CHARGE-TRANSFER AND LOW-TEMPERATURE ELECTRON-MOBILITY IN A STRAINED SI LAYER IN RELAXED SI1-XGEX

Calculated results for charge transfer and low-temperature electron mobility in strained silicon grown epitaxially on relaxed Si1-xGex are presented versus the thickness of an undoped spacer layer and other structural and materials parameters. The indicated conduction band offset for Si on relaxed Si0.7Ge0.3 is 180 +/- 15 meV. Scattering by the remote doping impurities that supply the carriers is found to be the dominant scattering mechanism in high-mobility samples. Samples with enhanced interface scattering are expected to have a stronger temperature dependence of mobility.