• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.495-502
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• 2005

Copper was plated on the tungsten substrate by use of a direct copper electroless plating. The optimum deposition conditions were found to be with a concentration of $CuSO_4$ 7.615 g/L, EDTA of 10.258 g/L, and glyoxylic acid of 7 g/L, respectively. The solution temperature was maintained at $60^{\circ}C$. The pH was varied from 11.0 to 12.8. After the deposition, the properties of the copper film were investigated with X-ray diffractometer (XRD), Field emission secondary electron microscope (FESEM), Atomic force microscope (AFM), X-ray photoelectron spectroscope (XPS), and Rutherford backscattering spectroscope (RBS). The best deposition condition was founded to be the solution pH of 11.8. In the case of 10 min deposition at the pH of 11.8, the grain shape was spherical, Cu phase was pure without impurity peak ($Cu_2O$ peak), and the surface root mean square roughness was about 11 nm. The thickness of the film turned out to be 140 nm after deposition for 12 min and the deposition rate was found to be about 12 nm/min. Increase in pH induced a formation of $Cu_2O$ phase with a long rectangular grain shape. The pH control seems to play an important role for the orientation of Cu in electroless deposition. The deposited copper concentration was 99 atomic percent according to RBS. The resulting Cu/W film yielded a good adhesive strength, because Cu/W alloy forms during electroless deposition.

• Journal of the Korean Ceramic Society
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• v.45 no.4
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• pp.191-195
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• 2008

Highly ordered silver nanowire with a diameter of 10 nm was arrayed by electroless deposition in a porous anodic aluminum oxide(AAO) membrane. The AAO membrane was fabricated electrochemically in an oxalic acid solution via a two-step anodization process, while growth of the silver nanowire was initiated by using electroless deposition at the long-range-ordered nanochannels of the AAO membrane followed by thermal reduction of a silver nitrate aqueous solution by increasing the temperature up to $350^{\circ}C$ for an hour. An additional electro-chemical procedure was applied after the two-step anodization to control the pore size and channel density of AAO, which enabled us to fabricate highly-ordered silver nanowire on a large scale. Electroless deposition of silver nitrate aqueous solution into the AAO membrane and thermal reduction of silver nanowires was performed by increasing the temperature up to $350^{\circ}C$ for 1 h. The morphologies of silver nanowires arrayed in the AAO membrane were investigated using SEM. The chemical composition and crystalline structure were confirmed by XRD and EDX. The electroless-deposited silver nanowires in AAO revealed a well-crystallized self-ordered array with a width of 10 nm.

• Journal of the Korean institute of surface engineering
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• v.43 no.2
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• pp.111-120
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• 2010

In this study, the effects of multi-complex agents addition on characteristics of electroless Ni plating solution are investigated. The species and the concentration of complexing agents are major factors to control the deposition rate, P concentration, and surface morphology of plating films. Adipic acid increases the deposition rate in regardless of single- or mutli-complex agent addition. However, lactic acid effectively increases the deposition rate in case of multi-addition as the complex agents with adipic or sodium succinate acid. In addition, sodium citric acid and malic acid show good stabilizing effects of plating solution and lowering the deposition rate, because they have high complexibility. Therefore, it is suggested that the development of Ni-P plating solution suitable for diverse usages can be carried out systematically using the database from this study.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.25.2-25.2
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• 2011

Recently, thin film capacitors used for vehicle inverters are small size, high capacitance, fast response, and large capacitance. But its applications were made up of liquid as electrolyte, so its capacitors are limited to low operating temperature range and the polarity. This research proposes using Ni-P alloys by electroless plating as the electrode instead of liquid electrode. Our substrate has a high aspect ratio and complicated shape because of anodic aluminum oxide (AAO). We used AAO because film thickness and effective surface area are depended on for high capacitance. As the metal electrode instead of electrolyte is injected into AAO, the film capacitor has advantages high voltage, wide operating temperature, and excellent frequency property. However, thin film capacitor made by electroless-plated Ni on AAO for full-filling into etched tunnel was limited from optimizing the deposition process so as to prevent open-through pore structures at the electroless plating owing to complicated morphological structure. In this paper, the electroless plating parameters are controlled by temperature in electroless Ni plating for reducing reaction rate. The Electrical properties with I-V and capacitance density were measured. By using nickel electrode, the capacitance density for the etched and Ni electroless plated films was 100 nFcm-2 while that for a film without any etch tunnel was 12.5 nFcm-2. Breakdown voltage and leakage current are improved, as the properties of metal deposition by electroless plating. The synthesized final nanostructures were characterized by scanning electron microscopy (SEM).

