Quantum transport calculations for silicon inversion layers in MOS structures

We evaluate the mobility of inversion layer electrons in silicon MOSFETs using a real-time Green's functions formalism. Simulation results suggest that interface-roughness considerably affects the low-field mobility, even at room temperature. We also find that an exponential model for the surface-roughness autocorrelation function, as well as Ando's model for the surface-roughness matrix element, leads to the best description of this scattering process over a wide range of inversion charge densities and temperatures. Universal mobility behavior is observed when the proper weighting coefficient for the depletion charge density is used in the definition of the effective field.