Quasi-Ballistic Drift-Diffusion Simulation of SiGe Nanowire MOSFETs Using the Kinetic Velocity Model

Abstract

This paper presents the calibration of the novel kinetic velocity model (KVM) in the drift-diffusion (DD) transport approach, which can account for the ballistic effect in short-channel devices. The KVM considers a thermionic emission limit and a free carrier acceleration limit for the mobility. We develop a methodology to extract the parameters for the KVM and for the high-field saturation velocity model for SiGe nanowires over the whole mole fraction range. The calibrated DD simulations with KVM show good agreement with Boltzmann transport equation results in terms of on-state current and carrier-weighted velocity distribution over a wide range of gate lengths for both linear and saturation regimes.

Keywords

• Ballistic mobility
• drift diffusion
• nanowire
• silicon germanium
• kinetic velocity
• thermal velocity