An analytical model for the electron effective mobility in a strained silicon inversion layer

An electron effective mobility analytical model without empirical parameters is investigated for the strained silicon inversion layer, which can be conveniently applied by device and circuit designers. Four kinds of scattering mechanisms, i.e., coulomb scattering, acoustic phonon scattering, intervalley phonon scattering and surface roughness scattering, are taken into account to calculate the electron mobility for the 2D (two-dimensional) inversion layer through a one-dimensional inverse transform. Considering the quantum confinement and strain effect, the valley electron occupancy variation is dissected. In regard to the Si/(001)Si1−xGex and Si/(110)Si1−xGex Si common orientation, the dependence of the electron effective mobility with various Ge content on the inversion charge density is analyzed in detail, and by means of this the mechanism of the mobility enhancement under different situations and the mobility saturation are brought to light.