3D quantum mechanical simulation of square nanowire MOSFETs by using NEGF method

Abstract

In order to investigate the specifications of nanoscale transistors, we have used a three dimensional (3D) quantum mechanical
approach to simulate square cross section silicon nanowire (SNW) MOSFETs. A three dimensional simulation of silicon nanowire
MOSFET based on self consistent solution of Poisson-Schrödinger equations is implemented. The quantum mechanical transport
model of this work uses the non-equilibrium Green’s function (NEGF) formalism. First, we simulate a double-gate (DG) silicon
nanowire MOSFET and compare the results with those obtained from nanoMOS simulation. We understand that when the transverse
dimension of a DG nanowire is reduced to a few nanometers, quantum confinement in that direction becomes important and 3D
Schrödinger equation must be solved. Second, we simulate gate-all-around (GAA) silicon nanowire MOSFETs with different shapes
of gate. We have investigated GAA-SNW-MOSFET with an octagonal gate around the wire and found out it is more suitable than
a conventional GAA MOSFET for its more I

on
/I

off
, less Drain-Induced-Barrier-Lowering (DIBL) and less subthreshold slope.

KeywordsNEGF–silicon nanowire–DG-MOSFET–GAA MOSFET–quantum transport