Effective Mobility and Backscattering Coefficient in Short Gate-Length Nanowire FETs

In this work we investigate the effective electron mobility and the backscattering coefficient in nanowire FETs operating under quasiballistic conditions. Starting from a general methodology worked out in a previous paper, we find the functional dependence of the effective mobility on device length, carrier mean-free path and barrier height. Next, we find the expression of the backscattering coefficient and its relationship with the effective mobility. These expressions are nonlocal for short gate lengths, but may be useful for the extraction of physical parameters from experimental measurements. Also, we demonstrate that mobility degradation at large gate voltages is predominantly due to carrier degeneracy, rather than an enhanced scattering rate.