• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.247-247
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• 2012

Plasmon subwavelength nanostructures enable the structurally modulated color due to the resonance conditions for the specific wavelength range of light with the nanoscale hole arrays on a metal layer. While the unique properties offered from a single layer of metal may open up the potential applications of integrated devices to displays and sensors, fabrication requirements in nanoscale, typically on the order of or smaller than the wavelength of light in a corresponding medium can limit the cost-effective implementation of the plasmonic nanostructures. Simpler nanoscale replication technologies based on the soft lithography or roll-to-roll nanoimprinting can introduce economically feasible manufacturing process for these devices. Such replication requires an optimal design of a master template to produce a stamp that can be applied for a roll-to-roll nanoimprinting. In this paper, a master mold with subwavelength nanostructures is fabricated and optimized using focused ion beam for the applications to nanoimprinting process. Au thin film layer is deposited by sputtering on a glass that serves as a dielectric substrate. Focused ion beam milling (FIB, JEOL JIB-4601F) is used to fabricate surface plasmon subwavelength nanostructures made of periodic hole arrays. The light spectrum of the fabricated nanostructures is characterized by using UV-Vis-NIR spectrophotometer (Agilent, Cary 5000) and the surface morphology is measured by using atomic force microscope (AFM, Park System XE-100) and scanning electron microscope (SEM, JEOL JSM-7100F). Relationship between the parameters of the hole arrays and the corresponding spectral characteristics and their potential applications are also discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.24-24
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• 2009

ENIG(Electroless Nickel Immersion Gold) is the surface treatment method that is used most widely at fine pitch's SMT and BGA packaging process. In this paper, we have studied the effect of P content variation during ENIG process on those phenomena related to the solder joint. The effect of P content was discussed using the results obtained from FE-SEM, EPMA, EDS and FIB. Finally, it was concluded that the more P-content in Ni layer, the thicker P-rich layer.

• Journal of the Korean institute of surface engineering
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• v.43 no.2
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• pp.64-72
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• 2010

CuSnZn electroplating was investigated as alternative to Ni plating. Evaluation of electrolyte and plating process was performed to control physical characteristics of the film, and to collect practical data for application. Hull-cell test was conducted for basic comparison of two commercialized products and developed product. Based on hull-cell test results, long term test of three electrolytes was performed. Various analysis on long term tested electrolyte and samples have been done. Reliable and practical data was collected using FE-SEM (FEI, Sirion), EDX (ThermoNoran SIX-200E), ICP Spectrometer (GBC Scientifi c, Integra XL), FIB (FEI, Nova600) for anlysis. Physical analysis and reliability test of the long term tested film were also carried out. Through this investigation plating time, plating speed, electrolyte composition, electrolyte metal consumption, hardness and corrosion resistance has been compared. This set of data is used to predict and control the chemical composition of the film and modify the physical characteristics of the CuSnZn alloy.

• Korean Journal of Metals and Materials
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• v.46 no.2
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• pp.58-64
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• 2008

Surface-void defects observed on the galvannealed(GA) steel sheets in Interstitial-free high-strengthened steels containing Si and Mn have been investigated using the combination of the FIB(Focused Ion Beam) and FE-TEM(Field Emission-Transmission Electron Microscope) techniques. The scanning ion micrographs of cross-section microstructure of defects showed that these defects were identified as craters which were formed on the projecting part of the substrate surface. Also, those craters were formed on the Si or Mn-Si oxides film through the whole interface between galvannealed coating and steel substrate. Interface enrichments and oxidations of the active alloying elements such as Si and Mn during reduction annealing process for galvanizing were found to interrupt Zn and Fe interdiffusion during galvannealing process. During galvannealing, Zn and Fe interdiffusion is preferentially started on the clean substrate surface which have no oxide layer on. And then, during galvannealing, crater is developed with consumption of molten zinc on the oxide layer.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.167-170
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• 2005

The two-dimensional (2D) and three-dimensional (3D) diamond-like carbon (DLC) stamps for ultraviolet nanoimprint lithography (UV-NIL) were fabricated using two kinds of methods, which were a DLC coating process followed by the focused ion beam (FIB) lithography and the two-photon polymerization (TPP) patterning followed by nano-scale thick DLC coating. We fabricated 70 nm deep lines with a width of 100 nm and 70 nm deep lines with a width of 150 nm on 100 nm thick DLC layers coated on quartz substrates using the FIB lithography. 200 nm wide lines, 3D rings with a diameter of $1.35\;{\mu}m$ and a height of $1.97\;{\mu}m$, and a 3D cone with a bottom diameter of $2.88\;{\mu}m$ and a height of $1.97\;{\mu}m$ were successfully fabricated using the TPP patterning and DLC coating process. The wafers were successfully printed on an UV-NIL using the DLC stamp. We could see the excellent correlation between the dimensions of features of stamp and the corresponding imprinted features.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.852-856
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• 2014

