• Korean Journal of Materials Research
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• v.31 no.10
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• pp.569-575
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• 2021

The reactivity evaluation of copper is performed using ethylenediamine, aminoethanol, and piperidine to apply organic chelators to copper etching. It is revealed that piperidine, which is a ring-type chelator, has the lowest reactivity on copper and copper oxide and ethylenediamine, which is a chain-type chelator, has the highest reactivity via inductively coupled plasma-mass spectroscopy (ICP-MS). Furthermore, it is confirmed that the stable complex of copper-ethylenediamine can be formed during the reaction between copper and ethylenediamine using nuclear magnetic resonance (NMR) and radio-thin layer chromatography. As a final evaluation, the copper reactivity is evaluated by wet etching using each solution. Scanning electron micrographs reveal that the degree of copper reaction in ethylenediamine is stronger than that in any other chelator. This result is in good agreement with the evaluation results obtained by ICP-MS and NMR. It is concluded that ethylenediamine is a prospective etch gas for the dry etching of the copper.

• The Korean Journal of Malacology
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• v.29 no.2
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• pp.129-137
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• 2013

This study was conducted to find out the changes of survivorship, respiration and organ structure of Mactra veneriformis exposed to copper (Cu). Experimental period was four weeks. Experimental groups were composed of one control condition and three copper exposure conditions (0.025, 0.050 and 0.100 mg/L). The results of the study confirmed that copper induces reduction of survival rate and respiration rate and histopathology of organ structure of the bivalve. In the copper concentration of 0.100 mg/L, mortality was 100% after Cu exposure of 3 weeks. Respiration rate was observed exposure groups lower than control decline by 75%. Histological analysis of organ system illustrated expansion of hemolymph sinus, disappearance of epidermal layer and degeneration of connective tissue layer of the mantle. Also, histological degenerations as epithelial necrosis and hyperplasia of mucous cells are recognized in the gill and it was observed expansion of hemolymph sinus, disruption of epithelial layer, decrease of mucous cell and degeneration of connective tissue layer in the foot. In the digestive diverticulum, it was showed atrophy of basophilic cell and degeneration of epithelial cell in the digestive tubules, and as the concentration of copper increased the accumulation of lipofuscin increased.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.1
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• pp.67-71
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• 2021

In this study, graphene layer was grown on metal microwire using chemical vapor deposition. The difference of carbon solubility between copper and nickel resulted in the formation of mono-layer and multi-layer graphene were formed on the surfaces of copper and nickel microwires, respectively. During the growth of graphene at high temperature, copper and nickel were recrytallized and the grain size increased. The ampacity of graphene/copper microwire was improved by approximately 27%, 1.91×105 A/㎠, compared to pristine copper microwire. Similar to this behavior, the ampacity of multilayer graphene/nickel microwire was 4.41×104 A/㎠ which is about about 36% improved compared to the pure nickel microwire. The excellent electrical properties of graphene/metal composites are beneficial for supplying the electrical energy to the high-power electronic devices and equipment.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.41.2-41.2
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• 2011

Recently, scaling down of ULSI (Ultra Large Scale Integration) circuit of CMOS (Complementary Metal Oxide Semiconductor) based electronic devices become much faster speed and smaller size than ever before. However, very narrow interconnect line width causes some drawbacks. For example, deposition of conformal and thin barrier is not easy moreover metallization process needs deposition of diffusion barrier and glue layer. Therefore, there is not enough space for copper filling process. In order to overcome these negative effects, simple process of copper metallization is required. In this research, Cu-V thin alloy film was formed by using RF magnetron sputter deposition system. Cu-V alloy film was deposited on the plane $SiO_2$/Si bi-layer substrate with smooth and uniform surface. Cu-V film thickness was about 50 nm. Cu-V layer was deposited at RT, 100, 150, 200, and $250^{\circ}C$. XRD, AFM, Hall measurement system, and XPS were used to analyze Cu-V thin film. For the barrier formation, Cu-V film was annealed at 200, 300, 400, 500, and $600^{\circ}C$ (1 hour). As a result, V-based thin interlayer between Cu-V film and $SiO_2$ dielectric layer was formed by itself with annealing. Thin interlayer was confirmed by TEM (Transmission Electron Microscope) analysis. Barrier thermal stability was tested with I-V (for measuring leakage current) and XRD analysis after 300, 400, 500, 600, and $700^{\circ}C$ (12 hour) annealing. With this research, over $500^{\circ}C$ annealed barrier has large leakage current. However V-based diffusion barrier annealed at $400^{\circ}C$ has good thermal stability. Thus, thermal stability of vanadium-based thin interlayer as diffusion barrier is good for copper interconnection.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.4 s.33
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• pp.1-5
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• 2004

A multi-layer flexible substrate is composed of copper(Cu)/polyimide that are known as good electrical conductivity, and low dielectric constant, respectively. In this study. conductor line of $5{\mu}m$-pitch was successfully fabricated without non-uniform pattern shape by electroplating copper and coating polyimide on patterned stainless steel. For multi-layer flexible substrate, via holes were drilled by UV laser and filled with electroplating copper and tin. And then, the PI layer with vias and conductor lines was stripped from stainless steel substrate. The PI layers were laminated at once with careful alignment between layers. Solid state reaction between tin and copper during lamination formed the intermetallic compounds of $Cu_6Sn_5$($\eta$-phase) and $Cu_3Sn$($\epsilon$-Phase) and achieved a complete inter-connection by vertically positioning the plugged via holes on via pad. The via formation process has several advantages; such as better electrical property and lower cost than V type via and paste via.

