Study of low field electron transport in ultra-thin single and double gate SOI MOSFETS

This paper studies the dependence on the silicon film thickness (T-SI) of the electron mobility in Single- (SG) and Double-Gate (DG) Ultra-Thin (UT) SOI MOSFETs. A comprehensive model was developed, including acoustic and, optical phonon scattering and the scattering with possible interface states and microscopic roughness at both interfaces. The T-SI dependence of the effective mobility (mu(eff)) predicted by simulations is, at moderate inversion densities (N-inv), weaker than what observed in experiments. We analyze the physical origin of this discrepancy, with particular attention to the phonon limited mobility. Our results indicate that scattering with surface optical phonons is strongly enhanced in UT silicon layers and that it may help explain the experimental behavior of mu(eff).