Carrier Mobility/Transport in Undoped-UTB DG FinFETs

A process/physics-based double-gate (DG) MOSFET model (UFDG), which includes a quantum-based carrier mobility model, is used to examine carrier transport in undoped ultrathin-silicon bodies/channels. The model predicts for {100}-surface devices, in accord with measurements, effective electron and hole mobilities that are dramatically higher than those in contemporary bulk-Si MOSFETs at the same integrated inversion-carrier density. Calibration of UFDG to undoped p- and n-channel DG FinFETs yields consistent results, showing very high mobilities in contemporary FinFETs, implying relatively smooth {110} fin-sidewall surfaces, and giving new insights on electron and hole mobilities in DG MOSFETs with {110} versus {100} surfaces. The calibrated model is used to simulate 17.5-nm DG FinFETs with midgap gates, predicting ballistic-like currents and, hence, suggesting that strained-Si channels are not needed for mobility enhancement in these nonclassical devices