NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity

碩士 === 國立成功大學 === 奈米積體電路工程碩士學位學程 === 107 === CMOS scaling has led to several issues that are necessary to be investigated further. In this thesis, the transport behavior of electrons in a nanoscale double-gate (DG) MOSFET is modeled by solving Schrödinger equation in non-equilibrium Green’s function...

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Main Authors: Si-HuaChen, 陳思樺
Other Authors: Kuo-Hsing Kao
Format: Others
Language:en_US
Published: 2019
Online Access:http://ndltd.ncl.edu.tw/handle/brm6j2
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spelling ndltd-TW-107NCKU57950022019-10-25T05:24:19Z http://ndltd.ncl.edu.tw/handle/brm6j2 NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity 具非等向性矽電容率奈米尺寸金氧半場效電晶體之非平衡態格林函數模擬 Si-HuaChen 陳思樺 碩士 國立成功大學 奈米積體電路工程碩士學位學程 107 CMOS scaling has led to several issues that are necessary to be investigated further. In this thesis, the transport behavior of electrons in a nanoscale double-gate (DG) MOSFET is modeled by solving Schrödinger equation in non-equilibrium Green’s function (NEGF) formalism which is solved self-consistently with the Poisson equation to obtain the potential profile, electron density, transmission coefficient and thus, the drain current versus gate voltage (I_DS-V_GS) curves. In addition to quantum effects which have been taken into account in the transport equation, the reduction of permittivity in the surface region and the anisotropic permittivity that influence the electrical properties are investigated and their influences on the electrical characteristics of MOSFETs are discussed. It is shown that the reduction of permittivity in the surface region slightly improves the subthreshold swing and slightly increases the threshold voltage due to the increase of the potential barrier for electrons in the transport direction. This suggests the better immunity to SCEs for materials of the channel with smaller permittivity. In the case of anisotropic permittivity, the subthreshold swing degrades and the off-leakage current becomes higher as the permittivity in the confinement direction becomes smaller due to the decrease of the potential barrier in the transport direction. This suggests the better immunity to SCEs for materials of the channel with larger permittivity in the confinement direction. For long channel devices, the variation in permittivity barely changes the potential barrier in the transport direction. Therefore, the variation in the permittivity has neglecting effects on the (I_DS-V_GS) characteristic. Kuo-Hsing Kao 高國興 2019 學位論文 ; thesis 79 en_US
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description 碩士 === 國立成功大學 === 奈米積體電路工程碩士學位學程 === 107 === CMOS scaling has led to several issues that are necessary to be investigated further. In this thesis, the transport behavior of electrons in a nanoscale double-gate (DG) MOSFET is modeled by solving Schrödinger equation in non-equilibrium Green’s function (NEGF) formalism which is solved self-consistently with the Poisson equation to obtain the potential profile, electron density, transmission coefficient and thus, the drain current versus gate voltage (I_DS-V_GS) curves. In addition to quantum effects which have been taken into account in the transport equation, the reduction of permittivity in the surface region and the anisotropic permittivity that influence the electrical properties are investigated and their influences on the electrical characteristics of MOSFETs are discussed. It is shown that the reduction of permittivity in the surface region slightly improves the subthreshold swing and slightly increases the threshold voltage due to the increase of the potential barrier for electrons in the transport direction. This suggests the better immunity to SCEs for materials of the channel with smaller permittivity. In the case of anisotropic permittivity, the subthreshold swing degrades and the off-leakage current becomes higher as the permittivity in the confinement direction becomes smaller due to the decrease of the potential barrier in the transport direction. This suggests the better immunity to SCEs for materials of the channel with larger permittivity in the confinement direction. For long channel devices, the variation in permittivity barely changes the potential barrier in the transport direction. Therefore, the variation in the permittivity has neglecting effects on the (I_DS-V_GS) characteristic.
author2 Kuo-Hsing Kao
author_facet Kuo-Hsing Kao
Si-HuaChen
陳思樺
author Si-HuaChen
陳思樺
spellingShingle Si-HuaChen
陳思樺
NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity
author_sort Si-HuaChen
title NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity
title_short NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity
title_full NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity
title_fullStr NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity
title_full_unstemmed NEGF Simulation of Nanoscale MOSFETs with Anisotropic Si Permittivity
title_sort negf simulation of nanoscale mosfets with anisotropic si permittivity
publishDate 2019
url http://ndltd.ncl.edu.tw/handle/brm6j2
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