Coulomb scattering in strained-silicon inversion layers on Si_1-xGe_x substrates

Results of electron mobility in strained-Si inversion layers grown on Si_1-xGe_x substrates are reported Drift velocities are calculated by Monte Carlo simulations including electron quantization and Coulomb scattering, in addition to phonon and surface roughness scattering. The strain is shown to contribute as well to the enhancement of the Coulomb-limited mobility due to better screening of the interface centers by the mobile carriers. Even in the case of high-doped substrates, Coulomb scattering does not cancel the mobility enhancement provided by the reduction of both intervalley scattering and conduction effective mass.