• Journal of the Korean Ceramic Society
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• v.26 no.2
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• pp.167-170
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• 1989

Al2O3/SiC composite-material was synthesized by the birth-spread mechanism through the carbothermal reduction reaction of SiO2 in Ha-Dong Kaolin with carbon powder under H2 gas atmosphere at 1300~140$0^{\circ}C$. Average diameter of synthesized SiC whiskers were 1${\mu}{\textrm}{m}$ and aspect ratio (c/a) was 10~100. Al2O3 particles and SiC whiskers were mixed homogeneously in the reacted pellet.

• Journal of the Korean Ceramic Society
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• v.35 no.2
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• pp.129-136
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• 1998

The effects of MgO on the resistance to corrosion and oxidation of Al2O3-SiC-C refractory have been in-vestigated. The resistance to oxidation was improved as the amount of MgO increased. The resistance to corrosion was enhanced until 2 wt% MgO content but degraded over that content. From the dependence of temperatuer on the oxidation resistance oxidation was suppressed by the microstructural densification caused by spinel formation over 1200~130$0^{\circ}C$and the formation MgO-Al2O3-SiO2 liguid-phase over 130$0^{\circ}C$ The weight loss of specimens containing MgO with various purity at range of 95 to 99% and par-ticle size of -0.045 mm to -0.074 mm was examined. The oxidation resistance was not changed signficantly with the particle size and purity of MgO powders.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.364.1-364.1
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• 2014

고효율 태양전지로 가기 위해서는 태양전지의 후면 패시베이션은 중요한 역할을 한다. 후면 패시베이션 막으로 사용되는 $Al_2O_3$ 막은 $Al_2O_3/Si$ 계면에서 높은 화학적 패시베이션과 Negative Fixed Charge를 가지고 있어 적합한 Barrier막으로 여겨진다. 하지만 이후에 전면 Metal paste의 소성 공정에 의해 $800^{\circ}C$이상 온도를 올려주게 됨에 따라 $Al_2O_3$ 막 내부에 결합되어 있던 수소들이 방출되어 blister가 생성되고 막 질은 떨어지게 된다. 우리는 blister가 생성되는 것을 방지하기 위한 방법으로 PECVD 장비로 SiNx를 증착하는 공정 중에 $N_2O$ 가스를 첨가하여 SiON 막을 증착하였다. SiON막은 $N_2O$가스량을 조절하여 막의 특성을 변화시키고 변화에 따라 소성시 막에 미치는 영향에 대하여 조사하였다. 공정을 위해 $156{\times}156mm2$, $200{\mu}m$, $0.5-3.0{\Omega}{\cdot}cm$ and p-type 단결정 실리콘 웨이퍼를 사용하였고, $Al_2O_3$ 막을 올리기 전에 RCA Cleaning 실행하였다. ALD 장비를 통해 $Al_2O_3$ 막을 10nm 증착하였고 RF-PECVD 장비로 SiNx막과 SiON막을 80nm 증착하였다. 소성로에서 $850^{\circ}C$ ($680^{\circ}C$) 5초동안 소성하고 QSSPC를 통해 유효 반송자 수명을 알아보았다.

• Korean Journal of Materials Research
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• v.2 no.6
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• pp.408-416
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• 1992

Stable TiS$i_2$was formed by RTA on single-Si and on poly-Si. Subsequently, an Al-1% Si layer with 600-nm thick was deposited on top of the TiS$i_2$, Finally, the specimens were annealed for 30min at 400-60$0^{\circ}C$in $N_2$ambient. The thermal stability of Al-1% Si/TiS$i_2$bilayer and interfacial reaction were investigated by measuring sheet resistance, Auger electron spectroscopy (AES), and scanning electron microscopy (SEM). The composition and phase of precipitates formed by the reaction of Al-1% Si with Ti-silicide were studied by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD). In the case of single-Si substrate the reaction of Al-1% Si layer with TiS$i_2$layer resulted in precipitates, consuming all TiS$i_2$layer at 55$0^{\circ}C$. On the other hand, the disappearance of TiS$i_2$on poly-Si occurred at 50$0^{\circ}C$ and more precipitates were formed by the reaction of Al-1% Si/TiS$i_2$on potty-Si substrate than those of the reaction on single-Si substrate. This phenomenon resulted from the fact that Ti-silicide formed on poly-Si was more unstable than on single-Si by the effect of grain boundary. By EDS analysis the precipitates were found tobe composed of Ti, Al, and Si. X-ray diffraction showed the phase of precipitates to be theT$i_7$A$l_5$S$i_12$ternary compound.

