Impact of the Back-Gate Biasing on Trigate MOSFET Electron Mobility

In this brief, the influence of the back-gate biasing, V_bg, on the electron mobility of Si trigates on ultrathin buried oxide is studied, using state of the art scattering models for 2-D confined devices. The variation of the back-gate influence with the device size is analyzed and explained addressing to the charge redistribution in the channel. The lower confinement of larger devices results in strong changes in the electron mobility as V_bg is modified, contrary to what is observed in smaller devices. The charge redistribution due to V_bg also affects the relative influence of the interface walls, which is analyzed in depth. The impact on the mobility of the main scattering mechanisms as a function of V_bg is also discussed.