• Journal of the Korean Ceramic Society
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• v.32 no.2
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• pp.209-216
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• 1995

In order to investigate the effect o green microstructure on the sintering behavior and properties of AlN ceramics, samples were prepared by slip casting and dry pressing. The slip cast samples had high green density, fine pore size and narrow pore size distribution. They showed much higher sinterability and more homogeneous sintered microstructure compared to the dry pressed samples. Both increased thermal conductivity and flexural strength for samples prepared by slip casting could be attributed to the improved microstructural homogeneity with isolated second phase(s).

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.88-88
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• 2007

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.159-159
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• 2012

티타늄-알루미늄(Titanium-Aluminum) 질화물(Nitride)은 고경도 난삭재의 고능률 절삭 분야에 사용되는 공구의 수명 향상을 위한 표면처리 소재로 각광을 받고 있다. 본 연구에서는 아크 소스로 TiAl 타겟을 사용 하였으며, $N_2$ 유량을 변화시키며 코팅을 실시하였다. 그 결과 경도 883~2510 Hv로 나타나는 것을 확인하였다.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.3
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• pp.158-162
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• 2000

The high temperature oxidation behavior and the surface defect in Fe-25Mn-1.5A1-0.5C steel was investigated by XRD (X-ray Diffractin) and electron microscopy. The intra- and inter-granular oxides were formed by the selective oxidation of manganese and aluminum, which were identified to MnAl2O4 phase. Aluminum nitride (AlN) was formed in front of these oxides. The ${\gamma}$-matrix was transformed to ${\alpha}$- and ${\varepsilon}$- phases by the selective oxidation of manganese. The surface defect, micro-scab was induced by the difference of the high temperature ductility between the matrix and the inter-granular oxide.

• Journal of the Korean institute of surface engineering
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• v.24 no.4
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• pp.196-205
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• 1991

Multi-level thin films are very important in ULSI applications because of their high electromigration resistance. This study presents the effects of titanium, titanium nitride and titanium tungsten underlayers of the stability of multi-aluminum thin films during isothermal annealing. High purity Al(99.999%) films have been electron-beam evaporated on Ti, TiN, TiW films formed on SiO2/Si (P-type(100))-wafer substrates by RF-sputtering in Ar gas ambient. The hillock growth was increased with annealing temperatures. Growth of hillocks was observed during isothermal annealing of the thin films by scanning electron microscopy. The hillock growth was believed to appear due to the recrystallization process driven by stress relaxation during isothermal annealing. Thermomigration damage was also presented in thin films by grain boundary grooving processes. It is shown that underlayers of Al/TiN/SiO2, Al/TiW/SiO2 thin films are preferrable to Al/SiO2 thin film metallization.

• Journal of the Korean institute of surface engineering
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• v.24 no.4
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• pp.215-221
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• 1991

Microstructure evolution during low temperature vapor deposition exhibits wel-developed columnar structure mainly owing to geometrical shadowing effect of surface roughness. It is concluded that this structure is concided with many theoretical models suggested so far. In case of aluminum nitride film deposition consisted of etching and nitriding step employing ECR plasma, the rougher the surface before etching, the finer and more cone-and-whisker structure can be developed. In turn, this fine structure affects the formation and growth of columnar as well as offers many sites available for mechanical lock-up. Conclusively, the formation of well-defined columnar structures depends on the initial surface roughness.

• Journal of the Korean institute of surface engineering
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• v.47 no.6
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• pp.282-286
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• 2014

Wear characteristic of the nitrided SKD61 which is a typical mold material using for the extrusion of Al6061 alloy was investigated. The surface of SKD61 was nitrided by salt bath and plasma processes. The thickness of surface nitride layer was about $8.9{\mu}m{\sim}21.3{\mu}m$. Reciprocating friction wear test conducted using pin on disk type indicated the plasma treatment followed salt bath has a lower friction coefficient and a smaller adhesive wear with Al6061 alloy. That was identified by the $Fe_4N$ which has a better wear resistance than FeN mainly formed by plasma nitriding.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.5
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• pp.223-228
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• 2017

Aluminum nitride (AlN) powder was successfully synthesized at low temperature via carbothermal reduction and nitridation (CRN) assisted by microwave heating. The synthesis processes of AlN powder were investigated with X-ray diffraction, FE-SEM, FT-IR and TGA/DSC. Aluminum nitrate was used as an oxidizer and aluminum source, urea as fuel, and glucose as carbon source. These starting materials were mixed with D.I water and reacted in a flask at $100^{\circ}C$ for 20 minutes. After the reaction was finished, black foamy intermediate product was formed, which was considered to be an amorphous $Al_2O_3$ particles through intermediate product obtained by solution combustion synthesis (SCS) at the results of X-ray diffraction patterns and FT-IR. This intermediate product was nitridated at temperatures of $1300^{\circ}C$ and $1400^{\circ}C$ in $N_2$ atmosphere by a microwave heating furnace and then decarbonated at $600^{\circ}C$ for 2 hours in air. It should be noticed from FE-SEM images that as nitridated particles, identified as AlN from X-ray diffraction patterns, are covered with carbon residues. After decarbonating the nitridated powders, the spherical pure AlN powders were obtained without alumina and their particle sizes were dependent on the nitridating temperature with high temperature of $1400^{\circ}C$ giving large particles of around 70~100 nm.

• Journal of IKEEE
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• v.24 no.2
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• pp.604-609
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• 2020

We investigated the influence of rapid thermal annealing on aluminum nitride (AlN) thin film Schottky barrier diodes (SBDs) manufactured structures deposited on a 4H-silicon carbide (SiC) wafer using radio frequency sputtering. The Ni/AlN/4H-SiC devices annealed at 400℃ exhibited Schottky barrier diode (SBDs) properties with an on/off current ratio that was approximately 10 times higher than that of the as-deposited device structures and the devices annealed at 600℃ as measured at room temperature. Auger electron spectroscopy (AES) measurements revealed that atomic oxygen concentrations in the annealed AlN devices at 400℃, is ascribed to the improvement in on/off ratio and the reduction of on-resistance. Additionally, we investigated the electrical characteristics of the AlN/SiC SBD structures depending on the frequency variation of sound waves.

• 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 > $BN/Al_2O_3$ > $Al_2O_3$.