• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.49-54
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• 2022

The copper plating process used to fabricate the submicron damascene pattern of Cu wiring for Si wafer was applied to the plating of a PCB pattern of several tens of microns in size using the same organic additives and current density conditions. In this case, the non-uniformity of the plating thickness inside the pattern was observed. In order to quantitatively analyze the cause, a numerical calculation considering the solution flow and electric field was carried out. The calculation confirmed that the depletion of Cu²⁺ ions in the solution occurred relatively earlier at the bottom corner than the upper part of the pattern due to the plating of the sidewall and the bottom at the corner of the pattern bottom. The diffusion coefficient of Cu²⁺ ions is 2.65 10^-10 m²/s, which means that Cu²⁺ ions move at 16.3 ㎛ per second on average. In the cases of small damascene patterns, the velocity of Cu²⁺ ions is high enough to supply sufficient ions to the inside of the patterns, while sufficient time is required to replenish the exhausted copper ions in the case of a PCB pattern having a size of several tens of microns. Therefore, it is found that the thickness uniformity can be improved by reducing the current density to supply sufficient copper ions to the target area.

• Journal of the Korean institute of surface engineering
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• v.43 no.6
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• pp.289-296
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• 2010

The effect of organic additives, thiourea (TU), on the copper electroplated layer of large rectangular size was investigated through physical and various electrochemical techniques. It was found that TU had strong adsorption characteristics on the Ni substrate and affected the initial electroplating process by inducing surface reaction instead of mass transfer in the bulk solution. TU additives had its critical micelle concentration at 200 ppm in copper sulphate solution and showed abrupt change in morphological and electrochemical impedance spectroscopic results around this concentration, which could be related with the destruction of adsorption structure of TU-Cu(I) complex formed at the Ni substrate surface. By conducting a commercial electroplating simulation, when TU additives was included at cmc in the plating solution, it acted as a depolarizer for copper electrodeposition and was effective to reduce the unevenness of copper deposits between centre and edge region at high current densities of 10 ASD.

• Journal of the Korean institute of surface engineering
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• v.41 no.4
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• pp.163-168
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• 2008

The dental orthodontic bracket requires good mechanical properties, such as elastic strength and frictional resistance, combined with a high resistance to corrosion. The objective of this study was to investigate the effects of TiN and ZrN coating on corrosion resistance of orthodontic brackets using various electrochemical methods. Brackets manufactured by Ormco Co. were used, respectively, for experiment. Ion plating was carried out for coatings of bracket using Ti and Zr coating materials with nitrogen gas. Ion plated surface of each specimen was observed with field emission scanning electron microscopy(FE-SEM), energy dispersive Xray spectroscopy(EDS) and electrochemical tester. The corrosion potential of the TiN and ZrN coated bracket was comparatively high. The current density of TiN and ZrN coated bracket was smaller than that of non-coated bracket in 0.9% NaCl solution. Pit nucleated at angle of bracket slot.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.343-352
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• 2013

Purpose: The purpose of this study was to investigate to effect of the ZrN coated on corrosion resistance and physical property of dental Co-Cr alloys using various instruments. Methods: The specimens were used, respectively, for experiment, Arc Ion plating was carried out for dental casting alloys using ZrN coated materials with nitrogen gas. ZrN coated surface of each specimen was observed with field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), vickers hardness tester, and electrochemical tester. Results: The current density of ZrN coated specimen was smaller than that of non-coated specimen in 0.9% NaCl solution. Pit nucleated at scratch of specimen. The pitting corrosion resistant |$E_{max}-E_{rep}$| increased in order of ZrN coated (110 mV), and non-coated wire (100 mV). Conclusion: The corrosion potential of the ZrN coated specimen was comparatively high. the surface of ZrN coated specimen was more smooth than that of other kinds of non-coated specimen. ZrN coated surface showed higher hardness than that of non-coated surface.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.5
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• pp.401-409
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• 2021

The combination of different concentrations of ZnSO₄ in acidic solution as electrolyte in Zn-air batteries was investigated by Zn symmetrical cell test, half-cell and full cell tests. Using 1 M ZnSO₄ + 0.05 M H₂SO₄ as electrolyte and MnO₂ as air cathode catalyst with Zn foil anode, this combination had a satisfactory performance with balance of electrochemical activity and stability. Its electrochemical activity was matched to or even better than the PtRu catalyst in different current density. And its cycle life was improved (more than 100 cycles stable) by suppressing the growth of zinc dendrites on anode obviously. This electrolyte overcame the shortcomings of alkaline electrolyte that are easy to react with CO₂ in the air, severely growth of Zn dendrites caused by uneven plating/stripping of Zn.

