• Journal of Welding and Joining
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• v.32 no.3
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• pp.68-73
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• 2014

Among through silicon via (TSV) technologies, for replacing Cu filling method, the method of molten solder filling has been proposed to reduce filling cost and filling time. However, because Sn alloy which has a high coefficient of thermal expansion (CTE) than Cu, CTE mismatch between Si and molten solder induced higher thermal stress than Cu filling method. This thermal stress can deteriorate reliability of TSV by forming defects like void, crack and so on. Therefore, we fabricated SiC composite filling material which had a low CTE for reducing thermal stress in TSV. To add SiC nano particles to molten solder, ball-typed SiC clusters, which were formed with Sn powders and SiC nano particles by ball mill process, put into molten Sn and then, nano particle-dispersed SiC composite filling material was produced. In the case of 1 wt.% of SiC particle, the CTE showed a lowest value which was a $14.8ppm/^{\circ}C$ and this value was lower than CTE of Cu. Up to 1 wt.% of SiC particle, Young's modulus increased as wt.% of SiC particle increased. And also, we observed cross-sectioned TSV which was filled with 1 wt.% of SiC particle and we confirmed a possibility of SiC composite material as a TSV filling material.

• Journal of Korea Foundry Society
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• v.22 no.1
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• pp.42-48
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• 2002

Effects of coating treatment of metallic Cu, Ni-P film on $SiC_p$, for $SiC_p$/iron aluminide composites were studied. Porous hybrid preforms were fabricated by reactive sintering after mixing the coated $SiC_p$, Fe and Al powders. Then the final composites were manufactured by squeeze casting after pouring AC4C Al alloy melts in preforms. The change of reactive temperature, density, microstructure of the preforms and microstructure of the composites were investigated. The exprimental results were summarized as follows. The thickness of Cu and Ni-P metallic layer formed on $SiC_p$ by electroless plating method were about $0.5{\mu}m$ and coated uniformly. There was no remakable change in the ignition temperature with variation of the mixing ratio of Fe and Al powder while in the case of coated $SiC_p$ it was lower about $20^{\circ}C$ than in the non-coated $SiC_p$. The maximum reaction temperature increased with increasing Al contents, but decreased with increasing $SiC_p$ contents. Expansion ratio of preform after reactive sintering increased with amount of Cu coated $SiC_p$. In the case of Fe-70at.%Al, the expansion ratio was about 7% up to 8wt.% of $SiC_p$, addition but further addition of $SiC_p$, increased the ratio significantly. And in the case of Fe-50 and 60at.%Al, it was about 20% up to 16wt.% of $SiC_p$ addition and about 28% in 24wt.% of $SiC_p$, addition. The microstructures of compounds showed that the grains became finer as amount of $SiC_p$, and mixing ratio of iron powder increased and the shape of compounds was changed gradually from irregular to spheroidal.

• Journal of the Korean Vacuum Society
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• v.6 no.2
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• pp.143-150
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• 1997

In this study, doffusion barrier properties of 1000 $\AA$ thick molybdenum compound(Mo, Mo-N, $MoSi_2$, Mo-Si-N) films were investigated using sheet resistance measurement, X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), Scanning electron mircoscopy(SEM), and Rutherford back-scattering spectrometry(RBS). Each barrier material was deposited by the dc magnetron sputtering and annealed at 300-$800^{\circ}C$ for 30 min in vacuum. Mo and MoSi2 barrier were faied at low temperatures due to Cu diffusion through grain boundaries and defects in Mo thin film and the reaction of Cu with Si within $MoSi_2$, respectively. A failure temperature could be raised to $650^{\circ}C$-30 min in the Mo barrier system and to $700^{\circ}C$-30 min in the Mo-silicide system by replacing Mo and $MoSi_2$ with Mo-N and Mo-Si-N, respectively. The crystallization temperature in the Mo-silicide film was raised by the addition of $N_2$. It is considered that not only the $N_2$, stuffing effect but also the variation of crystallization temperature affects the reaction of Cu with Si within Mo-silicide. It is found that Mo-Si-N is the more effective barrier than Mo, $MoSi_2$, or Mo-N to copper penetraion preventing Cu reaction with the substrate for $30^{\circ}C$min at a temperature higher than $650^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.30 no.5
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• pp.415-422
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• 1986

