• Journal of Institute of Convergence Technology
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• v.8 no.1
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• pp.33-39
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• 2018

The screen printing method for forming the electrode by applying the existing pressure is difficult to apply to thin wafers, and since expensive Ag paste is used, it is difficult to solve the problem of cost reduction. This can solve both of the problems by forming the front electrode using a plating method applicable to a thin wafer. In this paper, the process conditions of electrode formation are optimized by using LIEP (Light-Induced Electrode Plating). Experiments were conducted by varying the Ni plating bath temperature $40{\sim}70^{\circ}C$, the applied current 5 ~ 15 mA, and the plating process time 5 ~ 20 min. As a result of the experiment, it was confirmed that the optimal condition of the structural characteristics was obtained at the plating bath temperature of $60^{\circ}C$, 15 mA, and the process time of 20 min. The Cu LIEP process conditions, experiments were conducted with Cu plating bath temperature $40{\sim}70^{\circ}C$, applied voltage 5 ~ 15 V, plating process time 2 ~ 15 min. As a result of the experiment, it was confirmed that the optimum conditions were obtained as a result of electrical and structural characteristics at the plating bath temperature of $60^{\circ}C$ and applied current of 15 V and process time of 15 min. In order to form Ni silicide, the firing process time was fixed to 2 min and the temperature was changed to $310^{\circ}C$, $330^{\circ}C$, $350^{\circ}C$, and post contact annealing was performed. As a result, the lowest contact resistance value of $2.76{\Omega}$ was obtained at the firing temperature of $310^{\circ}C$. The contact resistivity of $1.07m{\Omega}cm^2$ can be calculated from the conditionally optimized sample. With the plating method using Ni / Cu, the efficiency of the solar cell can be expected to increase due to the increase of the electric conductivity and the decrease of the resistance component in the production of the solar cell, and the application to the thin wafer can be expected.

• Journal of the Korean institute of surface engineering
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• v.27 no.4
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• pp.223-233
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• 1994

It is well known that compositionally modulated Cu-Ni alloy can be produced by an electrochemical method in Ni sulfate solution containing trace amount of Cu. a mathematical model is presented to describe the current distribution and weight percent of Cu in Ni layer on the rotating disk electrode. The model includes convective-diffusion equation, the Laplace's equation and various overpotentials, and is solved numerically. The thickness of Cu layer is almost uniform whereas the thickness of Ni layer as well as the Ni/Cu weight ratio are increased approaching to the edge of the disk. These results agree well with the experimental values. The ohmic potential drop is suggested as a major cause of a nonuniformity in Ni layer. The optimum plating condition for the fabrication of susperlattice is proposed based on the results of this study.

• Korean Journal of Materials Research
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• v.27 no.11
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• pp.624-630
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• 2017

In this study, we investigated the overpotential of precipitation related to the catalytic activity of electrodes on the initial process of electrodeposition of Co and Co-Ni alloys on polycrystalline Cu substrates. In the case of Co electrodeposition, the surface morphology and the magnetic property change depending on the film thickness, and the relationship with the electrode potential fluctuation was shown. Initially, the deposition potential(-170 mV) of the Cu electrode as a substrate was shown, the electrode potential($E_{dep}$) at the $T_{on}$ of electrodeposition and the deposition potential(-600 mV) of the surface of the electrodeposited Co film after $T_{off}$ and when the pulse current was completed were shown. No significant change in the electrode potential value was observed when the pulse current was energized. However, in a range of number of pulses up to 5, there was a small fluctuation in the values of $E_{dep}$ and $E_{imm}$. In addition, in the Co-Ni alloy electrodeposition, the deposition potential(-280 mV) of the Cu electrode as the substrate exhibited the deposition potential(-615 mV) of the electrodeposited Co-Ni alloy after pulsed current application, the $E_{dep}$ of electrodeposition at the $T_{on}$ of each pulse and the $E_{imm}$ at the $T_{off}$ varied greatly each time the pulse current was applied. From 20 % to less than 90 % of the Co content of the thin film was continuously changed, and the value was constant at a pulse number of 100 or more. In any case, it was found that the shape of the substrate had a great influence.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.2
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• pp.134-140
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• 2019

Oxide ($SnO_2$)/metal alloy (Cu(Ni))/oxide ($SnO_2$) multilayer films were fabricated using the magnetron sputtering technique. The oxide and metal alloy were $SnO_2$ and Ni-doped Cu, respectively. The structural, optical, and electrical properties of the multilayer films were investigated using X-ray diffraction (XRD), ultraviolet-visible (UV-vis) spectrophotometry, and 4-point probe measurements, respectively. The properties of the $SnO_2/Cu(Ni)/SnO_2$ multilayer films were dependent on the thickness and Ni doping of the mid-layer film. Since Ni atoms inhibit the diffusion and aggregation of Cu atoms, the grain growth of Cu is delayed upon Ni addition. For $250^{\circ}C$, the Haccke's figure of merit (FOM) of the $SnO_2$ (30 nm)/Cu(Ni) (8 nm)/$SnO_2$ (30 nm) multilayer film was evaluated to be $0.17{\times}10^{-3}{\Omega}^{-1}$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.878-881
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• 2006

In this paper, the luminance and resistance from different electrode materials of external electrode fluorescent lamp are measured and analyzed. New materials and process technology of external electrode are very important for the developed characteristics in lamp fabrication. In this experiments, three different types for the forming of external electrode are Cu and Al taping, silver paste, Ni and Cu electrode-less plating methods. In the measurements of luminance, the results of brightness by Ni and Au plating methods for the external electrode on lamp glass are presented and also compared with the results by the methods using different electrode materials. The measured resistance values of Ni and Au plating process showed a little bit higher than that of silver paste process in spite of developed results of brightness. But the Ni and Ni/Au plating processes are demonstrated best results and are also showed a little bit different brightness due to different previous sulfate etching treatments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.549-554
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• 2007

