Band bending engineering in p-i-n gate all around Carbon nanotube field effect transistors by multi-segment gate

Document Type : Reasearch Paper

Authors

• Ali Naderi ¹
• Behrooz Abdi Tahne ²

¹ Electrical and Computer Engineering Faculty, Kermanshah University of Technology, Kermanshah, Iran.

² Young Researchers and Elite Club, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran.

Abstract

The p-i-n carbon nanotube (CNT) devices suffer from low ON/OFF current ratio and small saturation current. In this paper by band bending engineering, we improved the device performance of p-i-n CNT field effect transistors (CNTFET). A triple gate all around structure is proposed to manage the carrier transport along the channel. We called this structure multi-segment gate (MSG) CNTFET. Band to band tunneling (B-B tunneling) is a dominant transport mechanism in p-i-n structures which is more controlled here by band bending engineering. Gate metal at source side causes more bands bending at channel to source interface and the gate metal at drain side acts as a filter which reduces the leakage current. Results demonstrate that by parameter engineering of gate metal, the proposed structure improves the saturation current, leakage current, current ratio, subthreshold swing, breakdown voltage and cut-off frequency in comparison with conventional structure. Also, to obtain the optimum parameters, design considerations has been done in terms of difference in workfunctions and change in the length of each part of gates. Simulations and comparisons have been performed using none equilibrium Green's function and self-consistent solution between Poisson and Schrodinger equations.

Keywords

• Current Ratio
• Cut-off Frequency
• Leakage Current
• MSG-T-CNTFET
• NEGF
• Saturation Current
• Subthreshold Swing

20.1001.1.20088868.2017.8.4.7.0

Main Subjects

• Carbon Nanotubs
• Nanochemistry
• Nanoelectronic

---

References

[1] Shaker A., Ossaimee M., Zekry A., Abouelatta M., (2015), Influence of gate ovelrap engineering on ambipolar and high frequency characteristics of tunnel-CNTFET. Superlat. Microst. 86: 518-530.

[2] Tans S., Verschueren A., Dekker C., (1998), Room-temperature transistor based on a single carbon nanotube. Nature. 393: 49-51.

[3] Arefinia Z., Orouji A. A., (2009), Quantum simulation study of a new carbon nanotube field-effect transistor with electrically induced source/drain extension. IEEE Trans. Device Mater. Reliab. 9: 237-243.

[4] Wei W., Lu Z., Xueying W., Zhubing W., Ting Z., Na L., Xiao Y., Gongshu Y., (2014), The combined effects of halo and linear doping effects on the high frequency and switching performance in ballistic CNTFET. J. Semicond.  35: 114004-114011.

[5] Wei W., Na L.,  Yuzhou R., Hao L., Lifen Z., Jin L., Junjie J., Xiaoping C., Kai W.,  Chunping X.,  (2013), A computational study of linear doping on the high-frequency and switching performances of hetero material gate CNTFET. J. Semicond. 34: 124002-124007.

[6]   Wei W., Xu M., Liu J., Li N., Zhang T., Jiang S., Zhang L., Wang H., Gao J., (2015), Investigation of hetero-material-gate in CNTFETs for ultra low power circuits. J. Semicond. Tech. Sci. 15: 131-144.

[7] Tahne B. A., Naderi A., (2016),  SLD-MOSCNT: Anew MOSCNT with step-linear doping  profile in the source and  drain  regions. Int. J. Mod. Phys. B. 30: 1650242-1650242.

[8] Rahman A., Guo J., Datta S., (2003), Theory of Ballistic Nanotransistors. IEEE Trans. Electron Devices. 50: 1853-1864.

[9] Shokri A. A., Karimi Z., (2014), Electronic band structure of a Carbon nanotube superlattice. Int. J. Nano Dimens. 5: 63-67.

[10] Ziabari S. A. S., Saravani M. J. T., (2017), A novel lightly doped drain and source Carbon nanotube field effect transistor (CNTFET) with negative differential resistance. Int. J. Nano Dimens. 8: 107-113.

[11] Koswatta S. O., Nikonov D. E., Lundstrom M. S., (2005), Computational study of carbon nanotube p-i-n tunnel FETs. IEDM Tech. Dig. 518-521.

[12] Pulfrey D. L., , Chen L., (2009), Comparison of p-i-n and n-i-n carbon nanotube FETs regarding high-frequency performance. Solid-State Electron. 53: 935-939.

[13] Appenzeller J., Lin Y. M., Knoch J., Chen Zh., Avouris Ph., (2005), Comparing carbon nanotube transistors the ideal choice: A novel tunneling device design. IEEE Trans. Electron Devices.  52: 2568-2576 .

 [14] Naderi A., Tahne B. A., (2016), T-CNTFET with gate-drain overlap two increased saturation current. ECS J. Solid State Sci. Technol. 5: 3032-3036.

‏[15] Nagavarapu V., Jhaveri R., Woo J. C. S., (2008), The tunnel source (PNPN) N-MOSFET: A novel high performance transistor. IEEE Trans. Electron Devices. 55: 1013-1019.

[16] Pan A., Chui C. O., (2015), Gate-Induced source tunneling FET (GISTFET). IEEE Trans. Electron Devices. 62: 2390-2395.

 [17] Wang H., Chang S., Hu Y., He H., He J., Huang Q., He F., Wang G., (2014), A novel barrier controlled tunnel FET. IEEE Trans. Electron Devices. 35: 797-802.

[18] Kordrostami Z., Sheikh M. H., Zarifkar A., (2012), Influence of channel and underlap engineering on the high-frequency and  switching performance of CNTFET. IEEE Trans. Nanotechnol. 11: 526-533.

[19] Naderi A., Keshavarzi P., Orouj A. A. i, (2011), LDC–CNTFET: A carbon nanotube field effect transistor with linear doping profile channel. Superlat. Microstr. 50: 145-156.

[20] Guo J., (2004), Carbon nanotube electronics: Modeling, physics, and applications, Phd thesis, Purdue University.