• 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.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.12
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• pp.48-54
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• 2003

Alumium alloys casting are gaining increased acceptance in the automotive and electronic industeries and squeeze casting is the most efficient method of manufacturing such mass produced parts. This study has been investigated the microstructures and mechanical properties of Al-7.0Si-0.4Mg (AC4C) alloy fabricated by squeeze casting process for development of Fuel system Parts (Fuel rail). The microstructure of squeeze casted specimen were composed of eutectic structure Alumimim solid solution and $Mg_2$Si precipitates. The tensile strength of as-solid solution treatment Al-7.0Si-0.4Mg ahoy revealed 298.5MPa. It was found that Al-7.0Si-0.4Mg alloy have good corrosion resistance in electrochemical polarization test.

• Journal of Korea Foundry Society
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• v.13 no.4
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• pp.342-349
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• 1993

The purpose of this study is to obtain basic information on the particle dispersion, the coefficient of thermal expansion and the thermal conductivity of compocasted Al-xSi-2Cu-1Mg/ySiC(x:6, 12, 18. $y:0{\sim}10wt.%$) composite. With increasing the content of SiC particles, the thermal expension coefficient and the thermal conductivity decrease. The coefficient of thermal expension between 20 and $300^{\circ}C$ is $21.3{\times}10^{-6}/^{\circ}C{\sim}18.0{\times}10^{-6}/^{\circ}C$ for the Al-Si alloys and $18.4{\times}10^{-6}/^{\circ}C{\sim}16.0{\times}10^{-6}/^{\circ}C$ for the composite with 10wt.% SiC. The thermal conductivity at $300^{\circ}C$ is $121{\sim}169W{\cdot}m^{-1}{\cdot}k^{-1}$ for the Al-Si alloys and $114{\sim}159W{\cdot}m^{-1}{\cdot}k^{-1}$ for the composite with 10wt.% SiC.

• Journal of Sensor Science and Technology
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• v.18 no.4
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• pp.311-315
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• 2009

This paper describes the characteristics of a poly 3C-SiC micro heater which was fabricated on AlN(0.1 $\mu$m)/3C-SiC(1.0 $\mu$m) suspended membranes by surface micro-machining technology. The 3C-SiC and AlN thin films which have wide energy band gap and very low lattice mismatch were used sensors for high temperature and voltage environments. The 3C-SiC thin film was used as micro heaters and temperature sensor materials simultaneously. The implemented 3CSiC RTD(resistance of temperature detector) and the power consumption of micro heaters were measured and calculated. The TCR(thermal coefficient of the resistance) of 3C-SiC RTD is about -5200 ppm/$^{\circ}C$ within a temperature range from 25 $^{\circ}C$ to 50 $^{\circ}C$ and -1040 ppm/$^{\circ}C$ at 500 $^{\circ}C$. The micro heater generates the heat about 500 $^{\circ}C$ at 10.3 mW. Moreover, durability of 3C-SiC micro heaters in high voltages is better than Pt micro heaters. A thermal distribution measured and simulated by IR thermovision and COMSOL is uniform on the membrane surface.

• Journal of Korea Foundry Society
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• v.17 no.4
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• pp.385-392
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• 1997

The main objective of this study is to investigate the microstructure and tensile strength of $SiC_p$/Al alloy composites fabricated by die casting method. Die casting was performed using the preheated mold at the pouring temperature range of $620{\sim}750^{\circ}C$ under the pressure of $1,039 kgf/cm^2$. The low speed and a following high injection speed were 0.4 and 2.1 m/s, respectively. The microstructure of $SiC_p$/Al alloy composites fabricated by die casting method was found to be finer than that of composites fabricated by gravity casting. Also, SiC particulates were homogeneously distributed in refined Al matrix due to rapid solidification. The tensile strength of $SiC_p$/Al alloy composites fabricated by die casting method was found to be varied with cast temperature. The maximun tensile strength of $SiC_p$(10 vol.% and 20 vol.%)/Al alloy composites showed 380 MPa at the cast temperature of $750^{\circ}C$ and 363 MPa at the cast temperature of $700^{\circ}C$, respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.11a
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• pp.133-133
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• 2001