We report mobility simulations for long channel Si and InGaAs MOSFETs as a function of the semiconductor film thickness and inversion charge. Calculations account for numerous relevant scattering mechanisms and surface roughness is described by the recently developed non-linear model [1]. Reasonable agreement with available experiments is obtained employing the measured surface roughness r.m.s. value. The results reveal that the film thickness dependence of mobility in III-V MOSFETs is weaker than predicted by the T6w law typically observed in silicon devices.
