Analytical Electron-Mobility Model for Arbitrarily Stressed Silicon

It was experimentally and numerically indicated that both the valley splitting and effective-mass variation contribute to the stress-induced enhancement of electron mobility in the MOSFET channel. In this paper, an analytical electron-mobility model for arbitrarily strained silicon is presented. The electron-mobility model includes the strain effects of both the effective-mass variation and valley degeneration. The expression of strained conduction band used in the analytical model is based on the theory and accords well with numerical results of nonlocal empirical pseudopotential method (EPM). By using the mobility model, mobilities under different stresses are investigated.