• 한국재료학회지
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• 제9권5호
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• pp.538-543
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• 1999

금속 배선 공정에서 응용되고 있는 reflow에 관한 이론올 살펴보고, 금속 박막 reflow에 영향을 미치는 인자 및 re­flow와 grain growth의 관계를 고찰하였다. 금속 박막 reflow의 구동력은 표연 위치에 따른 chemical potential의 차이이며, 이러 한 구동력에 의하여 원자가 이동하게 된다. 반도체 소자의 금속 배선을 제작하는 조건에서 원자의 이동은 주로 surface diffusion에 의하여 이루어진다. 금속 박막의 reflow에 영향율 미치는 인자로는 reflow 온도, reflow 시간, reflow 분위기, 박막 두께, 박막 재료, underlayer 재료, 패턴 size, aspect ratio가 있으며, 박막을 reflow시키는 동안에 발생하는 grain growth에 의하여 reflow 특성이 변할 것으로 예상되므로 reflow 시 grain growth의 영향을 고려하여야 하리라 생각된다.

• 한국전자통신학회논문지
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• 제9권3호
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• pp.273-278
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• 2014

다결정 및 단결정 Cu 시편에 CVD를 이용하여 그래핀을 합성 하였으며, 광학현미경 조직사진을 이미지 조절 및 분석 가능한 소프트웨어를 활용하여 광학현미경 조직사진 상에서는 구분이 어려운 그래핀 합성에 따른 미세한 특성들을 이미지 분석을 통하여 구현하였다. 그래핀이 Cu 시편의 결정입계에서 핵 생성하여 Cu 입내로 성장하는 거동을 보이고, 그래핀 성장 시 그래핀 입계의 이동이 Cu 입계 및 기공과 상호작용하는 현상들에 대하여 설명하고, 결과적으로 야기되는 문제들의 원인과 결과를 논하였다.

• The Korean Journal of Ceramics
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• 제4권3호
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• pp.207-212
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• 1998

By comparison of the experimental results in two systems of ZnO varistors, it's appear that Sb2O3 is the indispensable element for twining in ZnO varistors and the Zn7Sb2O12 spinel acts as the nucleus to form twins. Al2O3 is not the origin of twining in ZnO varistor, but it was found that Al2O3 could strengthen the twining and form a deformation twining by ZnAl2O4 dragging and pinning effect. The inhibition ratios of grain and nonuniformity of two systems ZnO varistors increase with the increase of Al2O3 content. The twins affect the inhibition of grain growth, the mechanism could be explained follow as: twins increase the mobility viscosity of ZrO grain and grain boundary, and drag ZrO grain and liquid grain boundary during the sintering, then the grain growth is inhibited and the microstructure becomes more uniform.

• 한국재료학회지
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• 제4권7호
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• pp.750-758
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• 1994

본 연구에서는 반구형(HSG) 다결성 실리콘 박막을 제조하여 박막에 존재하는 결정립들의 특성과 각 결정립들의 형성기구를 예측하고자 하였다. LPCVD법으로 실리콘 박막을 증착하여 미세구조를 관찰, 분석한 결과 $575^{\circ}C$ 증착온도에서 HSG 다결정 실리콘 박막이 형성되었음을 관찰하였다. 이 HSG 박막은 비정질 및 결정질 상으로 구성되어 있었으며 결정립은 박막의 표면에 존재하는 upper grain들과 $SiO_{2}$와의계면에 존재하는 lower grain들로 구분되었다. Upper grain은 실리콘 원자의 표면확산에 의하여 형성되었으며, lower grain은 고상성장에 의하여 형성되었다. 성장한 결정립들의 성장방위를 분석한 결과 주로 upper grain은 <110>, lower grain은 <311>과 <111>방위를 나타내었다. 이러한 방위관계는 각 결정립들의 형성기구(formation mechanism)의 차이에 기인한다고 사료된다. 또한 HSG박막의 미세구조와 진공열처리한 시편을 관찰한 결과 HSG 박막의 형성은 실리콘 원자의 표면확산에 의해 지배됨을 알았다.

