HIGH-FIELD TRANSPORT OF HOT-ELECTRONS IN STRAINED SI SIGE HETEROSTRUCTURE/

Monte Carlo simulation of two-dimensional electron gas in strained Si/ SiGe heterostructures has been carried out to investigate the high ele ctric field transport phenomena. In the Monte Carlo simulation we take into account the intervalley scattering due to the f-type phonons bet ween twofold and fourfold valleys of Si well layer split by the tensil e strain in addition to the g-phonon scattering. We obtained the elect ron drift velocity at room temperature of as high as 1 X 10(7) cm/s at 10 kV/cm. Calculated results at 4.2 and 77 K show negative differenti al mobility beyond 10 kV/cm. At 77 K, transient response of the drift velocity shows a marked overshoot reaching about 3 X 10(7) cm/s at 0.2 ps and 10 kV/cm. Ohmic mobility calculated using self-consistent wave functions is also demonstrated. Results are given for the strained Si well width of 10 nm. Obtained low field electron mobility at high tem peratures shows a good agreement with the experimental results reporte d so far.