Modeling of High-Performance p-Type III–V Heterojunction Tunnel FETs

The impact of band lineup and source doping concentration on the performance of heterojunction tunnel FETs (H-TFETs) with type-II heterointerface is investigated by simulations. Exemplarily, H-TFETs based on InAs/Al
_x
Ga
_1-x
Sb heterostructures are studied. Varying the Al content x, the band lineup can be adjusted from staggered to broken. We find that a staggered band lineup and a medium source doping concentration yield the best ON/OFF-state performance in terms of an inverse subthreshold slope that is smaller than 60 mV/dec and f
_T
values in the terahertz range.