A Monte Carlo study on the electron-transport properties of high-performance strained-Si on relaxed Si_1-xGe_x channel MOSFETs

We have studied the electron-transport properties of strained-Si on relaxed Si_1-xGe_x channel MOSFETs using a Monte Carlo simulator adapted to account for this new heterostructure. The low-longitudinal field as well as the steady- and unsteady-state high-longitudinal field transport regimes have been described in depth to better understand the basic transport mechanisms that give rise to the performance enhancement experimentally observed. The different contributions of the conductivity-effective mass and the intervalley scattering rate reduction to the mobility enhancement as the Ge mole fraction rises have been discussed for several temperature, effective, and longitudinal-electric field conditions. Electron-velocity overshoot effects are also studied in deep-submicron strained-Si MOSFETs, where they show an improvement over the performance of their normal silicon counterparts.