• Journal of Surface Science and Engineering
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• v.39 no.4
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• pp.166-172
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• 2006

Metallized Polyimide films are extensively used as base materials in microelectronics, optical and automotive applications. However it is difficult to deposit metals on those because of their structural stabilities. In this work, polyimide films are modified by a wet process with alkalinemetalhydroxide and additives to introduce functional groups. The surface molecular structures of polyimide are investigated using X-ray photoelectron spectroscopy(XPS), fourier transform infrared reflection spectroscopy(FTIR-ATR), atomic force micro-scopic(AFM). XPS spectra and FTIR spectra show that the surface structure of polyimide is converted into potassium polyamate. AFM image and AFM cross-sectional analyses reveal the increased roughness on the modified surface of polyimide films. As a result, it is shown that the adhesion strength between polyimide surface and electroless nickel layer is increased by the nano-anchoring effect.

• Journal of Surface Science and Engineering
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• v.22 no.4
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• pp.161-167
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• 1989

Effects of bath composition on electroless deposition of Ni-W-B from sulphate solution were invesrigated in terms of deposition kinetics, electro resistivity and composition of deposit film. The microstruigated and crystataine structure of the films were also studied using a scanning electron microscope and X-ray diffractometer. The deposition rate increased linearly with increasing the concentration of nickel sulphate in bath solution, wheras the rate decreasing with sodium citrate. The rate was also affected by sodium tungstate, which was maaximum at the concentration of 0.06 M/1 in sodium tungstate, The content of W in the deposit increased with increased with increasing the sodium citrate had on opposite effect on the composition of W and B in the deposit. The crystal change film from armorphous to cryatallicne nature by heat treatments was proved by the reduction of specific resistance and X-ray diffration.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.619-622
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• 2005

본 논문에서는 서로 다른 Si 두께 ($T_{Si}$ = 27, 50 nm) 를 갖는 SOI (Silicon On Insulator) 기판 위에 다양한 두께의 Ni/Co를 순차적으로 증착한 후 Bulk-Si과의 비교를 통해 Silicide의 형성 특성에 대하여 분석하였다. 우선 급속 열처리 (RTP, Rapid Thermal Processing) 를 통하여 Silicide를 형성한 후 측정결과 Si두께에 따라 Silicide의 특성이 달라짐을 확인하였다. 두꺼운 두께의 Si-film을 갖는 SOI 기판을 사용한 경우 증착된 금속의 두께에 따라 Bulk-Si와 비슷한 면저항 특성을 보였으나, 얇은 두께의 Si-film을 갖는 SOI기판을 사용한 경우에는 제한된 Si의 공급으로 인한 Silicide의 비저항 증가로 인하여 증착된 금속의 두께에 따라 면저항이 감소하다가 다시 증가하는 'V' 자형 곡선을 나타내었다.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.502-505
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• 2005

Researches about micro technology travel lively in these days. Such many researches are concentrated in the field of materials and a process field. But properties of micro materials should be known to give results of research developed into still more. In these various material properties, mechanical property such as tensile strength, elastic modulus, etc is the basic property. To measure mechanical properties in micro or nano scale, actuating must be very precise. PZT is a famous actuator which becomes a lot of use to measure very precise mechanical properties in micro research field. But PZT has a nonlinearity which is called as hysteresis. Not precision result is caused because of this hysteresis property in PZT actuator. Therefore feedback control method is used in many researches to prevent this hysteresis of PZT actuator. Feedback control method produce a good result in processing view, but cause a loss in a resolution view. In this paper, hysteresis is compensated by open loop control method. Hysteresis property is modeled in Mathematical function and compensated control input is constructed using inverse function of original data. Reliability of this control method can be confirmed by testing nickel thin film that is used in MEMS material broadly.

• Journal of Surface Science and Engineering
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• v.39 no.3
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• pp.121-128
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• 2006

A set of Quartz Crystal Microbalances (QCM's) was used to observe the film removal characteristics of three different $CO_2-nitric$ acid microemulsions. QCM's electroplated with nickel or copper were used as specimens. F-AOT, NP-4 and the newly synthesized Proline Surfactant-1 were used as surfactants to create microemulsions. While the F-AOT microemulsion yielded a relatively low removal rate, that of the Proline Surfactant-1 completely removed the Cu metal film within a short period of time. The NP-4 microemulsion removed the metal surface. However, removal rate measurements per QCM were not possible due to the instability of the microemulsion when Cu ions were present in the nitric solution. The reaction kinetics and metal removal capabilities of microemulsions formed by the different surfactants are explained along with the characteristics of reverse micelles.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.226-226
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• 2012

The electronic and electrical properties of nickel oxide (NiO) thin films were investigated by reflection electron energy loss spectroscopy (REELS), x-ray photoelectron spectroscopy (XPS), and Hall Effect measurements. REELS spectra revealed that the band gap of the NiO thin film was increased from 3.50 eV to 4.02 eV after annealing the sample at $800^{\circ}C$. Our XPS spectra showed that the amount of Ni2O3 decreased after annealing. The Hall Effect results showed that the doping type of the sample changed from n type to p type after annealing. The resistivity decreased drastically from $4.6{\times}10^3$ to $3.5{\times}10^{-2}$ ${\Omega}{\cdot}cm$. The mobility of NiO thin films was changed form $3.29{\times}10^3$ to $3.09{\times}10^5cm^2/V{\cdot}s$. Our results showed that the annealing temperature plays a crucial role in increasing the carrier concentration and the mobility which leads to lowering resistivity of NiO thin films.

