Non-local transport effects in semiconductors under low-field conditions

Abstract

Macroscopically non-local effects arise in semiconductor devices whenever the mean free path and/or the deBroglie wavelength are not small compared to geometry/flow length scales. In such cases standard diffusion-drift (DD) theory becomes inaccurate and in need of revision, with the best known example being density-gradient (DG) theory. Here we consider a similarly motivated gradient correction to the electron-lattice interaction that accounts for non-locality in the transport physics. Versions of DD and DG theory with this correction are discussed and the DD-based approach is illustrated by applying it to the analysis of long-channel field-effect transistors where it provides a new physics-based approach for treating surface scattering.