Effects of phonon confinement on electron transport in superlattices

The effect of LO-phonon confinement within each layer of semiconductor superlattices on electron transport parallel to their interfaces at room temperature is evaluated numerically using Monte Carlo methods on a GaAs/AlAs superlattice and bulk GaAs. The calculated results for the superlattice with 50-Å-thick GaAs layers show that the electron mobility is enhanced by a factor of 2.5, and that the effective high-field velocity in a 0.35-μm-long channel is 25% greater in the superlattice than in bulk GaAs because the velocity-overshoot effect is more evident in the superlattice.