중앙-채널 이중게이트 MOSFET의 양자역학적 모델링 및 시뮬레이션 연구

김기동,원태영,Kim, Ki-Dong,Won, Tae-Young 대한전자공학회 2005 電子工學會論文誌-SD (Semiconductor and devices) Vol.42 No.7

본 논문에서는 결합된 슈뢰딩거-푸아송 방정식과 전류연속방정식을 셀프-컨시스턴트하게 계산함으로써, 나노-스케일 center-channel (CC) double-gate (DG) MOSFET 디바이스의 전기적 특성 및 구조해석에 관한 연구를 시행하였다. 10-80 nm 게이트 길이의 조건에서 수행한 CC-NMOS의 시뮬레이션 결과를 DG-NMOS 구조에서 시행한 시뮬레이션 결과와의 비교를 통하여 CC-NMOS 구조에서 나타나는 CC 동작특성 메커니즘과, 이로 인한 전류 및 G$_{m}$의 상승을 확인하였다. 문턱 전압 이하 기울기, 문턱 전압 롤-오프, 드레인 유기 장벽 감소의 파라미터를 통하여 단채널 효과를 최소화하기 위한 디바이스 최적화를 수행하였다. 본 나노-스케일 전계 효과 트랜지스터를 위한 2차원 양자역학적 수치해석의 관한 연구를 통하여, CC-NMOS를 포함한 DG-MOSFET 구조가 40나노미터급 이하 MOSFET 소자의 물리적 한계를 극복하기 위한 이상적인 구조이며, 이와 같은 나노-스케일 소자의 해석에 있어서 양자역학적 모델링 및 시뮬레이션이 필수적임을 알 수 있었다. The device performance of nano-scale center-channel (CC) double-gate (DG) MOSFET structure was investigated by numerically solving coupled Schr$\"{o}$dinger-Poisson and current continuity equations in a self-consistent manner. The CC operation and corresponding enhancement of current drive and transconductance of CC-NMOS are confirmed by comparing with the results of DG-NMOS which are performed under the condition of 10-80 nm gate length. Device optimization was theoretically performed in order to minimize the short-channel effects in terms of subthreshold swing, threshold voltage roll-off, and drain-induced barrier lowering. The simulation results indicate that DG-MOSFET structure including CC-NMOS is a promising candidates and quantum-mechanical modeling and simulation calculating the coupled Schr$\"{o}$dinger-Poisson and current continuity equations self-consistently are necessary for the application to sub-40 nm MOSFET technology.

16종 다용한약재의 산지별 As, Cd, Pb, Co, Cr 농도 및 특성고찰 -한국과 중국산의 평균농도, 최소-최대농도와 법적 허용농도초과비율을 중심으로-

김기동,박해모,서용찬,이선동,Kim, Kee-Dong,Park, Hae-Mo,Seo, Yong-Chan,Lee, Sun-Dong 대한예방한의학회 2012 대한예방한의학회지 Vol.16 No.3

Objective : Average, lowest, highest concentration and exceeding value of legal allowance of As, Cd, Pb, Co, Cr in frequently using 16 oriental herbal medicines in korea(Astragali Radix, Ginseng, Citri Unshii Pericarpium, Aurantii Fructus Immaturus, Angelicae Gigantis Radix, Cnidii Rhizoma, Paeoniae Radix, Rehmanniae Radix Preparata, Zingiberis Rhizoma Crudus, Zizyphi Fructus, Atractylodis Rhizoma Alba, Hoelen, Dioscoreae Rhizoma, Corni Fructus, Schisandrae Fructus, Lycii Fructus) was evaluated according to their origines (korea, china) and property was also discussed according to the medicinally active part and individuals regardless origines. Method : Korean and Chinese herbal medicines were evenly sampled from corresponding country nationwide. Pre-treatment was executed according to the KFDA(Korea Food and Drug Administration) regulation and analysis was performed according to the Korean Environmental Analysis QA/QC. Result : Not much difference was observed according to their origines. However, lowest, highest and percent exceeding value of legal allowance was showed some consistent differences according to the medicinally active part and individuals. Co and Cr was can not be evaluated since their legal regulation was not established yet. Conclusion : The average concentration of As, Cd, Pb, Co, Cr in frequently using 16 oriental herbal medicines in korea showed no noticeable difference according to their origines. Regardless the origin, some consistent differences were observed according to the individuals and medicinally active parts.

