Calculation of hole mobility in doped SiGe alloys using a Monte Carlo method with a bond orbital band structure

Abstract

Hole mobility in strained Si1−xGex/Si(001) layers is calculated as functions of temperature and doping concentration for various Ge contents using a Monte Carlo technique. In the Monte Carlo simulation, the band structure is computed by using a bond orbital model, which combines the k⋅p and the tight-binding methods with a strain Hamiltonian. The Fermi–Dirac distribution is employed for heavily doped impurity scattering. The alloy interaction potential of 1.0 eV for the Monte Carlo model is obtained by fitting the measured velocity-field characteristics in strained Si1−xGex alloys. The calculated hole mobilities compare well with experimental results. The strain effect on hole transport is also evaluated.