An electron mobility model for ultra-thin gate-oxide MOSFETs including the contribution of remote scattering mechanisms

The effect of remote scattering mechanisms ( such as remote Coulomb scattering and remote surface-roughness scattering) on electron mobility in ultra-thin oxide MOSFETs was studied. We highlighted the important role these scattering mechanisms play in state-of-the-art devices, mainly at low temperatures. As a consequence, the effects of these remote mechanisms on the electron mobility should be taken into account in accurate ultra-thin gate-oxide device simulations. We have developed a mobility model which takes into account the contribution of remote scattering mechanisms in ultra-thin oxide MOSFETs ( including both the polysilicon-oxide surface-roughness and Coulomb scattering due to the polysilicon depletion charge). The proposed expression allowed us to reproduce the Monte Carlo simulation results obtained for several of these ultra-thin gate oxide devices. We also used this model along with previously developed models to account for the different scattering mechanisms usually included in mobility analytical calculations to reproduce the experimental results for very thin oxide MOSFETs.