• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1374-1375
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• 2006

Ar/$Cl_2$ 유도결합 플라즈마 (ICP)의 가스 혼합비에 따른 $(Bi_{4-x}La_x)Ti_{3}O_{12}$ 박막의 식각 메커니즘과 식각면에서의 플라즈마 손상을 조사하였다. BLT 박막의 최대식각률은 Ar/$Cl_2$ 플라즈마에서의 Ar 가스 혼합비가 80%일 때 50.8 nm의 값을 보였다. 정전 탐침을 통해 Ar 가스의 혼합비에 따른 전자온도와 전자밀도를 관측하였다. 박막 표면의 X-ray photoemission spectroscopy 분석과 박막의 이력곡선을 통해 BLT 박막의 식각 손상은 Cl 원자와의 반응에 의한 화학적 식각 손상이 BLT 박막 표면에서의 Ar 이온충돌에 의한 물리적 손상보다 더 크다는 것을 확인 할 수 있었다.

• 한국입자에어로졸학회지
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• 제11권3호
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• pp.87-92
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• 2015

MCM-41 (Mobil Composition of Matter) and SBA-15 (Santa Barbara Amorphous) were used as a supported catalyst for ethylene polymerization due to their combination of large surface area and wide range of pore size distribution. The morphology of supports was used to control the morphology of the resulting polymer. Different molar ratios of Al/Ti were used for ethylene polymerization at $60^{\circ}C$ under atmospheric pressure. The effect of different mass ratios of MCM-41/SBA-15 and 1-hexene concentration on polymerization activity and polymer properties was investigated. The catalytic activity and the crystallinity reached the highest value at Al/Ti of 480. Upon incorporation of MCM-41 and SBA-15 into $MgCl_2/TiCl_4$ catalyst, the molecular weight and crystallinity of polyethylene were enhanced. The obtained polyethylene showed melting temperature between 130 and $135^{\circ}C$. The polyethylene with replication structure of support and bimodal MWD was expected.

• 한국세라믹학회지
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• 제37권10호
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• pp.933-937
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• 2000

고기능성 전자재료용 TiO$_2$분말 및 박막제조에 사용되는 중간생성물인 TiCl$_4$는 99% 이상의 고순도가 요구된다. 고순도.미립의 TiO$_2$분말 및 TiCl$_4$는 황산법으로 제조한 저순도 TiO$_2$원료를 사용하여 염소화법으로 Ti-염화물 및 염화불순물로 제조한 후, 대부분의 염화불순물들은 3단계 과정을 거쳐 고순화 하였다. 대부분의 염화불순물은 분리.응축 및 분별증류로, VOCl$_3$는 mineral oil을 첨가하여 비등점을 변화시켜, 그리고 미량의 염화불순물은 열가수분해하여 침전시킨 후 유기용제 처리하여 제거하였다. 유기용제 처리는 TiO$_2$분말의 고순도화에 도움이 되었으며, 입자간의 응집을 적게 하여 TiO$_2$입자크기도 작아졌다. 또한 anatase에서 rutile 결정구조로의 전이온도도 낮아지는 부수적인 효과를 보였다.

• 한국표면공학회지
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• 제15권3호
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• pp.138-145
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• 1982

The effects of the simultaneous variations of the ratio of feed gases(H2/N2 Flow ratio), feed gas flow rate (H2/N2, total-flow rate) and partial pressures of TiCl4 (PTiCl41) as well as deposition time and cobalt content of the substrate on the deposition rate of the TiN Coated Cemented Tungsten Carbide Tools were investigated. Deposition was carried out in the temperature range of 930$^{\circ}C$-1080$^{\circ}C$ and an activation energy of 46.5 Kcal/mole can be calculated. Transverse rupture strength was noticeably reduced by the TiN coating on the virgin surfa-ce of Cemented Tungsten Carbide, the extent of which was decreased according to the coa-ting thickness. Microhardness value observed on the work was in the range of 1700∼2000kg/mm, which were in well agreement with the value of bult TiN. The wear resistance of TiN layers was performed by turning test and it was observed that crater and flank resistance remarkably enhanced by TiN coating.

• 한국표면공학회지
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• 제41권2호
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• pp.57-62
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• 2008

Electrochemical properties of Ti-30Ta-$(3{\sim}15)$Nb alloys coated by HA/Ti compound layer have been studied by various electrochemical method. Ti-30Ta binary alloys contained 3, 7, 10, and 15 wt% Nb contents were manufactured by the vacuum furnace system. The specimens were homogenized for 24 hrs at $1000^{\circ}C$. The samples were cut and polished for corrosion test and coating. It was coated with HA/Ti compound layer by magnetron sputter. The HA/Ti non-coated and coated morphology of Ti alloy were analyzed by x-ray diffractometer(XRD) and filed emission scanning electron microscope(FE-SEM). The corrosion behaviors were investigated using potentiodynamic method in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The homoginazed Ti-30Ta-$(3{\sim}15wt%$)Nb alloys showed the ${\alpha}+{\beta}$ phase, and ${\beta}$ phase peak was predominantly appeared with increasing Nb content. The microstructure of Ti alloy was transformed from needle-like structure to equiaxed structure as Nb content increased. HA/Ti composite surface showed uniform coating layer with 750 nm thickness. The corrosion resistance of HA/Ti composite coated Ti-alloys were higher than those of the non-coated samples in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. Especially, corrosion resistance of Ti-Ta-Nb system increased as Nb content increased.

