Monte Carlo simulation of high-energy transport of electrons and holes in bulk SiGeC alloys

High-energy transport properties of charge carriers in ternary random Si1−x−yGexCy alloys are investigated using Full-Band Monte Carlo simulations. Models for scattering mechanisms include phonon scattering, impact ionization and alloy scattering. Phonon scattering rates are wave-vector dependent and calculated consistently with the Full-Band structure. Impact ionization rates are modeled using analytical Keldysh formulas fitted to previously reported ab initio results. We derive a model for alloy scattering rate specific to ternary random alloys. It involves 2 effective alloy potentials which are independently calibrated on experimental mobility measurements. Presented Monte Carlo simulation results are shown to be in very good agreement with a variety of high-energy transport measurements, including drift velocities, impact ionization coefficients and quantum yields. Effects of alloy composition on the electrical characteristics of Si1−x-yGexCy alloys are investigated.