Fig. 1.
The device of simulated HMG-CNTFETs. (a) Cross-sectional view of the proposed CNTFETs. It is symmetrical with respect to the center of the channel. (b) Doping profile.
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Wei Wang, Na Li, Yuzhou Ren, Hao Li, Lifen Zheng, Jin Li, Junjie Jiang, Xiaoping Chen, Kai Wang, Chunping Xia. A computational study of the effects of linear doping profile on the high-frequency and switching performances of hetero-material-gate CNTFETs[J]. Journal of Semiconductors, 2013, 34(12): 124002. doi: 10.1088/1674-4926/34/12/124002
W Wang, N Li, Y Z Ren, H Li, L F Zheng, J Li, J J Jiang, X P Chen, K Wang, C P Xia. A computational study of the effects of linear doping profile on the high-frequency and switching performances of hetero-material-gate CNTFETs[J]. J. Semicond., 2013, 34(12): 124002. doi: 10.1088/1674-4926/34/12/124002.
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A computational study of the effects of linear doping profile on the high-frequency and switching performances of hetero-material-gate CNTFETs
doi: 10.1088/1674-4926/34/12/124002
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Abstract
The effects of linear doping profile near the source and drain contacts on the switching and high-frequency characteristics for conventional single-material-gate CNTFET (C-CNTFET) and hetero-material-gate CNTFET (HMG-CNTFET) have been theoretically investigated by using a quantum kinetic model. This model is based on two-dimensional non-equilibrium Green's functions (NEGF) solved self-consistently with Poisson's equations. The simulation results show that at a CNT channel length of 20 nm with chirality (7, 0), the intrinsic cutoff frequency of C-CNTFETs reaches up to a few THz. In addition, a comparison study has been performed between C-and HMG-CNTFETs. For the C-CNTFET, results reveal that a longer linear doping length can improve the cutoff frequency and switching speed. However, it has the reverse effect on on/off current ratios. To improve the on/off current ratios performance of CNTFETs and overcome short-channel effects (SCEs) in high-performance device applications, a novel CNTFET structure with a combination of an HMG and linear doping profile has been proposed. It is demonstrated that the HMG structure design with an optimized linear doping length has improved high-frequency and switching performances as compared to C-CNTFETs. The simulation study may be useful for understanding and optimizing high-performance of CNTFETs and assessing the reliability of CNTFETs for prospective applications.-
Keywords:
- CNTFET,
- NEGF,
- linear doping,
- SCE,
- hetero-material-gate
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References
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