Electron transport properties of a strained Si layer on a relaxed Si _1-xGe_x substrate by Monte Carlo simulation

The in-plane transport properties of a strained (100) Si layer on a relaxed Si_1-xGe_x substrate are studied with an ensemble Monte Carlo technique. Similar velocity (-field) characteristics are found for strained Si with any valley splitting energy ΔE≥0.1 eV. These phonon-limited electron mobilities reach 4000 cm²/V s at 300 K, and 23 000 cm²/V s at 77 K. There is only a slight increase in the saturation velocity at both temperatures. However, a significant overshoot peak transient velocity is found to depend upon ΔE, and for ΔE=0.4 eV, reaches 4.1×10⁷ cm/s at 300 K, and 5.2×10⁷ cm/s at 77 K.