Thermal dewetting of Pt thin film: Etch-masks for the fabrication of semiconductor nanostructures

Lee, Ji-Myon,Kim, Byung-Il Elsevier 2007 Materials science & engineering. properties, micro Vol.449 No.-

<P><B>Abstract</B></P><P>Nanometer scale Pt metal islands formed by the dewetting of two-dimensional film on SiO<SUB>2</SUB> dielectric materials during rapid thermal annealing were investigated. For the case of 30nm thick Pt films, pattern formation and dewetting were initiated at temperatures of >600°C. Controlling the annealing temperature and time as well as the thickness of the Pt metal film permitted the size and density of Pt islands to be controlled. Furthermore, the islands show good resistance to dry-etching by a CF<SUB>4</SUB>-based plasma for dielectric etching, indicating that the metal islands produced by dewetting are suitable for use as an etch-mask in the fabrication of nano-scale structures.</P>

Plasma로 활성화된 질소 원자를 사용한 사파이어 기판 표면의 저온 질화처리의 XPS 연구

이지면(Ji-Myon Lee),백종식(Jong-Sik Paek),김경국(Kyonng-Kook Kim),김동준(Dong-Joon Kim),김효근(Hyo-Gun Kim),박성주(Seong-Ju Park) 한국진공학회(ASCT) 1998 Applied Science and Convergence Technology Vol.7 No.4

원격 플라즈마 화학기상증착법(Remote Plasma Enhanced-Ultrahigh Vacuum Chemical Vapor Deposition)에 의해 활성화된 질소 원자를 사용하여 사파이어 기판의 표면을 저온에서 질화처리한 후 표면의 화학적 조성을 조사하였다. 질화처리에 의해 주로 표면에 형성된 물질은 AlN임을 X-선 광전자 분광방법(X-ray photoelectron spectroscopy: XPS)을 사용하여 확인하였다. 또한 플라즈마의 RF 출력, 반응 온도 및 시간에 따라서 기판의 Al과 반응한 질소의 상대적인 양과, 표면 형태를 XPS와 AFM(atomic force microscopy)을 사용하여 조사하였다. 플라즈마에 의해서 활성화되어 기판과 반응한 질소의 양은 RF 출력에 따라 증가하지만 Al과 반응하여 AlN을 형성시킨 질소는 RF 출력에 따라 증가한 후 일정하게 됨을 관찰하였다. 그러나 질화 처리 온도와 시간의 증가에 따른 AlN의 상대적인 양은 비교적 무관함을 관찰하였다. 또한 Ar 스퍼터링을 통한 XPS의 depth profile을 관찰한 결과 질화층은 깊이에 따라 3개의 다른 층으로 이루어져 있음을 확인하였다. The chemical aspects of nitridated surface of sapphire(0001) have been studied by X-ray photoelectron spectroscopy. Nitridated layer was formed by remote plasma enhanced-ultrahigh vacuum deposition at a low temperature range. It was confirmed that this nitridated surface was mainly consists of AlN layer. The relative amounts of nitrogen reacted with Al on the sapphire surface and their surface morphology were investigated with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) as a function of radio-frequency power, reaction temperature, and reaction time. The amounts of atomic nitrogen activated by plasma which was subsequently incorporated into sapphire were increased with RF power. But the amounts of nitrogen reacted with Al in sapphire was initially increased and then remained constant. However, the relative amounts of AlN were nearly constant with irrespective of nitridation temperature and time. Furthermore, a depth profile of nitridated layer with XPS showed that the nitridated surface consisted of three layers with different stoichiometry.

Symposium 8 : Developmental Biology ; Calcineurin, A Component of G-protein Coupled Phosphorylation Pathways, Is Involved in Movement, Fertility, Egg Laying, and Growth in C. elegans

( Jaya Bandyopadhyay ),( Ji Yeon Lee ),( Jung Soo Lee ),( Jin Il Lee ),( Jae Ran Yu ),( Chang Hoon Jee ),( Jeong Hoon Cho ),( Sun Ki Jung ),( Myon Hee Lee ),( Sonia Zannoni ),( Andrew Singson ),( Do H 한국생화학분자생물학회 (구 한국생화학회) 2002 추계학술대회집 Vol.2002 No.-

한국 철도산업의 범위와 구조적 특성변화분석

이경철(Kyung-Chul LEE),이진면(Jin Myon Lee),오지택(Ji-Taek Oh),김정현(Jeong-Hyun Kim),이상근(Sang-Keun Lee),박선희(Seon-Hee Park) 한국철도학회 2012 한국철도학회 학술발표대회논문집 Vol.2012 No.10

