This research is focusing on the geometrical variation effects of carbon nanotube field effect transistor (CNTFET). The characteristics of the CNTFET are observed based on different CNTFET diameter, the oxide thickness and the chiral vector. The characteristics under study includes the drain current, ION/IOFF, the quantum capacitance as well as the threshold voltage. The work is carried out using CNTFET labtool of nanoHUB.org includes the FETToy Simulator which based MATLAB script that calculate the ballistic I-V characteristic and MSL Nanomaterials Simulator that used to design and analyse electronic properties of various nano materials. The results show that small difference of chiral vector, (4, 0) will produce large threshold voltage. The quantum capacitance is observed to be decreased with decreasing oxide thickness as gate voltage reaches 0.5 V and above. The ION/IOFF ratio will increase as the CNTFET diameter increased. As a conclusion, CNTFET is a perfect choice to substitute conventional MOSFET with their remarkable features.

中文翻译：

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表征碳纳米管场效应晶体管：几何变异研究

这项研究的重点是碳纳米管场效应晶体管 (CNTFET) 的几何变化效应。根据不同的 CNTFET 直径、氧化物厚度和手性矢量观察 CNTFET 的特性。正在研究的特性包括漏极电流、ION/IOFF、量子电容以及阈值电压。这项工作是使用 nanoHUB.org 的 CNTFET 实验室工具进行的，其中包括基于 MATLAB 脚本的 FETToy 模拟器，用于计算弹道 IV 特性和用于设计和分析各种纳米材料电子特性的 MSL 纳米材料模拟器。结果表明，手性矢量(4, 0)的小差异会产生大的阈值电压。当栅极电压达到 0 时，观察到量子电容随着氧化物厚度的减小而减小。5 V 及以上。ION/IOFF 比率将随着 CNTFET 直径的增加而增加。总而言之，CNTFET 是替代传统 MOSFET 的完美选择，具有卓越的特性。