• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.98-103
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• 2002

BGA(Ball Grid Array) 패키지의 솔더볼 패드 중의 하나인 Au/Ni-Co/Cu 금속층 위에 Bi가 첨가된 Sn-3.5Ag-$\chi$Bi 솔더볼을 리플로우시켰다. 리플로우한 후 130 $^{\circ}C$에서 열처리함에 따른 계면상 및 솔더 내부의 상변화를 관찰하였다. 계면에는 (Ni,Co)$_3$Sn$_4$외에 (Au,Ni,Co,Bi)Sn$_4$가 생성되었음을 관찰할 수 있었고, 솔더 내부에는 (Au,Ni,Co,Bi)SH$_4$, Ag$_3$Sn, Bi 상이 혼재되어 있었다. Nano-indentation에 의한 경도 측정 결과, Bi 함량 증가에 따라 경도는 증가하였으나, 볼전단(Ball Shear) 테스트 결과는 Bi가 증가됨에 따라 오히려 볼전단 강도값이 감소하였다. 이는 파면 검사 결과, 파괴 경로가 주로 계면의 금속간 화합물과 솔더 사이에서 진행함에 기인한 것이다. 솔더 내부의 파괴 경로를 가진 2.5Bi가 가장 우수한 볼전단 강도값을 나타내었는데, 이는 솔더내의 Bi의 고용강화에 기인한 것으로 보인다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.05a
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• pp.32-32
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• 1999

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.10
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• pp.934-937
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• 2008

Organic field-effect transistors (OFETs) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine (CuPc) based field-effect transistor with different metal electrode. So we need the effect of the substituent group attached to the phthalocyanine on the surface potential was investigated by Kelvin probe method with varying temperature of the substrate. We were obtained the positive shift of the surface potential for CuPc thin film. We observed the electron displacement at the interface between Au electrode and CuPc layer and we were confirmed by the surface potential measurement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.492-493
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• 2007

Organic field-effect transistors (OFETs) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine(CuPc) based field-effect transistor with different metal electrode. So we need the effect of the substituent group attached to the phthalocyanine on the surface potential was investigated by Kelvin probe method with varying temperature of the substrate. We were obtained the positive shift of the surface potential for CuPc thin film. We observed the electron displacement at the interface between Au electrode and CuPc layer and we were confirmed by the surface potential measurement.

• Journal of Technologic Dentistry
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• v.20 no.1
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• pp.37-49
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• 1998

The specimens used were Ag-25 Pd-15 Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age- hardening characteristics of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing. X-ray diffraction and electron microscope observations, electrical resistance, ergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, i.e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the $L1_0$ type face-centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affected by the Cu concentration. In stage II, decomposition of the ${\alpha}$ solid solution to a PdCu ordered phase($L1_0$ type) and an Ag-rich ${\alpha}2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was conclued that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipetation procedure was ${\alpha}{\to}{\alpha}+{\alpha}_2+PdCu {\to}{\alpha}_1+{\alpha}_2+PdCu$ at Pd/Cu = 1.7 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.219-219
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• 2012

The formation and thermal desorption behaviors of octanethiol (OT) SAMs on single crystalline Au (111) and polycrystalline Au, Ag, and Cu substrates were examined by X-ray photoelectron microscopy (XPS), thermal desorption spectroscopy (TDS), and contact angle (CA) measurements. XPS and CA measurements revealed that the adsorption of octanethiol (OT) molecules on these metals led to the formation of chemisorbed self-assembled monolayers (SAMs). Three main desorption fragments for dioctyl disulfide (C8SSC8+, dimer), octanethiolate (C8S+), and octanethiol (C8SH+) were monitored using TDS to understand the effects of surface morphology and the nature of metal substrates on the thermal desorption behavior of alkanethiols. TDS measurements showed that a sharp dimer peak with a very strong intensity on single crystalline Au (111) surface was dominantly observed at 370 K, whereas a broad peak on the polycrystalline Au surface was observed at 405 K. On the other hand, desorption behaviors of octanethiolates and octanethiols were quite similar. We concluded that substrate morphology strongly affects the dimerization process of alkanethiolates on Au surfaces. We also found that desorption intensity of the dimer is in the order of Au＞＞Ag＞Cu, suggesting that the dimerization process occurs efficiently when the sulfur-metal bond has a more covalent character (Au) rather than an ionic character (Ag and Cu).

