• Electronics and Telecommunications Trends
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• v.13 no.5 s.53
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• pp.38-52
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• 1998

Phase-shifting masks (PSM), optical proximity correction (OPC), off-axis illumination (OAI), annular illumination (AI)의 리소그래피 분해능 향상 기법과 deep ultraviolet photoresist의 개발 및 리소그래피의 최근 기술 동향을 요약 소개한다. DUV 리소그래피의 대안으로 관심을 끌고 있는 scattering with angular limitation projection electron-beam lithography (SCALPEL), extreme ultraviolet lithography (EUVL), X-ray lithography (XRL), ion projection lithography (IPL) 등의 새로운 리소그래피 기술들의 기본 원리와 최근 기술 동향도 소개하였다. 리소그래피는 반도체 공정에 있어서 가장 중요한 부분을 차지하기 때문에 리소그래피의 최근 기술 동향을 검토해 봄으로써 국내 리소그래피 장비 산업의 기술 개발을 위한 방향 설정에 도움이 될 것으로 생각한다.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.125-129
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• 2016

In this study, we have investigated a high-temperature AlN nucleation layer and AlGaN epilayers on c-plane sapphire substrate by low-pressure metal-organic chemical vapor deposition (LP-MOCVD). High resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), scanning electron microscope (SEM) and Raman scattering measurements have been exploited to study the crystal quality, surface morphology, and residual strain of the HT-AlN nucleation layer. These analyses reveal that the insertion of an LT-AlN nucleation layer can improve the crystal quality, smooth the surface morphology of the HT-AlN nucleation layer and further reduce the threading dislocation density of AlGaN epifilms. The mechanism of inserting an LT-AlN nucleation layer to enhance the optical properties of HT-AlN nucleation layer and AlGaN epifilm are discussed from the viewpoint of driving force of reaction in this paper.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.02a
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• pp.25-26
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• 1997

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.70.1-70.1
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• 2010

We present the far-ultraviolet (FUV) emission line morphologies in the whole region of the supernova remnant G65.3+5.7 using the FIMS/SPEAR data. The morphologies of the C IV ${\lambda}{\lambda}1548$, 1551, $H2{\lambda}1608 $, He II ${\lambda}1640$, and O III] ${\lambda}{\lambda}1661$, 1666 lines appear to correlate clearly with the optical emission line images or the ROSAT X-ray (0.11-0.284 keV) image obtained in some of the previous studies. We found that a foreground dust cloud, resonant scattering, and incompleteness of radiative shocks have made the definite differences between the morphologies of the above FUV emission lines. We also present the FUV spectra and line intensities from a few sub-regions.

• Journal of The Korean Astronomical Society
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• v.47 no.1
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• pp.15-39
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• 2014

Polarization is a basic property of light and is fundamentally linked to the internal geometry of a source of radiation. Polarimetry complements photometric, spectroscopic, and imaging analyses of sources of radiation and has made possible multiple astrophysical discoveries. In this article I review (i) the physical basics of polarization: electromagnetic waves, photons, and parameterizations; (ii) astrophysical sources of polarization: scattering, synchrotron radiation, active media, and the Zeeman, Goldreich-Kylafis, and Hanle effects, as well as interactions between polarization and matter (like birefringence, Faraday rotation, or the Chandrasekhar-Fermi effect); (iii) observational methodology: on-sky geometry, influence of atmosphere and instrumental polarization, polarization statistics, and observational techniques for radio, optical, and $X/{\gamma}$ wavelengths; and (iv) science cases for astronomical polarimetry: solar and stellar physics, planetary system bodies, interstellar matter, astrobiology, astronomical masers, pulsars, galactic magnetic fields, gamma-ray bursts, active galactic nuclei, and cosmic microwave background radiation.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.4
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• pp.326-332
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• 2008

In this work CdS films were prepared by using chemical bath deposition, which is simple and inexpensive technique suitable for large deposition area. Annealing in air at different temperatures (300, 350, 400, 450 and $500^{\circ}C$) at constant time of 30 min, also for different times (15, 30, 45, 60 and 90 min) at constant temperature ($300^{\circ}C$) is achieved. X-Ray analysis has confirmed the formation of cadmium oxide (CdO) with slight increase in grain size, shift towards lower scattering angle due to relaxation in the tensile strain for deposition films, and structure change from cubic and hexagonal to the hexagonal. From electrical properties, significant increase in electrical conductivity appeared in samples annealed at $300^{\circ}C$ for 60 min, and at $350^{\circ}C$ for 30 min.

