• Journal of IKEEE
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• v.22 no.1
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• pp.74-79
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• 2018

We analyzed the relationship between center potential and subthreshold swing (SS) of Junctionless Cylindrical Surrounding Gate (JLCSG) and Junctionless Double Gate (JLDG) MOSFET. The SS was obtained using the analytical potential distribution and the center potential, and SSs were compared and investigated according to the change of channel dimension. As a result, we observed that the change in central potential distribution directly affects the SS. As the channel thickness and oxide thickness increased, the SS increased more sensitively in JLDG. Therefore, it was found that JLCSG structure is more effective to reduce the short channel effect of the nano MOSFET.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2183-2188
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• 2014

This paper has analyzed threshold voltage movement for channel doping concentration of asymmetric double gate(DG) MOSFET. The asymmetric DGMOSFET is generally fabricated with low doping channel and fully depleted under operation. Since impurity scattering is lessened, asymmetric DGMOSFET has the adventage that high speed operation is possible. The threshold voltage movement, one of short channel effects necessarily occurred in fine devices, is investigated for the change of channel doping concentration in asymmetric DGMOSFET. The analytical potential distribution of series form is derived from Possion's equation to obtain threshold voltage. The movement of threshold voltage is investigated for channel doping concentration with parameters of channel length, channel thickness, oxide thickness, and doping profiles. As a result, threshold voltage increases with increase of doping concentration, and that decreases with decrease of channel length. Threshold voltage increases with decrease of channel thickness and bottom gate voltage. Lastly threshold voltage increases with decrease of oxide thickness.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.1
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• pp.123-128
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• 2014

This paper analyzed the change of subthreshold current for channel dimension of double gate(DG) MOSFET. The nano-structured DGMOSFET to reduce the short channel effect had to be preciously analyze. Poisson's equation had been used to analyze the potential distribution in channel, and Gaussian function had been used as carrier distribution. The subthreshold current had been analyzed for device parameters such as channel dimension, and projected range and standard projected deviation of Gaussian function. Since this potential model was verified in the previous papers, we used this model to analyze the subthreshold current. Resultly, we know the subthreshold current was influenced on parameters of Gaussian function and channel dimension for DGMOSFET.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1764-1770
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• 2011

In this paper, the subthreshold swings for doping distribution in the channel have been analyzed in double gate MOSFET(DGMOSFET). The DGMOSFET is extensively been studying since it can lessen the short channel effects(SCEs) as next -generation nano device. The degradation of subthreshold swing(SS) known as SCEs has greatly influenced on application of digital devices, and has been analyzed for structural parameter and variation of channel doping profile in DGMOSFET. The analytical model of Poisson equation has been derived from nonuniform doping distribution for DGMOSFET. To verify potential and subthreshold swing model based on this analytical Poisson's equation, the results have been compared with those of the numerical Poisson's equation, and subthreshold swing for DGMOSFET has been analyzed using these models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.768-771
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• 2013

This paper analyzed the change of subthreshold current for channel doping concentration of double gate(DG) MOSFET. Poisson's equation had been used to analyze the potential distribution in channel, and Gaussian function had been used as carrier distribution. The potential distribution was obtained as the analytical function of channel dimension, using the boundary condition. The subthreshold current had been analyzed for channel doping concentration, and projected range and standard projected deviation of Gaussian function. Since this analytical potential model was verified in the previous papers, we used this model to analyze the subthreshold current. As a result, we know the subthreshold current was influenced on parameters of Gaussian function and channel doping concentration for DGMOSFET.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.753-756
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• 2013

This paper analyzed the change of subthreshold current for channel dimension of double gate(DG) MOSFET. The nano-structured DGMOSFET to reduce the short channel effect had to be preciously analyze. Poisson's equation had been used to analyze the potential distribution in channel, and Gaussian function had been used as carrier distribution. The subthreshold current had been analyzed for device parameters such as channel dimension, and projected range and standard projected deviation of Gaussian function. Since this potential model was verified in the previous papers, we used this model to analyze the subthreshold current. Resultly, we know the subthreshold current was influenced on parameters of Gaussian function and channel dimension for DGMOSFET.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.863-865
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• 2015

