• Korean Journal of Materials Research
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• v.25 no.1
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• pp.21-26
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• 2015

CMP(Chemical Mechanical Polishing) Processes have been used to improve the planarization of the wafers in the semiconductor manufacturing industry. Polishing performance of CMP Process is determined by the chemical reaction of the liquid sol containing abrasive, pressure of the head portion and rotational speed of the polishing pad. However, frictional heat generated during the CMP process causes agglomeration of the particles and the liquidity degradation, resulting in a non-uniform of surface roughness and surface scratch. To overcome this chronic problem, herein, we introduced NaCl salt as an additive into silica sol for elimination the generation of frictional heat. The added NaCl reduced the zata potential of silica sol and increased the contact surface of silica particles onto the sapphire wafer, resulting in increase of the removal rate up to 17 %. Additionally, it seems that the silica particles adsorbed on the polishing pad decreased the contact area between the sapphire water and polishing pad, which suppressed the generation of frictional heat.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.5
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• pp.212-217
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• 2021

The applicability of the white LED from the blue LED of the coating film as a binder for surface and curved coatings were confirmed. The particle size of YAG is D₅₀: 9~10 ㎛, and the crystal structure is garnet (Y₃Al₅O₁₂), cubic. The coating film had no cracks, at the same time, the silica sol was uniformly coated with YAG phosphor, and the YAG content and thickness in the coating film showed a tendency to increase up to 40 ㎛ in proportion to the increase in the amount added. Furthermore, as the YAG content increased, the PL emission intensity increased and the color coordinate shift toward the end of the chromatic locus curve was confirmed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.156-161
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• 1998

As grouting materials for ground improvement, silicate materials such as water glass, silica-sol and so forth are used worldwide. However, they may pollute underground water. In this study, fish poison test(Korean standard industrial code KS M 0111) which estimates toxicity for fish is applied to evaluate the toxic effect by grouting materials. From the test result of the sample made of LW, LC50(Median Lethal Concentration) reaches within 24 hours. In case of the silica-sol, it does not even in 96 hours. Therefore, we can conclude that the sililca-sol grouting method is more free from the danger of underground water pollution. From the result that the mortality of fish under the condition of pH 8.6 is 0% within 96 hours, the groundwater can be saved by controlling pH below 8.6 for the grouting in the field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.214-215
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• 2006

Colloidal Silica(CS)와 유기수지를 혼합하여 서로의 단점을 보완하는 나노복합재료를 합성하기 위해 친수성인 CS를 유기실란으로 표면처리하여 소수성화하고 유기수지와 복합체를 제조하였다. CS표면의 -OH기와 실란의 -OH기가 축합반응하여 화학결합을 형성함으로서 CS의 표면은 실란의 $CH_3$에 의해 소수성화되어 CS sol이 제조된다. CS sol과 유기수지는 공동용매에 의해 균일한 분산이 가능하고 필름 및 코팅제로의 제조가 가능하다. 사용된 무기물은 40nm 의 크기를 가지므로 가시광선영역의 빛을 산란하지 않아 투명하고 사용된 수지 또한 투명하여 우수한 광학적 특성을 나타낸다. 만들어진 필름은 CS의 영향으로 유기수지의 내열성보다 향상된 열분해온도와 높은 접촉각, 높은 절연율을 보였다.

• Korean Journal of Materials Research
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• v.16 no.10
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• pp.599-605
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• 2006

N-(3-triethoxysilylpropyl)-1,4-diaminoanthrquinone-2,3-dicarboximide (TESP-DADI), an organic blue pigment, has been prepared and incorporated into silica solid matrix reacting triethyl orthosilicate (TEOS) via sol-gel method. Morphology and microstructure of resulting hybrid pigment were studied employing SEM and TEM. The micrographs and particle size distributions showed that uniform pigment can be obtained employing TEOS-based sol-gel method forming silica core. Particle size distribution of dispersed pigment in water was examined using the technique of dynamic light scattering. The ensuing pigment dispersion ink was subjected to various physicochemical evaluation such as viscosity, surface tension, inkjet stability, storage stability, and color change as inkjet ink using spectrophotometric, and microscopic techniques.

• Transactions on Electrical and Electronic Materials
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• v.16 no.1
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• pp.5-9
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• 2015

Optical and electrical properties were studied for Antimony doped tin oxide thin films from precursors containing 10, 30, 50, and 70 atom% of Sb deposited on bare sodalime silica, barrier layer coated sodalime silica, and pure silica glass substrates by sol-gel spinning technique. The direct band gaps were found to vary from 3.13~4.12 eV when measured in the hv range of 2.5~5.0 eV, and varied from 4.22~5.08 eV when measured in the range of 4.0~7.0 eV. Indirect band gap values were in the range of 2.35~3.11 eV. Blue shift of band gap with respect to bulk band gap and Moss-Burstein shift were observed. Physical thickness of the films decreased with the increase in % Sb. Resistivity of the films deposited on SLS substrate was in the order of $10^{-2}$ ohm cm. Sheet resistance of the films deposited on barrier layer coated soda lime silica glass substrate was found to be relatively less.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.553-554
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• 2007

By sol-gel method, we have fabricated silica-titania hybrid film using silane treated colloidal $TiO_2$ and characterized the film through FT-IR, TGA, UV-VIS and AFM. The silica-titania hybrid film showed Ti-O-Si chemical bond at FT-IR peak of $910{\sim}940cm^{-1}$. The fabricated hybrid film showed thermal stability of around $350^{\circ}C$(5wt% loss temperature) and transparency more than 90%. In addition, the good surface smoothness was confirmed by AFM. Therefore, the silica-titania hybrid film with outstanding properties can be potential for application in electronics and displays.

• Proceedings of the Korean Society of Rheology Conference
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• 2001.09a
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• pp.156.6-157
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• 2001

(No abstract, see full-text)

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.339-342
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• 2007

• Clean Technology
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• v.16 no.2
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• pp.140-144
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• 2010

Titania-silica composite materials were obtained by sol-gel method from TiCl4 and TEOS precusors, and they were applied to anode materials of lithium ion battery. Uniformly distributed composite materials can be manufactured by sol-gel method. The composite materials were heat treated by microwave to obtain materials with new properties. The experimental variables were composition of the material, heat treatment temperature, and microwave exposure. The structure and surface properties of the materials were analyzed by XRD, SEM, and the electrochemical capacity was measured with charge/discharge cycler.