An efficient method is developed for multiband simulation of quantum transport in nanowire electronic devices within nonequilibrium Green's function formalism. The efficiency relies on a model order reduction technique, which projects the k.p Hamiltonian into a much smaller subspace constructed by sampling the Bloch modes of each cross-section layer. Several sampling approaches are discussed to obtain a minimum and accurate basis with reduced computational overhead. The technique is verified by calculating the valence bands of silicon nanowires (SiNWs) and by solving I-V curves of p-type SiNW transistors. This enables us to study for the first time the performances of large cross-section p-type junctionless (JL) transistors in the quantum ballistic transport limit. The influences of doping density, transport direction, channel length, and cross-section size are examined. We find that larger doping densities may lead to worse sub-threshold slopes due to the enhanced source-to-drain tunneling. Compared with their counterparts, i.e., classical inversion-mode (IM) transistors, they have better sub-threshold behaviors, but they do not necessarily provide a better ON/OFF ratio except when the channel is short or thin. In addition, unlike IM transistors, [110] and [111] channel directions in JL transistors are very robust against channel thicknes scaling. © 1963-2012 IEEE.


Electrical and Computer Engineering

Keywords and Phrases

Junctionless transistors; k.p approach; model order reduction (MOR); multiband simulation; nonequilibrium Green's function (NEGF); quantum transport; silicon nanowire transistors

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2024 Institute of Electrical and Electronics Engineers, All rights reserved.

Publication Date

15 Jul 2013