Quantum-Corrected Drift-Diffusion Models for Transport in Semiconductor Devices
Friday 14th May 2004
de Falco, Carlo; Gatti, Emilio; Lacaita, Andrea L.; Sacco, Riccardo
In this article, we propose a unified framework for Quantum-Corrected Drift-Diffusion (QCDD) models in nanoscale semiconductor device simulation. QCDD models are presented as a suitable generalization of the classical Drift-Diffusion (DD) system, each particular model being identified by the constitutive relation for the quantum-correction to the electric potential. We examine two special, and relevant, examples of QCDD models the first one is the modified DD model named Schroedinger-Poisson-Drift-Diffusion, and the second one is the Quantum-Drift-Diffusion QDD model. For the decoupled solution of the two models, we introduce a functional iteraction technique that extends the classical Gummel algotithm widely used in the iterative solution of the DD system. We discuss the finite element discretization of the various differential subsystems, with special emphasis on their stability properties, and illustrate the performance of the proposed algorithms and models on the numerical simulation of nanoscale devices in two spatial dimensions.