• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.266-275
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• 1993

We made $P_2O_5-SiO_2$ films on silicon for integrated optics application by low pressure chemical vapor deposition using TEOS (tetraethylorthosilicate) and TMPite (trimethylphosphite) and studied the deposition characteristics. The activation energy of the reaction was changed from 54.6 kcal/mole to 39.2 kcal/mole by incorporating the TMPite into the reaction of TEOS. The deposition rate and the P concentration of films increased in proportion to the flow of TMPite. As the deposition temperature increased, the deposition rate of the films increased but the P concentration decreased. The fabricated films showed the increase of refractive index of 0.0019 per 1 wt% of P concentration. The nonuniformity of films was ${\pm}$7% in thickness and ${\pm}$0.5wt% in P concentration and we showed this'nonuniformity is due to the nonuniform transport of TMPite. The films of more than 10wt% P concentration developed phosphoric acid on its surface when exposed to air for long time.

• Membrane Journal
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• v.24 no.6
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• pp.438-447
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• 2014

The amorphous and porous borosilicate without any cracks was obtained under the following condition : 0.01~ 0.10 mole ratio of trimethylborate (TMB)/ tetraethylorthosilicate (TEOS) and the temperature of $700{\sim}800^{\circ}C$. According to the BET and SEM measurements, borosilicate heat-treated in between 700 and $800^{\circ}C$ showed the surface area of $251.12{\sim}355.62m^2/g$, the pore diameter of 3.5~4.9 nm, and the particle size of 30~60 nm. According to the TGA measurements, the thermal stability of poly[1-(trimethylsilyl)propyne](PTMSP) membrane was enhanced by inserting borosilicate. SEM observation showed that the size of dispersed borosilicate in the composite membrane was $1{\mu}m$. The results showed that the permeability of $H_2$ and $N_2$ increased and the selectivity of $H_2/N_2$ decreased upon the addition of borosilicate into PTMSP membranes. Addition of borosilicate may possibly increase the free volume, cavity and porosity of membranes indicating that permeation occurred by molecular sieving, surface and Knudsen diffusion rather than solution diffusion of gases.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.164-164
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• 2012

저진공 (＞100 mTorr)에서 냉음극 변압기 전원 소스를 이용하여 플라즈마를 발생시키는 시스템을 개발하였다. 또한 이 장치를 이용하여 Tetraethylorthosilicate (TEOS)를 기화시켜 이산화규소 ($SiO_2$) 박막 증착 기술을 연구하였다. 공정 압력은 400~1,000 mT이었다. 증착된 박막의 박막 두께, 굴절률 등의 측정을 실시하였다. 결과를 요약하면, 플라즈마 공정 압력이 증가함에 따라 박막 증착 속도는 약 200~300 A/min이었다. 또한 전압이 1,100에서 2,100 V로 증가함에 따라 산화막의 증착 속도는 약 300에서 40 nm/min으로 증가하였다. TEOS만을 사용하였을 때 굴절률은 약 1.5~1.6정도였다. 그러나 TEOS에 산소를 추가하면 자연 산화막의 굴절률인 1.46을 쉽게 얻을 수 있었다. 초기 연구 결과를 정리하면 냉음극 변압기 플라즈마 장치는 향후 실용적인 산화막 플라즈마 증착 연구 장치로 사용될 수 있을 것으로 생각된다.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.399-402
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• 2006

Porous organic-inorganic hybrids have been prepared from tetraethylorthosilicate (TEOS) and organosilane precursors by sol-gel method. Two organosilanes, 3-(2,4-dinitrophenylamino)propyltriethoxysilane (DNPTES) and N-[[(2-nitrophenyl)methoxy]carbonyl]-3-triethoxysilylpropylamine (NPTES) were used to incorporate electron-accepting (di)nitrophenyl groups into the hybrids. The hybrids were characterized by FT-IR spectroscopy and elemental analysis, and their pore characteristics were studied by nitrogen sorption porosimetry. Surface area of the hybrids ranged from 563 to 770 $m^2$/g, pore volume, 0.23-0.30 $cm^3$/g, and porosity, 35-41%. It was demonstrated by UV-vis spectroscopy that aniline, ethylenediamine, and 1-aminonaphthalene could be removed from their hexane solutions in the presence of the hybrid powders. The removal of amines is attributable to donor-acceptor interaction between the electron-donating amines and electron-accepting (di)nitrophenyl moiety.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.235-239
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• 2001

In recent years, as Chemical Mechanical Planarization(CMP) has been routinely utilized in integrated circuit(IC) fabrication, the consumption of slurry, main consumable in a CMP process, is greatly increased. Thus the reprocess of CMP slurries has been actively considered in the industry to reduce cost-of-consumable (COC). The main purpose of this study was to recycle the used oxide slurry using filters as a new method. As a result, Ultra Fine(UF) Filter could distinguish silica from the used oxide slurry and Reverse Osmosis(RO) Filter could distinguish Deionized(DI) Water and chemistry from chemistry solution. The tetraethylorthosilicate removal rate was almost the same as the number of recycle polishing was increased, when it was modified by slightly adding new SS-12 slurry. The microscratch didnt found as the number of recycle polishing was increased.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.421-427
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• 2016