$BaTiO_3$ nano powder can be synthesized by hydrate salt method at $120^{\circ}C$ in air. Decreasing the thickness of thick film, the nano dielectric particle is needed in electronic ceramics. However, the synthesis of $BaTiO_3$ nano particle at low temperature in air and their mechanism were not reported enough. And ultrasonic treatment can be tried because of low temperature process in air. Therefore, in this study, the $BaTiO_3$ nano powder was synthesised with the synthesis time and ultrasonic treatment at $120^{\circ}C$ in air. In the synthesis process, the effects of process were evaluated. From the experimental observation, the synthesis mechanism was proposed. The homogeneous $BaTiO_3$ particle was synthesised by KOH salt solution at $120^{\circ}C$ for 1hour. It was conformed that the ultrasonic treatment effected on the increase of synthesis rate. After cutting the salt powder using FIB, $BaTiO_3$ nano particles observed homogeneously in the cross-section of the salt particle.

• Corrosion Science and Technology
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• v.14 no.2
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• pp.64-75
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• 2015

Single $TiO_2$ coating prepared by sol-gel process usually experiences cracks in coating layer. In order to prevent cracks, an inorganic-organic hybrid $TiO_2-SiO_2$ coating was synthesized by combining precursors with an organic functional group. Five different coatings with various ratios of (1:8, 1:4, 1:1, 1:0.25 and 1:0.125) titanium alkoxide (TBOT, Tetrabutylorthotitanate) to organo-alkoxysilane (MAPTS, ${\gamma}$-Methacryloxy propyltrimethoxysilane) on carbon steel substrate were made by sol-gel dip coating. The prepared coatings were analyzed to study the coating properties (surface crack, thickness, composition) by scanning electron microscope (SEM), focused ion beam (FIB), and Fourier transform infrared spectroscopy (FT-IR). Potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) were also performed to evaluate the corrosion characteristics of the coatings. Crack free $TiO_2-SiO_2$ hybrid coatings were prepared with the optimization of the ratio of TBOT to MAPTS. The corrosion rates were significantly decreased in the coatings for the optimized precursor ratio without cracks.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.192-197
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• 2016

We have surveyed on technical method of fault analysis of semiconductor device. Fault analysis of semiconductor should first be found the places of fault spots. For this process they are generally used the testers; EB(emission beam tester), EM(emission microscope), OBIRCH(optical beam induced resistance change method) and LVP(laser voltage probing) etc. Therefore we have described about physical interpretation and technical method in using scanning electron microscope, transmission electron microscope, focused ion beam tester and Nano prober.

• Korean Journal of Materials Research
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• v.20 no.12
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• pp.645-648
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• 2010

The structure and morphology of epitaxial layer defects in epitaxial Si wafers produced by the Czochralski method were studied using focused ion beam (FIB) milling, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Epitaxial growth was carried out in a horizontal reactor at atmospheric pressure. The p-type Si wafers were loaded into the reactor at about $800^{\circ}C$ and heated to about $1150^{\circ}C$ in $H_2$. An epitaxial layer with a thickness of $4{\mu}m$ was grown at a temperature of 1080-$1100^{\circ}C$. Octahedral void defects, the inner walls of which were covered with a 2-4 nm-thick oxide, were surrounded mainly by $\{111\}$ planes. The formation of octahedral void defects was closely related to the agglomeration of vacancies during the growth process. Cross-sectional TEM observation suggests that the carbon impurities might possibly be related to the formation of oxide defects, considering that some kinds of carbon impurities remain on the Si surface during oxidation. In addition, carbon and oxygen impurities might play a crucial role in the formation of void defects during growth of the epitaxial layer.

• Publications of The Korean Astronomical Society
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• v.11 no.1
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• pp.163-175
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• 1996

We propose the development and test result of new optical axis alignment system for the interchangeable F/8 secondary mirror of the BOAO 1.8m telescope system. Since the original system was not equipped with a suitable optical alignment facility, the whole alignment process was performed by hand. It was necessary at least three persons working more than 2 nights and the altitude of the telescope could not exceed 10 degrees, in such altitude the alignment quality was not so good by atmospheric effect. The new system adopts position readable motorized system and remote control operation by the computer installed in observation room, which reduces the number of workers to only one and eliminates the altitude restriction. The defocused CCD image pair obtained at higher altitude makes the aberration estimates more accurately and the number of required alignment loops is reduced from 10 to 4. The system has been installed on September 1, and performed alignment three times. The test results show that the system is stable and accurate, gives better optical performance of the telescope under F/8 focus. We hope to emphasize the fact that the new system will increase observation time of the telescope by about 20 nights per year assuming one alignment in every month.