실버 나노분말을 이용한 메탈메쉬용 페이스트의 충전 및 와이핑 특성

김기동,남현민,양상선,박이순,남수용,Kim, Gi-Dong,Nam, Hyun-Min,Yang, Sangsun,Park, Lee-Soon,Nam, Su-Yong 한국분말야금학회 2017 한국분말재료학회지 (KPMI) Vol.24 No.6

A metal mesh TCE film is fabricated using a series of processes such as UV imprinting of a transparent trench pattern (with a width of $2-5{\mu}m$) onto a PET film, filling it with silver paste, wiping of the surface, and heat-curing the silver paste. In this work nanosized (40-50 nm) silver particles are synthesized and mixed with submicron (250-300 nm)-sized silver particles to prepare silver paste for the fabrication of metal mesh-type TCE films. The filling of these silver pastes into the patterned trench layer is examined using a specially designed filling machine and the rheological testing of the silver pastes. The wiping of the trench layer surface to remove any residual silver paste or particles is tested with various mixture solvents, and ethyl cellosolve acetate (ECA):DI water = 90:10 wt% is found to give the best result. The silver paste with 40-50 nm Ag:250-300 nm Ag in a 10:90 wt% mixture gives the highest electrical conductance. The metal mesh TCE film obtained with this silver paste in an optimized process exhibits a light transmittance of 90.4% and haze at 1.2%, which is suitable for TSP application.

향토문화축제 관광자원 활성화: 허균.허난설헌 축제를 중심으로

김기동,Kim, Gi-Dong 한국산학경영학회 2009 산학경영연구 Vol.22 No.1

본 연구는 강릉지역의 대표적인 향토문화관광축제인 허 균 허난설헌 문화제를 대상으로 독특한 정체성과 향토성이 축제관광 프로그램 개발의 질적 향상을 가져다주며, 지역의 특성 및 관광자원을 활용한 프로그램 개발과 지역 활성화의 관점에서 고찰하였다. 그 결과 첫째, 허 균 허난설헌 문화제에 대하여 참가자들의 정보는 대부분 옥외 광고물이나 구전 혹은 친지나 동료들에게 들어 참가한 것으로 조사되었다. 둘째, 연령에 따른 만족도에서는 화장실과 편의시설 등의 시설성과 강릉시 이미지 고양 그리고 가족, 친지와의 친목도모 등의 효과성에 만족도의 차이를 보이고 있다. 셋째, 각종 행사에 참여한 사람들은 행사의 종류에 따라 만족도에 차이를 보이고 있다. 넷째, 강릉지역에서 개최되는 지역축제에 대하여 미리 인지하고 참여한 참가자는 인지하지 못하고 참여한 참가자보다 대부분 만족도가 높았다. The purposes of this study are the analysis by content of satisfaction level of participants in the event for the systematic, efficient event tourism program. For this analysis, it was researched if there was any difference in satisfaction level of participants in event by demographic characteristics, participation level and content of program. The results of this analysis are as follows: There was a difference in satisfaction level by participants characteristics in the event tourism. There was the more recognition, the higher participation level. There was higher participation and satisfaction level in participational and special program than exhibitory program. This study has a limit that can"ft grasp the foreign visitors"f recognition for the event tourism in Gangnueng district. But, it is very important to analyze the voluntary participation and interest of local residents and it may be the fruit of this study to of a new program and suggestion point through the analysis of satisfaction level for the Heo-kyun & Heo_Nan_Sul_Hun Cultural Festival.

Determination of gravity at MunGyung (Mungyeong) superconducting gravity observatory, Korea

김기동,Jeong Woo Kim,Juergen Neumeyer,Ricky Kao,Cheinway Hwang,박혁진,Ik Woo,Young Wook Lee 한국지질과학협의회 2009 Geosciences Journal Vol.13 No.2

