• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.320-326
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• 1999

Aluminum oxynitride spinel (ALON) was synthesized by the direct melt nitridation (DMN) process using aluminum metal and aluminium oxide. The amount of ALON increased with increasing the reaction sintering temperature. The specimen containing up to 10 wt% Al showed ALON phase only when heat-treated beyond $1750^{\circ}C$. Whereas the specimen composed of more than 12 wt% Al showed unreacted AlN phase. Bulk density of reaction-sintered specimen was increased with increasing sintering temperature, except the speimen containing unreacted AlN where the density slightly decreased when heat-treated beyond $1750^{\circ}C$, Transgranular fracture mode was observed predominantly in the specimen with higher Al content.

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.341-346
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• 1989

In order to evaluate the oxidation behavior of $\beta$-Sialon, $\beta$-Sialon ceramics was prepared from Si3N4, Al2O3, AlN and Y2O3 system. The specimens were oxidized in an oxygen atmosphere at 1, 20$0^{\circ}C$ for 9days. Oxidation behavior was evaluated by weight gain oxidation process, surface roughness. Microscopy, EDX and X-ray diffraction analysis were also used for the evaluation. The weight and surface roughness ofoxidized specimens were increased with increasing the oxidation time. Oxidized products were mullite, $\alpha$-cristobalite, yttrium aluminum oxide and yttrium silicate oxide.

• Journal of the Korean Ceramic Society
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• v.42 no.1
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• pp.16-21
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• 2005

The effect of additive composition, using AlN and $Er_{2}O_{3}$ as sintering additives, on the mechanical properties of liquid-phase-sintered, and subsequently annealed SiC ceramics was investigated. The microstructures developed were quantitatively analyzed by image analysis. The average thickness of SiC grains increased with increasing the $Er_{2}O_{3}/(AlN + Er_{2}O_{3})$ ratio in the additives whereas the aspect ratio decreased with increasing the ratio. The mechanical properties versus $Er_{2}O_{3}/(AlN + Er_{2}O_{3})$ ratio curve had a maximum; i.e., there was a small composition range at which optimum mechanical properties were realized. The best results were obtained when the ratio ranged from 0.4 to 0.6. The flexural strength and fracture toughness of the SiC ceramics were $550\~650\;MPa$ and $5.5\~6.5$ MPa${\cdot}m^{1/2}$, respectively.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.267-270
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• 2011

In the process of inkjet-printed zinc tin oxide thin-film transistor, the effect of metallic interlayer underneath of source and drain electrode was investigated. The reason for the improved electrical properties with thin molybdenum oxide ($MoO_3$) layer was due to the chemically intermixed state of metallic interlayer, aluminum source and drain, and oxide semiconductor together. The atomic configuration of three Mo $3d_3$ and $3d_5$ doublets, three different Al 2p core levels, two Sn $3d_5$, and four different types of oxygen O 1s in the interfaces among those layers was confirmed by X-ray photospectroscopy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04a
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• pp.72-73
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• 2009

In this study, we fabricated of pentacene organic thin film trasistor(OTFT), which used aluminum oxide for the gate insulator on glass substrate. Aluminum oxide for OTFTs was deposited on the gate layer by E-beam evaporation. aluminum oxide fabricated various deposition rate. In this case of the deposition rate of $0.1\;{\AA}$, the fabricated aluminum oxide gate insulator OTFT showed a threshold voltage of -1.36V, an on/off current ratio of $1.9{\times}l0^3$ and field effect mobility $0.023\;cm^2/V_s$.

• Journal of the Korean Chemical Society
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• v.60 no.3
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• pp.169-176
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• 2016

In a borate buffer solution, the growth kinetics and the electronic properties of passive film on aluminum were investigated, using the potentiodynamic method, chronoamperometry, and multi-frequency electrochemical impedance spectroscopy. The corrosion of aluminum was heavily influenced by the degree of oxygen concentration because of the increasing reduction current. The oxide film formed during the passivation process of aluminum has showed the electronic properties of n-type semiconductor, which follow from the Mott-Schottky equation. It was found out that the passive film (Al(OH)₃) of Al formed in the low electrode potential changes to Al₂O₃ while the electrode potential increases. The growth kinetics data as measured by chronoamperometry suggests a mechanism in which the growth of the film of Al₂O₃ is determined by field-assisted transport of ions through the film.

