강섬록암과 복운모 화강암)이 보이는 165 Ma를 전후한 연령은 저온단계에서 얼마간의 알곤가스 방출이 있었으며 또 기발표된 Rb/Sr 전암년령과 비교하여 젊은 년령을 보이는 것으로 미루어 이 시기는 대보운동의 영향을 받은 시기로 생각된다. 이들 40Ar/39Ar 광물년령과 기발표된 Rb/Sr 전암년령 및 K/Ar 광물년령은 옥천대 남서부지역이 100~150 m/m.y.의 느린 속도로 그리고 산이반도 지역은 100 m/m.y. 이하의 보다 느린 속도로 상승했음을 알려준다. 이 지역에서 가장 강력했던 지각변동 또는 화성활동은 원생대 중기(1360 Ma 전후)와 중생대 쥬라기 중기(약 165 Ma 전후)에 있었다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 D
• /
• pp.1553-1555
• /
• 1999

Recently, $SrBi_2Ta_2O_9$(SBT) and $Pb(ZrTi)O_3$(PZT) were much attracted as materials of capacitor for ferroelectric random access memory(FRAM) showing higher read/write speed, lower power consumption and nonvolartility. Bi-layered SBT thin film has appeared as the most prominent fatigue free and low operation voltage for use in nonvolatile memory. To highly integrate FRAM, SBT thin film should be etched. A lot of papers on SBT thin film and its characteristics have been studied. However, there are few reports about SBT thin film due to difficulty of etching. In order to investigate properties of etching of SBT thin film, SBT thin film was etched in $CF_4$/Ar gas plasma using magnetically enhanced inductively coupled plasma (MEICP) system. When $CF_4/(CF_4+Ar)$ is 0.1, etch rate of SBT thin film was $3300{\AA}/min$, and etch rate of Pt was $2495{\AA}/min$. Selectivities of SBT to Pt. $SiO_2$ and photoresist(PR) were 1.35, 0.6 and 0.89, respectively. With increasing $CF_4$ gas, etch rate of SBT thin film and $P_t$ decreased.