Non-parabolic band effects on the electrical properties of superlattice FETs

The effect of non-parabolic energy-bands on the electrical properties of an InGaAs/InAlAs superlattice FET are investigated. We fitted an energy-dependent effectivemass on k·p simulation results and implemented the new band model into a self-consistent Schrödinger-Poisson solver. We show that non-parabolicity effects lead to noticeable changes of the device characteristics, namely: an increase of the on-state current and a steeper transition from the off to the on state, at the expense of an increased off-state current. Moreover, the larger density of states in the non-parabolic model causes a 47% growth of the output conductance at low VDS, as well as an increased drain conductance in saturation.