Integration of quantum transport models in classical device simulators

Abstract

We consider semiconductor devices that are composed of two parts: first, a small quantum structure constituting the active region, and second, a classical environment with larger typical length scales. While in general the classical environment should be represented by a drift–diffusion model, we consider here only simple contacts which we take as ideal metals with infinite conductivity. The transport through the quantum structure is described as in the Landauer–Büttiker formalism through electronic scattering wave functions which define the electron density in the quantum system. Further sources of the self-consistent Coulomb field are layers of classical charges in the contacts at each of the interfaces to the quantum system. We present further a capacitance model that takes into account the openness of the quantum structure and the existence of finite contacts embedding the system. As particular quantum structures we study simple tunneling barriers.