• 열처리공학회지
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• 제11권4호
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• pp.324-332
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• 1998

The grain growth characteristics of dual-phase (${\alpha}+{\gamma}$) containing high Cr-steel have investigate using ${\alpha}$-, ${\gamma}$-single phases and (${\alpha}+{\gamma}$)dual-phase of 12%Cr Steel. The heat treatment has performed at $1000-1200^{\circ}C$ for 1-100hr. The results are as follows : 1) The grain growth rate in (${\alpha}+{\gamma}$) dual phase was substantially slower than that of single grain. 2) The relation between mean grain radius $\bar{{\gamma}}$ and annealing time t is, in general, described as following equation : $$(\bar{{\gamma}})^n-(\bar{{\gamma}_o})^n=K_n{\cdot}t{\cdots}{\cdots}(1)$$ i) In the case of single phase of high Cr steel, Eq.(1) is described as $(\bar{{\gamma}})^2-(\bar{{\gamma}_o})^2=K_2{\cdot}t$ and the grain growth is controlled by boundary migration. ii) In dual phase, the grain growth needs diffusion of alloying elements because the chemical composition of ${\alpha}$- and ${\gamma}$- phases differs from each other. When the volume fraction of ${\alpha}$-, ${\gamma}$-phase was almost equal and ${\gamma}$-phase in the case of 80 and $90%{\gamma}$. Eq.(1) is described as $(\bar{{\gamma}})^3-(\bar{{\gamma}_o})^3=K_3{\cdot}t$ because the grain growth is controlled by volume diffusion iii) In the case of ${\gamma}$-rich phase (80 and $90%{\gamma}$), the grain growth of minor phase (10 and $20%{\alpha}$) is described as $(\bar{{\gamma}})^4-(\bar{{\gamma}_o})^4=K_4{\cdot}t$ because the boundary diffusion is predominent rather than volume diffusion.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.798-802
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• 2002

Metallurgical studies on the bonded interlayer of directionally solidified Ni-base superalloy GTD111 joints were carried out during transient liquid phase bonding. The formation mechanism of solid during solidification process was also investigated. Microstructures at the bonded interlayer of joints were characterized with bonding temperature. In the bonding process held at 1403K, liquid insert metal was eliminated by well known mechanism of isothermal solidification process and formation of the solid from the liquid at the bonded interlayer were achieved by epitaxial growth. In addition, grain boundary formed at bonded interlayer is consistent with those of base metal. However, in the bonding process held at 1453K, extensive formation of the liquid phase was found to have taken place along dendrite boundaries and grain boundaries adjacent to bonded interlayer. Liquid phases were also observed at grain boundaries far from the bonding interface. This phenomenon results in liquation of grain boundaries. With prolonged holding, liquid phases decreased gradually and changed to isolated granules, but did not disappeared after holding for 7.2ks at 1473K. This isothermal solidification occurs by diffusion of Ti to be result in liquation. In addition, grain boundaries formed at bonded interlayer were corresponded with those of base metal. In the GTD-ll1 alloy, bonding mechanism differs with bonding temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.1057-1060
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• 2001

By comparison of the experimental results in two systems of ZnO varistors, its appear that Sb$_2$O$_3$is the indispensable element for twinning in ZnO varistors, and the Zn$_{7}$Sb$_2$O$_{12}$ spinel acts as the nucleus to form twins. A1$_2$O$_3$is not the origin of twinning in ZnO varistor, but it was found that A1$_2$O$_3$could strengthen the twinning and form a deformation twinning by ZnA$_{12}$O$_4$-dragging and pinning effect. The inhibition ratios of grain growth and nonuniformity of two systems ZnO varistors increase with the increase of A1$_2$O$_3$content. The twins affect the inhibition of grain growth, the mechanism could be explained follow as : twins increase the mobility viscosity of ZnO grain and grain boundary, and drag ZnO grain and liquid grain boundary during the sintering, then the grain growth is inhibited, and the microstructure becomes more uniform.orm.m.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1998년도 춘계학술대회 및 발표대회 강연 및 발표논문 초록집
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• pp.20-21
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• 1998

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.533-538
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• 2000

Ductile fracture of dual phase steel begins with void nucleation, at martensite-ferrite interface of deformed martensite particle. In this study, void nucleation, growth, and coalescence under various strain were studied in dual phase steel. Therefore, by means of the heat treatment of low carbon steel, the study deals with void nucleation and growth for ferrite grain size and martensite volume fraction of dual phase steel using statistical method. Void nucleation and growth with increasing strain are shown depend upon the ferrite grain size. Voids volume fraction generally increase as ferrite grain size decease.

• Journal of Magnetics
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• 제11권3호
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• pp.111-114
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• 2006

We electroplated copper-cobalt thin films on a silicon substrate, which had 150 nm thick copper seed layer. The adhesion between the two metallic layers could be increased by utilizing a proper organic additive, pulse plating technique, and high temperature annealing. The thin films exhibited columnar growth of the deposits and enhanced adhesion. This is attributed to the grain growth mechanism introduced by the additive and annealing.