• 대한환경공학회지
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• 제27권9호
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• pp.932-938
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• 2005

[ $400^{\circ}C$ ]에서 소성한 $TiO_2$ 나노입자의 congo red 분해속도상수가 $0.0319\;min^{-1}$로써 최적의 광촉매 활성을 나타내었다. $TiO_2$ 광촉매의 congo red 분해 속도상수는 $400^{\circ}C$ 이하의 소성온도에서는 온도에 비례하여 증가하였고 $400^{\circ}C$ 이상의 소성온도에서는 온도에 비례하여 감소하였다. $TiO_2$ 광촉매는 사용빈도가 촉매 활성에 큰 영향을 주지 않았다. 유사한 반응조건에서 $TiO_2$의 광촉매 활성은 $TiCl_4$로 합성한 촉매가 $Ti(OC_3H_7)_4$로 합성한 촉매와 비교 했을 때 8.8% 증가하는 것으로 나타났다. 또한, 다양한 조건에서 $Ti(OC_3H_7)_4$로 합성한 $TiO_2$ 광촉매의 활성을 논의하였다.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2003년도 추계학술대회 발표 논문집
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• pp.1-6
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• 2003

Flow modulation chemical vapor deposition process has been reported as an alternative way to obtain low resistivity, low residual chlorine content and good step-coverage titanium nitride film. Flow and concentration characteristics in a vertical FMCVD reactor are analyzed by using computational fluid dynamics method. The results show that 1.0 second as Cl reduction period is too short and there is still $TiCl_4$ gas above the holder at the end of the period. Time variation of $TiCl_4$ gas concentration on the holder shows that at least 3.0 second is necessary as Cl reduction time for the sake of film characteristics.

• 공업화학
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• 제16권6호
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• pp.853-856
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• 2005

자성 메모리반도체의 핵심 소자인 magnetic tunnel junction (MTJ) stack에 대한 고밀도 유도결합 플라즈마 반응성 식각이 연구되었다. MTJ stack은 electron(e)-beam lithography 공정을 사용하여 나노미터 크기의 패턴 형성이 되었으며 식각을 위한 하드 마스크(hard mask)로서 TiN 박막이 이용되었다. TiN 박막은 Ar, $Cl_2/Ar$, 그리고 $SF_6/Ar$들의 가스를 사용하여 식각공정이 연구되었다. E-beam lithography로 패턴된 TiN/MTJ stack은 첫 번째 단계로 TiN 하드 마스크가 식각되고 두 번째로 MTJ stack이 식각되어 완성되었다. MTJ stack은 Ar, $Cl_2/Ar$, $BCl_3/Ar$을 이용하여 식각되었으며 각각의 가스농도와 가스 압력을 변화시켜 MTJ stack의 식각특성이 조사되었다.

• 한국세라믹학회지
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• 제37권4호
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• pp.308-313
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• 2000

Hydrous titanium oxide particles with anatase phase were prepared from 0.05 mol TiCl4 solution using NH4HCO3 as precipitant by the droopping precipitant method. The sequential change of pH is completed by a sudden and steep increase in a pH value of the range of 6~7 to which the concentration of adsorbed OH- and H+ ions on TiO2 surface is equal. Rutile phase started precipitating with anatase phase as an increase of reaction temperature above 6$0^{\circ}C$ in aqueous 0.05mol TiCl4 solution and its specific surface area was found to decrease from 452 $m^2$/g($25^{\circ}C$) to 164$m^2$/g(8$0^{\circ}C$). Specific surface area decreased rapidly when anatase powders precipitated at 4$0^{\circ}C$ were heat-treated at temperature higher 40$0^{\circ}C$. FT-IR result confirmed that it was due to the decrease of OH species within hydrous titanium oxides. The loss of ethanol after illumination of the powder heated at $600^{\circ}C$ and $700^{\circ}C$ for 4 h was 66 and 68.8%, respectively.

• 한국표면공학회지
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• 제31권6호
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• pp.359-370
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• 1998

TiAl-based intermetallic compounds were electro-bornizel in the mixture of $Na_2B_4O_7$, KCL and LiCl in the termetature rage between 850 and $1000^{\circ}C$for various times (1-5 hours)under the fixed current density of 0.5 A/$cm^2$. The optimized composition of electrolyte in this work was decided to be 76.9 wt% $Na_2B_4O_7$-19.2 wt.%(0.7KCl-0.3LiCl) -3.9 wt.% al. The samples with boronized layer were investigated by SEM, XRD and EDS. The surface micro-hardness of boronized TiAl was also evaluated using Micro Vickers Hardness Tester. The sample, boronized at $900^{\circ}C$ for 4 hours in the above composition of electrolyte under the current density of 0.5 A/$\textrm{cm}^2$, has about 36$\mu\textrm{m}$ think layer on the surface, and its surface micro-hardness was measured to be 1263 Hv. From the results of SEM, XRD and EDS, the layer consisted of $TiB_2$ sublayer and Al-oxide sub layer. Al-depleted layer below the Al-oxide sudlayer was also detected. The activation energy for formation of boronized layer in this study was calculated as 178 Kcal/moleK.