철도정책 수립 시 산업통계가 기본적으로 요구되나 국내에는 철도산업을 종합적으로 포괄하는 통계체계가 아직 구축되어 있지 않다. 본 연구는 철도산업 통계체계구축 필요성 관련 논의를 확산시키기 위한 기초 연구로 우선 활용이 가능한 정부 승인통계 중 전국 사업체 조사, 광업·제조업 조사, 도·소매업조사, 운수업조사 결과를 분석하여 철도산업의 구조적 특성변화를 분석하였다. 결과를 요약하면, 철도산업은 2,187개의 기업에서 약 56천인을 고용하였다(08년). 철도장비 제조업은 년간 출하액이 3조296억원(09년)으로 국내 전체 제조업의 0.29% 수준이며, 철도관련 수송용 기계 및 장비 도매업의 매출액은 9,496억원(08년)으로 전체 도소매업의 0.15%, 철도운수업은 매출액 6조3537억원(09년) 으로 전체 5% 수준이다. 철도산업 내부에서는 철도운송업, 철도건설업, 철도차량제조업의 순으로 부가가치규모가 크고, 경제적인 위상이 높은 것으로 파악되었다. This article aims to develop discussions on the necessity of official statistics system for railroad industry which is indispensable in planning, every five years, the Railroad Industry Development Plan. To reach this goal, it was necessary to define the scope of railroad industry and extract railroad industry related figures from the surveys of the Korea National Statistics Office : census on establishments, mining & manufacturing, wholesale & retail, and transport. Railroad Industry employed 56 thousand workers in 2,187 establishments in 2008. Railroad equipments manufacturing occupied, in 2009, 0.29% of country‘s whole manufacturing by the market price. Sales of Railroad transport related machineries and equipments, in 2008, were 0.15% in the nation"s wholesale and retail takings. The share of Railroad transport sales were 5% in whole domestic transport sales. Within railroad industry, added value was important in the order of rail transport, rail construction and manufacturing of rolling stocks.

Effect of Copper Ion on Oxygen Damage in Superoxide Dismutase-Deficient Saccharomyces Cerevisiae

Lee, Jeong-Ki,Kim, Ji-Myon,Kim, Su-Won,Nam, Doo-Hyun,Yong, Chul-Soon,Huh, Keun The Pharmaceutical Society of Korea 1996 Archives of Pharmacal Research Vol.19 No.3

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxidative stresses induced by 0.1 mM of copper ion $(Cu^{++})$ was studied. In aerobic culture condition, yeasts lacking MnSOD (mitochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared withwild type were observed under anaerobic condition. It was found that, under aerobic condition, the supplementation of 0.1 mM copper ioh:(Cu") into culture medium caused the remarkable increase of CuZnSOD but not so significant change in MnSOD. It was also observed that catalase activities appeared to be relatively high in the presence of copper ion in spite of the remarkable reduction of glutathion peroxidase in CuZnSOD-deficient yeasts, but the slight increments of catalase and glutathion peroxidase were detected in MnSOD-deficient strains. It implies that the lack of cytoplasmic SOD could be compensated mainly by catalase. However, these phenomena resulted in the significantincrease of cellular lipid peroxides content in CuZnSOD-deficient yeasts and the slight increment of lipid peroxides in MNSOD-deficient cells. In anaerobic cultivation supplementing copper ion, the cellular enzyme activities of catalase and glutathion peroxidase in SOD-deficient yeasts were slightly increased without any significant changes of lipid peroxides in cell membrane. It suggests that a little amount of free radicals generated by copper ion under anaerobic condition could be sufficiently overcome by catalase as well as glutathion peroxidase.dase.

Effect of Copper lon on Oxygen Damage in Superoxide Dismutase-Deficient Saccharomyces cerevisiae

Lee, Jeong Ki,Kim, Ji Myon,Nam, Doo Hyun,Yong, Chul Soon,Huh, Keun 영남대학교 약품개발연구소 1996 영남대학교 약품개발연구소 연구업적집 Vol.6 No.-

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxidative stresses induced by 0.1mM of copper ion (Cu^(++)) was studied. In aerobic culture condition, yeasts lacking MnSOD (mitochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared with wild type were observed under anaerobic condition. It was found that, under aerobic condition, the supplementation of 0.1 mM copper ion (Cu^(++)) into culture medium caused the remarkable increase of CuZnSOD but not so significant change in MnSOD. It was also observed that catalase activities appeared to be relatively high in the presence of copper ion in spite of the remarkable reduction of glutathion peroxidase in CuZnSOD-deficient yeasts, but the slight increments of catalase and glutathion peroxidase were detected in MnSOD-deficient strains. It implies that the lack of cytoplasmic SOD could be compensated mainly by catalase. However, these phenomena resulted in the significant increase of cellular lipid peroxides content in CuZnSOD-deficient yeasts and the slight increment of lipid peroxides in MnSOD-deficient cells. In anaerobic cultivation supplementing copper ion, the cellular enzyme activities of catalase and glutathion peroxidase in SOD-deficient yeasts were slightly increased without any significant changes of lipid peroxides in cell membrane. It suggests that a little amount of free radicals generated by copper ion under anaerobic condition could be sufficiently overcome by catalase as well as glutathion peroxidase.