Absolute gravity measurements were made to calibrate Korea’s first superconducting gravimeter (SG) at MunGyung (MG, Mungyeong) Observatory. A calibration coefficient (CC) of the MG SG was determined by a parallel registration with an FG5 absolute gravimeter. A total of 8,541 drops were measured over a period of 37 hours between October 8th and 10th, 2007. We first determined the absolute gravity value to be 979,859,179.3 ± 88.481 μGal (μGal=10−8 m·s−2) after atmospheric pressure, Earth tide and ocean loading corrections. In a linear regression analysis between the FG5 recordings and the raw SG data, a CC of 64.548 ± 0.224 μGal· volt–1 was determined, having previously removed invalid drops and outliers from the data sets. Together with the absolute measurements, a vertical gravity gradient of 2.72 μGal·cm–1 was calculated using a Graviton-EG spring gravimeter to take the absolute gravity value down to the SG observatory platform level. The validity of the CC was additionally tested by a comparison between the recorded SG data and the theoretical tides (HW95 and Wahr-Dehant models) as reference. Gravity variations induced by atmospheric pressure and ocean loading were added to the theoretical Earth tides. The CC based on the theoretical tide was determined to be 64.560 μGal·volt–1. The difference between the two coefficients is 0.012 μGal· volt–1, which lies within the standard error of the determined coefficient, 0.224 μGal·volt–1. Therefore, a value of 64.548 μGal·volt–1, determined by the parallel registration with the absolute gravimeter, was accepted as the CC of the SG (GWR Instrument Inc. #045) installed at MG Observatory. During the gravity measurements, the other gravity values and heights such as normal gravity and the gravity gradient, orthometric and dynamic heights were also calculated Absolute gravity measurements were made to calibrate Korea’s first superconducting gravimeter (SG) at MunGyung (MG, Mungyeong) Observatory. A calibration coefficient (CC) of the MG SG was determined by a parallel registration with an FG5 absolute gravimeter. A total of 8,541 drops were measured over a period of 37 hours between October 8th and 10th, 2007. We first determined the absolute gravity value to be 979,859,179.3 ± 88.481 μGal (μGal=10−8 m·s−2) after atmospheric pressure, Earth tide and ocean loading corrections. In a linear regression analysis between the FG5 recordings and the raw SG data, a CC of 64.548 ± 0.224 μGal· volt–1 was determined, having previously removed invalid drops and outliers from the data sets. Together with the absolute measurements, a vertical gravity gradient of 2.72 μGal·cm–1 was calculated using a Graviton-EG spring gravimeter to take the absolute gravity value down to the SG observatory platform level. The validity of the CC was additionally tested by a comparison between the recorded SG data and the theoretical tides (HW95 and Wahr-Dehant models) as reference. Gravity variations induced by atmospheric pressure and ocean loading were added to the theoretical Earth tides. The CC based on the theoretical tide was determined to be 64.560 μGal·volt–1. The difference between the two coefficients is 0.012 μGal· volt–1, which lies within the standard error of the determined coefficient, 0.224 μGal·volt–1. Therefore, a value of 64.548 μGal·volt–1, determined by the parallel registration with the absolute gravimeter, was accepted as the CC of the SG (GWR Instrument Inc. #045) installed at MG Observatory. During the gravity measurements, the other gravity values and heights such as normal gravity and the gravity gradient, orthometric and dynamic heights were also calculated

Float 공법을 고려한 Plasma Display Panel용 기판유리 용융체의 특성

김기동,정우만,정현수,권성구,최세영,Kim, Ki-Dong,Jung, Woo-Man,Jung, Hyun-Su,Kwon, Sung-Ku,Choi, Se-Young 한국세라믹학회 2006 한국세라믹학회지 Vol.43 No.7

In order to examine the working condition of melts in tin bath of float process it was investigated Sn diffusion behavior and solidification rate of melts for alkali-alkaline earth-silica PDP substrate glasses such as commercial CaO rich CS-77 glass, commercial $Al_2O_3$ rich PD-200 glass and self developed $SiO_2$ rich T-series (T-2, T-4, T-6) glasses. In the case of Sn depth and concentration created in glass surface by ion exchange between Sn and alkali, T-series showed lower value than CS-77, especially T-2 is more excellent than PD-200. The solidification rate of melts expressed by cooling time between $log{\eta}=4\;and\;7.6dPa{\cdot}s$ was low for T-series comparing with CS-77 and PD-200. Therefore, it was concluded that T-series is desirable considering forming condition in the tin bath of the float process.

