A Physical Modeling Study of Mobility Enhancement in Stressed Ge-on-insulator pMOSFET

This work presents a theoretical assessment of the mobility enhancement in state-of-the-art Ge-on-insulator (GeOI) pMOSFET fabricated by wafer bonding. Beyond the conventional TCAD framework with analytical mobility models, our study encompassed systematic physical based models for more accurate mobility prediction, i.e., 1) k·p model with Poisson solver for electrostatics; 2) Kubo-greenwood model for complex carrier scatterings. Our numerical results conclude that high mobility is indeed achieved in GeOI channel. The mobility enhancement is attributed to an in-plane biaxial stress and high-quality Ge/oxide interface. With the decrease of GeOI layer from 100 to 10nm, the gate demonstrates better channel control ability and worse transfer characteristic of GeOI junction-less transistor.