Multibranch Mobility Analysis for the Characterization of FDSOI Transistors

A novel technique for the accurate carrier mobility evaluation in ultrathin fully depleted SOI-MOSFETs is proposed. The mobility representation, obtained from the combination of Poisson-Schrödinger numerical simulations and split C(V) experimental results, discloses the mobility dependence on the effective field by accounting for the actual electric field and carrier profiles in the body of the device. As example of this technique, we show that the apparent larger mobility enhancement, due to back-gate bias, observed in thin-BOX transistors with respect to thick-BOX devices, is related to an electric field reduction rather than other technological factors.