Revised analysis of Coulomb scattering limited mobility in biaxially strained silicon MOSFETs

We present a simulation study of the dependence of the Coulomb limited mobility on the biaxial strain in -type (001) Si MOSFETs. By using a model based on the Momentum Relaxation Time (MRT) approximation, we first reproduce fairly well a wide set of published experiments, then we use our simulations to explain the dependence on the strain of the mobility limited by interface states and substrate impurities. Differently from the experiments, the MRT approach allows us to study the different mobility components without resorting to the Matthiessen’s rule, which can lead to large errors in the extrated mobility. Simulations indicate that the strain reduces the interface state limited mobility, while it leaves essentially unchanged the substrate impurity limited mobility.