Transient Effects of Band Non-Parabolicity in DGFETs for RF Applications

The atomistic investigation of modern nanoscale devices for RF applications requires time-resolved simulations, which often come with a high computational burden. Thus, the effective mass approximation is usually employed to reduce the complexity and computation times. Here, a novel approach combining a tight-binding like ansatz with a Quantum Liouville-type Equation is presented, that can effectively take into account any arbitrary energy dispersion relation. It is applied to analyze the charge carrier transport in a DGFET in a single non-parabolic valley and compared to the parabolic case for the stationary and transient cases. As it is shown, the application of the parabolic approximation leads to a severe underestimation of the current densities and does not capture distortion effects when RF amplifier operation is considered.