A Physically-Based Electron Mobility Model for Silicon Device Simulation

Abstract

We present an analytical low-field electron mobility formula for silicon which treats the dependence on all common dopants, such as P, As, Sb, and B in a unified manner. The expressions are derived from Monte-Carlo (MC) calculations which are based on a theoretical approach to ionized impurity scattering that inherently distinguishes the dopant species. From these first principle data we derive analytical expressions for the majority and minority mobility valid in the temperature range (70–500 K) and up to an impurity concentration of 10²² cm^-3. The agreement with experimental data is excellent. Not only the lower majority electron mobility in As- and Sb-doped Si, but also the higher minority electron mobility in B-doped Si compared to the majority mobility is confirmed. Hence, this universally usable mobility model is very well suited for device simulation purposes.