J. Semicond. > 2013, Volume 34 > Issue 12 > 124002
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SEMICONDUCTOR DEVICES

A computational study of the effects of linear doping profile on the high-frequency and switching performances of hetero-material-gate CNTFETs

Wei Wang, Na Li, Yuzhou Ren, Hao Li, Lifen Zheng, Jin Li, Junjie Jiang, Xiaoping Chen, Kai Wang and Chunping Xia

+ Author Affiliations

 Corresponding author: Wang Wei, wangwej@njupt.edu.cn

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.

Key words: CNTFET, NEGF, linear doping, SCE, hetero-material-gate



[1]
Lu R F, Lu Y P, Lee S Y, et al. Terahertz response in single-walled carbon nanotube transistor:a real-time quantum dynamics simulation. Nanotechnology, 2009, 20(50):505401 doi: 10.1088/0957-4484/20/50/505401
[2]
Kienle D, Léonard F. Terahertz response of carbon nanotube transistors. Phys Rev Lett, 2000, 103(2):026601 https://arxiv.org/abs/0906.2826?context=cond-mat.mtrl-sci
[3]
Tans S J, Verschueren A R M, Dekker C. Room-temperature transistor based on a single carbon nanotube. Nature, 1998, 393(7):49 http://www.nature.com/nature/journal/v393/n6680/abs/393049a0.html?foxtrotcallback=true
[4]
Hazeghi A, Krishnamohan T, Wong H. Schottky-barrier carbon nanotube field-effect transistor modeling. IEEE Trans Electron Devices, 2007, 54(3):439 doi: 10.1109/TED.2006.890384
[5]
Guo J, Lundstrom M, Datta S. Performance projections for ballistic carbon nanotube field-effect transistors. Appl Phys Lett, 2002, 80(17):3192 doi: 10.1063/1.1474604
[6]
Fiori G, Iannaccone G, Klimeck G. A three-dimensional simulation study of the performance of carbon nanotube field-effect transistors with doped reservoirs and realistic geometry. IEEE Trans Electron Devices, 2006, 53(8):1782 doi: 10.1109/TED.2006.878018
[7]
Orouji A A, Arefinia Z. Detailed simulation study of a dual material gate carbon nanotube field-effect transistor. Phys E:Low-Dimensional Syst Nanostructures, 2009, 41(10):552 http://www.sciencedirect.com/science/article/pii/S1386947708003767?via%3Dihub
[8]
Arefinia Z, Orouji A A. Quantum simulation study of a new carbon nanotube field-effect transistor with electrically induced source/drain extension. IEEE Trans Device Mater Reliab, 2009, 9(2):237 doi: 10.1109/TDMR.2009.2015458
[9]
Xia T S, Register L F, Banerjee S K. Simulation study of the carbon nanotube field effect transistors beyond the complex band structure effect. Solid-State Electron, 2005, 49(3):860 http://www.sciencedirect.com/science/article/pii/S003811010500064X?via%3Dihub
[10]
Guo J, Hasan S, Javey A, et al. Assessment of high-frequency performance potential for carbon nanotube transistors. IEEE Trans Nanotechnol, 2005, 4(6):715 doi: 10.1109/TNANO.2005.858601
[11]
Chen L, Pulfrey D L. Comparison of p-i-n and n-i-n carbon nanotube FETs regarding high-frequency performance. Solid-State Electron, 2009, 53(9):935 doi: 10.1016/j.sse.2009.05.006
[12]
Naderi A, Keshavarzi P, Orouji A A. LDC-CNTFET:a carbon nanotube field effect transistor with linear doping profile channel. Superlattices and Microstructures, 2011, 50(2):145 doi: 10.1016/j.spmi.2011.05.011
[13]
Hassaninia I, Sheikhi H M, Kordrostami Z. Simulation of carbon nanotube FETs with linear doping profile near the source and drain contacts. Solid-State Electron, 2008, 52(6):980 doi: 10.1016/j.sse.2008.01.021
[14]
Datta S. Nanoscale device modeling:the Green's function method. Superlatt Microstruct, 2000, 28(4):253 doi: 10.1006/spmi.2000.0920
[15]
Venugopal R, Ren Z, Datta S, et al. Simulating quantum transport in nanoscale MOSFETs:real versus mode-space approaches. J Appl Phys, 2002, 92(7):3730 doi: 10.1063/1.1503165
[16]
Wang W, Gu N, Sun J P, et al. Gate current modeling of high-k stack nanoscale MOSFETs. Solid-State Electron, 2006, 50(9/10):1489 https://experts.umich.edu/en/publications/gate-current-modeling-of-high-k-stack-nanoscale-mosfets
[17]
Sun J P, Wang W, Toyabe T, et al. Modeling of gate current and capacitance in nanoscale-MOS structures. IEEE Trans Electron Devices, 2006, 53(12):2950 doi: 10.1109/TED.2006.885637
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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Fig. 2.  Output characteristics of a C-CNTFET and an HMG-CNTFET.

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Fig. 3.  Transfer characteristics of C-, LD-, HMG-and LD-HMG-CNTFET structures at $V_{\rm DS}$ $=$ 0.7 V.

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Fig. 4.  Shift in the threshold voltage of CNTFET with different gate structures at $T_{\rm ox}$ $=$ 1.5 nm, $L_{\rm g}$ $=$ 6 nm, $n$ $=$ 7.

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Fig. 5.  Electron potential profile along the channel of a dual material gate CNTFET at different drain biases. The drain bias starts from 0 to 0.4 V, and the step of drain voltage is 0.1 V.