The metal-support interaction of copper oxide supported on ${\gamma}$-alumina and silica was studied by X-ray diffraction (XRD) and temperature-programmed reduction(TPR). It was found that XRD pattern of CuO can not be observed up to 5.0wt % copper content for CuO/${\gamma}-Al_2O_3$ while CuO/$SiO_2$ sample shows the CuO pattern even at 2.5wt% copper content. $H_2-$TPR of CuO/${\gamma}-Al_2O_3$ system shows four major peaks at 145${\circ}C$, 185${\circ}C$, 210${\circ}C$, and 250${\circ}C$. In the case of CuO/$SiO_2$, a large peak at 250${\circ}C$ was appeared accompanying a small peak at 425${\circ}C$. Comparing the TPR peaks with that of copper aluminate which was prepared from the calcination of CuO/${\gamma}-Al_2O_3$ at 1000${\circ}C$, the peaks at around 145${\circ}C$, 200${\circ}C$ (185${\circ}C$ and 210${\circ}C$), and 250${\circ}C$ were corresponded to $Cu^+$ ion in CuO interacting ${\gamma}-Al_2O_3$, $Cu^+$ ions in defect sites of ${\gamma}-Al_2O_3$ and $Cu^{2+}$ ion in the bulk CuO layer, respectively. From the results, it was concluded that there is considerable metal-support interaction in CuO on ${\gamma}-Al_2O_3$ and the interaction results in a stabilization of $Cu^+$ ion in the system.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.1
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• pp.47-58
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• 2004

Loss factors of A356, Mn-Cu alloy and aluminum matrix composites reinforced with $SiC_p$ and Ni-coated graphite particles at various contents have been investigated using clamped-free cantilever beam method. The loss factors of half-power bandwidth of the specimens were measured over a wide range of frequencies from 50 to 3300Hz. Among the specimens, Al-10%$SiC_p$-10%$C_p$ showed the highest loss factor at the mode I, while Mn-Cu alloy showed the highest loss factors at the modes II and III. Consequently, at the mode I the Al-10%$SiC_p$--10%$C_p$ showed the loss factor of 0.00093, which is 2.64 and 1.58 times higher than those of A356 and Mn-Cu alloy, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.4
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• pp.210-214
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• 2002

The crystallization behavior of amorphous silicon (a-Si) film was investigated by using Cu-field aided lateral crystallization (Cu-FALC) process below $450^{\circ}C$. The lateral crystallization was induced from the Cu deposited region outside of pattern toward the Cu-free region inside of the pattern by applying an electric field during heat treatment. As expected, the lateral crystallization toward Cu-free region proceeded from negative toward positive electrode side. The occurrence of Cu-FALC phenomenon was interpreted in terms of dominant diffusing species in the reaction between Cu and Si. Even at the annealing temperature of $350^{\circ}C$, the large dendrite-shaped branches were formed in the crystallized region and the polarity in the lateral crystallization was clearly observed. Consequently, we could successfully crystallize the a-Si at the temperature as low as $350^{\circ}C$ by an electric field of 30 V/cm with fast crystallization velocity of 12 $\mu$m/h.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.144-147
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• 2003

