The effect of general strain on the band structure and electron mobility of silicon

A model capturing the effect of general strain on the electron effective masses and band-edge energies of the lowest conduction band of silicon is developed. Analytical expressions for the effective mass change induced by shear strain and valley shifts/splittings are derived using a degenerate k center dot p theory at the zone-boundary X point. Good agreement to numerical bandstructure calculations using the nonlocal empirical pseudopotential method with spin-orbit interactions is observed. The model is validated by calculating the bulk electron mobility under general strain with a Monte Carlo technique using the full-band structure and the proposed analytical model for the band structure. Finally, the impact of strain on the inversion-layer mobility of electrons is discussed.