Interpretation of mobility universality against effective electric field of Si nMOSFETs based on nonlinear model of surface roughness scattering

Abstract The universality of mobility against the effective electric field of Si n-channel MOSFETs (nMOSFETs) is not guaranteed under the nonlinear model of surface roughness scattering, which has been recently proposed and is more quantitative than the conventional linear model. Therefore, in this study, the mechanism of the universality of the mobility is quantitatively examined for (100) and (110) Si nMOSFETs based on the nonlinear model. As a result, the coefficient η in the effective field to provide the universality is theoretically shown to be 1/2 and 1/3 for (100) and (110) Si nMOSFETs, respectively, and the physical origin is addressed.