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Fig. 6.  $I_{\rm on}$/$I_{\rm off}$ and cutoff frequency versus linear doping length of C-CNTFET for $L_{\rm ld}$ $=$ 0-18 nm.

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Fig. 7.  Gate capacitance and switching delay time versus linear doping length of C-CNTFET for $L_{\rm ld}$ $=$ 0-14 nm. The gate length of the CNTFET is fixed to 20 nm, the oxide thickness is 2 nm, the chirality of the CNT is (7, 0). $V_{\rm DS}$ $=$ $V_{\rm GS}$ $=$ 0.7 V.

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Fig. 8.  $I_{\rm on}$/$I_{\rm off}$ and cutoff frequency versus linear doping length of HMG-CNTFET for $L_{\rm ld}$ $=$ 0-18 nm.

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Fig. 9.  $I_{\rm on}$ and $I_{\rm off}$ versus linear doping length of HMG-CNTFET for $L_{\rm ld}$ $=$ 0-18 nm.

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[1]
Lu R F, Lu Y P, Lee S Y, et al. Terahertz response in single-walled carbon nanotube transistor:a real-time quantum dynamics simulation. Nanotechnology, 2009, 20(50):505401 doi: 10.1088/0957-4484/20/50/505401
[2]
Kienle D, Léonard F. Terahertz response of carbon nanotube transistors. Phys Rev Lett, 2000, 103(2):026601 https://arxiv.org/abs/0906.2826?context=cond-mat.mtrl-sci
[3]
Tans S J, Verschueren A R M, Dekker C. Room-temperature transistor based on a single carbon nanotube. Nature, 1998, 393(7):49 http://www.nature.com/nature/journal/v393/n6680/abs/393049a0.html?foxtrotcallback=true
[4]
Hazeghi A, Krishnamohan T, Wong H. Schottky-barrier carbon nanotube field-effect transistor modeling. IEEE Trans Electron Devices, 2007, 54(3):439 doi: 10.1109/TED.2006.890384
[5]
Guo J, Lundstrom M, Datta S. Performance projections for ballistic carbon nanotube field-effect transistors. Appl Phys Lett, 2002, 80(17):3192 doi: 10.1063/1.1474604
[6]
Fiori G, Iannaccone G, Klimeck G. A three-dimensional simulation study of the performance of carbon nanotube field-effect transistors with doped reservoirs and realistic geometry. IEEE Trans Electron Devices, 2006, 53(8):1782 doi: 10.1109/TED.2006.878018
[7]
Orouji A A, Arefinia Z. Detailed simulation study of a dual material gate carbon nanotube field-effect transistor. Phys E:Low-Dimensional Syst Nanostructures, 2009, 41(10):552 http://www.sciencedirect.com/science/article/pii/S1386947708003767?via%3Dihub
[8]
Arefinia Z, Orouji A A. Quantum simulation study of a new carbon nanotube field-effect transistor with electrically induced source/drain extension. IEEE Trans Device Mater Reliab, 2009, 9(2):237 doi: 10.1109/TDMR.2009.2015458
[9]
Xia T S, Register L F, Banerjee S K. Simulation study of the carbon nanotube field effect transistors beyond the complex band structure effect. Solid-State Electron, 2005, 49(3):860 http://www.sciencedirect.com/science/article/pii/S003811010500064X?via%3Dihub
[10]
Guo J, Hasan S, Javey A, et al. Assessment of high-frequency performance potential for carbon nanotube transistors. IEEE Trans Nanotechnol, 2005, 4(6):715 doi: 10.1109/TNANO.2005.858601
[11]
Chen L, Pulfrey D L. Comparison of p-i-n and n-i-n carbon nanotube FETs regarding high-frequency performance. Solid-State Electron, 2009, 53(9):935 doi: 10.1016/j.sse.2009.05.006
[12]
Naderi A, Keshavarzi P, Orouji A A. LDC-CNTFET:a carbon nanotube field effect transistor with linear doping profile channel. Superlattices and Microstructures, 2011, 50(2):145 doi: 10.1016/j.spmi.2011.05.011
[13]
Hassaninia I, Sheikhi H M, Kordrostami Z. Simulation of carbon nanotube FETs with linear doping profile near the source and drain contacts. Solid-State Electron, 2008, 52(6):980 doi: 10.1016/j.sse.2008.01.021
[14]
Datta S. Nanoscale device modeling:the Green's function method. Superlatt Microstruct, 2000, 28(4):253 doi: 10.1006/spmi.2000.0920
[15]
Venugopal R, Ren Z, Datta S, et al. Simulating quantum transport in nanoscale MOSFETs:real versus mode-space approaches. J Appl Phys, 2002, 92(7):3730 doi: 10.1063/1.1503165
[16]
Wang W, Gu N, Sun J P, et al. Gate current modeling of high-k stack nanoscale MOSFETs. Solid-State Electron, 2006, 50(9/10):1489 https://experts.umich.edu/en/publications/gate-current-modeling-of-high-k-stack-nanoscale-mosfets
[17]
Sun J P, Wang W, Toyabe T, et al. Modeling of gate current and capacitance in nanoscale-MOS structures. IEEE Trans Electron Devices, 2006, 53(12):2950 doi: 10.1109/TED.2006.885637

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    Received: 11 January 2013 Revised: 27 August 2013 Online: Published: 01 December 2013

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      Article Navigation >  Journal of Semiconductors  > 2013  >  34(12): 124002
      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.
      Citation:
      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.
      shu

      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

      • College of Electronic Science Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210046, China

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      • Corresponding author: Wang Wei, wangwej@njupt.edu.cn
      • Received Date: 2013-01-11
      • Revised Date: 2013-08-27
      • Published Date: 2013-12-01

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