Hole transport in strained Si1−xGex alloys on Si1−yGey substrates

Hole transport at 300 K in (001)-strained Si1−xGex alloys grown on unstrained Si1−yGey is theoretically analyzed considering the full band structure and new, accurate mobility experiments. Ohmic in-plane and out-of-plane drift mobilities are computed over the whole range of x and y. Velocity-field characteristics and transient overshoot effects are studied for fields along the 〈100〉 and 〈110〉 directions in technologically relevant configurations with Monte Carlo simulation. Overshoot peaks around 2×107 cm/s are found in strained Si and Ge-rich SiGe for 100 kV/cm and the 〈100〉 direction.