• Journal of Korean Vacuum Science & Technology
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• v.6 no.2
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• pp.55-57
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• 2002

Metal-vapor-vacuum-arc ion source is an ideal source for both high current metal ion implanter and high current plasma thin-film deposition systems. It uses the direct evaporation of metal from surface of cathode by vacuum arc to produce a very high flux of ion plasmas. The MEVVA ion source, the high-current metal-ion implanter and high-current magnetic-field-filtered plasma thin-film deposition systems developed in Beijing Normal University are introduced in this paper.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.182-182
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• 2010

The behavior of properties of ion exchanged substrate glasses was investigated in this study. In order to study the effects of ion exchange, ion exchange behavior with ion penetration depth, amount of ion exchange, density and thermal expansion was measured according to the time and temperature. The mechanical properties were evaluated by the three point bending test and curvature change, and then fracture patterns were investigated by optical microscope.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.157-162
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• 2012

In this study, we have for the first time applied increased surface area fractional precipitation in order to decrease the particle size of the anticancer agent paclitaxel from plant cell cultures. When compared with the case where no surface area increasing material was employed, the addition of ion exchange resin as a surface area increasing material resulted in a considerable decrease in the size of the paclitaxel precipitate. When ion exchange resin was used, the paclitaxel particles were four to five times smaller, having less than a 20 ${\mu}m$ radius, than those obtained in the absence of ion exchange resin. This is presumably because the growth of paclitaxel particles was impeded by the addition of ion exchange resin. The size of the paclitaxel precipitate also depended on the material used to increase the surface area, a result considered to be due to differences in the affinity between the particular ion exchange resin used and the paclitaxel particles. The yield of paclitaxel was significantly improved when ion exchange resin was used as a material to increase surface area. Paclitaxel, with a reduced particle size due to the addition of a surface area increasing material during the fractional precipitation process, is believed to be particularly useful for practical applications of the drug.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.5-18
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• 1996

The solid state cesium ion source os alumino-silicate based zeolite which contains cerium. The material is an ionic conductor. Cesiums are stably stored in the material and one can extract the cesiums by applying electric field across the electrolyte. Cesium ion bombardment has the unique property of producing high negative ion yield. This ion source is used as the primary source for the production of a negative ion without any gas discharge or the need for a carrier gas. The deposition of materials as an ionic species in the energy range of 1.0 to 300eV is recently recognized as a very promising new thin film technique. This energetic non-thermal equilibrium deposition process produces films by “Kinetic Bonding / Energetic Condensation" mechansim not governed by the common place thermo-mechanical reaction. Under these highly non-equilibrium conditions meta-stable materials are realized and the negative ion is considered to be an optimum paeticle or tool for the purpose. This process differs fundamentally from the conventional ion beam assisted deposition (IBAD) technique such that the ion beam energy transfer to the deposition process is directly coupled the process. Since cesium ion beam sputter deposition process is forming materials with high kinetic energy of metal ion beams, the process provider following unique advantages:(1) to synthesize non thermal-equilibrium materials, (2) to form materials at lower processing temperature than used for conventional chemical of physical vapor deposition, (3) to deposit very uniform, dense, and good adhesive films (4) to make higher doposition rate, (5) to control the ion flux and ion energy independently. Solid state cesium ion beam sputter deposition system has been developed. This source is capable of producing variety of metal ion beams such as C, Si, W, Ta, Mo, Al, Au, Ag, Cr etc. Using this deposition system, several researches have been performed. (1) To produce superior quality amorphous diamond films (2) to produce carbon nitirde hard coatings(Carbon nitride is a new material whose hardness is comparable to the diamond and also has a very high thermal stability.) (3) to produce cesiated amorphous diamond thin film coated Si surface exhibiting negative electron affinity characteristics. In this presentation, the principles of solid state cesium ion beam sputter deposition and several applications of negative metal ion source will be introduced.

• Applied Microscopy
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• v.48 no.2
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• pp.49-53
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• 2018

A successful transmission electron microscope (TEM) analysis is closely related to the preparation of the TEM specimen and should be followed by the suitable TEM specimen preparation depending on the purpose of analysis and the subject materials. In the case of the Si-based anode material, lithium atoms of formed Li silicide were removed due to ion beam and electron beam during TEM specimen preparation and TEM observation. To overcome the problem, we proposed a new technique to make a TEM specimen without the ion beam damage. In this study, two types of test specimens from the Si-based anode material of Li-ion battery were prepared by respectively adopting the only focused ion beam (FIB) method and the new FIB-ultramicrotome method. TEM analyses of two samples were conducted to compare the Ga ion damage of the test specimen.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.8
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• pp.726-730
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• 2002

Electro-optical (EO) performances of the ion beam (IB) aligned twisted-nematic (TN)-liquid crystal display (LCD) with ion beam exposure on the new diamond-like carbon (DLC) thin film surface were investigated. A good voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min was observed. Also, the fast response time of the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved. Finally, the residual DC voltage of the ion beam aligned TN-LCD on the DLC thin film surface is almost the same as that of the rubbing aligned TN-LCD on a polyimide (Pl) surface.