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.2
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• pp.238-241
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• 1987

ITO thin film was prepared by the electroless deposition technique. ITO thin film had a high transmittance in the visible region and a high reflectance in the near infrared region. The energy gap of the thn film (Sn/Im=0.1) was 4.05 eV, the carrier concentration was 2x10**21 cm**-3, and the electric resistivity was 1.5x10**-3 ohm-cm. We confirmed that ITO thin film was a degenerated n-type semiconductor.

• Korean Journal of Materials Research
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• v.24 no.11
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• pp.632-638
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• 2014

We investigated the effects of DMAB (Borane dimethylamine complex, C2H10BN) in electroless Ni-B film with addition of DMAB as reducing agent for electroless Ni plating. The electroless Ni-B films were formed by electroless plating of near neutral pH (pH 6.5 and pH 7) at $50^{\circ}C$. The electroless plated Ni-B films were coated on screen printed Ag pattern/PET (polyethylene terephthalate). According to the increase of DMAB (from 0 to 1 mole), the deposition rate and the grain size of electroless Ni-B film increased and the boron (B) content also increased. In crystallinity of electroless Ni-B films, an amorphization reaction was enhanced in the formation of Ni-B film with an increasing content of DMAB; the Ni-B film with < 1 B at.% had a weak fcc structure with a nano crystalline size, and the Ni-B films with > 5 B at.% had an amorphous structure. In addition, the Ni-B film was selectively grown on the printed Ag paste layer without damage to the PET surface. From this result, we concluded that formation of electroless Ni-B film is possible by a neutral process (~green process) at a low temperature of $50^{\circ}C$.

• Journal of the Korean institute of surface engineering
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• v.55 no.2
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• pp.102-119
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• 2022

Gold plating is used as a coating of connecter in printed circuit boards, ceramic integrated circuit packages, semiconductor devices and so on, because the film has excellent electric conductivity, solderability and chemical properties such as durability to acid and other chemicals. As increasing the demand for miniaturization of printed circuit boards and downsizing of electronic devices, several types of electroless gold plating solutions have been developed. Most of these conventional gold plating solutions contain cyanide compounds as a complexing agent. The gold film obtained from such baths usually satisfies the requirements for electronic parts mentioned above. However, cyanide bath is highly toxic and it always has some possibility to cause serious problems in working environment or other administrative aspects. The object of this investigation was to develop a cyanide-free electroless gold plating process that assures the high stability of the solution and gives the excellent solderability of the deposited film. The investigation reported herein is intended to establish plating bath composition and plating conditions for electroless gold plating, with thiomalic acid as a complexing agent. At the same time, we have investigated the solution stability against nickel ion and pull strength of solder ball. Furthermore, by examining the characteristics of the plated Au plating film, the problems of the newly developed electroless Au plating solution were improved and the applicability to various industrial fields was examined. New type electroless gold-plating bath which containing thiomalic acid as a complexing agent showing so good solution stability and film properties as cyanide bath. And this bath shows the excellent stability even if the dissolved nickel ion was added from under coated nickel film, which can be used at the neutral pH range.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.141-149
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• 2009

The Cu thin film material and process, which have been already used for metallization of CMOS(Complementary Metal Oxide Semiconductor), has been highlighted as the Cu metallization is introduced to the metallization process for giga - level memory devices. The recent progresses in the development of key elements in electrochemical processes like surface pretreatment or electrolyte composition are summarized in the paper, because the semiconductor metallization by electrochemical processes such as electrodeposition and electroless deposition controls the thickness of Cu film in a few nm scales. The technologies in electrodeposition and electroless deposition are described in the viewpoint of process compatibility between copper electrodeposition and damascene process, because a Cu metal line is fabricated from the Cu thin film. Silver metallization, which may be expected to be the next generation metallization material due to its lowest resistivity, is also introduced with its electrochemical fabrication methods.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.743-748
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• 2014

In this work, we describe a very simple electroless deposition method to prepare moderate-SERS-active nanostructured Pd films deposited on the glass substrates. To the best of our knowledge, this is the first report on the one-pot electroless method to deposit Pd nanostructures on the glass substrates. This method only requires the incubation of negatively charged glass substrates in ethanol-water mixture solutions of $Pd(NO_3)_2$ and butylamine at elevated temperatures. Pd films are then formed exclusively and evenly on glass substrates. Due to the aggregated structures of Pd, the SERS spectra of benzenethiol and organic isonitrile could be clearly identified using the Pd-coated glass as a SERS substrate. This one-step fabrication method of Pd thin film on glass is cost-effective and suitable for the mass production.

• Journal of the Korean institute of surface engineering
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• v.37 no.6
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• pp.335-343
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• 2004

Bath stabilizers in the electroless nickel(EN) plating solution are known to prevent sudden bath decomposition and extend its lifetime. Further, every stabilizer has a different role and function in EN solution and it influences the surface structure. In this study, the effects of various stabilizers on the deposition rate, surface morphology, deposition content of phosphor and hardness were investigated.