• Journal of the Korean Chemical Society
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• v.61 no.1
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• pp.29-33
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• 2017

Formation of Au particles in nonstoichiometric $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxide from aniline + hydrochloric acid mixtures and chloroauric acid in the ratios 30 : 1; 60 : 1; 90 : 1 (S1-S3) by volume and 0.01 mol of copper acetate, $Cu(OCOCH_3)_2.H_2O$, in each case is performed by sol-gel growth. Powder x-ray diffraction (XRD) results show Au particles are dispersed in tetragonal nonstoichiometric dicopper (I) dicopper (II) oxides, $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$). Average crystallite sizes of Au particles determined using Scherrer equation are found to be in the approximate ranges ${\sim}85-140{\AA}$, ${\sim}85-150{\AA}$ and ${\sim}80-150{\AA}$ in S1-S3, respectively which indicate the formation of Au nano-micro size particles in $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Hysteresis behaviour at 300 K having low loop areas and magnetic susceptibility values ${\sim}5.835{\times}10^{-6}-9.889{\times}10^{-6}emu/gG$ in S1-S3 show weakly ferromagnetic nature of the samples. Broad and isotropic electron paramagnetic resonance (EPR) lineshapes of S1-S4 at 300, 77 and 8 K having $g_{iso}$-values ${\sim}2.053{\pm}0.008-2.304{\pm}0.008$ show rapid spin-lattice relaxation process in magnetic $Cu^{2+}$ ($3d^9$) sites as well as delocalized electrons in Au ($6s^1$) nano-micro size particles in the $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Broad and weak UV-Vis diffuse reflectance optical absorption band ~725 nm is assigned to $^2B_{1g}{\rightarrow}^2A_{1g}$ transitions, and the weak band ~470 nm is due to $^2B_{1g}{\rightarrow}^2E_g$ transitions from the ground state $^2B_{1g}$(${\mid}d_{x^2-y^2}$>) of $Cu^{2+}$ ($3d^9$) ions in octahedral coordination having tetragonal distortion.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.6
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• pp.241-248
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• 2003

$Bi_{1.84}Pb_{0.34}Sr_{1.91}Ca_{2.03}Cu_{3.06}O_{10+\delta}$ high $T_{c}$ superconductors containing Ag as an additive were fabricated by a solid-state reaction method. The superconducting properties, such as the structural characteristics, the critical temperatures, the grain size and the image of mapping on the surface were investigated. Samples with Ag and Au of 50 wt% each were sintered at various temperature(820~$850^{\circ}C$). The structural characteristics, the microstructure of surface and the critical temperature with respect to the each samples were analyzed by XRD and SEM, EDS and four-prove methode respectively. The critical temperature showed the result which the Ag additive samples are higher than Au additive samples. The microstructure of the surface showed the tendency which the Ag additive samples become more minuteness than Au additive samples.

• Proceedings of the Korean Vacuum Society Conference
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• 1995.02a
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• pp.057-58
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• 1995

극소전자 디바이스의 고집적화에 의해 박막배선의 선폭은 0.5$mu extrm{m}$ 이하로 축소되고 있고 상대적으로 높은 전류밀도가 흐르게 된다. 높은 전류밀도하에서는 현재 일반적으로 사용되고 있는 Al을 기본으로 하는 박막배선에서의 electromigration에 의한 결함 발생 그리고 비교적 낮은 전기전도도가 심각한 문제점으로 제기된다. 본 연구에서는 Al과 고전기전도도 물질인 Ag, Cu, 그리고 Au 박막배선에 대해 electromigration에 대한 저항성, 즉 activation energy를 측정 비교함으로써 차세대 극소전자 디바이스를 위한 박막배선재료로서의 가능성을 알아보고자 한다. Electromigration test 및 activation energy를 구하기 위해 순수 Ag, Cu, Al, Au 박막배선을 0.05$\mu\textrm{m}$ 두께, 100$\mu\textrm{m}$ 선폭, 그리고 5000$\mu\textrm{m}$ 길이로 SiO2 열산화막 처리된 pp-Si(100) 기판 위에 진공 증착시켰다. 가속화 실험을 위해 인가된 d.c. 전류밀도는 2$\times$106A/$ extrm{cm}^2$ 이었고, Al과 Au에서는 6$\times$106A/$\textrm{cm}^2$이었다. 실온에서 24$0^{\circ}C$까지의 온도범위에서 d.c.인가후의 저항변화를 측정하여 Median-Time-to-Failure(MTF)를 구한 후 Black 방정식을 이용하여 activation energy를 측정하였다. Activation energy는 Cu가 1.34eV로서 가장 높게 나타났고 Au가 1.01eV, Al이 0.66eV, Ag가 0.29eV의 순으로 측정되었다. 따라서 Cu와 Au 박막배선의 경우 Al보다 electromigration에 대한 저항력이 강한 고활성화에너지 특성을 갖는 고전기전도도 재료로서 차세대 극소전자 디바이스를 위한 대체 박막배선재료로서의 가능성을 보인다.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.187-189
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• 2006

최근 유연솔더에서 무연솔더로 전환함에 따라서 PCB의 도금이 솔더접합부의 각도에 미치는 영향이 중요하게 되었다. 현재 PCB 도금은 Sn, Au, OSP 등으로 다양하게 진행되고 있다. 그러나 PCB 도금이 솔더접합부의 강도에 미치는 영향에 대한 연구는 아직 미비하다. 따라서 본 연구에서는 PCB 도금(Sn, Au, OSP)이 무연솔더(Sn-3.0Ag-0.5Cu) 접합부의 초기 전단강도에 미치는 영향과 열사이클시험 후 솔더접합부의 전단강도에 미치는 영향에 대해서 연구하였다.