본 연구에서는 비대칭 이중게이트 MOSFET의 채널 내 도핑농도분포에 대한 드레인유도장벽감소(Drain Induced Barrier Lowering; DIBL)에 대하여 분석하고자한다. DIBL은 드레인 전압에 의하여 소스 측 전위장벽이 낮아지는 효과로서 중요한 단채널 효과이다. 이를 분석하기 위하여 포아송방정식을 이용하여 해석학적 전위분포를 구하였으며 전위분포에 영향을 미치는 채널도핑농도의 분포함수변화에 대하여 DIBL을 관찰하였다. 채널길이, 채널두께, 상하단 게이트 산화막 두께, 하단 게이트 전압 등을 파라미터로 하여 DIBL을 관찰하였다. 결과적으로 DIBL은 채널도핑농도분포함수의 변수인 이온주입범위 및 분포편차에 변화를 나타냈다. 특히 두 변수에 대한 DIBL의 변화는 최대채널도핑농도가 $10^{18}/cm^3$ 정도로 고도핑 되었을 경우 더욱 현저히 나타나고 있었다. 채널길이가 감소할수록 그리고 채널두께가 증가할수록 DIBL은 증가하였으며 하단 게이트 전압과 상하단 게이트 산화막 두께가 증가할수록 DIBL은 증가하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.745-748
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• 2014

본 연구에서는 비대칭 이중게이트(double gate; DG) MOSFET의 채널길이에 대한 문턱전압이하 스윙의 변화에 대하여 분석하였다. 문턱전압이하 스윙은 트랜지스터의 디지털특성을 결정하는 중요한 요소로서 채널길이가 감소하면 특성이 저하되는 문제가 나타나고 있다. 이러한 문제를 해결하기 위하여 개발된 DGMOSFET의 문턱전압이하 스윙의 채널길이에 대한 변화를 채널두께, 산화막두께, 상하단 게이트 전압 및 도핑농도 등에 따라 조사하고자 한다. 특히 하단 게이트 구조를 상단과 달리 제작할 수 있는 비대칭 DGMOSFET에 대하여 문턱전압이하 스윙을 분석함으로써 하단 게이트 전압 및 하단 산화막 두께 등에 대하여 자세히 관찰하였다. 문턱전압이하 스윙의 해석학적 모델을 구하기 위하여 포아송방정식에서 해석학적 전위분포모델을 유도하였으며 도핑분포함수는 가우스분포함수를 사용하였다. 결과적으로 문턱전압이하 스윙은 상하단 게이트 전압 및 채널도핑농도 그리고 채널의 크기에 매우 민감하게 변화하고 있다는 것을 알 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2643-2648
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• 2015

This paper analyzes the phenomenon of drain induced barrier lowering(DIBL) for doping profiles in channel of asymmetric double gate(DG) MOSFET. The DIBL, the important short channel effect, is described as lowering of source barrier height by drain voltage. The analytical potential distribution is derived from Poisson's equation to analyze the DIBL, and the DIBL is observed according to the change of doping profile to influence on potential distribution. As a results, the DIBL is significantly influenced by projected range and standard projected deviation, the variables of channel doping profiles. The change of DIBL shows greatly in the range of high doping concentration such as $10^{18}/cm^3$. The DIBL increases with decrease of channel length and increase of channel thickness, and with increase of bottom gate voltage and top/bottom gate oxide film thickness.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.793-798
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• 2012

In this paper, dependence of subthreshold current has been analyzed for doping distribution and channel structure of double gate(DG) MOSFET. The charge distribution of Gaussian function validated in previous researches has been used to obtain potential distribution in Poisson equation. Since DGMOSFETs have reduced short channel effects with improvement of current controllability by gate voltages, subthreshold characteristics have been enhanced. The control of current in subthreshold region is very important factor related with power consumption for ultra large scaled integration. The deviation of threshold voltage has been qualitatively analyzed using the changes of subthreshold current for gate voltages. Subthreshold current has been influenced by doping distribution and channel dimension. In this study, the influence of channel length and thickness on current has been analyzed according to intensity and distribution of doping.