• Journal of the Korean Electrochemical Society
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• v.24 no.4
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• pp.100-105
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• 2021

Recently, all-solid-state batteries have attracted much attention to improve safety of rechargeable lithium batteries, but the solid-state batteries of conductive ceramics or solid polymer electrolytes show poor electrochemical properties because of several problems such as high interfacial resistance and undesired reactions. To solve the problems of the reported all-solid-state batteries, a hybrid solid electrolyte is suggested, in this study, NASICON-type nanoparticle Li_1.5Al_0.5Ti_1.5P₃O₁₂ (LATP) conductive ceramic, PVdF-HFP, and a carbonate-based liquid electrolyte were composited to prepare a quasi-solid electrolyte. The hybrid solid electrolyte has a high voltage stability of 5.6 V and shows an suppress effect of lithium dendrite growth in the stripping-plating test. The LiNi_0.83Co_0.11Mn_0.06O₂ (NCM811)-based battery with the hybrid solid electrolyte exhibits a high discharge capacity of 241.5 mAh/g at a high charge-cut-off voltage of 4.8V and stable electrochemical reaction. The NCM811-based battery also shows 139.4 mAh/g discharge capacity without short circuit or explosion at 90℃. Therefore, the LATP-based hybrid solid electrolyte can be an effective solution to improve the safety and electrochemical properties of rechargeable lithium batteries.

• Journal of the Korean Electrochemical Society
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• v.16 no.1
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• pp.46-51
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• 2013

In order to monitor in situ electrochemical reaction we prepared the gold microshells on silica microspheres of $2{\mu}m$ in diameter which were able to not only work as electrodes but also surface enhanced Raman scattering (SERS) active substrates. Previously reported gold microshell using polystyrene as core material have a few serious problems, mostly coming from solubility in organic solvent, nonuniform distribution in size and toxicity of the polystyrene. Here we prepared silica core-gold microshell to obtain a strong SERS active platform benefitting from the physicochemical stability, uniformity and non-toxicity of silica. Varying the concentration of 3-aminopropyl triethoxysilane (APTES), the surfaces of silica beads were modified and the optimal condition was determined to be 1% APTES that made the SERS activity of gold microshell strongest. The gold microshells as made were characterized by homemade Micro-Raman system spectrometer, Field-Emission Scanning Electron Microscope.

• Journal of the Korean Electrochemical Society
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• v.8 no.3
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• pp.130-134
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• 2005

To the best knowledge, the formation and characterization of InSb nanowires have not been reported yet in spite of its good characteristics as a III-V compound semiconductor. The nanowire arrays were potentiostatically electrodeposited in a mixing solution of indium chloride, antimony chloride, citric acid, and potassium citrate according to our previous work on the electrodeposition of the stoichiometric InSb films. The electrical properties of nanowire arrays were measured by semiconductor parameter analyzer, and the microstructural analysis of the nanowires was conducted by employing XRD. Our experimental results indicate that the InSb nanowires have a highly preferred orientation of (220) direction and also exhibit electrical characteristics of n-type semiconductors which we, however, similar to semi-metals mainly due to their narrow band-gap and high electron mobility.

• Transactions of the Korean hydrogen and new energy society
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• v.4 no.2
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• pp.23-28
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• 1993

The $(LM)Ni_{4.5}Co_{0.1}Mn_{0.2}Al_{0.2}$ hydrogen storage alloy powders were conducted 25wt% electroless copper plating in an acidic bath. For the preparation of a hydride electrodes, the copper coated alloy powder was mixed with Si-sealant(organosilicon) and compacted with $6t/cm^2$ at room temperature. The electrode characteristics were examined through electrochemical measurements in a half cell. As a sealant contents increased, the initial discharge capacity of si-sealant bounded electrode was lower and the activation rate in high current density was slower. For extended cycles, however, the electrodes with the Si-sealant were superior in a high rate discharge and useful range of temperature over the sealant-free electrode. In addition, the cycle life increased with increasing the amount of Si-sealant added. It can be suggested from the results that the Si-sealant as a binder could be applied to the preparation of the metal hydride electrode.

• Journal of the Korean institute of surface engineering
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• v.28 no.4
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• pp.199-206
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• 1995

A kinetic study on the electrodeposition of Ni-Zn-P ternary alloys onto a steel in chloride solutions was carried out using a rotating disc electrode. The coatings were characterized using SEM/EPMA and A. A. analysis. The results showed that the plating rates of three components were increased with applied potential, disc rotating speed and temperature. The activation energies of Ni, Zn and P of the coatings were 6.1, 5.1 and 8.0 kcal/mole respectively. Therefore, the deposition rates were controlled partly by surface electrochemical reaction and partly by mass transport. As the potential, temperature of bath and rotating speed of cathode disc were raised, the vol. % ratios of Ni and P of coating layer were increased but that of Zn decreased. The effect of coating parameters on the surface morphology was also examined.