• Corrosion Science and Technology
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• v.2 no.2
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• pp.88-92
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• 2003

The technique for in situ simultaneous measurements of IR-RAS and QCM, which has been developed for investigation of corrosion in gaseous environments, was employed to study the effects of an extremely thin water layer on the corrosion rate. An evaporated copper film on a QCM element was exposed to air containing water vapor and $SO_2$, and time-resolved IR-RAS spectra were measured and mass gains were simultaneously followed with QCM. The tested ranges of relative humidity (RH) and concentration of $SO_2$ were 60% - 90% and 1 - 20 ppm, respectively. On the basis of 2D-IR analysis, the corrosion products were determined to be Chevreul's salt ($CuSO_3Cu_2SO_3{\cdot}2H_2O$) and $CuSO_4{\cdot}5H_2O$. By constructing curves of the relations between band intensities of IR spectra and mass gains of QCM for the corrosion products, the time variations in each product were determined from spectral experiments on copper plates. The thicknesses of physically adsorbed water layers in course of the corrosion process were also determined from water band intensities. The results showed that the thickness of the physically adsorbed water layer increased with increase in RH, and it also increased with increase in accumulation of corrosion products. The latter is probably due to the capillary effect of the corrosion products.

• Journal of Magnetics
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• v.10 no.2
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• pp.48-51
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• 2005

The spin transfer induced magnetization switching has been reported to occur in magnetic multilayer structures whose scope usually consists of one stack of ferromagnetic / non-ferromagnetic / ferromagnetic (F / N / F) materials. In this work, it is shown that: 1) Copper used as a buffer layer between the free Co and the Au cap-layer can clearly increase the probability to get the spin transfer induced magnetization switching in a simple spin valve Co 11 / Cu 6/ Co 2 (nm); 2) Furthermore, when Ruthenium is simultaneously applied as a buffer layer on the Si-substrate, the critical switching currents can be reduced by $30\%$, and the absolute resistance change delta R $[{\Delta}R]$ of that stack can be enlarged by $35\%$. The enhancement of the spin transfer induced magnetization switching can be ascribed to a lower local stress in the thin Co layer caused by a better lattice match between Co and Cu and the smoothening effect of Ru on the thick Co layer.

• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.307-311
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• 1999

Interfacial properties of electrode and organic thin layer is one of the most important factor in performing a Light Emitting Diodes(LED). Phthalocyanine copper was used as a buffer layer to improve interface characteristic, so that device efficiency was improved. In this study, LEDs were fabricated as like structures of Indium-Tin-Oxide (ITO) / N,N' -Diphenyl-N,N'-di(m-tolyl)-benzidine (TPD) / 8-Hydroxyquinoline aluminum(Alq) / Aluminum(Al) and Indium-Tin-Oxide(ITO) / N,N'-Diphenyl-N,N' -di(m-tolyl)-benzidine(TPD) / 2-(4-Biphenylyl)-5(4-tert-butyl-phenyl)-1,3,4-oxadiazole(PBD) / Aluminum(Al). In these devices, CuPC was layered at electrode/organic layer interface. As position is changing and thickness is changing, devices showed characteristic luminescence efficiency and luminescence inensity respectively. We showed in this study that luminescence efficiency was improved with CuPC layer in LEDs. The efficiency of device with layer CuPC is higher than that of 2 layer CuPC. However, the luminescence of 2 layer CuPC device got higher value.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2004.11a
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• pp.238-244
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• 2004

In this study we have examined Copper and Nickel double metal layer on the synthetic fabrics by electroless chemical plating. We have focused on the shielding effect of the four kinds of woven and none-woven structure against electromagnetic fields. The shielding effectiveness of Copper and Nickel double metal layer showed between 90dB and 70dB, which are closely related to the fabric structure, that is cover factor and density. The more dense, The better shielding effect.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.173-178
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• 2008

This is green roof bottom system which composed by aluminum valve and glass fiber together as major reinforcement, so the cooper sheet can have root proof, and using recycled tire gel-type membrane waterproofing system which dost not contains VOCs. The copper sheet reduce the plants' root growing, so it helpes to maintain the waterproofing layer and stability of root proofing. Gel type membrane waterproofing system can do waterproofing, stress dispersion, and reducing leakage expansion. So those two materials can help each other to make green roof bottom layer would have the stability and durability.