Influence of image force and many-body correction on electron mobility in ultrathin double gate silicon on insulator inversion layers

Abstract

We study the influence of the image and exchange-correlation effects in double-gate silicon-on-insulator (DGSOI) devices, in the calculation of both charge distribution and electron mobility. The image and exchange correlation potentials produce a greater confinement of the carriers and, according to the uncertainty principle, a greater phonon scattering rate, which produces a decrease in electron mobility. Moreover, the influence of image and exchange-correlation potentials on electron mobility, while almost negligible for bulk silicon inversion layers, becomes increasingly important as the silicon thickness decreases, due to the effect of volume inversion in DGSOI inversion layers. These effects must then be taken into account in order to achieve a correct evaluation of the charge distribution and of mobility in DGSOI inversion layers.