Cu+ ions drift diffusion in formal oxide film and SiOCH film for interlayer dielectric is evaluated. The diffusion is investigated by measuring shift in the flatband voltage of capacitance/voltage measurements on Cu gate capacitors after bias temperature stressing. At a field of 0.2MV/cm and temperature $200^{\circ}C,\;300^{\circ}C,\;400^{\circ}C,\;500^{\circ}C$ for 10min, 30min, 60min. The Cu+ ions drift rate of $SiOCH(k=2.85{\pm}0.03)$ film is considerable lower than termal oxide. As a result of the experiment, SiOCH film is higher than Thermal oxide film for Cu+ drift diffusion resistance. The important conclusion is that SiOCH film will solve a causing reliability problems aganist Cu+ drift diffuion in dielectric materials.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.589-594
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• 1997

Superconducting $YBa_2Cu_3O_y$ thin films were prepared at the deposition temperature of $650^{\circ}C$ under oxygen partial pressure of 0.0126 Torr on Si(111) and SrTiO3(100) substrates by chemical vapor deposition technique using $\beta$-diketonates of Y, Ba and Cu as source materials. The thin film fabricated on $SrTiO_3(100)$ had a $T_{c,onset}$ of 91K and $T_{c.0}$ of 87K. The thin film prepared on Si(111) had a $T_{c,onset}$ of 91K but didn't have a $T_{c.0}$ at liquid nitrogen boiling point(77.3K). Dense and two-dimensionally well alligned microstructure was developed for the film deposited on $SrTiO_3(100)$ substrate whereas a relatively porous and randomly distributed microstructure was developed for the film prepared on Si(111) substrate.

• Journal of Korea Foundry Society
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• v.7 no.2
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• pp.114-121
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• 1987

In order to determine the plane strain fracture toughness of Al-Si-Cu-Mg alloy castings, solution heat treatments have been conducted at $530^{\circ}C$ for 8hr and aged for 10hr at $145^{\circ}C$, $160^{\circ}C$ and $175^{\circ}C$. Effects of aging treatment and of Si contents on the fracture toughness have been investigated by a three point loaded bend test, using the artificial notch. The results obtained are as follows; 1) The fracture toughness is appreciably affected by the aging treatment temperature and Si contents. The specimen aged for 10hr at $145^{\circ}C$ has the highest fracture toughness. 2) Increasing Si contents from 5% to 9% results in decrease of fracture toughness. 3) Increasing the aging temperature and Si contents, C.O.D. value was decreased. The specimen aged for 10hr at $145^{\circ}C$ has the highest C.O.D. value. 4) Dimple patterns were observed in the specimens of containing under 7% Si, while mixed cleavage-dimple patterns in those of over 8% Si.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.155-155
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• 2008

계속되는 반도체 산업의 발달로 반도체 배선 공정에서는 Al을 대체할 배선 금속으로 Cu에 대한 관심이 집중되고, 일부 공정에서는 Al을 대신하여 사용하고 있다. 이러한 Cu는 Al에 비교하여 많은 장점을 가지고 있지만 Si 기판과 저온에서 쉽게 확산되는 큰 문제점을 가지고 있다. 따라서 이러한 문제를 해결하기 위한 방법으로 현재까지 연구된 대안으로는 Cu와 Si기판 사이에 확산방지막을 삽입하는 것이 대안으로 알려져 있다. 본 연구는 Cu 금속배선 공정을 위하여 Cu와 Si기판과의 확산을 효과적으로 방지할 확산방지막을 텅스텐(W)을 주 구성 물질로 여기에 불순물을 첨가한 W-C-N 확산방지막에 대하여 연구하였으며, 특히 W-C-N 확산방지막의 결정 및 표면 구조에 대한 물성 특성을 연구하였다. 여러 조건변화에 따라서 확산방지막의 특성을 확인하기 위하여 조건이 다르게 증착된 W-C-N 확산방지막을 상온에서 고온으로 열처리하여 열처리 전후를 WET-SPM (Scanning Probe Microscope)을 사용하여 그 물리적 특성을 조사하였다. 이러한 분석을 통하여 가장 안정된 W-C-N 확산방지막의 증착조건을 확인하였으며, 이를 기반으로 박막의 물리적 특성을 연구하였다.