National Biotechnology Innovation System in the United States

김기동,황용식,Kim, Ki-Dong,Hwang, Yong-Sik The Korean Society of Business Venturing 2010 벤처창업연구 Vol.5 No.2

Biotechnology has strategic importance related to the development of start-up companies, industries and nations in the near future. Therefore, many countries have promoted and developed biotechnology. The United States has led the world in promoting biotechnology. American biotechnology policies are diverse, and thus no comprehensive systematic studies have been done on it. In our paper, we will discuss American biotechnology policy in detail. For effective analysis, we will rely on the concept of a national innovation system, which emphasizes the institutional settings of innovation actors and their interaction. This paper deals with the American national innovation system for biotechnology. We will analyze the role of major actors, academia, public research institutes, and venture companies and their interactions. The American biotechnological innovation system is composed of diverse actors and numerous start-up companies in the biotechnology industry. In addition, there are many diverse policy programs for promoting biotechnology. Because of country-specific frame conditions, every country has different institutional settings and policies for promoting biotechnology. Our paper will render meaningful implications for various countries. We also think that this paper will be of interest for international readers.

나노-스케일 전계 효과 트랜지스터 모델링 연구 : FinFET

김기동,권오섭,서지현,원태영,Kim, Ki-Dong,Kwon, Oh-Seob,Seo, Ji-Hyun,Won, Tae-Young 대한전자공학회 2004 電子工學會論文誌-SD (Semiconductor and devices) Vol.41 No.6

본 논문에서는 2차원 양자 역학적 모델링 및 시뮬레이션(quantum mechanical modeling and simulation)으로써, 자기정렬 이중게이츠 구조(self-aligned double-gate structure)인 FinFET에 관하여 결합된 푸아송-슈뢰딩거 방정식(coupled Poisson and Schrodinger equations)를 셀프-컨시스턴트(self-consistent)한 방법으로 해석하는 수치적 모델을 제안한다. 시뮬레이션은 게이트 길이(Lg)를 10에서 80nm까지, 실리콘 핀 두께($T_{fin}$)를 10에서 40nm까지 변화시켜가며 시행되었다. 시뮬레이션의 검증을 위한 전류-전압 특성을 실험 결과값과 비교하였으며, 문턱 전압 이하 기울기(subthreshold swing), 문턱 전압 롤-오프(thresholdvoltage roll-off), 그리고 드레인 유기 장벽 감소(drain induced barrier lowering, DIBL)과 같은 파라미터를 추출함으로써 단채널 효과를 줄이기 위한 소자 최적화를 시행하였다. 또한, 고전적 방법과 양자 역학적 방법의 시뮬레이션 결과를 비교함으로써,양자 역학적 해석의 필요성을 확인하였다. 본 연구를 통해서, FinFET과 같은 구조가 단채널 효과를 줄이는데 이상적이며, 나노-스케일 소자 구조를 해석함에 있어 양자 역학적 시뮬레이션이 필수적임을 알 수 있었다. We performed two-dimensional (20) computer-based modeling and simulation of FinFET by solving the coupled Poisson-Schrodinger equations quantum-mechanically in a self-consistent manner. The simulation results are carefully investigated for FinFET with gate length(Lg) varying from 10 to 80nm and with a Si-fin thickness($T_{fin}$) varying from 10 to 40nm. Current-voltage (I-V) characteristics are compared with the experimental data. Device optimization has been performed in order to suppress the short-channel effects (SCEs) including the sub-threshold swing, threshold voltage roll-off, drain induced barrier lowering (DIBL). The quantum-mechanical simulation is compared with the classical appmach in order to understand the influence of the electron confinement effect. Simulation results indicated that the FinFET is a promising structure to suppress the SCEs and the quantum-mechanical simulation is essential for applying nano-scale device structure.

낙석방지울타리의 성능평가 I: 성능평가기준

김기동,고만기,김달성,문병갑,Kim, Kee Dong,Ko, Man Gi,Kim, Dal Sung,Moon, Byung Gab 대한토목학회 2015 대한토목학회논문집 Vol.35 No.1

