• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.476-478
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• 2005

We have fabricated a Fabry-Perot etalon around $1.3\;{\mu}m$ wavelength utilizing $Al_{2}O_3$ and a-Si thin films. A full width at half maximum of ${\sim}12.1nm$ and a finesse value of 53 were found from the measured resonant transmission spectra. Single thin film of $Al_{2}O_3$ was analyzed by spectroscopic ellipsometry. A refractive index of a-Si thin film was measured as 3.120 in the real part and 0.002 in the imaginary part, respectively. The thin-film pairs of $Al_{2}O_3$ and a-Si are applicable to output mirrors of vertical-cavity surface-emitting lasers at $1.3{\mu}m$ waveband.

• Transactions of Materials Processing
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• v.27 no.6
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• pp.339-346
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• 2018

This study investigated the microstructure and wear properties of extruded hyper-eutectic Al-Si (15wt.%) alloy in an engine oil environment. The wear mechanism of the material was also analyzed and compared to conventional gray cast iron. In microstructural observation results of Al-15wt.%Si alloy, primary Si phase ($45.3{\mu}m$) and eutectic Si phase ($3.1{\mu}m$) were found in the matrix, and the precipitations of $Mg_2Si({\beta}^{\prime})$, $Al_2Cu({\theta}^{\prime})$ and $Al_6(Mn,Fe)$ were also detected. In the case of gray cast iron, ferrite and pearlite were observed. It was also observed that flake graphite ($20-130{\mu}m$) were randomly distributed. Wear rates were lower in the Al-Si alloy as compared to those of gray cast iron in all load conditions, confirming the outstanding wear resistance of Al-15wt.%Si alloy in engine oil environment. In the $4kg_f$ condition, the wear rate of gray cast iron was $6.0{\times}10^{-5}$ and that of Al-Si measured $0.8{\times}10^{-5}$. The microstructures after wear of the two materials were analyzed using scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The primary Si and eutectic Si of Al-Si alloy effectively mitigated the abrasive wear, and the Al matrix effectively endured to accept a significant amount of plastic deformation caused by wear.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.1
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• pp.8-13
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• 2014

As packing density in integrated circuits increases, multilevel metallization process has been widely used. But hillock formed in the bottom layers of aluminum are well known to make interlayer short in multilevel metallization. In this study, the effects of ion implantation to the metal film and deposition temperature on the hillock formation were investigated. The Al-1%Si thin film of $1{\mu}m$ thickness was DC sputtered with substrate ($SiO_2/Si$) temperature of $20^{\circ}C$, $200^{\circ}C$, and $400^{\circ}C$, respectively. Ar ions ($1{\times}10^{15}cm^{-2}$: 150 keV) and B ions ($1{\times}10^{15}cm^{-2}$, 30 keV, 150 keV) were implanted to the Al-Si thin film. The deposited films were evaluated by SEM, surface profiler and resistance measuring system. As a results, Ar implanting to Al-Si film is very effective to reduce hillock size in the metal deposition temperature below than $200^{\circ}C$, and B implanting to an Al-Si film is effective to reduce hillock density in the high temperature deposition conditions around $400^{\circ}C$. Line width less than $3{\mu}m$ was free of hillock after alloying.

• Bulletin of the Korean Chemical Society
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• v.11 no.1
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• pp.1-7
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• 1990

We present a theoretical investigation on the etching of an Al solid by $SiCl_4$ molecules at a collision energy of 600 eV. The classical trajectory method is employed to calculate Al etching yields, degree of anisotropy, kinetic energy distribution and angular distribution. The calculated results are compared with the reaction of a Cu solid by $SiCl_4$. The major products of the reaction are aluminum monomers and dimers together with considerable quantities of multimers. The Al solid shows better etching yield and better anisotropy than the Cu solid. This is consistent with the problem in the CMOS micro-fabrication of the CuAl and CuAlSi alloys. The relevance of these calculations for the dry etching of CuAl alloy is discussed.

• Korean Journal of Materials Research
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• v.28 no.9
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• pp.499-505
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• 2018

This investigates the microstructure and mechanical properties of Al hybrid material prepared by electromagnetic duo-casting to determine the effect of heat treatment. The hybrid material is composed of an Al-Mg-Si alloy, pure Al and the interface between the Al-Mg-Si alloy and pure Al. It is heat-treated at 373, 573 and 773K for 1h and T6 treated (solution treatment at 773K for 1h and aging at 433K for 5h). As the temperature increases, the grain size of the Al-Mg-Si alloy in the hybrid material increases. The grain size of the T6 treated Al-Mg-Si alloy is similar to that of one heat-treated at 773K for 1h. The interface region where the micro-hardness becomes large from the pure Al to the Al-Mg-Si alloy widens with an increasing heat temperature. The hybrid material with a macro-interface parallel to the tensile direction experiences increased tensile strength, 0.2 % proof stress and the decreased elongation after T6 heat treatment. On the other hand, in the vertical direction to the tensile direction, there is no great difference with heat treatment. The bending strength of the hybrid material with a long macro-interface to the bending direction is higher than that with a short macro-interface, which is improved by heat treatment. The hybrid material with a long macro-interface to the bending direction is fractured by cracking through the eutectic structure in the Al-Mg-Si alloy. However, in the hybrid material with a short macro-interface, the bending deformation is observed only in the limited pure Al.

