• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.715-717
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• 2010

In this paper, the subthreshold characteristics have been alanyzed using MicroTec4.0 for double gate MOSFET(DGMOSFET). The DGMOSFET is extensively been studing since it can reduce the short channel effects due to structural characteristics. We have presented the short channel effects such as subthreshold swing and threshold voltage for DGMOSFET, using MicroTec, semiconductor simulator. We have analyzed for channel length, thickness and width to consider the structural characteristics for DGMOSFET. The subthreshold swing and threshold voltage have been analyzed for DGMOSFET using MicroTec since MicroTec is well verified as comparing with results of the numerical three dimensional models.

• Journal of the Korean Electrochemical Society
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• v.9 no.4
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• pp.170-177
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• 2006

Optimum design of flow channel in the separation plate of Proton Exchange Membrane Fuel Cell is very prerequisite to reduce concentration over potential at high current region and remove the water generated in cathode effectively. In this paper, fully 3 dimensional computational model which solves anode and cathode flow fields simultaneously is developed in order to compare the performance of fuel cell with parallel and interdigitated flow channels. Oxygen and water concentration and pressure drop are calculated and i-V performance characteristics are compared between flows with two flow channels. Results show that performance of fuel cell with interdigitated flow channel is hi민or than that with parallel flow channel at high current region because hydrogen and oxygen in interdigitated flow channel are transported to catalyst layer effectively due to strong convective transport through gas diffusion layer but pressure drop is larger than that in parallel flow channel. Therefore Trade-off between power gain and pressure loss should be considered in design of fuel cell with interdigitated flow channel.

• Journal of the Korean Electrochemical Society
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• v.11 no.1
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• pp.51-58
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• 2008

Many researches for effects of different flow configurations on performance of Proton Exchange Membrane Fuel Cell have extensively been done but the effects of flow direction at the same flow channel shape should be considered for optimal operation of fuel cell as well. In this paper a numerical computational methode for simulating entire reactive flow fields including anode and cathode flow has been developed and the effects of different flow direction at parallel flow was studied. Pressure drop along the flow channel and density distribution of reactant and products and water transport, ion conductivity across the membrane and I-V performance are compared in terms of flow directions(co-flow or counter-flow) using above numerical simulation method. The results show that the performance under counter-flow condition is superior to that under co-flow condition due to higher reactant and water transport resulting to higher ion conductivity of membrane.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.651-656
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• 2014

This paper analyzed the change of subthreshold swing for channel doping of asymmetric double gate(DG) MOSFET. The subthreshold swing is the factor to describe the decreasing rate of off current in the subthreshold region, and plays a very important role in application of digital circuits. Poisson's equation was used to analyze the subthreshold swing for asymmetric DGMOSFET. Asymmetric DGMOSFET could be fabricated with the different top and bottom gate oxide thickness and bias voltage unlike symmetric DGMOSFET. It is investigated in this paper how the doping in channel, gate oxide thickness and gate bias voltages for asymmetric DGMOSFET influenced on subthreshold swing. Gaussian function had been used as doping distribution in solving the Poisson's equation, and the change of subthreshold swing was observed for projected range and standard projected deviation used as parameters of Gaussian distribution. Resultly, the subthreshold swing was greatly changed for doping concentration and profiles, and gate oxide thickness and bias voltage had a big impact on subthreshold swing.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1941-1943
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• 2003

본 논문은 광 검출을 이용한 전기화학발광 (Electrochemiluminescence : ECL)을 마이크로시스템에 적용하여 소형화하였으며, 기존 광 검출 시스템과 결과를 비교하여 그 특성을 분석하였다. ECL은 전기에너지를 촉매로 사용하기 때문에 화학발광 보다 마이크로채널 내에서 발생하는 층류문제를 해결할 수 있는 적합한 방법이다. 유리기판에 Au를 박막으로 증착하여 전극으로 사용하였으며, SU-8 구조물을 이용한 PDMS mold를 사용하여 마이크로채널을 제작하였다. 전극과 PDMS는 $O_2$ 플라즈마를 이용하여 접합하였다. luminol과 과산화수소는 Syringe pump로 구동하였으며, 발생된 빛은 반도체 공정기술로 제작한 P-N접합 포토다이오드를 이용하여 전류신호로 측정하였다. 새로 구성된 시스템을 이용하여 마이크로채널 내에서의 luminol과 과산화수소의 유속, 농도변화에 따른 광전류 변화를 측정하여 기존시스템과 비교하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.11
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• pp.21-28
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• 2008

In this paper, we suggest an analytical model that can derive the I-V characteristics in the saturation region of a short channel GaAs MESFET. Instead of the pinch-off concept that has been used in the conventional models we can derive the two-dimensional potential in the depletion region in order that the velocity saturation region cannot be pinched-off and the current continuity condition can be satisfied. Obtained expression for the velocity saturation length is expressed in terms of the total channel length, channel doping density, gate voltage, and drain voltage. Compared with the conventional channel length shortening models, the present model seems to be considerably accurate and more reasonable in explaining the Early effect.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.805-811
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• 2012

In this paper, movement of conduction path has been analyzed for electron distribution in the channel of double gate(DG) MOSFET. The analytical potential distribution model of Poisson equation, validated in previous researches, has been used to analyze transport characteristics. DGMOSFETs have the adventage to be able to reduce short channel effects due to improvement for controllability of current by two gate voltages. Since short channel effects have been occurred in subthreshold region including threshold region, the analysis of transport characteristics in subthreshold region is very important. Also transport characteristics have been influenced on the deviation of electron distribution and conduction path. In this study, the influence of electron distribution on conduction path has been analyzed according to intensity and distribution of doping and channel dimension.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.156-162
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• 2015

This paper has analyzed how conduction path and electron concentration for the device parameters such as oxide thickness, channel doping, and top and bottom gate voltage influence on subthreshold swing of asymmetric double gate MOSFET. Compared with symmetric and asymmetric double gate MOSFET, asymmetric double gate MOSFET has the advantage that the factors to be able to control the short channel effects increase since top and bottom gate oxide thickness and voltages can be set differently. Therefore the conduction path and electron concentration for top and bottom gate oxide thickness and voltages are investigated, and it is found the optimum conditions that the degradation of subthreshold swing, severe short channel effects, can reduce. To obtain the analytical subthreshold swing, the analytical potential distribution is derived from Possion's equation. As a result, conduction path and electron concentration are greatly changed for device parameters, and subthreshold swing is influenced by conduction path and electron concentration of top and bottom.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.2
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• pp.1-6
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• 1983

The reduction of threshold voltage and punchthrough voltage of short channel MOS transistors has been measured experimentally with silicon gate NMOS transistors. The effects of the gate oxide thickness and substrate doping concentration on the threshold voltage and punch-through voltage have also been measured with sample devices with boron implantation and gate oxide thickness of 50 nm and 70 nm. Hot electron emission has been measured by floating gate method for the samples with 3 ${\mu}{\textrm}{m}$ channel length. It has been concluded from this measurement that hot electron emission is not significant for the channel length of 3${\mu}{\textrm}{m}$.