• Fibers and Polymers
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• v.6 no.4
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• pp.289-296
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• 2005

Biodegradable nanocomposites were prepared by mixing a polymer resin and layered silicates by the melt intercalation method. Internal structure of the nanocomposite was characterized by using the small angle X-ray scattering (SAXS) and transmission electron microscope (TEM). Nanocomposites having exfoliated and intercalated structures were obtained by employing two different organically modified nanoclays. Rheological properties in shear and extensional flows and biodegradability of nanocomposites were measured. In shear flow, shear thinning behavior and increased storage modulus were observed as the clay loading increased. In extensional flow, strain hardening behavior was observed in well dispersed system. Nanocomposites with the exfoliated structure had better biodegradability than nanocomposites with the intercalated structure or pure polymer.

• Macromolecular Research
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• v.14 no.4
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• pp.424-429
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• 2006

The synthesis of a series of poly(POSS-NBE-b-MTD) copolymers was successfully accomplished, taking advantage of sequential, ring-opening, metathesis block copolymerization using $RuCl_2(=CHPh)(PCy_3)_2$ catalyst. By using cyclopentyl-POSS-norbornene (POSS-NBE) monomer as the first block in the block copolymer, living poly(POSS-NBE) with controlled molecular weight and narrow molecular weight distribution was produced. Then, poly(POSS-NBE-b-MTD) copolymers were successfully prepared, in which sequential monomer addition of methyltetracyclododecene (MTD) to the living poly(POSS-NBE) chain ends was utilized to achieve quantitative crossover efficiency. Characterization by $^1H$ NMR spectroscopy and GPC confirmed the high definition and structural integrity of the poly(PO$S-NBE-b-MTD) copolymers. Thermal properties-and morphologies of the POSS-containing block copolymer nanocomposites were also investigated by using thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and wide-angle X-ray scattering (WAXS).

• Macromolecular Research
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• v.11 no.3
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• pp.152-156
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• 2003

We investigated epitaxial relations of phase transitions between the lamellar (L), hexagonally perforated layers (HPL), and gyroid (G) morphologies in styrene-isoprene diblock copolymer (PSI) and polyisoprene (PI)/PSI blend using rheology and small angle X-ray scattering (SAXS) techniques. In HPLlongrightarrowG transitions, six spot patterns of G phase were observed in two-dimensitional SAXS pattern. On the other hand, in direct L-longrightarrowG transition without appearance of HPL phase, the polydomain patterns of G phase were observed. From present study, it was understood that direct LlongrightarrowG transition of blend may be suppressed by high-energy barrier of transition and mismatches in domain orientation between epitaxially related lattice planes.

• Journal of radiological science and technology
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• v.23 no.1
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• pp.29-37
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• 2000

Because vocal technique is the basis of singing a song beautifully, so this study was undertaken to use the scientific and correct technique in order to get much better musical expressions. Shimadzu X - ray remote control TV system was used for checking the supporting state of diaphragmatic respiration after 5, 10, 15, 20, 25 and 30 sec during phonation in the state of full inhalation between professional singer and non - professional singer. Shimadzu Magnet $nex-{\alpha}$(SMT -50CX/H) was used for examining the scattering state from the resonance of nasal cavity to that of cranial cavity on the basis of diaphragmatic respiration. The results obtained were summerized as follows : 1. The resonance of cranial cavity must be scattered by the energy of diaphragmatic respiration after gathering the foci of the fundamental 5 vowels. 2. while raising the epiglottis, the resonance of nasal cavity must be clearly in order to maintain the resonance of cranial cavity beautifully. 3. We can get musical expressions by maintaining the elasticity of diaphragmatic respiration.