The steady state and transient drift velocity of holes in silicon have been investigated using Monte Carlo techniques. The valence band is modeled by warped nonparabolic heavy and light hole bands, and a spherical spin-orbit band. The nonparabolicity of the heavy and light hole bands is included using piecewise continuous functions. The calculated velocities are in better agreement with experimental steady state drift velocity values compared to previous Monte Carlo calculations using only a heavy hole band. Transient calculations show the magnitude of the velocity overshoot for holes is smaller than electrons in silicon but is significantly higher than the steady state drift velocity when high fields are applied.

The transport of minority electrons in silicon has been investigated using an ensemble Monte Carlo approach at room temperature with electron-hole scattering rates which take into account the ellipsoidal nature of the conduction band valleys. Mobility calculations showed quantitative agreement with experimental values at an acceptor concentration of 4.5×1016 cm−3 while qualitative agreement with the electron-hole drag effect was observed at 3.8×1018 cm−3. Transient calculations showed the electron-hole interactions decrease electron energy, reduce steady-state velocity, and decrease the transfer rate of electrons to the cold valleys.

No abstract

The effects of electron-hole scattering on the transient transport of minority electrons in room-temperature silicon is examined using an ensemble Monte Carlo approach. The transport model includes the dynamics of both electrons and holes with coupling between the electron and hole systems through their Coulombic interaction. Calculations are reported for an acceptor concentration of 10" cmm3 with applied electric field strengths of 10 and 20 kV cm-'. The calculations show that electron-hole scattering reduces mobility, velocity overshoot and energy in both hot and cold valleys. and that the valley repopulation rate is reduced for an applied field of 10 kVcm-' while at 20 kVcm-' it is enhanced at times longer than one picosecond.Electron-hole interactions have been shown to have a strong effect on the transport properties of electrons in semiconductor materials McLean