• Korean Journal of Materials Research
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• v.19 no.9
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• pp.462-467
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• 2009

The Charge Trap Flash (CTF) memory device is a replacement candidate for the NAND Flash device. In this study, Pt/$Al_2O_3/La_2O_3/SiO_2$/Si multilayer structures with lanthanum oxide charge trap layers were fabricated for nonvolatile memory device applications. Aluminum oxide films were used as blocking oxides for low power consumption in program/erase operations and reduced charge transports through blocking oxide layers. The thicknesses of $SiO_2$ were from 30 $\AA$ to 50 $\AA$. From the C-V measurement, the largest memory window of 1.3V was obtained in the 40 $\AA$ tunnel oxide specimen, and the 50 $\AA$ tunnel oxide specimen showed the smallest memory window. In the cycling test for reliability, the 30 $\AA$ tunnel oxide sample showed an abrupt memory window reduction due to a high electric field of 9$\sim$10MV/cm through the tunnel oxide while the other samples showed less than a 10% loss of memory window for $10^4$ cycles of program/erase operation. The I-V measurement data of the capacitor structures indicated leakage current values in the order of $10^{-4}A/cm^2$ at 1V. These values are small enough to be used in nonvolatile memory devices, and the sample with tunnel oxide formed at $850^{\circ}C$ showed superior memory characteristics compared to the sample with $750^{\circ}C$ tunnel oxide due to higher concentration of trap sites at the interface region originating from the rough interface.

• Journal of Powder Materials
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• v.10 no.5
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• pp.337-343
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• 2003

Nanostructured Cu-$Al_2O_3$ composite powders were synthesized by thermochemical process. The synthesis procedures are 1) preparation of precursor powder by spray drying of solution made from water-soluble copper and aluminum nitrates, 2) air heat treatments to evaporate volatile components in the precursor powder and synthesis of nano-structured CuO + $Al_2O_3$, and 3) CuO reduction by hydrogen into pure Cu. The suggested procedures stimulated the formation of the gamma-$Al_2O_3$, and different alumina formation behaviors appeared with various heat treating temperatures. The mean particle size of the final Cu/$Al_2O_3$ composite powders produced was 20 nm, and the electrical conductivity and hardness in the hot-extruded bulk were competitive with Cu/$Al_2O_3$ composite by the conventional internal oxidation process.

• Elastomers and Composites
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• v.52 no.2
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• pp.136-142
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• 2017

Using various compositions of thermally conductive inorganic fillers with boron nitride (BN) and aluminum oxide ($Al_2O_3$), solventless UV-curable thermally conductive acrylic pressure sensitive adhesives (PSAs) were prepared. The base of the PSAs consists of 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and isobornyl acrylate.The compositions of the thermally conductive inorganic fillers were 10, 15, 20, and 25 phr in case of BN, and 20:0, 15:5, 10:10, 5:15, and 0:20 phr in case of $BN/Al_2O_3$. The adhesion properties like peel strength, shear strength, and probe tack, and the thermal conductivity of the prepared PSAs were investigated with different thermally conductive inorganic filler contents. There were no significant changes in photo-polymerization behavior with increasing BN or $BN/Al_2O_3$ content. Meanwhile, the conversion rate and transmittance of the PSAs decreased and their thermal stabilities increased with increasing BN content. Their adhesion properties were also independent of the BN or $BN/Al_2O_3$ content. The dispersibility of BN in the acrylic PSAs was better than that of $Al_2O_3$ and it ranked the thermal conductivity in the following order: BN > $BN/Al_2O_3$ > $Al_2O_3$.

• Journal of the Semiconductor & Display Technology
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• v.12 no.3
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• pp.41-46
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• 2013

Efficient and inexpensive solar cells are necessary for photo-voltaic to be widely adopted for mainstream electricity generation. For this to occur, the recombination losses of charge carriers (i.e. electrons or holes) must be minimized using a surface passivation technique suitable for manufacturing. Recently it has been shown that aluminum oxide thin films are negatively charged dielectrics that provide excellent surface passivation of silicon solar cells to attract positive-charged holes. Especially aluminum oxide thin film is a quite suitable passivation on the rear side of p-type silicon solar cells. This paper, it demonstrate the interfacial microstructure and electrical properties of mono-crystalline silicon surface passivated by $Al_2O_3$ films during firing process as applied for screen-printed solar cells. The first task is a comparison of the interfacial microstructure and chemical bonds of PECVD $Al_2O_3$ and of PEALD $Al_2O_3$ films for the surface passivation of silicon. The second is to study electrical properties of double-stacked layers of PEALD $Al_2O_3$/PECVD SiN films after firing process in the temperature range of $650{\sim}950^{\circ}C$.