The purpose of this study is to suggest performance levels, a test method, and assessment criteria for the performance assessment to allow standardized tests for rockfall protection systems. The range of rockfall impact energy was determined by using domestic rockfall data and a total of 9 performance levels from 50kJ to 1500kJ were suggested. The performance assessment is implemented by two types of full-scale free-fall impact tests to investigate the serviceability and the maximum capacity as in European and American standards. It was considered to be reasonable that the specimens of rockfall protection systems consist of 3 spans and the concrete block of a polyhedron with 26 faces, similar to spheres, impacts at the center of a center span. Assessment criteria were constructed to investigate whether a rockfall penetrated rockfall protection systems and whether the deformed specimen encroached on the roadway or obstructed the vehicle traffic. 본 연구에서는 낙석방지울타리에 대한 표준화된 시험이 가능하도록 성능평가에 필요한 성능등급, 시험방법, 평가기준을 제안하고자 하였다. 국내 낙석자료를 이용하여 낙석에너지의 범위를 결정하고 50kJ에서 1500kJ까지 총 9등급의 성능등급을 제시하였다. 성능평가는 유럽과 미국의 기준과 같이 사용성과 최대성능을 조사하기 위한 2종류의 실물 자유낙하 충격시험으로 이루어진다. 낙석방지울타리의 시험체는 3경간으로 구성되고 구형에 가까운 26면체 콘크리트 블록이 중앙 경간의 중앙에 충돌하는 것이 합리적인 것으로 판단되었다. 시험의 평가기준은 낙석의 관통여부와 변형을 겪은 낙석방지울타리가 도로를 침범하거나 차량통행을 방해할 가능성이 있는지를 검토하도록 구성되었다.

PECVD에 의한 YSZ(Yttria Stabilized Zirconia)박막 제조

김기동,신동근,조영아,전진석,최동수,박종진,Kim, Gi-Dong,Sin, Dong-Geun,Jo, Yeong-A,Jeon, Jin-Seok,Choe, Dong-Su,Park, Jong-Jin 한국재료학회 1999 한국재료학회지 Vol.9 No.3

PECVD(Plasma enhanced chemical vapor deposition)을 이용하여 yttria-stabilized zirconia(YSZ) 박막을 제조하였다. 반응물질로 금속유기화합물을 $Zr[TMHD]_4$와 $Y[TMHD]_3$그리고 산소를 사용하였으며, 증착온도는 $425^{\circ}C$, rf power는 0~100W까지 적용하였다. YSZ 박막은 (200)면이 기판에 평행한 입벙정상 구조를 가졌으며, 1시간 내에 $1\mu\textrm{m}$ 두께를 형성하였다. EDX에 의한 막의 성분분석 결과로부터 환산된 박막내의 $Y_2O_3$의 함량은 0-36%의 범위였다. 버블러의 온도 및 운반기체의 유량이 증가함에 따라 박막의 두께 역시 비례하여 증가하였는데, 이는 precursor의 flux 증가로 인한 박막내의 $Y_2O_3$의 함량증가에 의한 것이었다. Zr 및 Y, O는 박막의 두께에 따라 일정한 조성비를 나타내었다. 운반기체를 Ar로 하였을 때 $1000\AA$이하의 크기를 갖는 YSZ 입자들이 column 모양으로 기판에 수직하게 성장하였으며, 운반기체가 He인 경우에도 column 모양으로 성장하였으며 입도가 $1000~2000\AA$으로 Ar의 경우보다 조대해졌다. XRD 분석결과 $Y_2O_3$의 함량이 증가함에 따라 YSZ의 격자상수 값이 약간씩 증가하였다. 이는 박막 전반에 걸쳐 형성된 균열에 의해 격자변형으로 인해 발생한 응력을 완화시켰지 때문이다. A Abstract Yttria-stabilized zirconia(YSZ) thin films were synthesized by plasma enhanced chemical vapor deposition process. $Zr[TMHD]_4$ $Y[TMHD]_3$ precursors and oxygen were used with the deposition temperature of $425^{\circ}C$ and rf power ranging 0-100 watt. Effects of the deposition parameters were studied by X-ray diffraction and thickness anal­ysis. YSZ thin films have cubic crystal structure with (200) orientation. From the results of EDX analysis, the converte ed content of $Y_2O_3$ was determined to be 0-36%, and the film thickness was increased with bubbling temperature which is considered to be due to increasing $Y_2O_3$ flux. The depth profiles of Zr, Y and 0 appeared relatively $\infty$nstant through film thickness. Columnar grains of $1000~2000\AA$ grew vertical to the substrate surface for the case of Ar carri­er gas. In case of He carrier gas, the grain size was observed to be about $1000~2000\AA$. X-ray diffraction data showed the increase of lattice constant with $Y_2O_3$ content. It was that the presence of the cracks formed during film deposition, partially released the stress generated by the increase of lattice constant.