• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2233-2236
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• 2011

We evaluate quantum-mechanical velocity autocorrelation functions from classical molecular dynamics simulations using quantum correction approaches. We apply recently developed approaches to supercritical argon and liquid neon. The results show that the methods provide a solution more efficient than previous methods to investigate quantum-mechanical dynamic behavior in condensed phases. Our numerical results are found to be in excellent agreement with the previous quantum-mechanical results.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 춘계공동학술발표회요약집
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• pp.115-115
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• 2002

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권1호
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• pp.20-27
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• 2010

Modeling is essential to simulate the operation of integrated circuit (IC) before its fabrication. Seeing a large number of Metal-Oxide-Silicon Field-Effect-Transistor (MOSFET) models available, it has become important to understand them and compare them for their pros and cons. The task becomes equally difficult when the complexity of these models becomes very high. The paper reviews the mainstream models with their physical relevance and their comparisons. Major short-channel and quantum effects in the models are outlined. Emphasis is set upon the latest compact models like BSIM, MOS Models 9/11, EKV, SP etc.

• JSTS:Journal of Semiconductor Technology and Science
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• 제4권1호
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• pp.27-31
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• 2004

Models and simulations of gate tunneling current for thinoxide MOSFETs and Double-Gate SOIs are discussed. A guideline in design of leaky MOS capacitors is proposed and resonant gate tunneling current in DG SOI simulated based on quantum-mechanicalmodels. Gate tunneling current in fully-depleted, double-gate SOI MOSFETs is characterized based on quantum-mechanical principles. The simulated $I_G-V_G$ of double-gate SOI has negative differential resistance like that of the resonant tunnel diodes.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.82-87
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• 2020

The comprehensive and physics-based compact noise models for advanced CMOS devices were presented. The models incorporate important physical effects in nanoscale MOSFETs, such as the low frequency correlation effect between the drain and the gate, the trap-related phenomena, and QM (quantum mechanical) effects in the inversion layer. The drain current noise model was improved by including the tunneling assisted-thermally activated process, the realistic trap distribution, the parasitic resistance, and mobility degradation. The expression of correlation coefficient was analytically described, enabling the overall noise performance to be evaluated. With the consideration of QM effects, the comprehensive low frequency noise performance was simulated over the entire bias range.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권1호
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• pp.1-9
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• 2006

We introduce our in-house program, NANOCAD, for the modeling and simulation of carrier transport in nanoscale MOSFET devices including quantum-mechanical effects, which implements two kinds of modeling approaches: the top-down approach based on the macroscopic quantum correction model and the bottom-up approach based on the microscopic non-equilibrium Green’s function formalism. We briefly review these two approaches and show their applications to the nanoscale bulk MOSFET device and silicon nanowire transistor, respectively.

• 대한전자공학회논문지SD
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• 제41권8호
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• pp.17-24
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• 2004

Density-gradient 방법을 이용하여 게이트의 양자효과가 double-gate MOSFET의 단채널 효과에 미치는 영향을 2차원으로 분석하였다. 게이트와 sidewall 산화막 경계면에서 발생하는 2차원 양자공핍 현상에 의하여 게이트 코너에 큰 전하 다이폴이 형성되며 subthreshold 영역에서 다이폴의 크기가 증가하고 classical 결과에 비하여 전자 농도와 전압 분포가 매우 다름을 알 수 있었다. Evanescent-nude분석을 통하여 게이트의 양자효과가 소자의 단채널 효과를 증가시키며 이는 기판에서의 양자효과에 의한 영향보다 크다는 것을 확인하였다. 양자효과에 의하여 게이트 코너에 형성되는 전하 다이폴이 단채널 효과를 증가시키는 원인임을 밝혔다.

• 대한기계학회논문집A
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• 제39권7호
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• pp.653-657
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• 2015

표면확산계수의 활성화를 통한 실리콘-게르마늄(silicon-germanium) 양자점의 성장을 수치해석적으로 구현하였다. 실리콘 기판 위에 증착된 실리콘-게르마늄 박막의 성장을 표현하는 비선형 지배방정식을 유도하였으며, 확산계수를 온도의 함수로 고려하여 표면확산계수의 국소적 향상이 미치는 효과를 살펴보았다. 해석결과는 안정상태의 박막이 섭동될 때에 양자점이 자기조립되는 과정을 보여주며, 박막표면의 국소부위에 선택적으로 구조물이 성장하는 현상을 나타낸다. 본 연구는 바텀업(bottom-up) 방식이 내재적으로 지닌 불규칙성을 해결할 대안을 마련하여 양자기기를 위한 공정개발의 방향을 제시한다.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.73-76
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• 2020

The physics-based compact gate leakage current noise models in nanoscale MOSFETs are developed in such a way that the models incorporate important physical effects and are suitable for circuit simulators, including QM (quantum-mechanical) effects. An emphasis on the trap-related parameters of noise models is laid to make the models adaptable to the variations in different process technologies and to make its parameters easily extractable from measured data. With the help of an accurate and generally applicable compact noise models, the compact noise models are successfully implemented into BSIM (Berkeley Short-channel IGFET Model) format. It is shown that the noise models have good agreement with measurements over the frequency, gate-source and drain-source bias ranges.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.303-315
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• 2008

In this paper, thermodynamical properties of crystalline silicon under strain are calculated using classical molecular dynamics (MD) simulations based on the Tersoff interatomic potential. The Helmholtz free energy of the silicon crystal under strain is calculated by using the ensemble method developed by Frenkel and Ladd (1984). To account for quantum corrections under strain in the classical MD simulations, we propose an approach where the quantum corrections to the internal energy and the Helmholtz free energy are obtained by using the corresponding energy deviation between the classical and quantum harmonic oscillators. We calculate the variation of thermodynamic properties with temperature and strain and compare them with results obtained by using the quasi-harmonic model in the reciprocal space.