In this paper, the luminance and resistance from different electrode materials of external electrode fluorescent lamp are measured and analyzed. New materials and process technology of external electrode are very important for the developed characteristics in lamp fabrication. This experiment, three different types for the forming of external electrode are Cu and Al taping, silver paste, Ni and Cu electrode-less plating methods. In the measurement of luminance, the results of brightness by Ni and Au plating methods for the external electrode on lamp glass are presented and also compared with the results by the methods using different electrode materials. The measured resistance values of Ni and Au plating process showed a little bit higher than that of silver paste process in spite of developed results of brightness. The Ni and Ni/Au plating processes are demonstrated best results and also showed a little bit different brightness due to different previous surface etching treatments.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.618-618
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• 2013

Graphene is only one atom thick planar sheet of sp2-bonded carbon atoms arranged in a honeycomb crystal lattice, which has flexible and transparent characteristics with extremely high mobility. These noteworthy properties of graphene have given various applicable opportunities as electrode and/or channel for various flexible devices via suitable physical and chemical modifications. In this work, for the development of all-graphene devices, we performed to synthesize alternately patterned structure of mono- and multi-layer graphene by using the patterned Ni film on Cu foil, having much different carbon solid solubilities. Depending on the process temperature, Ni film thickness, introducing occasion of methane and gas ratio of CH4/H2, the thickness and width of the multi-layer graphene were considerably changed, while the formation of monolayer graphene on just Cu foil was not seriously influenced. Based on the alternately patterned structure of mono- and multi-layer graphene as a channel and electrode, respectively, the flexible TFT (thin film transistor) on SiO2/Si substrate was fabricated by simple transfer and O2 plasma etching process, and the I-V characteristics were measured. As comparing the change of resistance for bending radius and the stability for a various number of repeated bending, we could confirm that multi-layer graphene electrode is better than Au/Ti electrode for flexible applications.

• Korean Journal of Materials Research
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• v.15 no.5
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• pp.318-322
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• 2005

Ti-capped NiSi contacts were formed on $p^+/n$ junctions to improve the leakage problem and then Cu was deposited without removing the Ti-capping layer in an attempt to utilize as a diffusion barrier. The electrical characteristics of these $p^+/n$ diodes with Cu/Ti/NiSi electrodes were measured as a function of drive-in RTA(rapid-thermal annealing) and silicidation temperature and time. When drive-in annealed at $900^{\circ}C$, 10 sec. and silicided at $500^{\circ}C$, 100 sec., the diodes showed the most excellent I-V characteristics. Especially, the leakage current was $10^{-10}A$, much lower than reported data for diodes with NiSi contacts. However, when the $p^+/n$ diodes with Cu/Ti/NiSi contacts were furnace-annealed at $400^{\circ}C$ for 40 min., the leakage current increased by 4 orders. The FESEM and AES analysis revealed that the Ti-capping layer effectively prohibited the Cu diffusion, but was ineffective against the NiSi dissociation and consequent Ni diffusion.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.136-145
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• 1994

Polymeric complexes such as M(Ⅱ)(PVPS)(SND), M(Ⅱ)(PVPS)(SOPD) have been prepared with monomeric complexes, M(Ⅱ)(SND) and M(Ⅱ)(SOPD)[M: Co(Ⅱ), Ni(Ⅱ), and Cu(Ⅱ)] and polymer PVPS. These complexes have been indentified by elemental analysis, spectroscopy, and T.G.A. From the results, it was found that M(Ⅱ)(PVPS)(SND), M(Ⅱ)(PVPS)(SOPD) complexes were penta-coordinated configuration. Electrochemical properties of these complexes studied by cyclic voltammetry and differential pulse polarography in 0.1 M TEAP-DMF solution at glassy carbon electrode. Co(Ⅱ)(PVPS)(SND) and Co(Ⅱ)(PVPS)(SOPD) showed irreversible two step reduction, such as Co(Ⅲ)/Co(Ⅱ) and Co(Ⅱ)/Co(Ⅰ), and Ni(Ⅱ)(PVPS)(SND), Ni(Ⅱ)(PVPS)(SOPD), Cu(Ⅱ)(PVPS)(SND), and Cu(Ⅱ)(PVPS)(SOPD) complexes showed irreversible one step reduction, such as Ni(Ⅱ)/Ni(Ⅰ) and Cu(Ⅱ)/Cu(Ⅰ), respectively.

• Korean Journal of Materials Research
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• v.13 no.8
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• pp.503-508
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• 2003

The purpose of this study is to investigate the effect of $V_2$$O_{5}$ addition on the Ag and Cu precipitation in the NiCuZn ferrite layers of 7.7${\times}$4.5${\times}$1.0 mm sized multi-layer chip inductors prepared by the screen printing method using 0∼0.5 wt% $V_2$$O_{5}$ -doped ferrite pastes. With increasing the $V_2$$O_{5}$ content and sintering temperature, Ag and Cu oxide coprecipitated more and more at the polished surface of ferrite layers during re-annealing at $840^{\circ}C$. It was thought that during the sintering process, V dissolved in the NiCuZn ferrite lattice and the Ag-Cu liquid phase of low melting point was formed in the ferrite layers due to the Cu segregation from the ferrite lattice and Ag diffusion from the internal electrode. During re-annealing at $840^{\circ}C$, the Ag-Cu liquid phase came out the polished surface of ferrite layers, and was decomposed into the isolated Ag particles and the Cu oxide phase during the cooling process.