• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.845-847
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• 2012

In this paper, the transport characteristics for doping concentration in the channel has been analyzed for DGMOSFET. The Possion equation is used to analytical. The DGMOSFET is extensively been studying because of advantages to be able to reduce the short channel effects(SCEs) to occur in conventional MOSFET. Since SCEs have been occurred in subthreshold region including threshold region, the analysis of transport characteristics in subthreshold region is very important. The threshold voltage roll-off and DIBL have been with various of doping concentration for DGMOSFET in this study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.835-837
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• 2012

In this paper, we have been analyzed conduction path by device parameter of double gate(DG) structure that have top gate and bottom gate. The Possion equation is used to analytical. The change of conduction path have been investigated for various channel lengths, channel thickness and gate oxide thickness using this model, given that these parameters are very important in design of DGMOSFET. The optimum channel doping concentration is determined as the deviation of conduction path is considered according to channel doping concentration.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.917-921
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• 2013

This paper have analyzed the change of breakdown voltage for conduction path of double gate(DG) MOSFET. The low breakdown voltage among the short channel effects of DGMOSFET have become obstacles of device operation. The analytical solution of Poisson's equation have been used to analyze the breakdown voltage, and Gaussian function been used as carrier distribution to analyze closely for experimental results. The change of breakdown voltages for conduction path have been analyzed for device parameters such as channel length, channel thickness, gate oxide thickness and doping concentration. Since this potential model has been verified in the previous papers, we have used this model to analyze the breakdown voltage. Resultly, we know the breakdown voltage is greatly influenced on the change of conduction path for device parameters of DGMOSFET.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.16-23
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• 2007

For a fully depleted SOI type symmetric double gate MOSFET, a simple expression for the threshold voltage has been derived in a closed-form To solve analytically the 2D Poisson's equation in a silicon body, the two-dimensional potential distribution is assumed approximately as a polynomial of fourth-order of x, vertical coordinate perpendicular to the silicon channel. From the derived expression for the surface potential, the threshold voltage can be obtained as a simple closed-form. Simulation result shows that the threshold voltage is exponentially dependent on channel length for the range of channel length up to $0.01\;[{\mu}m]$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.336-339
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• 2004

In this paper the two-dimensional scattering rates were calculated in pseudomorphic Al/sub x//Ga/sub 1-x//As/Ga/sub y/In/sub l -y//As/GaAs heterostructure systems. The electronic states of the square quantum well were determined by the numerical self-consistent solution of Poisson's and Schrodinger's equations. The numerically obtained wave functions and energy levels were used to obtain the major two-dimensional scattering rates in this structure. Polar optical- and acoustic-phonon scattering, piezoelectric, ionized impurity and alloy scattering were considered for the first two sub-bands. The results were compared to the three-dimensional scattering rates also calculated in the same region.

• Journal of KIISE:Information Networking
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• v.30 no.3
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• pp.416-423
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• 2003

This paper proposes a continuous-time queuing model of a shared-buffer packet switch and an approximate algorithm. N arrival processes have heterogeneous busty traffic characteristics. The arrival processes are modeled by Coxian distribution with order 2 that is equivalent to Interruped Poisson Process. The service time is modeled by Erlang distribution with r stages. First the approximate algorithm performs the aggregation of N arrival processes as a single state variable. Next the algorithm discompose the queuing system into N subsystems which are represented by aggregated state variables. And the balance equations based on these aggregated state variables are solved for by iterative method. Finally the algorithm is validated by comparing the results with those of simulation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.90-100
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• 2011

We present a parallel bi-conjugate gradient (Bi-CG) matrix solver for large scale Bio-FET simulations based on recent graphics processing units (GPUs) which can realize a large-scale parallel processing with very low cost. The proposed method is focused on solving the Poisson equation in a parallel way, which requires massive computational resources in not only semiconductor simulation, but also other various fields including computational fluid dynamics and heat transfer simulations. As a result, our solver is around 30 times faster than those with traditional methods based on single core CPU systems in solving the Possion equation in a 3D FDM (Finite Difference Method) scheme. The proposed method is implemented and tested based on NVIDIA's CUDA (Compute Unified Device Architecture) environment which enables general purpose parallel processing in GPUs. Unlike other similar GPU-based approaches which apply usually 32-bit single-precision floating point arithmetics, we use 64-bit double-precision operations for better convergence. Applications on the CUDA platform are rather easy to implement but very hard to get optimized performances. In this regard, we also discuss the optimization strategy of the proposed method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.6
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• pp.25-31
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• 2004

In this paper, we introduce kinetic Monte Carlo (kMC) methods for simulating diffusion process in nano-scale device fabrication. At first, we review kMC theory and backgrounds and give a simple point defect diffusion process modeling in thermal annealing after ion (electron) implantation into Si crystalline substrate to help understand kinetic Monte Carlo methods. kMC is a kind of Monte Carlo but can simulate time evolution of diffusion process through Poisson probabilistic process. In kMC diffusion process, instead of. solving differential reaction-diffusion equations via conventional finite difference or element methods, it is based on a series of chemical reaction (between atoms and/or defects) or diffusion events according to event rates of all possible events. Every event has its own event rate and time evolution of semiconductor diffusion process is directly simulated. Those event rates can be derived either directly from molecular dynamics (MD) or first-principles (ab-initio) calculations, or from experimental data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.731-733
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• 2012

Because the Double gate MOSFET has two gates, it has more efficient on controling current than the exisiting MOSFET, and it can also decrease short channel effects in the nano-device. In this study, during the manufacturing the Double gate MOSFET, we will analyze the change of threshold voltage according to doping concentration that makes a significant impact on short channel effects. One of the structural factors that affect the threshold voltage on the Double gate MOSFET is the doping concentration, and it is very important device parameter. In this paper, we can find that the threshold voltage became larger when the doping concentration increased from $10^{15}cm^{-3}$ to $10^{19}cm^{-3}$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.709-712
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• 2012

In this paper, current-voltage have been considered for DGMOSFET, using the analytical model. The Possion equation is used to analytical. Threshold voltage is defined as top gate voltage when drain current is $10^{-7}A$. Investigated current-voltage characteristics of channel length changed length of channel from 20nm to 100nm. Also, The changes of current-voltage have been investigated for various channel thickness and doping concentration using this model, given that these parameters are very important in design of DGMOSFET. The deviation of conduction path and the influence of conduction path on current-voltage have been considered according to the dimensional parameters of DGMOSFET.