• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.244-245
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• 2015

PEALD TiN 금속 전극을 갖는 MOS device에서 SC1 ($NH_4/H_2O_2/H_2O=1:2:5$), SPM ($H_2SO_4/H_2O_2=10:1$), $H_2O_2$ etch chemical을 이용해 TiN 식각 후 oxide 표면 잔류 Ti에 의한 전기적 특성 분석을 진행 하였다. Etch chemical 중 SPM을 이용한 소자의 전기적 특성이 우수하였는데, 이는 잔류Ti atom의 양이 다른 etch chemical을 사용한 것 대비 낮았기 때문이다. 이로 인하여 낮은 leakage current, less frequency dependence의 특성이 관찰되었다. 또한, 후속 열처리를 통해 더욱 우수한 특성이 관찰 되었다. 이러한 공정기술은 single 전극을 갖는 CMOS 형성 시 사용 될 수 있을 것으로 기대된다.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.341-353
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• 1974

The electrochemical reduction of triphenylphosphine penylimide in nonaqueous media has been examined by polarography, cyclic voltammetry, controlled-potential coulometry and electron spin resonance spectroscopy. The reduction of triphenylphosphine phenylimide proceeds by a one-electron transfer to form anion radical which undergoes both protonation and a second one-electron reduction followed by cleavage of the phosphorus-nitrogen double bond. Aniline is a major product. The cleavage of a phosphorus-phenyl bond was also observed after reduction of triphenylphosphine oxide which is one of the major products of the chemical reaction which follow the primary process.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1408-1411
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• 2009

This paper describes organic acid-based wet chemical etching behaviors of amorphous Ga-doped zinc oxide (GZO) thin film sputter-deposited at low temperature (room temperature). Wet etch parameters such as etching time, temperature, and etchant concentration are investigated for formic and citric acid etchants, and their effects on the etch rate, etch residue and the feature of edge line are compared.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.1
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• pp.28-32
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• 2003

In this paper, we have studied the in-situ end point detection (EPD) for direct chemical mechanical polishing (CMP) of shallow trench isolation (STI) structures without the reverse moat etch process. In this case, we applied a high selectivity $1n (HSS) that improves the silicon oxide removal rate and maximizes oxide to nitride selectivity Quite reproducible EPD results were obtained, and the wafer-to-wafer thickness variation was significantly reduced compared with the conventional predetermined polishing time method without EPD. Therefore, it is possible to achieve a global planarization without the complicated reverse moat etch process. As a result, the STI-CMP process can be simplified and improved using the new EPD method.

• Journal of Industrial Technology
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• v.42 no.1
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• pp.19-27
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• 2022

This review will discuss the effort to understand the interfacial reactions at the anode and cathode sides of all-solid-state batteries. Antiperovskite solid electrolytes have received increasing attention due to their low melting points and anion tunability which allow controlling microstructure and crystallographic structures of this material system. Antiperovskite solid electrolytes pave the way for the understanding relationship between critical current density and mechanical properties of solid electrolytes. Microstructure engineering of cathode materials has been introduced to mitigate the volume change of cathode materials in solid-state batteries. The hollow microstructure coupled with a robust outer oxide layer effectively mitigates both volume change and stress level of cathode materials induced by lithium insertion and extraction, thus improving the structural stability of the cathode and outer oxide layer, which results in stable cycling performance of all-solid-state batteries.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.567-573
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• 2012

Compared with the natural marble, the artificial marble has the advantages of excellent appearance, high degree of finish, even color, fine pressure and wear resistance, bear erosion and weathering, etc. It can be widely used in kitchen countertops, bath vanity tops, table tops, furniture, reception desks, etc. However, large amounts of artificial marble waste such as scraps or dust have been generated from sawing and polishing processes in artificial marble industry. Waste from artificial marble industry is increasing according to demand magnification of luxurious interior material. Artificial marble wastes can be recycled as aluminum oxide used as raw materials in electronic materials, ceramics production, etc., and methyl methacrylate(MMA) which become a raw material of artificial marble by pulverization, pyrolysis and distillation processes. The characteristics of artificial marble wastes was analyzed by using TGA/DSC and element analysis. Crude aluminum oxide was obtained from artificial marble waste by pulverization and thermal decomposition under nitrogen atmosphere. In this work, Box-Behnken design was used to optimize the pyrolysis process. The characteristics of crude aluminum oxide was evaluated by chromaticity analysis, element analysis, and surface area.

