Impact of Body-Thickness-Dependent Band Structure on Scaling of Double-Gate MOSFETs: A DFT/NEGF Study

Martinez, A., Kalna, K., Sushko, P.V., Shluger, A.L., Barker, J.R. and Asenov, A. (2009) Impact of Body-Thickness-Dependent Band Structure on Scaling of Double-Gate MOSFETs: A DFT/NEGF Study. IEEE Transactions on Nanotechnology, 8(2), pp. 159-166. (doi: 10.1109/TNANO.2008.917776)

Abstract

First principles density functional theory has been used to calculate the 2-D band structure of Si slabs with different thicknesses. From the calculated 2-D band structure, electron longitudinal and transverse effective masses have been extracted as a function of the slab thickness. These thickness-dependent electron effective masses have then been used to simulate IID-V-G characteristics of scaled, sub-10 nm double-gate (DG) MOSFETs and to compare them with the results obtained using bulk masses. The channel thickness dependence of the Si band structure starts to affect noticeably DG MOSFET performance at channel lengths below 10-nm, lowering the ON-current by approximately 10, for transistors with a body thickness of 2.6 mn, and by 20, for transistors with a body thickness of 1.3 nm. On the other hand, the subthreshold swing is improved by 10, in the 6-nm-gate length DG MOSFET and by 15, in the 4-nm-gate length device. Finally, the impact of thickness-dependent effective masses has been related to the behavior of the transmission coefficients

• Item Type: Articles
• Keywords: 2-D band structure, band, Behavior channel, Density, density functional theory (DFT, Dependence device, double-gate (DG) nano-MOSFETs effective mass electron transport HARTREE-FOCK impact MOSFET MOSFETS nm nonequilibrium Green's functions performance si silicon thickness transistor transistors transmission
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Barker, Professor John and Asenov, Professor Asen and Kalna, Dr Karol and Martinez, Dr Antonio
• Authors: Martinez, A., Kalna, K., Sushko, P.V., Shluger, A.L., Barker, J.R., and Asenov, A.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: IEEE Transactions on Nanotechnology
• ISSN: 1536-125X

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
35857	3	Sub 100nm 111-V MOSFET's for Digital Applications	Iain Thayne	Engineering & Physical Sciences Research Council (EPSRC)	GR/S61218/01	Electronic and Nanoscale Engineering