Strain impacts on electron mobility in silicon nanowires

In this paper, we report the impact of lattice-mismatch-induced strain and radial-force-induced strain on the conduction band structures, the acoustic-phonon-limited and optical-phonon-limited electron mobility of silicon nanowires is also presented. Our simulation result shows that high-k gate dielectric (HfO₂) induces compressive strain into silicon nanowire due to lattice mismatch, but the radial force has the contrary effect. The compressive strain dominates the reshaping of the conduction band. The down-shifting of the band leads to higher electron density in the strained nanowire. However, the electron mobility is degraded due to the much heavier effective masses.