Physical insights on electron mobility in contemporary FinFETs

Calibration of a physics/process-based model for double-gate (DG) MOSFETs to contemporary nanoscale undoped n-channel DG FinFETs reveals that 1) significant densities of source/drain donor dopants readily diffuse to the ultrathin (fin) body/channel, even with relatively long fin extensions, degrading electron mobility at low/moderate levels of inversion-carrier density (N_inv), 2) surface-roughness scattering of electrons is less severe at the {110} silicon-fin surfaces than anticipated, and 3) strong-inversion electron mobility is quite high (e.g., ≅290 cm²/V·s at N_inv=10¹³ cm^-2), being about three times higher than that in contemporary bulk-Si MOSFETs.