• Korean Journal of Materials Research
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• v.9 no.2
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• pp.217-225
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• 1999

The effect on the pitting corrosion resistance of laser welding and surface treatment developed as a repair method of stream generator tubing material that was a major component of primary system at nuclear power plant was observed. Some heat-treated Alloy 600 tubing materials used at domestic nuclear power plants were laser-surface observed. Some heat-treated Alloy 600 tubing materials used at domestic nuclear power plants were laser-surface melted and the microstructural characteristics were examined. The pitting corrosion resistance was examined through Ep(pitting potential) and degree of pit generation by means of the electrochemical tests and the immersion tests respectively. The pit formation characteristics were investigated through microstructural changes and the pit initiation site and pit morphology. The test results showed that the pitting corrosion resistances was increased in the order of the followings; sensitized Alloy 600, solution annealed alloy600, and laser surface melted Alloy 600. Pits were initiated preferably at Ti-containing inclusions and their surroundings in all tested specimens and it is believed that higher pitting resistance of laser-surface treated Alloy 600 was caused by fine, homogeneous distribution of non-soluble inclusions, the disappearance of grain boundary, and the formation of dense, stable oxide film. The major element of corrosion products filled in the pit was Cr. On the other hand, Fe was enriched in the deposit formed on the pit.

• Journal of Hydrogen and New Energy
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• v.29 no.5
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• pp.434-441
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• 2018

The pore size of nickel (Ni) bottom electrode layer (BEL) for low-temperature solid oxide fuel cells embedded with ultrathin-film electrolyte was controlled by changing the substrate surface morphology and deposition process parameters. For ~150-nm-thick Ni BEL, the upper side of an anodic aluminum oxide (AAO) substrate with ~65-nm-sized pores provided ~1.7 times smaller pore size than the lower side of the AAO substrate. For ~100-nm-thick Ni BEL, the AAO substrate with ~45-nm-sized pores provided ~2.6 times smaller pore size than the AAO substrate with ~95-nm-sized pores, and the deposition pressure of ~4 mTorr provided ~1.3 times smaller pore size than that of ~48 mTorr. On the AAO substrate with ~65-nm-sized pores, the Ni BEL deposited for 400 seconds had ~2 times smaller pore size than the Ni BEL deposited for 100 seconds.

• Transactions on Electrical and Electronic Materials
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• v.9 no.2
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• pp.47-51
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• 2008

In this paper, thermal stability of Nickel silicide formed on p-type silicon wafer using Ni-V alloy film was studied. As compared with pure Ni, Ni-V shows better thermal stability. The addition of Vanadium suppresses the phase transition of NiSi to $NiSi_2$ effectively. Ni-V single structure shows the best thermal stability compared with the other Ni-silicide using TiN and Co/TiN capping layers. To enhance the thermal stability up to $650^{\circ}C$ and find out the optimal thickness of Ni silicide, different thickness of Ni-V was also investigated in this work.

• Journal of Surface Science and Engineering
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• v.19 no.3
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• pp.92-108
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• 1986

An electroplating on the lead frame fabricated from domestic copper plate was studied experimentally. In this study, nickel was plated on the thin copper lead frame and silver layer was coated on the nickel film in the cyanide electrolyte. The effect of process variables such as current density, plating time, coating thickness and flow rate of electrolytic solution on the properties of coating was investigated. Some samples on each step were fabricated during electroplating. The results obtained from polarization measurement, observation of SEM photograph, adhesion test of coating and microhardness test are as follows. On silver plating, polarization resistance of potentiostatic cathodic polarization curve is reduced as the flow rate of Ag electrolytic solution increases. And above resistance is also reduced when the minor chemicals of sodium cyanide and sodium carbonate are added in potassium silver cyanide bath. The reduced polarization resistance makes silver deposition on the cathode easy. An increase in the current density and the coating thickness causes the particle size of deposit to coarsen, and consequently the Knoop microhardness of the coating decreases. On selective plating an increase in the flow rate of plating solution lead to do high speed plating with high current density. In this case, the surface morphology of deposit is of fine microstructure with high Knoop hardness. An increasing trend of the adhesion of coating was shown with increasing the current density and flow rate of electrolytic solution.