关键词: 量子电容, 异质栅, 碳纳米场效应管, 双极性传输, 非平衡格林函数

Abstract:

The dualgatematerial MOSlike Carbon Nanotube Field Effect Transistors (CCNFETs) based device design, proposed by our research group, can not only increase the ONOFF current ratio, tune the subthreshold voltage, decrease the device power, but also eliminate the ambipolar transport property of the traditional MOSlike CNFETs effectively. However, as a typical lowdimensional system, such CCNFETs design suffers from the effect of quantum capacitance inevitably. In this paper, based on a study of the working principle of this novel device design, we make a first research into the effect of quantum capacitance on the transport property of it. The results show that quantum capacitance can not only result in a great increase of the OFF current and a corresponding decrease of the ONOFF current ratio, but also destroy the unipolar transport property of this novel device design, which would have a negative impact on its application in circuits. In order to decrease the impacts of quantum capacitance as greatly as possible, several suggestions are given at the end of the paper.

Key words: quantum capacitance;dualgatematerial;carbon nanotubeFETs;ambipolar transport;nonequilibrium Green’s function