Nanosized hollow silica was prepared by $St{\ddot{o}}ber$ method in the presence of aluminum isopropoxide. The mixture of polyelectrolytes such as poly(sodium 4-styrene sulfonate)(PSS) and polyacrylic acid(PAA) were used as templates. Tetraethylorthosilicate(TEOS) and aluminum isopropoxide were used as precursors for silica and alumina, respectively. The function of aluminum isopropoxide is to increase the porosity of silica shell. The characterizations of hollow silica were examined by TEM(transmission electron microscopy), TGA(thermogravimetric analysis), BET(Brunauer Emmett Teller), Energy-dispersive X-ray spectroscopy(EDS), and FT-IR spectrum. It was found that the shell thickness of hollow silica was around 8 nm and the core diameter was around 20 nm by TEM.

• The Korean Journal of Ceramics
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• v.1 no.1
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• pp.1-6
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• 1995

Submicrometer, monosized ceramic powder of $Al_2TiO_5$$Al_2O_3$ ethanolic solutions. All particles produced by sol-gel-process were amprphous, monodispersed and with a narrow particle-size distribution. Compacts fired above $1300^{\circ}C$ formed aluminium titanate. Mullite formed first at $1480^{\circ}C$. After decomposition test at $1100^{\circ}C$, and cyclic thermal decomposition test at 750-1400-$750^{\circ}C$ for 100hrs., aluminium titanate was well stablized by composition with mullite.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.77-83
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• 2007

Nanoporous silica aerogels with various surface modifiers were prepared by ambient drying process. Tetraethylorthosilicate (TEOS) were used a raw material. Ambient drying process for various surface modifier was studied in the point of view of a crack-free monolith and thin films and low cost. Various kinds of surface modifiers like as hexamethyldisilazane (HMDSZ), trimethlychlorosilane (TMCS), methlytriethoxylsilane (MTES), and methlytrimethoxysilane (MTMS) were studied in order to enhance hydrophobicity for the silica aerogel. Surface modified aerogels were evaluated by FT-IR, TG, BET, SEM and wetting angle measurement. Homogeneous and crack-free aerogels were obtained by modifying the HMDSZ and the TMCS. However silica xerogel was obtained when modified with MTMS, MTES.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.241-241
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• 2003

실리카 나노 분말의 제조공정과 얻어진 나노분말의 자기조립 현상에 대하여 연구하였다. 나노분말은 TEOS(Tetraethylorthosilicate)를 이용하여 Stober process로 단분산 콜로이드 SiO2를 제조하였다. 다양한 응용을 위해서 좁은 입도분포를 가지면서도 다양한 크기를 가지는 분말을 제조하고자 TEOS, NH4OH, 에탄올, 증류수 등의 절대량과 몰비를 변화시키면서 나노분말을 제조하였다. 실험조건에 대한 입도분포와 평균 입자크기의 변화는 핵생성 이론으로 설명될 수 있었다. 얻어진 나노분말을 이용하여 dipcoating과 electron plating방법으로 단층 혹은 여러층의 박막을 형성하였다. 자기배열에 기초한 두 가지 증착방법에서 박막층에 미치는 변수들의 영향을 주로 electorn plating 방법에 대하여 고찰하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.10a
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• pp.55-57
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• 1996

다공성 무기막은 높은투과도와 뛰어난 내열.내화학성, 그리고 경제성 때문에 기존의 PSA공정이나 증류와 같은 고에너지 분리공정을 대체하는 공정으로 각광을 받고 있다. 무기재료막의 제조하는 방법으로 주로 알콕사이드를 사용하는 솔-젤법(1)과 금속(2) 또는 기상반응(3)을 이용하는 화학증착법이 사용된다. 또한 고온에서 수소를 연속적으로 분리하여 화학평형에 기인한 한계를 극복하여 높은 수율을 얻고자하는 막반응기에 관한 연구가 활발히 진행되고 있다. 본 연구에서는 $\alpha$-알루미나 지지체의 미세한 다공성 구조 내부에서 TEOS(Tetraethylorthosilicate)와 산성의 알코올-물 혼합물을 확산시켜 실리카 솔을 생성시킴과 동시에 젤화시켜 기공의 크기를 감소시켜 막을 제조하였다. 이렇게 제조된 막은 높은 투과도와 낮은 수소선택도(selectivity=3-4)를 보였고, 두번째 단계로 silica sol을 제조하여 진공 하에서 dip-coating을 행하였다. 이렇게 2단계로 기공 구조를 개선시킨 실리카 막은 저압에서 상대적으로 높은 수소의 분리도(selectivity=5-7)를 보였으며 여전히 높은 투과도를 갖는다.