• Polymer(Korea)
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• v.37 no.1
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• pp.80-85
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• 2013

Anionic polymerization of hexafluoropropylene oxide (HFPO) was investigated under various reaction conditions such as various hexafluoropropylene (HFP) oligomers composed of dimer and trimer, reaction temperatures, and feeding rates of hexafluoropropylene oxide monomer. HFP oligomer was synthesized from cesium fluoride (CsF) and HFP in tetraethyleneglycol dimethylether (TG). Under 5 g of CsF, 200 g of HFP, 10 g of TG, and reaction temperature $30^{\circ}C$, HFP dimer content in oligomer was relatively increased. HFPO oligomer with a high molecular weight ($M_w$ 3600) was synthesized in conditions of reaction temperature $0^{\circ}C$, HFP oligomer with 35.1% of dimer, and 1.85 g/min of HFPO feeding rate. Otherwise, chain transfer was increased under unoptimized reaction conditions. Consequently, it was found that reaction conditions impact chain propagation and chain transfer in the anionic polymerization of HFPO.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.264-271
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• 2023

In this study, ASCO^Ⓡ SLES-430 surfactant was synthesized by adducting 3 moles of ethylene oxide and 1 mole of propylene oxide to lauryl alcohol followed by a sulfation process, and the structure of the synthesized ASCO^Ⓡ SLES-430 was elucidated by performing FT-IR, ¹H-NMR and ¹³C-NMR analyses. Interfacial properties such as critical micelle concentration, static surface tension, emulsification index, and contact angle were measured, and environmental compatibility indices such as oral toxicity and skin irritation were also estimated for ASCO^Ⓡ SLES-430. Both results were compared with ASCO^Ⓡ SLES-226 and ASCO^Ⓡ SLES-328 SLES surfactants possessing 2 moles and 3 moles of ethylene oxide, respectively. In particular, both foaming ability and foam stability were evaluated for ASCO^Ⓡ SLES-430 and compared with ASCO^Ⓡ SLES-226 and ASCO^Ⓡ SLES-328, which have been widely used in detergent products, in order to test the potential applicability of ASCO^Ⓡ SLES-430 in detergent product formulation for a small capacity built-in washing machine.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.885-889
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• 2012

In this study, amine and metal oxide additives were investigated to improve $CO_2$ adsorption capacity of activated carbons (ACs). The characteristics of surface modified ACs were studied by X-ray photoelectron spectroscopy (XPS), $N_2$ adsorption, X-ray diffraction (XRD), and BET. Amine surface treatment decreased specific surface area and pore volume of ACs, but increased alkalinity by the incorporated nitrogen functional groups. Adsorption capacities of amine functionalized ACs was larger than original ACs, because basic group which can react with $CO_2$ was grafted on the ACs surface. Presence of copper oxides on ACs also enhances the carbon dioxide adsorption. The copper oxides could increase the adsorption rate of carbon dioxides due to the acid-base interaction (or electron acceptor-donor interaction). It was found that copper oxide loading was a promising method to improve the $CO_2$ adsorption capacity of ACs.

• Toxicological Research
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• v.34 no.4
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• pp.343-354
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• 2018

Aluminum oxide nanoparticles ($Al_2O_3$ NPs) are among the most widely used nanomaterials; however, relatively little information about their risk identification and assessment is available. In the present study, we aimed to investigate the potential toxicity of $Al_2O_3$ NPs following repeated inhalation exposure in male Sprague-Dawley rats. Rats were exposed to $Al_2O_3$ NPs for 28 days (5 days/week) at doses of 0, 0.2, 1, and $5mg/m^3$ using a nose-only inhalation system. During the experimental period, we evaluated the clinical signs, body weight change, hematological and serum biochemical parameters, necropsy findings, organ weight, and histopathology findings. Additionally, we analyzed the bronchoalveolar lavage fluid (BALF), including differential leukocyte counts, and aluminum contents in the major organs and blood. Aluminum contents were the highest in lung tissues and showed a dose-dependent relationship in the exposure group. Histopathology showed alveolar macrophage accumulation in the lungs of rats in the $5mg/m^3$ group during exposure and recovery. These changes tended to increase at the end of the recovery period. In the BALF analysis, total cell and neutrophil counts and lactate dehydrogenase, tumor necrosis factor-${\alpha}$, and interleukin-6 levels significantly increased in the 1 and $5mg/m^3$ groups during exposure. Under the present experimental conditions, we suggested that the no-observed-adverse-effect level of $Al_2O_3$ NPs in male rats was $1mg/m^3$, and the target organ was the lung.