• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.131-135
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• 1989

Hot electron simulation of silicon using Monte Carlo method was carried out to investigate impact ionization characteristics near the drain of MOSFET's at 77 and 300K. We successfully characterized drift velocity and impact ionization at 77 and 300K employing a simplified energy band structure and phonon scattering mechanisms. Woods' soft energy threshold model was introduced to the Monte Carlo simulation of impact ionization, and good agreement with reported experimental results was resulted by employing threshold energy of 1.7 eV. It is suggested that the choice of the critical angle between specular reflection and diffusive scattering of surface roughness scattering may be important in determining the impact ionization charateristics of Monte Carlo simulation near the drain of MOSFET's.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.342-345
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• 2005

This paper describes the electron energy distribution function characteristics in $SF_6-He$ gas calculated for range of E/N values from $50{\sim}700[Td]$ by the Monte Carlo simulation(MCS) and Boltzmann equation(BE) method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters are obtained by time of flight(TOF) method. The results gained that the values of the electron swarm parameters such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients agree with the experimental and theoretical for a range of E/N. The results of Boltzmann equation and Monte carlo simulation have been compared with experimental data by Pollock, Ohmori, cottrell and Walker.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.169-174
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• 1996

In this paper, the electron transport characteristic in CF$_4$has been analysed over the E/N range 1~300(Td) by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The alteration of cross sections from the literature is avoided as much as possible in the analysis. The motion has been calculated to give swarm parameters for the electron drift velocity(W), diffusion coefficient(D$_{L}$), the ratio of the diffusion coefficient to the mobility(D$_{L}$/$\mu$), mean energy($\varepsilon$), the electron energy distribution function. The electron energy distribution function has been analysed in CF$_4$at E/N=50, 100 and 200(Td) for a case of the equilibrium region in the mean electron energy. The results of Boltzmann equation and Monte Carlo simulation have been compared with experimental data by Y. Nakamura and M. Hayashi.shi.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.696-699
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• 1999

The electron transport coefficients in $SF_6+N_2$ gas is analysed in range of E/N values from 100~900(Td) by a Monte Carlo simulation and Boltzmann method, using a set of electron collision cross sections determined by the authors. The result of the Monte Carlo simulation such as electron drift velocity, ionization and electron attachment coefficients, longitudinal and transverse diffusion coefficients in nearly agreement with the respective experimental and theoretical for a range of E/N.

• Transactions on Electrical and Electronic Materials
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• 제3권3호
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• pp.1-7
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• 2002

The developed patterns by direct writing of electron beam are measured by AFM, FESEM and optical profiler of WYKO NT3300. From different measurement methods, the measured linewidths of the patterns are shown a little bit wider than designed pattern size due to electrons scattering effect during direct writing of electron beam. The optimized conditions of these experiments are suggested and explained for the forming of structures below 0.1 ㎛ dimension size. Because of electron scattering effects from the different under layers such as Si, Si$_3$N$_4$ and aluminum, the developed pattern size is also influenced by the accelerated energy of electrons, dose, resist and soft and hard bake conditions in PMMA. The distributions of electron beam and calculations of backscattering coefficient are demonstrated by Monte Carlo simulation. From the measured results, the developed linewidth of PMMA/Al /silicon is shown a little bit wider than that of PMMA/Si$_3$N$_4$/silicon structure due to the backscattering effects.

• 한국의학물리학회지:의학물리
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• 제19권1호
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• pp.21-34
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• 2008

환자의 CT자료를 기반으로 만들어진 3차원상의 표적물질에 전자 및 광자의 전달 현상을 계산하는 몬테카를로(MC) 도즈계산용 병렬프로그램 (PMCEPT 코드)을 개발하여 베어울프 PC 클러스터에 탑제하였다. 시뮬레이션에서 오차를 최소화하고 코드를 더욱 발전시키기 위해서는 현재의 MC 코드의 한계를 아는 것이 매우 유익하다. 이러한 관점에서 저자는 PMCEPT코드를 이용하여 이질 혹은 동질의 표적물질에서 표준화된 깊이 도즈를 계산하여 잘 알려진 다른 코드들, MCNP5, EGS4, DPM, GEANT4 및 실험결과와 비교를 하였다. PMCEPT결과는 이질 혹은 동질의 표적에서 다른 코드들과 $1{\sim}3%$ 오차 범위 안에서 잘 일치하였다. 계산시간 비교에 있어서도 PMCEPT 코드가 MCNP5 보다는 약 20배, GEANT4코드보다는 약 3배정도 빨랐다. 이러한 결과를 종합하면, PMCEPT코드는 의학물리분야의 시뮬레이션 코드로 사용하기에 매우 좋은 것으로 사료된다.

• 대한전자공학회논문지
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• 제26권6호
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• pp.63-70
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• 1989

액체금속이온원으로 부터 발생한 AuGe 이온빔을 GaAs기판에 주입시킨 후 이 시료의 표면성분과 구조를 AES(Auger electron spectroscopy), RHEED(reflection high energy electron diffraction), SEM(scanning electron microscopy) and EPMA(electron probe microanalysis)등으로 조사하였으며 AES depth profile 실험결과를 이체충돌에 의한 Monte Carlo simulation과 비교하였다. AuGe 이온이 주입된 시료를 AES, EPMA로 측정한 결과 As의 preferential스피터링이 나타났으며 300$^{circ}$C로 열처리하면 Ga과 outdiffusion되었다. 또한 측정한 Au와 Ge의 depth profile은 이체충돌에 의한 Monte Carlo simulation의 결과와 잘 일치하였다.

• 한국전기전자재료학회논문지
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• 제11권6호
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• pp.423-427
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• 1998

In this paper the electron mobility in $Ga{1-X}In_xAs$alloy semiconductors is simulated by using the ensemble Monte Carlo method. The simulations for Ga\ulcornerIn\ulcornerAs with In mole fraction, doping concentration and temperature as parameters are performed. The electron mobility for alloys which perfectly orderd alloys without the alloy scattering mechanism are assumed, the results show that mobility in Ga\ulcornerIn\ulcornerAs is improved by 11%, 12% and 7% for 0.25, 0.53 and 0.75. In mole fractions, respectively, We reported the theoretical results of electron mobility in $Ga{1-X}In_xAs$alloys, so those will contribute to the research and development into materials for high-speed semiconductor devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.878-881
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• 2002

Energy distribution function for electrons in $SF_6+Ar$ mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30 ~ 300[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6+Ar$ mixtures were measured by time-of-flight(TOF) method, The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1150-1153
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• 2004

Diffusion coefficients Of electrons in $SF_6$-Ar mixtures gas used by MCS- BEq algorithm has been analysed over the E/N range $30\sim300$(Td) by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight(TOF) method, The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.