The valence bandstructure and the hole mobility in silicon

Abstract

The hole mobility in silicon is calculated as a function of temperature. The calculation takes into account both the non-parabolicity and the warping of the valence band. The effect of both light and heavy holes on the total mobility is considered. The contribution of light holes varies from 30% at low temperature to 15% at room temperature. The values of the band parameters are correlated to the temperature dependence of the mobility and the results agree very well with experimental data in the entire range from 10 to 450 K. For best fit the value of the acoustic deformation potential constant Eeff is found to be 5.2 eV and the optical phonon coupling constant DtK is found to be 7 × 108 eV/cm.