Calculation of Hole Mobility in Ge and III-V p-Channels

Abstract

We present theoretical results regarding the hole mobility in Ge, GaAs, InGaAs, InSb and GaSb p-channels with SiO 2 insulator. The valence subband structure is calculated self-consistently within the framework of a six-band k . p and finite-difference methods. Various scattering processes, non-polar (NP) phonon scattering (acoustic and optical), longitudinal-optical (LO) phonon scattering (Frohlich scattering, III-Vs only), alloy scattering (AL) (InGaAs only) and surface roughness (SR) scattering are included in the calculation. Dielectric screening effects on SR and LO scattering are also taken into account. The results show that Ge and III-V materials have great potential in enhancing hole mobility above the 'universal' Si value. The application of strain, especially uniaxial stress for Ge p-channels and biaxially compressive stress for III-V p-channels, is found to have a significant beneficial effect. Among strained p-channels, InSb yields the largest mobility enhancement. Our theoretical results will finally be compared with available experimental data.