Cardiovascular Health Metrics and All-cause and Cardiovascular Disease Mortality Among Middle-aged Men in Korea: The Seoul Male Cohort Study

Kim, Ji Young,Ko, Young-Jin,Rhee, Chul Woo,Park, Byung-Joo,Kim, Dong-Hyun,Bae, Jong-Myon,Shin, Myung-Hee,Lee, Moo-Song,Li, Zhong Min,Ahn, Yoon-Ok The Korean Society for Preventive Medicine 2013 예방의학회지 Vol.46 No.6

Objectives: This study estimated the association of cardiovascular health behaviors with the risk of all-cause and cardiovascular disease (CVD) mortality in middle-aged men in Korea. Methods: In total, 12 538 men aged 40 to 59 years were enrolled in 1993 and followed up through 2011. Cardiovascular health metrics defined the following lifestyle behaviors proposed by the American Heart Association: smoking, physical activity, body mass index, diet habit score, total cholesterol, blood pressure, and fasting blood glucose. The cardiovascular health metrics score was calculated as a single categorical variable, by assigning 1 point to each ideal healthy behavior. A Cox proportional hazards regression model was used to estimate the hazard ratio of cardiovascular health behavior. Population attributable risks (PARs) were calculated from the significant cardiovascular health metrics. Results: There were 1054 total and 171 CVD deaths over 230 690 person-years of follow-up. The prevalence of meeting all 7 cardiovascular health metrics was 0.67%. Current smoking, elevated blood pressure, and high fasting blood glucose were significantly associated with all-cause and CVD mortality. The adjusted PARs for the 3 significant metrics combined were 35.2% (95% confidence interval [CI], 21.7 to 47.4) and 52.8% (95% CI, 22.0 to 74.0) for all-cause and CVD mortality, respectively. The adjusted hazard ratios of the groups with a 6-7 vs. 0-2 cardiovascular health metrics score were 0.42 (95% CI, 0.31 to 0.59) for all-cause mortality and 0.10 (95% CI, 0.03 to 0.29) for CVD mortality. Conclusions: Among cardiovascular health behaviors, not smoking, normal blood pressure, and recommended fasting blood glucose levels were associated with reduced risks of all-cause and CVD mortality. Meeting a greater number of cardiovascular health metrics was associated with a lower risk of all-cause and CVD mortality.

InP/InGaAsP 광자결정 구조 제작을 위한 건식 식각 특성

이지면,Lee, Ji-Myon 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.12

Two-dimensionally arrayed nanocolumn lattices were fabricated by using double-exposure laser holographic method. The hexagonal lattice was formed by rotating the sample with 60 degree while the square lattice by 90 degree before the second laser-exposure. The reactive ion etching for a typical time of 30 min using CH$_4$/H$_2$ plasma enhanced the aspect-ratio by more than 1.5 with a slight increase of the bottom width of columns. The etch-damage was observed by photoluminescence (PL) spectroscopy which was removed by the wet chemical etching using HBr/$H_2O$$_2$/$H_2O$ solution, leading into the enhanced PL intensities of the PCs.

Externally modulated ns-pulse amplification using an all-fiber system

Sahnggi Park,Chul-Wook Lee,Hyunsung Ko,Ji-Myon Lee,Joon-Tae Ahn,Moon-Ho Park,Su Hwan Oh 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.6

An all ber system of standard single-mode cascaded erbium doped ber ampliers (EDFAs) was used to amplify 3-ns externally modulated pulses, where an ecient removal of background cw power was an inevitable step to avoid gain saturation by the unwanted cw source in high power pulse amplication. It is shown that an appropriate thickness of saturable absorbers can remove, almost completely, the background cw power, as well as the amplied spontaneous emission (ASE). We claim that this experiment demonstrates a most eective way of pulse amplication for all ber systems. We also experimentally and theoretically analyzed the pulse behavior for dierent duty rates as a function of the pump power.

Ohmic contact to nonpolar<i>a</i>-plane p-type GaN using Ni/Au

Kim, Jae-Kwan,Lee, Dong-min,Lee, Sung-Nam,Song, Keun-Man,Yoon, Jae-Sik,Lee, Ji-Myon IOP Publishing 2014 Japanese journal of applied physics Vol.53 No.5

<P>In this study, we examined the characteristics of Ni/Au (20 nm/80 nm) ohmic contacts to non-polar a-plane p-GaN as a function of annealing temperature. The current-voltage (I-V) curves were showed an upward curve with annealing when Ni/Au metals were used as ohmic metals to nonpolar p-GaN, which was similar to those of the other crystalline planes. The contact resistivity decreased from 2.36 to 6.95 x 10(-3)Omega cm(2). Secondary ion mass spectroscopy showed that the Ga atoms out-diffused from the GaN substrate after annealing at 400 degrees C, which led to the generation of Ga vacancies. The formation of Ga and N vacancies was found to be a competing process during annealing. (C) 2014 The Japan Society of Applied Physics</P>