• Journal of Applied Reliability
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• v.16 no.3
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• pp.202-207
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• 2016

Purpose: The purpose of this study is main factors (environmental conditions, pattern spacing, pattern material) that effect the ion-migration of PCB. Methods: Recently, the electronic components are becoming more high density of electronic device, so that electronic circuits have smaller pitches between the patten and more vulnerable to insulation failure. so the reliability of electric insulation of device has become an ever important issue as device contact pitches of pattern. Usually, ion-migration occurs in high temperature and high humidity environment as voltage is applied to the circuit. Under high temperature and high humidity, voltage applied electronic components respond to applied voltages by metals's electrochemical ionization and a conducting filament forms between the anode and cathode across a nonmetallic medium. This leads to short-circuit failure of the electronic component. Results: we studied ion-migration that occurs in accordance with the main factors (environmental conditions, pitches, pattern material). The PCB pattern material was made by two different types of material (free solder, OSP) for this research and pitches of pattern is 0.15mm, 0.3mm, 0.5mm. PCB was experimented in the environmental conditions (high temperature $120^{\circ}C$, high temperature and high humidity $85^{\circ}C$, 85%RH) and was analyzed for ion-migration through the experiment results. Conclusion: We confirmed that environmental condition, pitches of pattern, pattern material had effect on ion-migration of PCB.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.3
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• pp.175-180
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• 2003

As the integrated circuit device shrinks to the deep submicron regime, the ion implantation process with high ion dose has been attracted beyond the conventional ion implantation technology. In particular, for the case of boron ion implantation with low energy and high dose, the stabilization and throughput of semiconductor chip manufacturing are decreasing because of trouble due to the machine conditions and beam turning of ion implanter system. In this paper, we focused to the improved characteristics of processing conditions of ion implantation equipment through the modified deceleration mode. Thus, our modified recipe with low energy and high ion dose can be directly apply in the semiconductor manufacturing process without any degradation of stability and throughput.

• Journal of the Korean Chemical Society
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• v.67 no.6
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• pp.429-440
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• 2023

1,1-Dialkyl-2,5-bis(trimethylsilylethynyl)-3,4-diphenylsiloles (R=Et, i-Pr, n-Hex; 3a-c) were prepared and utilized as anode active materials for lithium-ion batteries; 3a was also used as a filler for the solid-state electrolytes (SSE). Siloles 3a-c were prepared by substitution reactions in which the two bromine groups of 1,1-dialkyl-2,5-dibromo-3,4-diphe- nylsiloles, used as precursors, were substituted with trimethylsilylacetylene in the presence of palladium chloride, copper iodide, and triphenylphosphine in diisopropylamine. Among siloles 3a-c, 3a had the best electrochemical properties as an anode material for lithium-ion batteries, including an initial capacity of 758 mAhg^-1 (0.1 A/g), which was reduced to 547 mAhg^-1 and then increased to 1,225 mAhg^-1 at 500 cycles. A 3a-composite polymer electrolyte (3a-CPE) was prepared using silole 3a as an additive at concentrations of 1, 2, 3, and 4 wt.%. The 2 wt.% 3a-CPE composite afforded an excellent ionic conductivity of 1.09 × 10^-3 Scm^-1 at 60℃, indicating that silole 3a has potential applicability as an anode active material for lithium-ion batteries, and can also be used as an additive for the SSE of lithium-ion batteries.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.326-329
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• 2005

As a flexible method to fabricate sub-micrometer patterns, Focused Ion Beam (FIB) instrument and Self-Assembled Monolayer (SAM) resist are introduced in this work. FIB instrument is known to be a very precise processing machine that is able to fabricate micro-scale structures or patterns, and SAM is known as a good etch resistance resist material. If SAM is applied as a resist in FIB processing fur fabricating nano-scale patterns, there will be much benefit. For instance, low energy ion beam is only needed for machining SAM material selectively, since ultra thin SAM is very sensitive to $Ga^+$ ion beam irradiation. Also, minimized beam spot radius (sub-tens nanometer) can be applied to FIB processing. With the ultimate goal of optimizing nano-scale pattern fabrication process, interaction between SAM coated specimen and $Ga^+$ ion dose during FIB processing was observed. From the experimental results, adequate ion dose for machining SAM material was identified.