Full-Band Monte Carlo investigation of hole mobilities in SiGe, SiC and SiGeC alloys

Hole transport properties in relaxed and biaxially strained Si1-xGex, Si1-yCy and Si1-x-yGexCy alloys are investigated using a Full-Band Monte Carlo simulator. Our results allow the extraction of bulk, in-plane and out-of-plane hole drift mobilities. Doping effects in SiGeC alloys are taken into account through an efficient ionized-impurity scattering model. This model is based on inverse momentum relaxation times derived from phase-shift theory.1 A new alloy scattering model relevant to the case of random ternary alloys is presented. It involves two effective alloy potential parameters, which account for the respective scattering strengths of Ge and C in the crystal lattice. From our mobility results we have derived an analytical hole mobility model which includes dependencies upon doping concentration, doping type, Ge content and C content.