• Journal of Powder Materials
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• v.1 no.1
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• pp.42-51
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• 1994

6061Al-SiCP metal matrix composite materials(MMCs) were fabricated by injecting SiCP particles directly into the atomized spray. The main attraction of this technique is the rapid fabrication of semi-finished, composite products in a combined atomization, particulate injection(10 $\mu\textrm{m}$, 40 $\mu\textrm{m}$, SiCP) and deposition operation. Conclusions obtained are as follows; The microstructure of the unreinforced spray formed 6061Al alloy consisted of relatively fine(50 $\mu\textrm{m}$) equiaxed grains. By comparision, the microstructure of the I/M materials was segregated and consisted of relatively coarse(150 $\mu\textrm{m}$) grains. The probability of clustering of SiCP particles in co-sprayed metal matrix composites increased it ceramic particle size(SiCP) was reduced and the volume fraction was held constant. Analysis of overspray powders collected from the spray atomization and deposition experiments indicated that morphology of powders were nearly spherical and degree of powders sphercity was deviated due to composite with SiCp particles. Interfacial bonding between matrix and ceramics was improved by heat treatment and addition of alloying elements(Mg). Maximum hardness values [Hv: 165 kg/mm2 for Al-10 $\mu\textrm{m}$ SiCp Hv--159 kg/mm2 for Al-40 $\mu\textrm{m}$SiCp] were obtained through the solution heat treatment at $530^{\circ}C$ for 2 hrs and aging at $178^{\circ}C$, and there by the resistance were improved.

• Journal of the Korean Ceramic Society
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• v.29 no.3
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• pp.223-231
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• 1992

CaO and ZnO were added to Al2O3-SiO2 binary system respectively as flux, then ZrO2 and TiO2 were applied as nucleating agent to these CaO-Al2O3-SiO2 and ZnO-Al2O3-SiO2 ternary system glass. The transparency could not be kept in CaO-Al2O3-SiO2 system glass, whereas the transparent glass-ceramics were prepared in ZnO-Al2O3-SiO2 system glass containing ZrO2 as the nucleating agent. At this time the optimum heating temperatures for the nucleation and the crystal growth were 78$0^{\circ}C$ and 97$0^{\circ}C$. The sizes of the precipitated crystals in the transparent glass-ceramics were below 0.1 ${\mu}{\textrm}{m}$, and their light transmissibilities were more than 80%.

• Journal of Korea Foundry Society
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• v.26 no.6
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• pp.241-248
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• 2006

The effects of silicon content and melt treatment on the fluidity of Al-Si alloys during squeeze casting were investigated. The fluidity of Al-3.0 wt%Si alloy was found to be lower than that of Al-1.0 wt%Si and the fluidity of the alloy with more than 3.0 wt%Si increased with the silicon content upto 13.0 wt% and rather decreased with15.0 wt%. The fluidity was also increased by the separated treatment of grain refinement or eutectic modification, and even more by the simultaneous treatment of both. The fluidity of hypereutectic alloy was increased by the refinement of primary silicon particle.

• Electrical & Electronic Materials
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• v.9 no.2
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• pp.188-195
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• 1996

The AlSi etching process using the MERIE type reactor carried out with different process parameters such as C1$_{2}$ and N$_{2}$ gas flow rate, RF power and chamber pressure. The etching characteristics were evaluated in terms of etch rate, selectivity, uniformity and etched profile. As the N2 gas flow rate is increased, the AlSi etch rate is decreased and uniformity has remained constant within .+-.5%. The etch rate is increased and uniformity is decreased, according to increment of the C1$_{2}$ gas flow rate, RF power and chamber pressure. Selective etching of TEOS with respect to AlSi is decreased as the RF power is increased while it is increased by increment of the C1$_{2}$ gas flow rate and chamber pressure, on the other hand, selective etching of photoresist with respect to AlSi is increased by increment of the C1$_{2}$ gas flow rate and chamber pressure, it is decreased as the N$_{2}$ gas flow rate is increased.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.393-396
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• 2005

This paper is concerned with the drawing process of $Al-1\%Si$ bonding wire. In this study, the finite-element model established in previous work was used to analyze the effect of various forming parameters, which included the reduction in area, the semi-die angle, the aspect ratio, the inter-particle spacing and orientation angle of the fine Si particle in drawing processes. The finite-element results gave the consolidation condition. From the results of analysis, the effects of each forming parameter were determined. It is possible to obtain the Important basic data which can be guaranteed in the fracture prevention of $Al-1\%Si$ wire by using FE-Simulation.